Studien zu Mikrowellen mit Zusammenfassung:
·
Adey WR, Byus CV, Cain CD, Higgins RJ, Jones RA, Kean
CJ, Kuster N,
MacMurray A, Stagg RB, Zimmerman G, Phillips JL, Haggren W, Spontaneous and
nitrosourea-induced primary tumors of the central nervous system in Fischer 344
rats chronically exposed to 836 MHz modulated microwaves. Radiat Res 152(3):293-302, 1999.
We have tested an 836.55
MHz field with North American Digital Cellular (NADC) modulation in a 2-year
animal bioassay that included fetal exposure. In
offspring of pregnant Fischer 344 rats, we tested both spontaneous
tumorigenicity and the incidence of induced central nervous system (CNS) tumors
after a single dose of the carcinogen ethylnitrosourea (ENU) in utero, followed
by intermittent digital-phone field exposure for 24 months. Far-field exposures
began on gestational day 19 and continued until weaning at age 21 days.
Near-field exposures began at 35 days and continued for the next 22 months, 4
consecutive days weekly, 2 h/day. SAR levels simulated localized peak brain
exposures of a cell phone user. Of the 236 original rats, 182 (77%) survived to
the termination of the whole experiment and were sacrificed at age 709-712
days. The 54 rats (23%) that died during the study ("preterm rats") formed
a separate group for some statistical analyses. There was no evidence of
tumorigenic effects in the CNS from exposure to the TDMA field. However, some
evidence of tumor-inhibiting effects of TDMA exposure was apparent. Overall,
the TDMA field-exposed animals exhibited trends toward a reduced incidence of
spontaneous CNS tumors (P < 0. 16, two-tailed) and ENU-induced CNS tumors (P
< 0.16, two-tailed). In preterm rats, where primary neural tumors were
determined to be the cause of death, fields decreased the incidence of
ENU-induced tumors (P < 0.03, two-tailed). We discuss a possible approach to
evaluating with greater certainty the possible inhibitory effects of TDMA-field
exposure on tumorigenesis in the CNS.
·
Adey
WR, Byus CV, Cain CD, Higgins RJ, Jones RA, Kean CJ, Kuster N,
MacMurray A, Stagg RB, Zimmerman G,Spontaneous and nitrosourea-induced primary
tumors of the central nervous system in Fischer 344 rats exposed to
frequency-modulated microwave fields. Cancer Res 60(7):1857-1863, 2000.
In a 2-year bioassay, we
exposed Fischer 344 rats to a frequency-modulated (FM) signal (836.55 MHz +/-
12.5 KHz deviation) simulating radiofrequency
exposures in the head of users of hand-held mobile phones. We tested for
effects on spontaneous tumorigenicity of central nervous system (CNS) tumors in
the offspring of pregnant rats and also for modified incidence of primary CNS
tumors in rats treated with a single dose of the neurocarcinogen
ethylnitrosourea (ENU) in utero. ENU dosage (4 mg/kg) was selected to give an
expected brain tumor incidence of 10-15% over the mean life span of 26 months.
Pregnant dams (n = 102) were randomly assigned to six groups. Their offspring
were treated as cohorts in each of the six groups (n = 90 per group; total, n =
540): Sham ENU/Sham Field, Sham ENU/Field Exposed, ENU/Sham Field, ENU/Field
Exposed, ENU/Cage Control, and Sham ENU/Cage Control. Intermittent field
exposures began on gestation day 19 and continued until weaning at 21 days,
resuming thereafter at 31 days and continuing until experiment termination at
731-734 days. Energy absorption rates (SARs) in the rats' brains were similar
to localized peak brain exposures of a phone user (female, 236 g, 1.0 W/kg;
male, 450 g, 1.2 W/kg). Of the original 540 rats, 168 died before the
termination of the experiment. In these rats, ENU significantly reduced
survival from a mean of 708 days in three groups without ENU treatment to 645
days in three groups treated with ENU (P < 0.0005). There were no effects on
survival attributable to FM field exposure in either ENU-treated or in
sham-treated groups. Spontaneous CNS tumor incidence in control groups was
1.1-4.4% but sharply higher in rats receiving ENU (14.4-22.2%; P < 0.0001).
No FM field-mediated changes were observed in number, incidence, or histological
type of either spontaneous or ENU-induced brain tumors, nor were gender
differences detected in tumor numbers. These negative findings with FM fields
contrast with our study using standard digital phone fields pulsed on and off
at 50/se, where a trend was noted toward reduced incidence of both spontaneous
and ENU-induced CNS tumors (W. R. Adey et al., Radiat. Res., 152: 293-302,
1999). Although consistent but not attaining significance in the experiment
overall (spontaneous CNS tumors, P < 0.08 one-tailed; P < 0.16
two-tailed; ENU-induced CNS tumors, P < 0.08 one-tailed, P < 0.16
two-tailed), the trend was significant (P < 0.015 one-tailed, P < 0.03,
two-tailed) in rats that received ENU and died prior to experiment termination,
with a primary brain tumor as the cause of death. We discuss differences in the
signaling structure of digital and FM fields. Certain bioeffects induced by
either amplitude-modulated or pulsed radiofrequency fields at athermal levels
have not been seen with fields of similar average power but unvarying in
intensity (continuous wave or frequency-modulated fields).
·
Anane
R, Geffard M, Taxile M, Bodet D, Billaudel B, Dulou PE, Veyret B. Effects of
GSM-900 microwaves on the experimental allergic encephalomyelitis (EAE) rat
model of multiple sclerosis. Bioelectromagnetics 24(3):211-213, 2003.
The effects of acute
exposure to GSM-900 microwaves (900 MHz, 217 Hz pulse modulation) on the
clinical parameters of the acute experimental allergic encephalomyelitis (EAE)
model in rats were investigated in two independent experiments: rats were
either habituated or nonhabituated to the exposure restrainers. EAE was induced
with a mixture of myelin basic protein and Mycobacterium tuberculosis. Female
Lewis rats were divided into cage control, sham exposed, and two groups exposed
either at 1.5 or 6.0 W/kg local specific absorption rate (SAR averaged over the
brain) using a loop antenna placed over their heads. There was no effect of a
21-day exposure (2 h/day) on the onset, duration, and termination of the EAE
crisis.
·
Antonopoulos
A, Eisenbrandt H, Obe G, Effects of high-frequency electromagnetic fields on
human lymphocytes in vitro. Mutat Res 395(2-3): 209-214, 1997.
Human peripheral
lymphocytes were incubated in the presence of high-frequency electromagnetic
fields of 380, 900 and 1800 MHz. The measured endpoints were
cell cycle progression and the frequencies of sister-chromatid exchanges. No
differences between treated and control cultures could be found.
·
Auvinen
A, Hietanen M, Luukkonen R, Koskela R-S, Brain Tumors and Salivary Gland
Cancers Among Cellular Telephone Users Epidemiology 13:356-359, 2002.
Background. Possible risk of cancer associated with use of cellular telephones
has lately been a subject of public debate. Methods. We conducted a
register-based, case-control study on cellular phone use and cancer. The study
subjects were all cases of brain tumor (N = 398) and salivary gland cancer (N =
34) diagnosed in Finland in 1996, with five controls per case. Results.
Cellular phone use was not associated with brain tumors or salivary gland
cancers overall, but there was a weak association between gliomas and analog
cellular phones. Conclusions. A register-based approach has limited value in
risk assessment of cellular phone use owing to lack of information on exposure.
·
Bartsch
H, Bartsch C, Seebald E, Deerberg F, Dietz K, Vollrath L, Mecke D.
Chronic Exposure to a GSM-like Signal (Mobile Phone) Does Not Stimulate the
Development of DMBA-Induced Mammary Tumors in Rats: Results of Three Consecutive
Studies. Radiat Res 157(2):183-190, 2002.
Certain epidemiological and
experimental studies raised concerns about the safety of radiofrequency (RF)
electromagnetic fields because of a possible increased risk of leukemia and
lymphoma. In this study, an RF field used in mobile telecommunication was
tested using 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in
female Sprague-Dawley rats as a model for human breast cancer. Three
experiments were carried out under strictly standardized conditions and were
started on the same day of three consecutive years. The field consisted of a
GSM-like signal (900 MHz pulsed at 217 Hz, pulse width 577 [mu]s) of relatively
low power flux density (100 [mu]W/cm(2) [plus minus] 3 dB) and was applied
continuously throughout each experiment to freely moving animals. The specific
absorption rates averaged over the whole body were 17.5--70 mW/kg. The highest
values in young animals were at or around the exposure limit permissible for
the general public (i.e. 80 mW/kg). The animals were palpated weekly for the
presence of mammary tumors and were killed humanely when tumors reached a
diameter of 1--2 cm to allow a reliable histopathological classification and a
distinction between malignant and benign subtypes. The overall results of the
three studies are that there was no statistically significant effect of
RF-field exposure on tumor latency and that the cumulative tumor incidence at
the end of the experiment was unaffected as well. The risk ratios were 1.08
(95% CI: 0.91--1.29) and 0.96 (95% CI: 0.85--1.07) for benign and malignant
tumors, respectively. These observations are in agreement with other published
findings. In the first experiment, however, the median latency for the
development of the first malignant tumor in each animal was statistically
significantly extended for RF-field-exposed animals compared to controls (278
days compared to 145 days, P = 0.009). No such differences were detected in the
two subsequent experiments. These results show that low-level RF radiation does
not appear to possess carcinogenic or cancer-promoting effects on DMBA-induced
mammary tumors. To explain the mechanisms underlying the different results
obtained in the three experiments, a hypothesis is presented which is based
upon the neuroendocrine control mechanisms involved in the promotion of
DMBA-induced mammary tumors. Despite the apparent absence of stimulatory
effects of low-level RF-field exposure on the development and growth of solid
tumors, it will be necessary to verify these results for leukemias and
lymphomas, which may have completely different biological control mechanisms.
·
Beason
RC, Semm P. Responses of neurons to an amplitude modulated microwave stimulus.
Neurosci Lett 333(3):175-178, 2002.
In this study we investigated
the effects of a pulsed radio frequency signal similar to the signal produced
by global system for mobile communication telephones (900 MHz carrier,
modulated at 217 Hz) on neurons of the avian brain. We found that such
stimulation resulted in changes in the amount of neural activity by more than
half of the brain cells. Most (76%) of the responding cells increased their
rates of firing by an average 3.5-fold. The other responding cells exhibited a
decrease in their rates of spontaneous activity Such responses indicate
potential effects on humans using hand-held cellular phones.
·
Bisht KS, Moros EG, Straube WL, Baty JD, Roti Roti JL, The Effect of 835.62 MHz
FDMA or 847.74 MHz CDMA Modulated Radiofrequency Radiation on the Induction of
Micronuclei in C3H 10T½ Cells. Radiat. Res. 157, 506–515, 2002.
To determine if radiofrequency (RF) radiation induces the formation of
micronuclei, C3H 10T½ cells were exposed to 835.62 MHz frequency division
multiple access (FDMA) or 847.74 MHz code division multiple access (CDMA)
modulated RF radiation. After the exposure to RF radiation, the micronucleus
assay was performed by the cytokinesis block method using cytochalasin B
treatment. The micronuclei appearing after mitosis were scored in binucleated
cells using acridine orange staining. The frequency of micronuclei was scored
both as the percentage of binucleated cells with micronuclei and as the number
of micronuclei per 100 binucleated cells. Treatment of cells with cytochalasin
B at a concentration of 2 g/ml for 22 h was found to yield the maximum number
of binucleated cells in C3H 10T½ cells. The method used for the micronucleus
assay in the present study detected a highly significant dose response for both
indices of micronucleus production in the dose range of 0.1–1.2 Gy and it was
sensitive enough to detect a significant (P > 0.05) increase in micronuclei
after doses of 0.3 Gy in exponentially growing cells and after 0.9 Gy in
plateau-phase cells. Exponentially growing cells or plateau-phase cells were
exposed to CDMA (3.2 or 4.8 W/kg) or FDMA (3.2 or 5.1 W/kg) RF radiation for 3,
8, 16 or 24 h. In three repeat experiments, no exposure condition was found by
analysis of variance to result in a significant increase relative to
sham-exposed cells either in the percentage of binucleated cells with
micronuclei or in the number of micronuclei per 100 binucleated cells. In this
study, data from cells exposed to different RF signals at two SARs were
compared to a common sham-exposed sample. We used the Dunnett's test, which is
specifically designed for this purpose, and found no significant
exposure-related differences for either plateau-phase cells or exponentially
growing cells. Thus the results of this study are not consistent with the
possibility that these RF radiations induce micronuclei.
·
Bolshakov MA, Alekseev SI, Bursting responses of Lymnea neurons to microwave
radiation. Bioelectromagnetics 13(2):119-129, 1992.
Microelectrode and
voltage-clamp techniques were modified to record spontaneous electrical
activity and ionic currents of Lymnea stagnalis neurons during exposure to a
900-MHz field in a waveguide-based apparatus. The field was pulse-modulated at
repetition rates ranging from 0.5 to 110 pps, or it was applied as a continuous
wave (CW). When subjected to pulsed waves (PW), rapid, burst-like changes in
the firing rate of neurons occurred at SARs of a few W/kg. If the burst-like
irregularity was present in the firing rate under control conditions,
irradiation enhanced its probability of occurrence. The effect was dependent on
modulation, but not on modulation frequency, and it had a threshold SAR near
0.5 W/kg. CW radiation had no effect on the firing rate pattern at the same
SAR. Mediator-induced, current activation of acetylcholine, dopamine,
serotonin, or gamma-aminobutyric-acid receptors of the neuronal soma was not
altered during CW or PW exposures and, hence, could not have been responsible
for the bursting effect.
·
Borbely,
AA, Huber, R, Graf, T, Fuchs, B, Gallmann, E, Achermann, P, Pulsed
high-frequency electromagnetic field affects human sleep and sleep
electroencephalogram. Neurosci Lett 275(3):207-210, 1999.
To investigate whether the
electromagnetic field (EMF) emitted by digital radiotelephone handsets affects
the brain, healthy, young subjects were exposed during an entire night-time
sleep episode to an intermittent radiation schedule (900 MHz; maximum specific
absorption rate 1 W/kg) consisting of alternating 15-min on-15-min off
intervals. Compared with a control night with sham exposure, the amount of
waking after sleep onset was reduced from 18 to 12 min. Spectral power of the
electroencephalogram in non-rapid eye movement sleep was increased. The maximum
rise occurred in the 10-11 Hz and 13.5-14 Hz bands during the initial part of
sleep and then subsided. The results demonstrate that pulsed high-frequency EMF
in the range of radiotelephones may promote sleep and modify the sleep EEG.
·
Bornhausen
M, Scheingraber H, Prenatal exposure to 900 MHz, cell-phone electromagnetic
fields had no effect on operant-behavior performances of adult rats.
Bioelectromagnetics 21(8):566-574, 2000.
To clarify potential health
risks of radio-frequency electromagnetic fields (EMFs) used in cellular
telephone technology to the developing brain, Wistar rats were continuously
exposed during pregnancy to a low-level (0.1 mW/cm(2)) 900 MHz, 217 Hz pulse
modulated EMF that approximated the highest legal exposure of normal
populations to the radiation of base antennas of the GSM digital cell-phone
technology. Whole body average specific absorption rate (SAR) values for the
freely roaming, pregnant animals were measured in models; they ranged between
17.5 and 75 mW/kg. The offspring of exposed and of sham-exposed dams were coded
and tested later as adults in a battery of ten simultaneously operated test
chambers (Skinner boxes) during night time. Eight groups of ten coded animals
in each group were tested for learning deficits in a sequence of nine,
computer-controlled, 15 h sessions of the food-reinforced contingency Differential
Reinforcement of Rate with increasing performance requirements. Two different
sets of events were recorded: The food-reinforced lever-pressing activity of
the animals and the inter-response intervals (IRIs) between consecutive lever
presses. IRI-occurence patterns discriminated consistently between
"learners" and "non-learners". Analyses of performance
scores and of IRI-patterns both showed that exposure in-utero to the GSM field
did not induce any measurable cognitive deficits.
·
Bortkiewicz
A, Pilacik B, Gadzicka E, Szymczak W. The excretion of 6-hydroxymelatonin
sulfate in healthy young men exposed to electromagnetic fields emitted by
cellular phone -- an experimental study. Neuroendocrinol Lett 23 Suppl 1:88-91,
2002.
OBJECTIVES: It is quite
likely that non-visible electromagnetic fields (EMF) may affect melatonin
production. Some studies confirmed this hypothesis and showed that extremely
low EMF altered pineal function in animals and humans. Thus, it is reasonable
to suppose that EMF emitted by cellular phones may also influence secretion of
melatonin. The present study sought to evaluate possible effect of the exposure
to EMF emitted by cellular phone on 6-hydroxymelatonin sulfate (6-OHMS)
excretion, which reflects melatonin levels in blood. MATERIAL AND METHODS: The
examined group consisted of 9 healthy males aged 19-29 years. The experiment
was performed under controlled conditions (the light intensity-50 lx till
midnight and 0 lx during night). Each person was examined twice: on a day
without exposure (control day, C-day) and on a day with continuous exposure (60
min. exposure from cellular phone, frequency 900 MHz, pulsed with 217 Hz, pulse
with 576 micros, SAR 1.23 W/kg, E-day). From 7 p.m. to 8 p.m. they used a
cellular phone. The subjects did not know which day was E-day, and which was
C-day. From 8 p.m. till midnight the subjects listened to music and than they
slept till 7 a.m. next day. Urine samples were collected at 7 p.m., at
midnight, and at 7 a.m. in the same way in C-day as in E-day. Sample were
frozen for later ELISA analysis of 6-OHMS. The 6-OHMS ELISA kit from
Immuno-Biological Laboratories (Hamburg) was used for measurement of 6-OHMS.
The data were analysed using Wilcoxon matched-pairs signed-ranks test for each
subject and for the whole group. We compared 6-OHMS level on the E-day and on
the C-day separately for 3 time-points - 7 p.m., midnight, 7 a.m. RESULTS: Mean
6-OHMS level in both experiments did not differ significantly for any of the
respective time points. Circadian variations of 6-OHMS level were detected in
all subjects. CONCLUSIONS: The results of our investigation has demonstrated
that EMF emitted by cellular phones has no distinct influence on the melatonin
level.
·
Braune,
S, Wrocklage, C, Raczek, J, Gailus, T, Lucking, CH, Resting blood pressure
increase during exposure to a radio-frequency electromagnetic field. Lancet
351(9119):1857-1858, 1998.
Exposure of the right
hemisphere to a radiofrequency EMF for 35 min causes in human subjects an
increase in sympathetic efferent activity with increases the resting blood
pressure between 5-10 mm Hg. The effect is likely caused by vasoconstriction.
·
Braune
S, Riedel A, Schulte-Monting J, Raczek J. Influence of a radiofrequency
electromagnetic field on cardiovascular and hormonal parameters of the
autonomic nervous system in healthy individuals. Radiat Res 158(3):352-356,
2002.
The potential health risks
of radiofrequency electromagnetic fields (EMFs) emitted by mobile phones are of
considerable public interest. The present study investigated the hypothesis,
based on the results of our previous study, that exposure to EMFs can increase
sympathetic vasoconstrictor activity. Forty healthy young males and females
underwent a single-blind, placebo-controlled protocol once on each of two different
days. Each investigation included successive periods of placebo and EMF
exposure, given in a randomized order. The exposure was implemented by a
GSM-like signal (900 MHz, pulsed with 217 Hz, 2 W) using a mobile phone mounted
on the right-hand side of the head in a typical telephoning position. Each
period of placebo exposure and of EMF exposure consisted of 20 min of supine
rest, 10 min of 70 degrees upright tilt on a tilt table, and another 20 min of
supine rest. Blood pressure, heart rate and cutaneous capillary perfusion were
measured continuously. In addition, serum levels of norepinephrine,
epinephrine, cortisol and endothelin were analyzed in venous blood samples
taken every 10 min. Similar to the previous study, systolic and diastolic blood
pressure each showed slow, continuous, statistically significant increases of
about 5 mmHg during the course of the protocol. All other parameters either
decreased in parallel or remained constant. However, analysis of variance
showed that the changes in blood pressure and in all other parameters were
independent of the EMF exposure. These findings do not support the assumption
of a nonthermal influence of EMFs emitted by mobile phones on the
cardiovascular autonomic nervous system in healthy humans.
·
Burch JB, Reif JS, Noonan CW, Ichinose T, Bachand AM,
Koleber TL, Yost MG. Melatonin
metabolite excretion among cellular telephone users. Int J Rad Biol 78:
1029-1036, 2002.
Abstract: Purpose: The
relationship between cellular telephone use and excretion of the melatonin
metabolite 6-hydroxymelatonin sulfate (6-OHMS) was evaluated in two populations
of male electric utility workers (Study 1, n=149; Study 2, n=77).
Materials and methods: Participants collected urine samples and recorded
cellular telephone use over 3 consecutive workdays. Personal 60-Hz magnetic
field (MF) and ambient light exposures were characterized on the same days
using EMDEX II meters. A repeated measures analysis was used to assess the
effects of cellular telephone use, alone and combined with MF exposures, after
adjustment for age, participation month and light exposure.
Results: No change in 6-OHMS excretion was observed among those with daily
cellular telephone use >25 min in Study 1 (5 worker-days). Study 2 workers
with >25 min cellular telephone use per day (13 worker-days) had lower
creatinine-adjusted mean nocturnal 6-OHMS concentrations (p=0.05) and overnight
6-OHMS excretion (p=0.03) compared with those without cellular telephone use.
There was also a linear trend of decreasing mean nocturnal 6-OHMS/creatinine
concentrations (p=0.02) and overnight 6-OHMS excretion (p=0.08) across
categories of increasing cellular telephone use. A combined effect of cellular
telephone use and occupational 60-Hz MF exposure in reducing 6-OHMS excretion was
also observed in Study 2.
Conclusions: Exposure-related reductions in 6-OHMS excretion were observed in
Study 2, where daily cellular telephone use of >25min was more prevalent.
Prolonged use of cellular telephones may lead to reduced melatonin production,
and elevated 60-Hz MF exposures may potentiate the effect.
·
Cain
CD, Thomas DL, Adey WR, Focus formation of C3H/10T1/2 cells and exposure to a
836.55 MHz modulated radiofrequency field. Bioelectromagnetics 18(3):237-243,
1997.
Disruption of communication
between transformed cells and normal cells is involved in tumor promotion. We
have tested the hypothesis that exposures
to radiofrequency (RF) fields using a form of digital modulation (TDMA) and a
chemical tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), are
copromoters that enhance focus formation of transformed cells in coculture with
parental C3H/10T1/2 murine fibroblasts. RF field exposures did not
influence TPA's dose-dependent promotion of focus formation in coculture. Cell
cultures were exposed to an 836.55 MHz TDMA-modulated field in TEM transmission
line chambers, with incident energies that simulated field intensities at a
user's head. Specific absorption rates (SARs) of 0.15, 1.5, and 15 muW/g were
used during each digital packet, and the packet frequency was 50/s. The TEM
chambers were placed in a commercial incubator at 37 degrees C and 95%
humidity/5% CO2. The RF field exposures were in a repeating cycle, 20 min on,
20 min off, 24 h/day for 28 days. At 1.5 muW/g, TPA-induced focus formation (at
10, 30, and 50 ng/ml) was not significantly different in RF-exposed cultures
compared to parallel sham-exposed cultures in ten independent experiments in
terms of the number, density, and area of foci. Similarly, at 0.15 and 15.0
muW/g, in two and four experiments, respectively, RF exposure did not alter
TPA-induced focus formation. The findings support a conclusion that repeated
exposures to this RF field do not influence tumor promotion in vitro, based on
the RF field's inability to enhance TPA-induced focus formation.
·
Chagnaud
JL, Veyret B In vivo exposure of rats to GSM-modulated microwaves: flow
cytometry analysis of lymphocyte subpopulations and of mitogen stimulation. Int
J Radiat Biol 75(1):111-113, 1999.
The effects of
GSM-modulated microwaves on lymphocyte sub-populations of Sprague-Dawley rats
and their normal mitogenic responses were investigated
using flow cytometry analysis and a colorimetric method. No alterations were
found in the surface phenotype of splenic lymphocytes or in their mitogenic
activity, indicating that low-level pulsed microwaves do not seem to affect the
integrity of the immune system.
·
Chagnaud,
JL, Moreau, JM, Veyret, B, No effect of short-term exposure to GSM-modulated
low-power microwaves on benzo(a)pyrene-induced tumours in rat. Int J Radiat
Biol 75(10):1251-1256, 1999.
PURPOSE: In view of current
interest in the biological effects of amplitude-modulated microwaves arising
from the rapid development of mobile communications, the effects of low-level
microwaves on cancer development were investigated using a rat sarcoma model.
MATERIALS AND METHODS: Two-month-old female Sprague-Dawley rats were treated by
injection of benzo(a)pyrene and irradiated with GSM (Global System for
Mobile)-modulated 900-MHz microwaves in an anechoic chamber at 55 or 200 microW
cm(-2) (75 and 270 mW kg(-1) average whole-body SAR, 2h daily for 2 weeks).
Rats were exposed from day 20, 40 or 75 after carcinogen injection. Additional
groups of rats were sham-exposed in a second anechoic chamber.
Anti-phosphatidylinositol autoantibody levels were evaluated in sera to monitor
malignant transformation. RESULTS: Microwave exposure had no effect on the
development of tumours. No acceleration or delays in tumour onset were
observed. Animal survival was not modified and serum autoantibody levels were
similar in exposed and sham-exposed groups.
CONCLUSION: Low-level GSM microwave exposure of rat bearing
benzo(a)pyrene-induced tumours had no effect on auto-antibody levels, tumour
appearance and survival. The low exposure levels used here correspond to
exposure limits for whole-body exposure of humans.
·
Chia
SE, Chia HP, Tan JS, Prevalence of headache among handheld cellular telephone
users in singapore: A community study. Environ Health Perspect 108(11):1059-1062,
2000.
We carried out a
cross-sectional community study in Singapore to determine the prevalence of
specific central nervous system (CNS) symptoms among hand-held cellular
telephone (HP) users compared to nonusers and to study the association of risk
factors and CNS symptoms among HP users. A total of 808 men and women between
12 and 70 years of age, who lived in one community, were selected using
one-stage cluster random sampling and responses to a structured questionnaire.
The prevalence of HP users was 44.8%. Headache was the most prevalent symptom
among HP users compared to non-HP users, with an adjusted prevalence rate ratio
of 1.31 [95% confidence interval, 1.00-1.70]. There is a significant increase
in the prevalence of headache with increasing duration of usage (in minutes per
day). Prevalence of headache was reduced by more than 20% among those who used
hand-free equipment for their cellular telephones as compared to those who
never use the equipment. The use of HPs is not associated with a significant
increase of CNS symptoms other than headache.
·
Cranfield
CG, Wood AW, Anderson V, Menezes KG. Effects of mobile phone type signals on
calcium levels within human leukaemic T-cells (Jurkat cells). Int J Radiat Biol
77(12):1207-1217, 2001.
PURPOSE: To test whether
exposure to simulated GSM mobile phone signals (915 MHz, 2 W kg(-1)) influences
the concentration of calcium or calcium signalling patterns in a human
lymphocyte cell line. MATERIALS AND METHODS: The radiofrequency (RF) energy was
delivered via a coaxial applicator to a perfused chamber where cells adherent
to a thin glass coverslip were imaged by laser scanning confocal microscopy.
Cell calcium concentration, estimated from Fluo-3 fluorescence, was monitored
over two 10-min periods; control followed by exposed/sham, with exposure status
assigned in a blind and randomized fashion. Both continuous wave (CW) and
pulsed wave (PW) RF (on both phytohaemagglutanin-activated and unactivated
cells) were studied (with an equal number of sham exposures) on 100 cells per
category (total 800 cells). RESULTS: No significant changes were noted for the
following: regression slope of calcium fluorescence; mean calcium
concentration; number of calcium 'spikes' in each 10 min; or mean height of
these 'spikes'. The average frequency from Fourier spectra of these periods
showed significant alteration in one category only: PW exposure of activated
cells. CONCLUSIONS: There is no clear indication that RF emissions from mobile
phones are associated with any changes in calcium levels or calcium signalling
in lymphocytes.
·
Croft
R, Chandler J, Burgess A, Barry R, Williams J, Clarke A. Acute mobile phone
operation affects neural function in humans. Clin Neurophysiol 113(10):1623,
2002.
OBJECTIVES: Mobile phones (MP)
are used extensively and yet little is known about the effects they may have on
human physiology. There have been conflicting reports regarding the relation
between MP use and the electroencephalogram (EEG). The present study suggests
that this conflict may be due to methodological differences such as exposure
durations, and tests whether exposure to an active MP affects EEG as a function
of time.METHODS: Twenty-four subjects participated in a single-blind fully
counterbalanced cross-over design, where both resting EEG and phase-locked
neural responses to auditory stimuli were measured while a MP was either
operating or turned off.RESULTS: MP exposure altered resting EEG, decreasing
1-4Hz activity (right hemisphere sites), and increasing 8-12Hz activity as a
function of exposure duration (midline posterior sites). MP exposure also
altered early phase-locked neural responses, attenuating the normal response
decrement over time in the 4-8Hz band, decreasing the response in the 1230Hz
band globally and as a function of time, and increasing midline frontal and
lateral posterior responses in the 30-45Hz band.CONCLUSIONS: Active MPs affect
neural function in humans and do so as a function of exposure duration. The
temporal nature of this effect may contribute to the lack of consistent results
reported in the literature.
·
d'Ambrosio
G, Massa R, Scarfi MR, Zeni O, Cytogenetic damage in human lymphocytes
following GMSK phase modulated microwave exposure. Bioelectromagnetics 23:7-13,
2002.
The present study investigated,
using in vitro experiments on human lymphocytes, whether exposure to a
microwave frequency used for mobile communication, either unmodulated or in
presence of phase only modulation, can cause modification of cell proliferation
kinetics and/or genotoxic effects, by evaluating the cytokinesis block
proliferation index and the micronucleus frequency. In the GSM 1800 mobile
communication systems the field is both phase (Gaussian minimum shift keying,
GMSK) and amplitude (time domain multiple access, TDMA) modulated. The present
study investigated only the effects of phase modulation, and no amplitude
modulation was applied. Human peripheral blood cultures were exposed to 1.748
GHz, either continuous wave (CW) or phase only modulated wave (GMSK), for 15 min.
The maximum specific absorption rate ( 5 W/kg) was higher than that occurring
in the head of mobile phone users; however, no changes were found in cell
proliferation kinetics after exposure to either CW or GMSK fields. As far as
genotoxicity is concerned, the micronucleus frequency result was not affected
by CW exposure; however, a statistically significant micronucleus effect was
found following exposure to phase modulated field. These results would suggest
a genotoxic power of the phase modulation per se.
·
Dasdag,
S, Ketani, MA, Akdag, Z, Ersay, AR, Sar,i I, Demirtas ,OC, Celik, MS,
Whole-body microwave exposure emitted by cellular phones and testicular
function of rats. Urol Res 27(3):219-223, 1999.
This study investigated
whether there are adverse effects due to microwave exposure emitted by cellular
phones in male rats. Eighteen Wistar Albino rats were separated into three
groups, a sham group and two experimental groups. The rats were confined in
Plexiglas cages and cellular phones were placed 0.5 cm under the cages. In the
first experimental group, cellular phones were in standby position for 2 h. In
the second experimental group, phones were turned to the speech position three
times each for 1 min duration over 2 h. Rats in the first and second experimental
groups were exposed to microwaves emitted by phones for 2 h/day for a duration
of 1 month. After the last exposure the rats were killed. Brain, eyes, ears,
liver, heart, lungs, stomach, kidneys, testes, small and large intestines and
skin of the rats were observed histologically. The decrease of epididymal sperm
counts in the speech groups were not found to be significant (P > 0.05).
Differences in terms of normal and abnormal sperm forms were not observed (P
> 0.05). Histological changes were especially observed in the testes of rats
of the speech groups. Seminiferous tubular diameter of rat testes in the
standby and speech groups was found to be lower than the sham group (P <
0.05). Rectal temperatures of rats in the speech group were found to be higher
than the sham and standby groups (P < 0.05). The rectal temperatures of rats
before and after exposure were also found to be significantly higher in the
speech group (P < 0.05). Specific absorption rate (SAR) was determined as
0.141 W/kg.
·
Dasdag
S, Zulkuf Akdag M, Aksen F, Yilmaz F, Bashan M, Mutlu Dasdag M, Salih Celik M.
Whole body exposure of rats to microwaves emitted from a cell phone does not
affect the testes. Bioelectromagnetics 24(3):182-188, 2003.
The objective of this study
was to investigate the effects of radiofrequency radiation emitted from
cellular phones on the lipid composition, malondialdehyde concentration, p53
immune reactivity, sperm count, morphology, histological structure of testes,
and on rectal temperature of rats exposed to microwave radiation emitted from
cellular phones. Sixteen Spraque-Dawley rats were separated into two groups of
eight, sham exposed (control) and experimental. The rats were confined in
plexiglas cages specially designed for this study, and cellular phones were
placed 0.5 cm under the cages. For the experimental group, cellular phones were
activated 20 min per day (7 days a week) for 1 month. For the control group,
the cellular phones were placed beneath the cages for 20 min a day, but the
phones were turned off. Rectal temperatures were measured weekly. For 250 mW
radiated power, the whole body average SAR (rms) is 0.52 W/kg and 1 g averaged
peak SAR (rms) is 3.13 W/kg. The Mann-Whitney U-test was used for statistical
comparisons of groups. No statistically significant alteration in any of the
endpoints was noted. This study found no evidence suggesting an adverse effect
of cell phone exposure on measures of testicular function or structure.
·
de
Seze R, Ayoub J, Peray P, Miro L, Touitou Y, Evaluation in humans of the
effects of radiocellular telephones on the circadian patterns of melatonin
secretion, a chronobiological rhythm marker. J Pineal Res 27(4):237-242, 1999.
A decrease in melatonin
secretion has been observed in small mammals under exposure to extremely low
frequency electromagnetic fields. As there is some
concern about possible health effects of the increasing use of radiocellular telephones
emitting radiofrequency electromagnetic fields, we examined
whether such fields would alter melatonin levels in the human. Volunteers were
two groups totalling 38 men, 20-32 yr old. Exposures were to commercially
available cellular telephones of the GSM 900 type (Global System for Mobile
communication at 900 MHz) or DCS 1800 type (Digital Communication System at
1800 MHz), for 2 hr/day, 5 days/wk, for 4 wk, at their maximum power. Attention
of the volunteers was sustained by TV projection of movies. Blood samples were
collected hourly during the night and every 3 hr in the daytime. Four sampling
sessions were performed at 15-day intervals: before the beginning of the
exposure period, at the middle and the end of the exposure period, and 15 days
later to evaluate the persistence or late appearance of potential effects.
Evaluated parameters were the maximum serum concentration, the time of this
maximum, and the area under the curve of the hormone profile. Melatonin
circadian profile was not disrupted in 37 young male volunteers submitted to a
typical pattern of exposure to the electromagnetic fields generated by two
common types of cell phones.
·
de
Seze R, Fabbro-Peray P, Miro L, GSM radiocellular telephones do not disturb the
secretion of antepituitary hormones in humans. Bioelectromagnetics
19(5):271-278, 1998.
It is known that the
endocrine system of experimental animals is susceptible to perturbation by
radiofrequency (RF) radiation. Because of the recent interest
in health and safety issues of cellular telephones, an experiment was designed
to evaluate the effect of a 900 MHz RF radiation emitted by a Global System for
Mobile radiotelephone (217 Hz impulses, one-eighth duty cycle, 2 W peak power)
on human endocrine functions. Twenty healthy male volunteers aged from 19 to 40
were inducted in the present experiment. Each subject was exposed to RF
radiation through the use of a cellular phone 2 h/day, 5 days/wk, for 1 month.
Subjects were their own control. End points were serum adrenocorticotropin,
thyrotropin, growth hormone, prolactin, luteinizing hormone, and follicle
stimulating hormone concentrations. These end points were determined in nine
weekly blood samples obtained starting 3 weeks before the commencement of the
exposure and ending 2 weeks after exposures. All but one blood sample was drawn
48 h after each weekly session. The seventh drawing was performed the morning
after the last weekly exposure. Within each individual, the preexposure hormone
concentration was used as a control. Results indicated that all hormone
concentrations remained within normal physiologic ranges. A difference was not
noted among the nine weekly samples in five of six hormones studied. There was
a significant change only in thyrotropin concentration, showing a 21% decrease
on the seventh sampling. Because this change recovered fully during the
postexposure period, it is concluded that 1 month of intermittent exposures to
RF radiation from a cellular telephone does not induce a long-lasting or
cumulative effect on the hormone secretion rate of the anterior pituitary gland
in humans.
·
Di
Carlo A, White N, Guo F, Garrett P, Litovitz T. Chronic electromagnetic field
exposure decreases HSP70 levels and lowers cytoprotection. J. Cell. Biochem.
84: 447-454, 2002.
Electromagnetic field (EMF) exposures have been shown to induce heat shock
proteins (HSPs), which help to maintain the conformation of cellular proteins
during periods of stress. We have previously reported that short-term exposure
of chick embryos to either 60 Hz (extremely low frequency: ELF), or
radio-frequency (RF: 915 MHz) EMFs induce protection against hypoxia.
Experiments presented in the current report are based on a study in which
long-term (4 days), continuous exposure to ELF-EMFs decreased protection
against ultraviolet radiation. Based on this result, it was hypothesized that
de-protection against hypoxia should also occur following long-term,
continuous, or daily, repeated exposures to EMFs. To test this hypothesis,
chick embryos were exposed to ELF-EMFs (8 T) continuously for 4 days, or to ELF
or RF (3.5 mW incident power)- EMFs repeated daily (20, 30, or 60 min once or
twice daily for 4 days). Several of the exposure protocols yielded embryos that
had statistically significant decreases in protection against hypoxic stress
(continuous and 30 or 60 min ELF twice daily; or 30 or 60 min once daily RF).
This is consistent with our finding that following 4 days of ELF-EMF exposure,
HSP70 levels decline by 27% as compared to controls. In addition, the
superposition of ELF-EM noise, previously shown to minimize ELF-EMF induced
hypoxia protection, inhibited hypoxia de-protection caused by long term,
continuous ELF or daily, repeated RF exposures. This EMF-induced decrease in
HSP70 levels and resulting decline in cytoprotection suggests a mechanism by
which daily exposure (such as might be experienced by mobile phone users) could
enhance the probability of cancer and other diseases.
·
Donnellan
M, McKenzie DR, French PW, Effects of exposure to electromagnetic radiation at
835 MHz on growth, morphology and secretory characteristics of a mast cell
analogue, RBL-2H3. Cell Biol Int 21:427-439, 1997.
A mast cell line, RBL-2H3,
was exposed to 835 MHz for 20 minutes, three times per day for 7 days at a
power density of 8.1 +/- 3 mW/cm2. From day 4 onwards, it was observed that the
rate of DNA synthesis and cell replication increased, that actin distribution
and cell morphology became altered, and the amount of beta-hexosaminidase (a
marker of granule secretion) released in response to a calcium ionophore was
significantly enhanced, in comparison to unexposed cultures. There were no
effects seen on levels of cytoskeletal protein synthesis or of beta-actin mRNA.
Morphological changes persisted following subculture for at least 7 days in the
absence of further exposure. It is hypothesized that effects of exposure to an
electromagnetic field at 835 MHz may be mediated via a signal transduction
pathway.
·
Dubreuil D,
Jay T, Edeline JM. Does
head-only exposure to GSM-900 electromagnetic fields affect the performance of
rats in spatial learning tasks? Behav Brain Res 129(1-2):203-210, 2002.
The rapid expansion of
mobile communication has generated intense interest, but has also fuelled
ongoing concerns. In both humans and animals, radiofrequency radiations are
suspected to affect cognitive functions. More specifically, several studies
performed in rodents have suggested that spatial learning can be impaired by
electromagnetic field exposure. However, none of these previous studies have
simulated the common conditions of GSM mobile phones use. This study is the
first using a head-only exposure system emitting a 900-MHz GSM electromagnetic
field (pulsed at 217 Hz). The two behavioural tasks that were evaluated here
have been used previously to demonstrate performance deficits in spatial
learning after electromagnetic field exposure: a classical radial maze
elimination task and a spatial navigation task in an open-field arena (dry-land
version of the Morris water maze). The performances of rats exposed for 45 min
to a 900-MHz electromagnetic field (1 and 3.5 W/kg) were compared to those of
sham-exposed and cage-control rats. There were no differences among exposed,
sham, and cage-control rats in the two spatial learning tasks. The discussion
focuses on the potential reasons that led previous studies to conclude that
learning deficits do occur after electromagnetic field exposure.
·
Edelstyn
N, Oldershaw A. The acute effects of exposure to the electromagnetic field
emitted by mobile phones on human attention. Neuroreport 13(1):119-121, 2002.
The aim of our study was to
investigate the effects of acute mobile phone exposure on a range of tasks
which tapped capacity and processing speed within the attentional system.
Thirty-eight healthy volunteers were randomly assigned to either an
experimental group which was exposed to a connected mobile phone or a control group
in which the mobile phone was switched off. Subjects remained blind to mobile
phone status throughout duration of study. The experimental group were exposed
to an electromagnetic field emitted by a 900 MHz mobile phone for 30 min.
Cognitive performance was assessed at three points (prior to mobile phone
exposure, at 15 and 30 min post-exposure) using six cognitive
neuropsychological tests (digit span and spatial span forwards and backwards,
serial subtraction and verbal fluency). Significant differences between the two
groups were evident after 5 min on two tests of attentional capacity (digit
span forwards and spatial span backwards) and one of processing speed (serial
subtraction). In all three instances, performance was facilitated following
mobile phone exposure. No deficits were evident. These findings are discussed
in terms of possible functional and neuroanatomical bases.
·
Eulitz,
C, Ullsperger, P, Freude, G, Elbert ,T, Mobile phones modulate response
patterns of human brain activity. Neuroreport 9(14):3229-3232, 1998.
Mobile phones emit a pulsed
high-frequency electromagnetic field (PEMF) which may penetrate the scalp and
the skull. Increasingly, there is an interest in the interaction of this pulsed
microwave radiation with the human brain. Our investigations show that these
electromagnetic fields alter distinct aspects of the brain's electrical
response to acoustic stimuli. More precisely, our results demonstrate that
aspects of the induced but not the evoked brain activity during PEMF exposure can
be different from those not influenced by PEMF radiation. This effect appears
in higher frequency bands when subjects process task-relevant target stimuli
but was not present for irrelevant standard stimuli. As the induced brain
activity in higher frequency bands has been proposed to be a correlate of
coherent high-frequency neuronal activity, PEMF exposure may provide means to
systematically alter the pattern fluctuations in neural mass activity.
·
Finnie
JW, Blumbergs PC, Manavis J, Utteridge TD, Gebski V, Swift JG, Vernon-Roberts
B, Kuchel TR. Effect of global system for mobile communication (gsm)-like
radiofrequency fields on vascular permeability in mouse brain. Pathology
33(3):338-340, 2001.
The effect of global system
for mobile communication (GSM) radiofrequency fields on vascular permeability
in the brain was studied using a purpose-designed exposure system at 898.4 MHz.
Mice (n= 30) were given a single far field, whole body exposure for 60 minutes
at a specific absorption rate of 4 W/kg. Control mice were also sham-exposed (n
= 10) or permitted free movement in a cage (n = 10) to exclude any
stress-related effects. Vascular permeability changes were detected using
albumin immunohistochemistry and the efficacy of this vascular tracer was
confirmed with a positive control group exposed to a clostridial toxin known to
increase vascular permeability in the brain. No significant difference in
albumin extravasation was detected between any of the groups at the light
microscope level using the albumin marker.
·
Finnie
JW, Blumbergs PC, Manavis J, Utteridge TD, Gebski V, Davies RA, Vernon-Roberts
B, Kuchel TR. Effect of long-term mobile communication microwave exposure on
vascular permeability in mouse brain. Pathology 34(4):344-347, 2002.
AIMS: To study the effect
of long-term exposure to global system for mobile communication (GSM)
radiofrequency fields on vascular permeability in murine brains. METHODS: Using
a purpose-designed exposure system at 900 MHz, mice were given a 60-minute
far-field, whole body exposure on each of 5 days perweekfor 104 weeks at
specific absorption rates (SAR) of 0.25, 1.0,2.0 and 4.0 W/kg. Control mice
were sham-exposed or permitted free movement in a cage to evaluate any
stress-related effects. Albumin immunohistochemistry was used to detect
increased vascular permeability and the efficacy of the vascular tracer was
confirmed with a positive control group exposed to a clostridial toxin known to
increase vascular permeability in the brain. RESULTS: In all exposed and
control groups, albumin extravasation was minimal, often leptomeningeal, and
was deemed insignificant as a maximum of three capillaries or venules in a
given brain showed leakage from the very many blood vessels present in the
three coronal brain sections. CONCLUSIONS: These results suggest that prolonged
exposure to mobile telephone-type radiation produces negligible disruption to
blood-brain barrier integrity at the light microscope level using endogenous
albumin as a vascular tracer.
·
French
PW, Donnellan M, McKenzie DR, Electromagnetic radiation at 835 MHz changes the
morphology and inhibits proliferation of a human astrocytoma cell line.
Bioelectrochem Bioenerg 43:13-18, 1997.
A human astrocytoma cell
line, U-87 MG, was exposed to 835 MHz electromagnetic radiation for 20 min, 3
times per day for 7 days, at a power density of either 40+15 mWcm-2 or 8.1 + 3
mWcm-2. At the low power density, it was observed that the rate of DNA
synthesis decreased, and that the cells flattened and spread out in comparison
to unexposed culture. At 40 mWcm-2, there were no effects seen on cell
proliferation, but alteration in cell morphology included increased cell
spreading and also the appearance of actin-containing blebs at localized sites
on the membrane. It is hypothesised that 835 MHz radiation at low power density
may be affecting a signal transduction pathway involved in cell proliferation.
·
Freude,
G, Ullsperger, P, Eggert ,S, Ruppe, I, Effects of microwaves emitted by
cellular phones on human slow brain potentials. Bioelectromagnetics
19(6):384-387, 1998.
The influence of
electromagnetic fields (EMF) emitted by cellular phones on preparatory slow
brain potentials (SP) was studied in two different experimental tasks: In the
first, healthy male human subjects had to perform simple self-paced finger
movements to elicit a Bereitschaftspotential; in the second, they performed a
complex and cognitive demanding visual monitoring task (VMT). Both tasks were
performed with and without EMF exposure in counterbalanced order. Whereas
subjects' performance did not differ between the EMF exposure conditions, SP
parameters were influenced by EMF in the VMT: EMF exposure effected a
significant decrease of SPs at central and temporo-parieto-occipital brain
regions, but not at the frontal one. In the simple finger movement task, EMF
did not affect the Bereitschaftspotential.
·
Freude,
G, Ullsperger, P, Eggert, S, Ruppe, I, Microwaves emitted by cellular
telephones affect human slow brain potentials. Eur J Appl Physiol 81(1-2):18-27, 2000.
The influence of
electromagnetic fields (EMF) emitted by cellular telephones on preparatory slow
brain potentials (SP) was studied in two experiments, about 6 months apart. In
the first experiment, a significant decrease of SP was found during exposure to
EMF in a complex visual monitoring task (VMT). This effect was replicated in
the second experiment. In addition to the VMT, EMF effects on SP were analysed
in two further, less demanding tasks: in a simple finger movement task to
elicit a Bereitschaftspotential (BP) and in a two-stimulus task to elicit a
contingent negative variation (CNV). In comparison to the VMT, no significant
main EMF effects were found in BP and CNV tasks. The results accounted for a
selective EMF effect on particular aspects of human information processing, but
did not indicate any influence on human performance, well-being and health.
·
Fritze
K, Wiessner C, Kuster N, Sommer C, Gass P, Hermann DM, Kiessling M, Hossmann
KA, Effect of global system for mobile communication microwave exposure on the
genomic response of the rat brain. Neuroscience 81(3):627-639, 1997.
The acute effect of global
system for mobile communication (GSM) microwave exposure on the genomic
response of the central nervous system was studied
in rats by measuring changes in the messenger RNAs of hsp70, the transcription
factor genes c-fos and c-jun and the glial structural gene GFAP using in situ
hybridization histochemistry. Protein products of transcription factors, stress
proteins and marker proteins of astroglial and microglial activation were
assessed by immunocytochemistry. Cell proliferation was evaluated by
bromodeoxyuridine incorporation. A special GSM radiofrequency test set,
connected to a commercial cellular phone operating in the discontinuous
transmission mode, was used to simulate GSM exposure. The study was
conducted at time averaged and brain averaged specific absorption rates of 0.3
W/kg (GSM exposure), 1.5 W/kg (GSM exposure) and 7.5 W/kg (continuous wave
exposure), respectively. Immediately after exposure, in situ hybridization
revealed slight induction of hsp70 messenger RNA in the cerebellum and
hippocampus after 7.5 W/kg exposure, but not at lower intensities. A slightly
increased expression of c-fos messenger RNA was observed in the cerebellum,
neocortex and piriform cortex of all groups subjected to immobilization, but no
differences were found amongst different exposure conditions. C-jun and GFAP
messenger RNAs did not increase in any of the experimental groups. 24 h after
exposure, immunocytochemical analysis of FOS and JUN proteins (c-FOS, FOS B,
c-JUN JUN B, JUN D), of HSP70 or of KROX-20 and -24 did not reveal any
alterations. Seven days after exposure, neither increased cell proliferation
nor altered expression of astroglial and microglial marker proteins were
observed. In conclusion, acute high intensity microwave exposure of immobilized
rats
may induce some minor stress response but does not result in lasting adaptive
or reactive changes of the brain.
·
Fritze
K, Sommer C, Schmitz B, Mies G, Hossmann KA, Kiessling M, Wiessner C, Effect of
global system for mobile communication (GSM) microwave exposure on blood-brain
barrier permeability in rat. Acta Neuropathol (Berl) 94(5):465-470, 1997.
We investigated the effects
of global system for mobile communication (GSM) microwave exposure on the
permeability of the blood-brain barrier using a
calibrated microwave exposure system in the 900 MHz band. Rats were restrained
in a carousel of circularly arranged plastic tubes and sham-exposed or
microwave irradiated for a duration of 4 h at specific brain absorption rates
(SAR) ranging from 0.3 to 7.5 W/kg. The extravasation of proteins was assessed
either at the end of exposure or 7 days later in three to five coronal brain
slices by immunohistochemical staining of serum albumin. As a positive control
two rats were subjected to cold injury. In the brains of freely moving control
rats (n = 20) only one spot of extravasated serum albumin could be detected in
one animal. In the sham-exposed control group (n = 20) three animals exhibited
a total of 4 extravasations. In animals irradiated for 4 h at SAR of 0.3, 1.5
and 7.5 W/kg (n = 20 in each group) five out of the ten animals of each group
killed at the end of the exposure showed 7, 6 and 14 extravasations,
respectively. In the ten animals of each group killed 7 days after exposure,
the total number of extravasations was 2, 0 and 1, respectively. The increase
in serum albumin extravasations after microwave exposure reached significance
only in the group exposed to the highest SAR of 7.5 W/kg but not at the lower
intensities. Histological injury was not observed in any of the examined
brains. Compared to other pathological conditions with increased blood-brain
barrier permeability such as cold injury, the here observed serum albumin
extravasations are very modest and, moreover, reversible. Microwave exposure in
the frequency and intensity range of mobile telephony is unlikely to produce
pathologically significant changes of the blood-brain barrier permeability.
·
Gos P,
Eicher B, Kohli J, Heyer WD, No mutagenic or recombinogenic effects of mobile
phone fields at 900 MHz detected in the yeast saccharomyces cerevisiae.
Bioelectromagnetics 21(7):515-523, 2000.
Both actively growing and
resting cells of the yeast Saccharomyces cerevisiae were exposed to 900-MHz
fields that closely matched the Global System for Mobile Communication (GSM)
pulsed modulation format signals for mobile phones at specific absorption rates
(SAR) of 0.13 and 1.3 W/kg. Two identical anechoic test chambers were constructed
to perform concurrent control and test experiments under well-controlled
exposure conditions. Using specific test strains, we examined the genotoxic
potential of mobile phone fields, alone and in combination, with a known
genotoxic compound, the alkylating agent methyl methansulfonate. Mutation rates
were monitored by two test systems, a widely used gene-specific forward
mutation assay at CAN1 and a wide-range assay measuring the induction of
respiration-deficient (petite) clones that have lost their mitochondrial
function. In addition, two further assays measured the recombinogenic effect of
mobile phone fields to detect possible effects on genomic stability: First, an
intrachromosomal, deletion-formation assay previously developed for genotoxic screening;
and second, an intragenic recombination assay in the ADE2 gene. Fluctuation
tests failed to detect any significant effect of mobile phone fields on forward
mutation rates at CAN1, on the frequency of petite formation, on rates of
intrachromosomal deletion formation, or on rates of intragenic recombination in
the absence or presence of the genotoxic agent methyl methansulfonate.
·
Goswami
PC, Albee LD, Parsian AJ, Baty JD, Moros EG, Pickard WF, Roti Roti JL, Hunt CR,
Proto-oncogene mRNA levels and activities of multiple transcription factors in
C3H 10T 1/2 murine embryonic fibroblasts exposed to 835.62 and 847.74 MHz
cellular phone communication frequency radiation. Radiat Res 151(3):300-309,
1999.
This study was designed to determine whether two differently modulated
radiofrequencies of the type generally used in cellular phone communications
could elicit a general stress response in a biological system. The two
modulations and frequencies studied were a frequency-modulated continuous wave
(FMCW) with a carrier frequency of 835.62 MHz and a code division
multiple-access (CDMA) modulation centered on 847.74 MHz. Changes in
proto-oncogene expression, determined by measuring Fos, Jun, and Myc mRNA
levels as well as by the DNA-binding activity of the AP1, AP2 and NF-kappaB
transcription factors, were used as indicators of a general stress response.
The effect of radiofrequency exposure on proto-oncogene expression was assessed
(1) in exponentially growing C3H 10T 1/2 mouse embryo fibroblasts during their
transition to plateau phase and (2) during transition of serum-deprived cells
to the proliferation cycle after serum stimulation. Exposure of serum-deprived
cells to 835.62 MHz FMCW or 847.74 MHz CDMA microwaves (at an average specific
absorption rate, SAR, of 0.6 W/kg) did not significantly change the kinetics of
proto-oncogene expression after serum stimulation. Similarly, these exposures
did not affect either the Jun and Myc mRNA levels or the DNA-binding activity
of AP1, AP2 and NF-kappaB in exponential cells during transit to plateau-phase
growth. Therefore, these results suggest that the radiofrequency exposure is
unlikely to elicit a general stress response in cells of this cell line under
these conditions. However, statistically significant increases (approximately
2-fold, P = 0.001) in Fos mRNA levels were detected in exponential cells in
transit to the plateau phase and in plateau-phase cells exposed to 835.62 MHz
FMCW microwaves. For 847.74 MHz CDMA exposure, the increase was 1.4-fold (P =
0.04). This increase in Fos expression suggests that expression of specific
genes could be affected by radiofrequency exposure.
·
Haarala
C, Bjornberg L, Ek M, Laine M, Revonsuo A, Koivisto M, Hamalainen H. Effect of
a 902 MHz electromagnetic field emitted by mobile phones on human cognitive
function: A replication study. Bioelectromagnetics 24(4):283-288, 2003.
Our study was a replication
and extension with methodological improvements to a previous study on effects
of the electromagnetic field (EMF) emitted by a 902 MHz mobile phone on human
cognitive functioning. Improvements on the previous study included multicentre
testing and a double blind design. A total of 64 subjects (32 men and 32 women)
in two independent laboratories performed a battery of 9 cognitive tasks twice:
while the EMF was on and while it was off. Reaction times (RTs) and accuracy
were recorded. The order of exposure and tasks was counterbalanced across
subjects and gender. There were no statistically significant differences in
performance between genders or laboratories. Although the RTs and the accuracy
of answers were very similar to those of our previous study, our previous
results were not replicated. We concluded that EMF had no effect on RTs or on
the accuracy of the subjects' answers. Further, our results indicate that our
EMF had no immediate effect on human cognitive functioning or that such effects
are so small that they are observed on behavior only occasionally.
·
Hardell
L, Hansson Mild K, Pahlson A, Hallquist A, Ionizing radiation, cellular
telephones and the risk of brain tumours. Europ J Cancer Prevent 10:523-529,
2001.
A case-control study on
brain tumours included 233 patients aged 20-80 years and alive at the study
time. They had histopathologically verified brain tumour and lived in the
Upsala-Orebro region (1994-1996) or in Stockholm region (1995-1996). Two
matched controls to each case were selected from the Swedish Population
Register. Two hundred and nine cases (90%) and 425 controls (91%) answered the
questionnaire. Results are presented for the whole study group, as given here,
and for malignant and benign tumours separately. For workers in the chemical
industry the odds ratio (OR) was 4.10, 95% confidence interval (95% CI)
1.25-13.4 and laboratory workers OR 3.21, 95%CI 1.16-8.85. Radiotherapy of the
head and neck region gave OR 3.61, 95% CI 0.65-19.9. Medical diagnostic X-ray
of the same area yielded OR 1.64, 95% CI 1.04-2.58. Work as a physician gave OR
6.00, 95% CI 0.62-57.7. All three cases had worked with fluoroscopy.
Ipsilateral (same side) use of a cellular telephone increased the risk of
tumours in the temporal, temporo-parietal and occipital areas, with OR 2.42,
95% CI 0.97-6.05 (i.e., the anatomical areas with highest exposure to
microwaves from a mobile phone).
·
Hardell,
L, Nasman, A, Pahlson, A, Hallquist, A, Hansson Mild, K, Use of cellular
telephones and the risk for brain tumours: A case-control study. Int J Oncol 15(1):113-116, 1999.
The use of cellular
telephones has increased dramatically during the 1990's in the world. In the
1980's the analogue NMT system was used whereas the digital GSM system was
introduced in early 1990's and is now the preferred system. Case reports of
brain tumours in users initiated this case-control study on brain tumours and
use of cellular telephones. Also other exposures were assessed. All cases, both
males and females, with histopathologically verified brain tumour living in
Uppsala-Orebro region (1994-96) and Stockholm region (1995-96) aged 20-80 at
the time of diagnosis and alive at start of the study were included, 233 in
total. Two controls to each case were selected from the Swedish Population
Register matched for sex, age and study region. Exposure was assessed by
questionnaires supplemented over the phone. The analyses were based on answers
from 209 (90%) cases and 425 (91%) controls. Use of cellular telephone gave
odds ratio (OR) = 0.98 with 95% confidence interval (CI) = 0. 69-1.41. For the
digital GSM system OR = 0.97, CI = 0.61-1.56 and for the analogue NMT system OR
= 0.94, CI = 0.62-1.44 were calculated. Dose-response analysis and using
different tumour induction periods gave similar results. Non-significantly
increased risk was found for tumour in the temporal or occipital lobe on the
same side as a cellular phone had been used, right side OR = 2.45, CI =
0.78-7.76, left side OR = 2.40, CI = 0.52-10.9 Increased risk was found only
for use of the NMT system. For GSM use the observation time is still too short
for definite conclusions. An increased risk for brain tumour in the anatomical
area close to the use of a cellular telephone should be especially studied in
the future.
·
Hardell
L, Nasman A, Pahlson A, Hallquist A, Case-Control Study on Radiology Work,
Medical X-ray Investigations, and Use of Cellular Telephones as Risk Factors
for Brain Tumors. Medscape General Medicine May 4, 2000.
Abstract
Context. Ionizing radiation is a well-established risk factor for brain tumors.
During recent years, microwave exposure from the use of cellular telephones has
been discussed as a potential risk factor.
Objective. To determine risk factors for brain tumors.
Design. A case-control study, with exposure assessed by questionnaires.
Participants. A total of 233 currently living men and women, aged 20 to 80
years, were included. The case patients had histopathologically verified brain
tumors and lived in the Uppsala-Orebro region (1994-1996) or the Stockholm
region (1995-1996). Two matched controls to each case were selected from the
Swedish Population Register. Main Outcome Measures. Ionizing radiation and use
of cellular telephones as risk factors for brain tumors.
Results. A total of 209 cases (90%) and 425 controls (91%) answered the
questionnaire. Work as a physician yielded an odds ratio (OR) of 6.00, with a
95% confidence interval (CI) of 0.62 to 57.7. All three case patients had
worked with fluoroscopy. Radiotherapy of the head and neck region yielded an OR
of 3.61 (95% CI, 0.65-19.9). Medical diagnostic x-ray examination of the same
area yielded an OR of 2.10 (95% CI, 1.25-3.53), with a tumor induction period
of 5 years or more. Chemical industry work yielded an OR of 4.10 (95% CI,
1.25-13.4), and laboratory work yielded an OR of 3.21 (95% CI, 1.16-8.85).
Ipsilateral use of cellular telephones increased the risk for tumors in the
temporal, temporoparietal, and occipital lobes (OR, 2.42; 95% CI, 0.97-6.05),
ie, the anatomic areas with highest exposure to microwaves from a mobile
telephone. The result was further strengthened (OR, 2.62; 95% CI, 1.02-6.71) in
a multivariate analysis that included laboratory work and medical diagnostic
x-ray investigations of the head and neck.
Conclusion. Exposure to ionizing radiation, work in laboratories, and work in
the chemical industry increased the risk of brain tumors. Use of a cellular
telephone was associated with an increased risk in the anatomic area with
highest exposure.
·
Hardell
L, Hallquist A, Hansson Mild K, Carlberg M, Pahlson A, Lilja A. cellular and
cordless telephones and the risk for brain tumours. Europ J Cancer Prevent
11:377-386, 2002.
Microwave exposure from the
use of cellular telephones ahs been discussed in recently years as a potential
risk factor for brain tumours. We included in a case-control study 1617
patients aged 20-80 years of both sexes with brain tumour diagnosed between 1
January 1997 and 30 June 2000. They were alive at the study time and had
histopathologically verified brain tumour. One matched control to each case was
selected from the Swedish Population Register. The study area was the
Uppsala-Orebro, Stockholm, Linkoping and Goteborg medical regions of Sweden.
Exposure was assessed by a questionnaire that was answered by 1429 (88%) cases
and 1470 (91%) controls. In total, use of analogue cellular telephones gave an
increased risk with an odds ratio (OR) of 1.3 (95% confidence interval (CI)
1.02-1.6). With a tumour induction period of >10 years the risk increased
further; OR 1.8 (95% CI 1.1-2.9). No clear association was found for digital or
cordless telephones. With regard to the anatomical area of the tumour and
exposure to microwaves, the risk was increased for tumours located in the
temporal area on the same side of the brain that was used during phone calls;
for analogue cellular telephones the OR was 2.5 (95% CI 1.3-4.9). Use of a
telephone on the opposite side of the brain was not associated with an
increased risk for brain tumours. With regard to different tumour types, the
highest risk was for acoustic neurinoma (OR 3.5, 95% CI 1.8-6.8) among analogue
cellular telephone users.
·
Hardell
L, Mild KH, Carlsberg M. Case-control study on the use of cellular and cordless
phones and the risk for malignant brain tumours. Int. J. Radiat. Biol. 78:931-936, 2002.
Purpose: To investigate the
use of cellular and cordless phones and the risk for malignant brain tumours.
Materials and Methods: A case-control study was performed on 649 patents aged
20-80 years of both sexes with malignant brain tumour diagnosed from 1 January
1997 to 30 June 2000. All patients were alive during the time of the study and
had histopathology verified brain tumours. One matched control to each case was
selected from the Swedish Population Register. The study area was the
Uppasala-Orebro, Stockholm, Linkoping and Goteborg medical regions of Sweden.
Results: Exposure was assessed by a questionnaire answered by 588 (91%) cases
and 581 (90%) controls. Phone usage was defined as ‘ever use’ and usage
starting 1 year before dagnosis was disregarded. Overall, no significantly
increased risks were found: analogue cellular phones yielded an odds ratio (OR)
=1.13, 95% confidence interval (CI) = 0.82-1.57, digital cellular phones OR =
1.13, CI = 0.86-1.48, and cordless phones OR = 1.13, CI =0.85-1.50. For
ipsilateral (same side) radiofrequency exposure, analogue mobile phones gave OR
= 1.85, CI = 1.16-2.96, for all malignant brain tumours. For astrocytoma, this
risk was OR = 1.95, CI = 1.12-3.39. For all malignant brain tumours, digital
mobile phones yielded OR = 1.59, CI = 1.05-2.41, and cordless phones yielded OR
= 1.46, CI = 0.96-2.23, in the analysis of ipsilateral exposure.
Conclusion: The ipsilateral use of an analogue cellular phone yielded a
significantly increased risk for malignant brain tumours.
·
Hardell
L, Mild KH, Carlberg M. Further aspects on cellular and cordless telephones and
brain tumours. Int J Oncol
22(2):399-407, 2003.
We included in a
case-control study on brain tumours and mobile and cordless telephones 1,617
patients aged 20-80 years of both sexes diagnosed during January 1, 1997 to
June 30, 2000. They were alive at the study time and had histopathology
verified brain tumour. One matched control to each case was selected from the
Swedish Population Register. The study area was the Uppsala-Orebro, Stockholm,
Linkoping and Goteborg medical regions of Sweden. Exposure was assessed by a
questionnaire that was answered by 1,429 (88%) cases and 1,470 (91%) controls.
In total use of analogue cellular telephones gave an increased risk with odds
ratio (OR)=1.3, 95% confidence interval (CI)=1.04-1.6, whereas digital and
cordless phones did not overall increase the risk significantly. Ipsilateral
use of analogue phones gave OR=1.7, 95% CI=1.2-2.3, digital phones OR=1.3, 95%
CI=1.02-1.8 and cordless phones OR=1.2, 95% CI=0.9-1.6. The risk for
ipsilateral use was significantly increased for astrocytoma for all studied
phone types, analogue phones OR=1.8,95% CI=1.1-3.2, digital phones OR=1.8, 95%
CI=1.1-2.8, cordless phones OR=1.8, 95% CI=1.1-2.9. Use of a telephone on the
opposite side of the brain was not associated with a significantly increased
risk for brain tumours. Regarding anatomical area of the tumour and exposure to
microwaves, the risk was increased for tumours located in the temporal area on
the same side of the brain that was used during phone calls, significantly so
for analogue cellular telephones OR=2.3, 95% CI=1.2-4.1. For acoustic neurinoma
OR=4.4, 95% CI=2.1-9.2 was calculated among analogue cellular telephone users.
When duration of use was analysed as a continuous variable in the total
material, the risk increased per year for analogue phones with OR=1.04, 95%
CI=1.01-1.08. For astrocytoma and ipsilateral use the trend was for analogue
phones OR=1.10, 95% CI=1.02-1.19, digital phones OR=1.11, 95% CI=1.01-1.22, and
cordless phones OR=1.09, 95% CI=1.01-1.19. There was a tendency of a shorter
tumour induction period for ipsilateral exposure to microwaves than for
contralateral, which may indicate a tumour promotor effect.
·
Hardell
L, Mild KH, Sandstrom M, Carlberg M, Hallquist A, Pahlson A. Vestibular
schwannoma, tinitus and cellular telephones. Neuroepidemiol 22:124-129, 2003.
Cases with tinnitus after
using analogue cellular telephones are presented. An increased odds radio of
3.45, 95% confidence interval (CI) 1.77-6.76, was found for vestibular
schwannoma (VS) associated with the use of analogue cell phones. During the
time period 1960-1998, the age-standardized incidence of VS in Sweden
significantly increased yearly by +2.53% (CI 1.71-3.35). A significant
increases in the incidence of VS was only found for the latter of the two time
period 1960-1979 and 1980-1998. For all other brain tumors taken together, the
incidence significantly increased yearly by +0.80% (CI 0.59-1.02) for the time
period 1960-1998, although the increase was only significant for benign tumors
other than VS during 1960-1979.
·
Harvey
C, French PW, Effects on protein kinase C and gene expression in a human mast
cell line, HMC-1, following microwave exposure. Cell Biol Int 23(11):739-748,
2000.
We used a resonant cavity
which delivered a continuous wave exposure at 864.3 MHz at an average specific
absorption rate (SAR) of 7 W/kg to determine non-thermal biological effects of
microwave exposure. A human mast cell line, HMC-1, was used as the biological
target. Cells were given three exposures each of 20-min duration daily for 7
days. The temperature of the cell culture medium during the exposure fell to
26.5 degrees C. Effects were seen on localization of protein kinase C, and
expression of three genes of 588 screened. The affected genes included the
proto-oncogene c-kit, the transcription factor Nucleoside diphosphate kinase B
and the apoptosis-associated gene DAD-1. Stress response genes were variably
upregulated. No significant effect on morphology or on F-actin distribution was
detected. We conclude that low-power microwave exposure may act on HMC-1 cells
by altering gene expression via a mechanism involving activation of protein
kinase C, and at temperatures well below those known to induce a heat shock
response.
·
Heikkinen
P, Kosma VM, Hongisto T, Huuskonen H, Hyysalo P, Komulainen H, Kumlin T,
Lahtinen T, Lang S, Puranen L, Juutilainen J. Effects of Mobile Phone Radiation
on X-Ray-Induced Tumorigenesis in Mice. Radiat Res 156(6):775-785, 2001.
The increased use of mobile
phones has raised the question of possible health effects of such devices,
particularly the risk of cancer. It seems unlikely that the low-level
radiofrequency (RF) radiation emitted by them would damage DNA directly, but
its ability to act as a tumor promoter is less well characterized. In the current
study, we evaluated the effect of low-level RF radiation on the development of
cancer initiated in mice by ionizing radiation. Two hundred female CBA/S mice
were randomized into four equal groups at the age of 3 to 5 weeks. The mice in
all groups except the cage-control group were exposed to ionizing radiation at
the beginning of the study and then to RF radiation for 1.5 h per day, 5 days a
week for 78 weeks. One group was exposed to continuous NMT (Nordic Mobile
Telephones)-type frequency-modulated RF radiation at a frequency of 902.5 MHz
and a nominal average specific absorption rate (SAR) of 1.5 W/kg. Another group
was exposed to pulsed GSM (Global System for Mobile)-type RF radiation
(carrier-wave frequency 902.4 MHz, pulse frequency 217 Hz) at a nominal average
SAR of 0.35 W/kg. The control animals were sham-exposed. Body weight, clinical
signs, and food and water consumption were recorded regularly. Hematological
examinations and histopathological analyses of all lesions and major tissues
were performed on all animals. The RF-radiation exposures did not increase the
incidence of any neoplastic lesion significantly. We conclude that the results
do not provide evidence for cancer promotion by RF radiation emitted by mobile
phones.
·
Hietanen
M, Kovala T, Hamalainen AM, Human brain activity during exposure to
radiofrequency fields emitted by cellular phones. Scand J Work Environ Health
26(2):87-92, 2000.
OBJECTIVES: The aim of this
study was to explore the possible influence of
radiofrequency (RF) radiation exposure on human brain function. METHODS: The
electroencephalographic (EEG) activity of 19 volunteers was quantitatively
analyzed. Ten of the subjects were men (28-48 years of age) and 9 were women
(32-57 years of age). The sources of exposure were 5 different cellular phones
(analogue and digital models) operating at a frequency of 900 MHz or 1800 MHz.
The EEG activity was recorded in an awake, closed-eyes situation. Six 30-minute
experiments, including 1 sham exposure, were made for each subject. The duration
of a real exposure phase was 20 minutes. RESULTS: Exposure to one of the phones
caused a statistically significant change in the absolute power at the delta
band of the EEG recording. However, no difference was seen in the relative
power of the same band, and no changes occurred during exposure to other phones
at any frequency bands. CONCLUSIONS: The findings of this study suggest that
exposure to radiofrequency fields emitted by cellular phones has no abnormal
effects on human EEG activity. The observed difference in 1 parameter was
probably caused by statistical chance.
·
Hietanen
M, Hämäläinen A-M, Husman T. Hypersensitivity symptoms associated with exposure
to cellular telephones: No causal link. Bioelectromagnetics 23:264-270, 2002.
The hypothesis that there
exist hypersensitive persons who perceive subjective symptoms from
radiofrequency (RF) fields emitted by hand held mobile phones (cellular phones)
was tested using double blind provocation experiments. We also tested whether
sensitive subjects are able to determine whether the phone is on or off by
sensing RF fields. The study group consisted of 20 volunteers (13 women and 7
men) who reported themselves as being sensitive to cellular phones. The RF
exposure sources were one analogue NMT phone (900 MHz) and two digital GSM
phones (900 and 1800 MHz). The duration of a test session was 30 min, and three
or four sessions were performed in random order for each subject during 1 day.
The subjects were asked to report symptoms or sensations as soon as they
perceived any abnormal feelings. In addition, the subjects' blood pressure,
heart rate, and breathing frequency were monitored every 5 min. The results of
the study indicated that various symptoms were reported, and most of them
appeared in the head region. However, the number of reported symptoms was
higher during sham exposure than during real exposure conditions. In addition,
none of the test persons could distinguish real RF exposure from sham exposure.
Hence, we conclude that adverse subjective symptoms or sensations, though
unquestionably perceived by the test subjects, were not produced by cellular
phones.
·
Higashikubo
R, Culbreth VO, Spitz DR, LaRegina MC, Pickard WF, Straube WL, Moros EG, Roti
JL, Radiofrequency electromagnetic fields have no effect on the in vivo
proliferation of the 9L brain tumor. Radiat Res 152(6):665-671, 1999.
The intracranial 9L tumor
model was used to determine if exposure to a radiofrequency (RF)
electromagnetic field similar to those used in cellular telephone has any effects
on the growth of a central nervous system tumor. Fischer 344 rats implanted
with different numbers of 9L gliosarcoma cells were exposed to 835.62 MHz
frequency-modulated continuous wave (FMCW) or 847.74 MHz code division multiple
access (CDMA) RF field with nominal slot-average specific absorption rates in
the brain of 0.75 +/- 0.25 W/kg. The animals were exposed to the RF field for 4
h a day, 5 days a week starting 4 weeks prior to and up to 150 days after the
implantation of tumor cells. Among sham-exposed animals injected with 2 to 10
viable cells (group 1), the median survival was 70 days, with 27% of the
animals surviving at 150 days. The median survival length and final survival
fraction for animals injected with 11 to 36 viable cells (group 2) were 52 days
and 14%, respectively, while the values for those injected with 37 to 100 cells
(group 3) were 45 days and 0%. The animals exposed to CDMA or FMCW had similar
survival parameters, and the statistical comparison of the survival curves for
each of the groups 1, 2 and 3 showed no significant differences compared to
sham-exposed controls.
·
Higashikubo
R, Ragouzis M, Moros EG, Straube WL, Roti Roti JL.
Radiofrequency Electromagnetic Fields do not Alter the Cell Cycle Progression
of C3H 10T and U87MG Cells. Radiat Res 156(6):786-795, 2001.
The effects of exposure to radiofrequency electromagnetic fields (RF EMFs) on
cell cycle progression of mouse fibroblasts C3H 10T(1/2) and human glioma U87MG
cells were determined by the flow cytometric bromodeoxyuridine pulse-chase
method. Cells were exposed to a frequency-modulated continuous wave at 835.62
MHz or a code division multiple access RF EMF centered on 847.74 MHz at an
average specific absorption rate of 0.6 W/kg. Five cell cycle parameters,
including the transit of cells through G(1), G(2) and S phase and the
probability of cell division, were examined immediately after the cells were
placed in the fields or after they had been kept in the fields for up to 100 h.
The only significant change observed in the study was that associated with C3H
10T(1/2) cell cultures moving into plateau phase toward the later times in the
long-exposure experiment. No changes in the cell cycle parameters were observed
in cells exposed to either mode of RF EMFs when compared to sham-exposed cells
in either of the cell lines studied during the entire experimental period. The
results show that exposure to RF EMFs, at the frequencies and power tested,
does not have any effect on cell progression in vitro.
·
Hladky,
A, Musil, J, Roth, Z, Urban, P, Blazkova, V, Acute effects of using a mobile
phone on CNS functions. Cent Eur J Public Health 7(4):165-167. 1999.
Twenty volunteers
participated in two experiments exploring the acute effects of using the mobile
phone Motorola GSM 8700 on the functions of the CNS. When
speaking (5 minutes reading a text from daily newspapers) the electromagnetic
fields from the mobile apparatus did not affect the visual evoked potentials.
Also a 6-min exposure did not reveal any effect of electromagnetic fields on
the results in two tests (memory and attention) performed while speaking into
the mobile. On the other hand the phone call itself strongly influenced the
performance in a secondary task applying a test of switching attention which is
a good model for driving a car. The response and decision speed were
significantly worse. This is a proof that even a slight psychological stress
involved in calling while driving can be a great risk.
·
Hocking,
B, Preliminary report: symptoms associated with mobile phone use. Occup Med
(Lond);48(6):357-360, 1998.
Mobile phone use is
ubiquitous, although the alleged health effects of low level radio-frequency
radiation (RFR) used in transmission are contentious. Following isolated
reports of headache-like symptoms arising in some users, a survey has been
conducted to characterize the symptoms sometimes associated with mobile phone
usage. A notice of interest in cases was placed in a major medical journal and
this was publicized by the media. Respondents were interviewed by telephone
using a structured questionnaire. Forty respondents from diverse occupations
described unpleasant sensations such as a burning feeling or a dull ache mainly
occurring in the temporal, occipital or auricular areas. The symptoms often
began minutes after beginning a call, but could come on later during the day.
The symptoms usually ceased within an hour after the call, but could last until
evening. Symptoms did not occur when using an ordinary handset, and were
different from ordinary headaches. There were several reports suggestive of
intra-cranial effects. Three respondents reported local symptoms associated
with wearing their mobile phone on their belts. There was one cluster of cases
in a workplace. Seventy-five per cent of cases were associated with digital
mobile phones. Most of the respondents obtained relief by altering their
patterns of telephone usage or type of phone. Cranial and other diverse
symptoms may arise associated with mobile phone usage. Physicians and users
alike should be alert to this. Further work is needed to determine the range of
effects, their mechanism and the possible implications for safety limits of
RFR.
·
Huber
R, Graf T, Cote KA, Wittmann L, Gallmann E, Matter D, Schuderer J, Kuster N,
Borbely AA, Achermann P, Exposure to pulsed high-frequency electromagnetic
field during waking affects human sleep EEG. Neuroreport 11(15):3321-3325,
2000.
The aim of the study was to
investigate whether the electromagnetic field (EMF) emitted by digital
radiotelephone handsets affects brain physiology. Healthy, young male subjects
were exposed for 30 min to EMF (900 MHz; spatial peak specific absorption rate
1 W/kg) during the waking period preceding sleep. Compared with the control
condition with sham exposure, spectral power of the EEG in non-rapid eye
movement sleep was increased. The maximum rise occurred in the 9.75-11.25 Hz
and 12.5-13.25 Hz band during the initial part of sleep. These changes
correspond to those obtained in a previous study where EMF was intermittently
applied during sleep. Unilateral exposure induced no hemispheric asymmetry of
EEG power. The present results demonstrate that exposure during waking modifies
the EEG during subsequent sleep. Thus the changes of brain function induced by
pulsed high-frequency EMF outlast the exposure period.
·
Huber
R, Treyer V, Borbély AA, Schuderer J, Gottselig JM, Landolt H-P, Werth E,
Berthold T, Kuster N, Buck A, Achermann P, Electromagnetic fields, such as
those from mobile phones, alter regional cerebral blood flow and sleep and waking
EEG. J Sleep Res 11: 289-295, 2002.
Usage of mobile phones is rapidly increasing, but there is limited data on the
possible effects of electromagnetic field (EMF) exposure on brain physiology.
We investigated the effect of EMF vs. sham control exposure on waking regional
cerebral blood flow (rCBF) and on waking and sleep electroencephalogram (EEG)
in humans. In Experiment 1, positron emission tomography (PET) scans were taken
after unilateral head exposure to 30-min pulse-modulated 900 MHz electromagnetic
field (pm-EMF). In Experiment 2, night-time sleep was polysomnographically
recorded after EMF exposure. Pulse-modulated EMF exposure increased relative
rCBF in the dorsolateral prefrontal cortex ipsilateral to exposure. Also,
pm-EMF exposure enhanced EEG power in the alpha frequency range prior to sleep
onset and in the spindle frequency range during stage 2 sleep. Exposure to EMF
without pulse modulation did not enhance power in the waking or sleep EEG. We
previously observed EMF effects on the sleep EEG (A. A. Borbély, R. Huber, T.
Graf, B. Fuchs, E. Gallmann and P. Achermann. Neurosci. Lett., 1999,
275: 207-210; R. Huber, T. Graf, K. A. Cote, L. Wittmann, E. Gallmann, D.
Matter, J. Schuderer, N. Kuster, A. A. Borbély, and P. Achermann. Neuroreport, 2000, 11: 3321-3325),
but the basis for these effects was unknown. The present results show for the
first time that (1) pm-EMF alters waking rCBF and (2) pulse modulation of EMF
is necessary to induce waking and sleep EEG changes. Pulse-modulated EMF exposure
may provide a new, non-invasive method for modifying brain function for
experimental, diagnostic and therapeutic purposes.
·
Huber
R, Schuderer J, Graf T, Jutz K, Borbely AA, Kuster N, Achermann P. Radio
frequency electromagnetic field exposure in humans: Estimation of SAR
distribution in the brain, effects on sleep and heart rate. Bioelectromagnetics
24(4):262-276, 2003.
In two previous studies we
demonstrated that radiofrequency electromagnetic fields (RF EMF) similar to
those emitted by digital radiotelephone handsets affect brain physiology of
healthy young subjects exposed to RF EMF (900 MHz; spatial peak specific
absorption rate [SAR] 1 W/kg) either during sleep or during the waking period
preceding sleep. In the first experiment, subjects were exposed intermittently
during an 8 h nighttime sleep episode and in the second experiment,
unilaterally for 30 min prior to a 3 h daytime sleep episode. Here we report an
extended analysis of the two studies as well as the detailed dosimetry of the
brain areas, including the assessment of the exposure variability and
uncertainties. The latter enabled a more in depth analysis and discussion of
the findings. Compared to the control condition with sham exposure, spectral
power of the non-rapid eye movement sleep electroencephalogram (EEG) was
initially increased in the 9-14 Hz range in both experiments. No topographical
differences with respect to the effect of RF EMF exposure were observed in the
two experiments. Even unilateral exposure during waking induced a similar
effect in both hemispheres. Exposure during sleep reduced waking after sleep
onset and affected heart rate variability. Exposure prior to sleep reduced
heart rate during waking and stage 1 sleep. The lack of asymmetries in the
effects on sleep EEG, independent of bi- or unilateral exposure of the cortex,
may indicate involvement of subcortical bilateral projections to the cortex in
the generation of brain function changes, especially since the exposure of the
thalamus was similar in both experiments (approx. 0.1 W/kg).
·
Imaida,
K, Taki, M, Watanabe, S, Kamimura, Y, Ito, T, Yamaguchi, T, Ito, N, Shirai, T,
The 1.5 GHz electromagnetic near-field used for cellular phones does not
promote rat liver carcinogenesis in a medium-term liver bioassay. Jpn J Cancer
Res 89(10):995-1002, 1998.
We have recently
established that local exposure to a 929.2 MHz electromagnetic near-field, used
for cellular phones, does not promote rat liver carcinogenesis in a medium-term
bioassay system. In the present study, a 1.439 GHz electromagnetic near-field
(EMF), another microwave band employed for cellular phones in Japan, was
similarly investigated. Time division multiple access (TDMA) signals for the
Personal Digital Cellular (PDC) Japanese cellular telephone standard system were
directed to rats through a quarter-wavelength monopole antenna. Numerical
dosimetry showed that the peak SARs within the liver were 1.91-0.937 W/kg,
while the whole-body average specific absorption rates (SARs) were 0.680-0.453
W/kg, when the time-averaged antenna radiation power was 0.33 W. Exposure was
for 90 min a day, 5 days a week, over 6 weeks, to male F344 rats given a single
dose of diethylnitrosamine (200 mg/kg, i.p.) 2 weeks previously. At week 3, all
rats were subjected to a two-thirds partial hepatectomy. At week 8, the
experiment was terminated and the animals were killed. Carcinogenic potential
was scored by comparing the numbers and areas of the induced glutathione
S-transferase placental form (GST-P)-positive foci in the livers of exposed
(48) and sham-exposed rats (48). Despite increased serum levels of
corticosterone, adrenocorticotropic hormone (ACTH) and melatonin, the numbers
and the areas of GST-P-positive foci were not significantly altered by the
exposure. These findings clearly indicated that local body exposure to a 1.439
GHz EMF, as in the case of a 929.2 MHz field, has no promoting effect on rat
liver carcinogenesis in the present model.
·
Imaida
K, Taki M, Yamaguchi T, Ito T, Watanabe S, Wake K, Aimoto A, Kamimura Y, Ito N,
Shirai T, Lack of promoting effects of the electromagnetic near-field used for
cellular phones (929.2 MHz) on rat liver carcinogenesis in a medium-term liver
bioassay. Carcinogenesis 19(2):311-314, 1998.
The possible cancer promotion potential of local exposure to a pulse modulated
929.2 MHz electromagnetic near-field on chemically-initiated rat liver
carcinogenesis was investigated employing a medium-term bioassay. A 929.2-MHz
electromagnetic near-field of time division multiple access (TDMA) signal for
PDC (Personal Digital Cellular, Japanese cellular telephone standard) system
was directed to rats through a quarter-wavelength monopole antenna. Maximum
local specific absorption rates (SARs) on temporal average were 7.2-6.6 W/kg
within the whole body and 2.0-1.7 W/kg within the liver, which was the target
organ. The whole-body average SARs on temporal average were 0.80-0.58 W/kg.
Temporal peak SARs had three times these values due to the duty ratio of the
PDC signal. Exposure was for 90 min a day, 5 days a week, over 6 weeks. The
exposure apparatus was specially designed for this experiment, to allow
exposure of the lateral mid-section of the rat body to the electromagnetic
near-field. Male F344 rats, 6 week-old, were initially (at week 0) given a
single dose of diethylnitrosamine (DEN, 200 mg/kg body wt, i.p.). At 2 weeks
later, exposure (48 rats) or sham-exposure (48 rats) was started. The exposure
of electromagnetic near-fields was performed using the exposure apparatus
mentioned above. At week 3, all rats were subjected to a 2/3 partial
hepatectomy. At week 8 (i.e. after 6 weeks exposure or sham-exposure), the
experiment was terminated and all rats were killed. Carcinogenic potential was
scored by comparing the numbers and areas of the induced glutathione S-transferase
placental form (GST-P) positive foci in the livers of the exposed and
sham-exposed rats. A further group of 24 animals, given only DEN and partial
hepatectomy, served as the controls. The numbers (no./cm2) of GST-P positive
foci were 4.61 +/- 1.77, 5.21 +/- 1.92 (P < 0.05, versus control) and 4.09
+/- 1.47 and the areas (mm2/cm2) were 0.30 +/- 0.16, 0.36 +/- 0.21 and 0.28 +/-
0.15, for the exposed, sham-exposed and control groups, respectively. There
were no significant differences between the exposed and sham-exposed groups.
These findings clearly indicated that local body exposure to a 929.2-MHz field,
modulated in a PDC waveform, has no significant effect on rat liver
carcinogenesis under the experimental conditions employed.
·
Inskip
PD, Tarone RE, Hatch EE, Wilcosky TC, Shapiro WR, Selker RG, Fine HA, Black PM,
Loeffler JS, Linet MS, Cellular-Telephone Use and Brain Tumors. N Engl J Med
344(2):79-86, 2001.
Background: Concern has
arisen that the use of hand-held cellular telephones might cause brain tumors.
If such a risk does exist, the matter would be of considerable public health
importance, given the rapid increase worldwide in the use of these devices.
Methods: We examined the use of cellular telephones in a case-control study of
intracranial tumors of the nervous system conducted between 1994 and 1998. We
enrolled 782 patients through hospitals in Phoenix, Arizona; Boston; and
Pittsburgh; 489 had histologically confirmed glioma, 197 had meningioma, and 96
had acoustic neuroma. The 799 controls were patients admitted to the same
hospitals as the patients with brain tumors for a variety of nonmalignant
conditions. Results: As compared with never, or very rarely, having used a
cellular telephone, the relative risks associated with a cumulative use of a
cellular telephone for more than 100 hours were 0.9 for glioma (95 percent
confidence interval, 0.5 to 1.6), 0.7 for meningioma (95 percent confidence
interval, 0.3 to 1.7), 1.4 for acoustic neuroma (95 percent confidence
interval, 0.6 to 3.5), and 1.0 for all types of tumors combined (95 percent
confidence interval, 0.6 to 1.5). There was no evidence that the risks were
higher among persons who used cellular telephones for 60 or more minutes per
day or regularly for five or more years. Tumors did not occur
disproportionately often on the side of head on which the telephone was
typically used. Conclusions: These data do not support the hypothesis that the
recent use of hand-held cellular telephones causes brain tumors, but they are
not sufficient to evaluate the risks among long-term, heavy users and for
potentially long induction periods.
·
Ivaschuk
OI, Jones RA, Ishida-Jones T, Haggren W, Adey WR, Phillips JL, Exposure of
nerve growth factor-treated PC12 rat pheochromocytoma cells to a modulated radiofrequency
field at 836.55 MHz: effects on c-jun and c-fos expression. Bioelectromagnetics
18(3):223-229, 1997.
Rat PC12 pheochromocytoma
cells have been treated with nerve growth factor And then exposed to athermal
levels of a packet-modulated radiofrequency field
At 836.55 MHz. This signal was produced by a prototype time-domain
multiple-access (TDMA) transmitter that conforms to the North American digital
cellular
telephone standard. Three slot average power densities were used: 0.09, 0.9,
and 9 mW/cm2. Exposures were for 20, 40, and 60 min and included an
intermittent exposure regimen (20 min on/20 min off), resulting in total
incubation times of 20, 60, and 100 min, respectively. Concurrent controls were
sham exposed. After extracting total cellular RNA, Northern blot analysis was
used to assess the expression of the immediate early genes, c-fos and c-jun, in
all cell populations. No change in c-fos transcript levels were detected after
20 min exposure at each field intensity (20 min was the only time period at
which c-fos message could be detected consistently). Transcript levels for
c-jun were altered only after 20 min exposure to 9 mW/cm2 (average 38%
decrease).
·
Jarupat
S, Kawabata A, Tokura H, Borkiewicz A. Effects of the 1900 MHz Electromagnetic
Field Emitted from Cellular Phone on Nocturnal Melatonin Secretion. J Physiol
Anthropol Appl Human Sci 22(1):61-63, 2003.
Exposure to cellular phone
EMF caused a significant reduction in salivary melatonin in female human
subjects.
·
Jech
R, Sonka K, Ruzicka E, Nebuzelsky A, Bohm J, Juklickova M, Nevsimalova S.
Electromagnetic field of mobile phones affects visual event related potential
in patients with narcolepsy. Bioelectromagnetics 22(7):519-528, 2001.
The effects of the mobile
phone (MP) electromagnetic fields on electroencephalography (EEG) and
event-related potentials (ERP) were examined. With regard to the reported
effects of MP on sleep, 22 patients with narcolepsy-cataplexy were exposed or
sham exposed for 45 min to the MP (900 MHz, specific absorption rate 0.06 W/kg)
placed close to the right ear in a double blind study. There were no changes of
the EEG recorded after the MP exposure. A subgroup of 17 patients was studied
on visual ERP recorded during the MP exposure. Using an adapted "odd-ball"
paradigm, each patient was instructed to strike a key whenever rare target
stimuli were presented. There were three variants of target stimuli (horizontal
stripes in (i) left, (ii) right hemifields or (iii) whole field of the screen).
The exposure enhanced the positivity of the ERP endogenous complex solely in
response to target stimuli in the right hemifield of the screen (P < 0.01).
The reaction time was shortened by 20 ms in response to all target stimuli (P
< 0.05). In conclusion, the electromagnetic field of MP may suppress the
excessive sleepiness and improve performance while solving a monotonous
cognitive task requiring sustained attention and vigilance.
·
Jensh
RP, Behavioral teratologic studies using microwave radiation: is there an
increased risk from exposure to cellular phones and microwave ovens? Reprod
Toxicol 11(4):601-611, 1997.
The objective of the
investigations presented in this review was to determine if there are adverse
effects due to chronic prenatal microwave exposure in rats at term and/or
alterations in neonatal and adult offspring psychophysiologic development and
growth. Following the establishment of a nonhyperthermal power density level of
microwave radiation, pregnant rats were exposed throughout pregnancy to
continuous wave 915 MHz, 2450 MHz, or 6000 MHz radiation at power density
levels of 10, 20, or 35 mW/cm2, respectively. Teratologic evaluation included
the following parameters: maternal weight and weight gain; mean litter size;
maternal organ weight and organ weight/body weight ratios; body weight ratios
of brain, liver, kidneys, and ovaries; maternal peripheral blood parameters
including hematocrit, hemoglobin, and white cell counts; number of resorptions
and resorption rate; number of abnormalities and abnormality rate; mean term
fetal weight. Mothers were rebred, and the second, nonexposed litters were
evaluated for teratogenic effects. Exposed offspring were evaluated using the
following perinatal and adult tests: eye opening, surface righting, negative
geotaxis, auditory startle, air righting, open field, activity wheel, swimming,
and forelimb hanging. Offspring were also monitored for weekly weight and
weight gain. Animals exposed to 915 MHz did not exhibit any consistent
significant alterations in any of the above parameters. Exposure to 2450 MHz
resulted only in a significantly increased adult offspring activity level
compared to nonexposed offspring. Offspring exposed to 6000 MHz radiation
exhibited an initial slight, but significant, retardation in term weight, while
mothers had a significantly reduced monocyte count. No changes in any of the
other term parameters were observed. A few postnatal parameters were affected
in offspring exposed to 6000 MHz. Weekly weights were lower in the exposed
offspring, but they recovered by the fifth week. Eye opening was delayed, and
there were changes in the water T-maze and open field performance levels.
Several organ/body weight ratios differed from those of the control offspring.
These results indicate that exposure to 6000 MHz radiation at this power
density level may result in subtle long-term neurophysiologic alterations.
However, in the absence of a hyperthermic state, the microwave frequencies
tested, which included frequencies used in cellular phones and microwave ovens,
do not induce a consistent, significant increase in reproductive risk as
assessed by classical morphologic and postnatal psychophysiologic parameters.
·
Johansen
C, Boice JD, McLaughlin JK, Olsen JH, Cellular Telephones and Cancer-a
Nationwide Cohort Study in Denmark. J Natl Cancer Inst 93(3):203-207, 2001.
BACKGROUND: Use of cellular
telephones is increasing exponentially and has become part of everyday life.
Concerns about possible carcinogenic effects of radiofrequency signals have
been raised, although they are based on limited scientific evidence. METHODS: A
retrospective cohort study of cancer incidence was conducted in Denmark of all
users of cellular telephones during the period from 1982 through 1995.
Subscriber lists from the two Danish operating companies identified 420 095
cellular telephone users. Cancer incidence was determined by linkage with the
Danish Cancer Registry. All statistical tests are two-sided. RESULTS: Overall,
3391 cancers were observed with 3825 expected, yielding a significantly decreased
standardized incidence ratio (SIR) of 0.89 (95% confidence interval [CI] = 0.86
to 0.92). A substantial proportion of this decreased risk was attributed to
deficits of lung cancer and other smoking-related cancers. No excesses were
observed for cancers of the brain or nervous system (SIR = 0.95; 95% CI = 0.81
to 1.12) or of the salivary gland (SIR = 0.72; 95% CI = 0.29 to 1.49) or for
leukemia (SIR = 0.97; 95% CI = 0.78-1.21), cancers of a priori interest. Risk
for these cancers also did not vary by duration of cellular telephone use, time
since first subscription, age at first subscription, or type of cellular
telephone (analogue or digital). Analysis of brain and nervous system tumors
showed no statistically significant SIRs for any subtype or anatomic location.
CONCLUSIONS: The results of this investigation, the first nationwide cancer
incidence study of cellular phone users, do not support the hypothesis of an
association between use of these telephones and tumors of the brain or salivary
gland, leukemia, or other cancers.
·
Johansen
C, Boice JD Jr, McLaughlin JK, Christensen HC, Olsen JH. Mobile phones and
malignant melanoma of the eye. Brit J Cancer 86:348-349, 2002.
Recently a four-fold
increase in the risk of malignant melanoma of the eye was associated with the
use of radiofrequency transmitting devices, including mobile phones in Germany.
We contrasted the incidence rates of this rare cancer with the number of mobile
phone subscribers in Denmark. We observed no increasing trend in the incidence
rate of melanoma, which was in sharp contrast to the exponentially increasing
number of mobile phone subscribers starting in the early 1980s. Our study
provides no support for an association between mobile phones and ocular
melanoma.
·
Kellenyi,
L, Thuroczy, G, Faludy, B, Lenard, L, Effects of mobile GSM radiotelephone
exposure on the auditory brainstem response (ABR). Neurobiology 7:79-81, 1999.
A 15-min exposure to GSM
phone radiation caused an increase in auditory brainstem response in the
exposed side of human subjects. Subjects also showed a hearing deficiency in
the high frequency range (20 dB hearing deficiency from 2 KHz to 10 KHz).
·
Khudnitskii,
SS, Moshkarev, EA, Fomenko, TV, [On the evaluation of the influence of cellular
phones on their users]. [Article in Russian] Med Tr Prom Ekol (9):20-24, 1999.
The authors studied
influence of ultrahigh frequency radiation caused by cellular phones on
functional state of central nervous, cardiovascular systems and local
temperature changes in cellular phones users. The head area near the phone
antenna appeared to be under the most intensive heating. Ultrahigh frequency
radiation induces significant changes in local temperature and in physiologic
parameters of central nervous and cardiovascular systems.
· Kimata H. Enhancement of allergic skin wheal responses by microwave radiation from mobile phones in patients with atopic eczema/dermatitis syndrome. Int Arch Allergy Immunol 129(4):348-350, 2002.
Microwave radiation from
mobile phones enhanced skin wheal responses induced by house dust mite and
Japanese cedar pollen while it had no effect on wheal responses induced by
histamine in patients with atopic eczema/dermatitis syndrome (AEDS). Microwave
radiation also increased plasma levels of substance P (SP) and vasoactive intestinal
peptide (VIP) in patients with AEDS. These results indicate that microwave
radiation from mobile phones may enhance allergen-induced wheal responses in
association with the release of SP and VIP. This finding may be useful in
elucidating the pathophysiology and treatment of AEDS.
·
Koivisto,
M, Revonsuo, A, Krause, C, Haarala, C, Sillanmaki, L, Laine, M, Hamalainen, H,
Effects of 902 MHz electromagnetic field emitted by cellular telephones on
response times in humans. Neuroreport 11(2):413-415, 2000.
The present study examined
possible influences of a 902 MHz electromagnetic field emitted by cellular
telephones on cognitive functioning in 48 healthy humans. A battery of 12
reaction time tasks was performed twice by each participant in a counterbalanced
order: once with and once without the exposure to the field. The results showed
that the exposure to the electromagnetic field speeded up response times in
simple reaction time and vigilance tasks and that the cognitive time needed in
a mental arithmetics task was decreased. The results suggest that exposure to
the electromagnetic field emitted by cellular telephones may have a
facilitatory effect on brain functioning, especially in tasks requiring
attention and manipulation of information in working memory.
·
Koivisto
M, Krause CM, Revonsuo A, Laine M, Hamalainen H, The effects of electromagnetic
field emitted by GSM phones on working memory. Neuroreport 11(8):1641-1643,
2000.
The influence of pulsed
radiofrequency (RF) electromagnetic fields of digital GSM mobile phones on
working memory in healthy subjects were studied. Memory load was varied from 0
to 3 items in an n-back task. Each subject was tested twice within a single
session, with and without the RF exposure (902MHz, 217Hz). The RF field speeded
up response times when the memory load was three items but no effects of RF
were observed with lower loads. The results suggest that RF fields have a
measurable effect on human cognitive performance and encourage further studies
on the interactions of RF fields with brain function.
·
Koivisto
M, Haarala C, Krause CM, Revonsuo A, Laine M, Hamalainen H,
GSM phone signal does not produce subjective symptoms. Bioelectromagnetics
22(3):212-215, 2001.
The influence of pulsed radiofrequency (RF) electromagnetic fields of digital
GSM mobile phones (902 MHz, 217 Hz pulse modulation) on subjective symptoms or
sensations in healthy subjects were studied in two single-blind experiments.
The duration of the RF exposure was about 60 min in Experiment 1 and 30 min in Experiment
2. Each subject rated symptoms or sensations in the beginning of the
experimental session and at the end of both the exposure and the nonexposure
conditions. The symptoms rated were headache, dizziness, fatigue, itching or
tingling of the skin, redness on the skin, and sensations of warmth on the
skin. The results did not reveal any differences between exposure and
non-exposure conditions, suggesting that a 30-60 min exposure to this RF field
does not produce subjective symptoms in humans.
·
Krause
CM, Sillanmaki L, Koivisto M, Haggqvist A, Saarela C, Revonsuo A, Laine M,
Hamalainen H, Effects of electromagnetic field emitted by cellular phones on
the EEG during a memory task. Neuroreport 11(4):761-764, 2000.
The effects of
electromagnetic fields (EMF) emitted by cellular phones on the ERD/ERS of the
4-6 Hz, 6-8 Hz, 8-10 Hz and 10-12 Hz EEG frequency bands were studied in 16
normal subjects performing an auditory memory task. All subjects performed the
memory task both with and without exposure to a digital 902 MHz EMF in
counterbalanced order. The exposure to EMF significantly increased EEG power in
the 8-10 Hz frequency band only. Nonetheless, the presence of EMF altered the
ERD/ERS responses in all studied frequency bands as a function of time and memory
task (encoding vs retrieval). Our results suggest that the exposure to EMF does
not alter the resting EEG per se but modifies the brain responses significantly
during a memory task.
·
Krause
CM, Sillanmaki L, Koivisto M, Haggqvist A, Saarela C, Revonsuo A, Laine M,
Hamalainen H, Effects of electromagnetic fields emitted by cellular phones on
the electroencephalogram during a visual working memory task. Int J Radiat Biol
76(12):1659-1667, 2000.
PURPOSE: To examine the effects of electromagnetic fields (EMF) emitted by
cellular phones on the event-related desynchronization/synchronization
(ERD/ERS) responses of the 4-6, 6-8, 8-10 and 10-12Hz EEG frequency bands
during cognitive processing. MATERIALS AND METHODS: Twenty-four subjects
performed a visual sequential letter task (n-back task) with three different
working memory load conditions: zero, one and two items. All subjects performed
the memory task both with and without exposure to a digital 902 MHz EMF in
counterbalanced order. RESULTS: The presence of EMF altered the ERD/ERS
responses in the 6-8 and 8-10 Hz frequency bands but only when examined as a
function of memory load and depending also on whether the presented stimulus
was a target or not. CONCLUSIONS: The results suggest that the exposure to EMF
modulates the responses of EEG oscillatory activity approximately 8 Hz
specifically during cognitive processes.
·
Kwee
S, Raskmark P, Changes in cell proliferation due to environmental non-ionizing
radiation 2. Microwave radiation. Bioelectrochem Bioenerg 44(2) 251-255, 1998.
Due to the use of mobile
telephones, there is an increased exposure of the environment to weak
radiofrequency (RF) electromagnetic fields, emitted by these devices. This
study was undertaken to investigate if the microwave radiation from these
fields will have a similar effect on cell proliferation as weak electromagnetic
(ELF) fields. The field was generated by signal simulation of the Global System
for Mobile communications (GSM) of 960 MHz. Cell cultures, growing in
microtiter plates, were exposed in a specially constructed chamber, a
Transverse Electromagnetic (TEM) cell. The Specific Absorption Rate (SAR)
values for each cell well were calculated for this exposure system. Experiments
were performed on cell cultures of transformed human epithelial amnion cells
(AMA), which were exposed to 960 MHz microwave fields at three different power
levels and three different exposure times, respectively. It was found that cell
growth in the exposed cells was decreased in comparison to that in the control
and sham exposed cells. Cell proliferation during the period following exposure
varied not only with the various SAR levels, but also with the length of
exposure time. On the other hand, repeated periods of exposure did not seem to
change the effects. There was a general linear correlation between power level
and growth change. However, the exposure time required to obtain the maximum
effect was not the same for the various power levels. It turned out that at low
power level, a maximum effect was first reached after a longer exposure time
than at higher power level. A similar phenomenon was registered in the studies
on ELF electromagnetic fields. Here, it was found that there was a linear
correlation between the length of exposure time to obtain maximum effect and
field strength.
·
Kwee
S, Raskmark P, Velizarov P. Changes in cellular proteins due to environmental
non-ionizing radiation. I. Heat-shock proteins. Electro- and Magnetobiology 20:
141-152, 2001.
This paper describes the effect of weak microwave fields on the amounts of
heat-shock proteins in cell cultures at various temperatures. The field was
generated by signal simulation of the Global System for Mobile communications
(GSM) of 960 Mhz, used in portable phones. Transformed human epithelial amnion
(AMA) cells, growing on glass coverslips, were exposed in a transverse
electromagnetic (TEM) cell to a microwave field, generating a specific
absorption rate (SAR) of 2.1 mW.kg-1 in the cells. Exposure temperatures were
35, 37, and 40 ± 0.1°C, respectively, and the exposure time was 20 min. The
heat-shock proteins Hsp-70 and Hsp-27 were detected by immuno-fluorescence.
Higher amounts of Hsp-70 were present in the cells exposed at 35 and 37°C than
in the sham-exposed cells. These effects can be considered to be athermal,
since the field strength was much lower than the safety standard for absence of
heat generation by microwave fields. There was no significant response in the
case of Hsp-27.
·
Lebedeva
NN, Sulimov AV, Sulimova OP, Kotrovskaya TI, Gailus T,
Cellular phone electromagnetic field effects on bioelectric activity of human
brain. Crit Rev Biomed Eng 28(1-2):323-337, 2000.
24 volunteers participated
in the experiments. The investigation of EEG reactions to cellular phone (EMF
frequency 902.4 MHz and intensity 0.06 mW/cm2) was conducted. Two experiments
were performed with each subject--cellular phone exposure and Placebo Duration
of the experiment was 60 min: 15 min--background; 15 min--EMF exposure or
Placebo; 30 min--afterexposure. EEG was recorded in 16 standard leads with
"eyes open" and "eyes closed". Special software with
non-linear dynamics was developed for EEG analyses. One parameter, multichannel
(global) correlation dimension, was calculated. The changes of these parameters
can be evidence of brain functional state changes. As a result of EEG record
processing, a significant increase of global correlation dimension during the
exposure and afterexposure period was discovered, more pronounced in the case
of "eyes closed". That can be viewed as the manifestation of cortex
activation under phone EMF exposure.
·
Lebedeva
NN, Sulimov AV, Sulimova OP, Korotkovskaya TI, Gailus T, Investigation of brain
potentials in sleeping humans exposed to the electromagnetic field of mobile
phones. Crit Rev Biomed Eng 29(1):125-133, 2001.
An investigation was made of 8-hour EEG tracings of sleeping humans exposed to
the electromagnetic field of a GSM-standard mobile phone. To analyze the
EEG-patterns, manual scoring, nonlinear dynamics, and spectral analysis were
employed. It was found that, when human beings were exposed to the
electromagnetic field of a cellular phone, their cerebral cortex biopotentials
revealed an increase in the alpha-range power density as compared to the
placebo experiment. It was also found that the dimension of EEG correlation
dynamics and the relation of sleep stages changed under the influence of the
electromagnetic field of a mobile phone.
·
Lee
TMC, Ho SMY, Tsang LYH, Yang SYC, Li LSW, Chan CCH, Effect on human attention
of exposure to the electromagnetic field emitted by mobile phones. NeuroReport
12:729-731, 2001.
This study examined the
effect of exposure to the electromagnetic field emitted by mobile phones on
human attention. Three measures of attention were administered to 72 teenagers,
37 of whom were mobile phone users. The results showed that the mobile phone
users performed better on one of the three measures of attention than did the
non-mobile phone users. The results suggest that exposure to the electro-
magnetic field emitted by mobile phones may have a mild facilitating effect on
attention functions, which is consistent with previous observations that
exposure to the electromagnetic field has a facilitating effect on cognitive
processing. The possibility that mobile phone users may be naturally better at
multiple tasking tasks was discussed.
·
Leszczynski
D, Joenväärä S, Reivinen J, Kuokka R, Non-thermal activation of the
hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial
cells: Molecular mechanism for cancer- and blood-brain barrier-related effects.
Differentiation 70:120 – 129, 2002.
We have examined whether
non-thermal exposures of cultures of the human endothelial cell line EA.hy926
to 900 MHz GSM mobile phone microwave radiation could activate stress response.
Results obtained demonstrate that 1-hour non-thermal exposure of EA.hy926 cells
changes the phosphorylation status of numerous, yet largely unidentified,
proteins. One of the affected proteins was identified as heat shock protein-27
(hsp27). Mobile phone exposure caused a transient increase in phosphorylation
of hsp27, an effect which was prevented by SB203580, a specific inhibitor of
p38 mitogen-activated protein kinase (p38MAPK). Also, mobile phone exposure
caused transient changes in the protein expression levels of hsp27 and p38MAPK.
All these changes were non-thermal effects because, as determined using
temperature probes, irradiation did not alter the temperature of cell cultures,
which remained throughout the irradiation period at 37 ± 0.3 °C. Changes in the
overall pattern of protein phosphorylation suggest that mobile phone radiation
activates a variety of cellular signal transduction pathways, among them the
hsp27/p38MAPK stress response pathway. Based on the known functions of hsp27,
we put forward the hypothesis that mobile phone radiation-induced activation of
hsp27 may (i) facilitate the development of brain cancer by inhibiting the
cytochrome c/caspase-3 apoptotic pathway and (ii) cause an increase in
blood-brain barrier permeability through stabilization of endothelial cell
stress fibers. We postulate that these events, when occurring repeatedly over a
long period of time, might become a health hazard because of the possible
accumulation of brain tissue damage. Furthermore, our hypothesis suggests that
other brain damaging factors may co-participate in mobile phone
radiation-induced effects.
·
Li,
JR, Chou, CK, McDougall, JA, Dasgupta, G, Wu, HH, Ren, RL, Lee, A, Han, J,
Momand J TP53 tumor suppressor protein in normal human fibroblasts does not
respond to 837 MHz microwave exposure. Radiat Res 151(6):710-716, 1999.
The TP53 tumor suppressor
protein (formerly known as p53) responds to a wide variety of environmental
insults. To evaluate the safety of cellular telephones, TP53 responses in human
fibroblast cells were studied after exposure to 837 MHz microwaves. Cells were
exposed in a temperature-controlled transverse electromagnetic (TEM) chamber to
a specific absorption rate (SAR) of 0.9 or 9.0 W/kg at 837 MHz continuous-wave
(CW) microwave irradiation for 2 h. The TP53 protein levels were measured by
Western blot at 2, 8, 24 and 48 h after treatment. The TP53 protein levels in
microwave-treated cells, sham-treated cells, and untreated cells remained
unchanged relative to each other at all times tested (Fisher test and
Student-Newman-Keuls test, P > 0.05). No morphological alterations were
observed in microwave-treated cells compared to sham-treated cells. We conclude
that TP53 protein expression levels in cultured human fibroblast cells do not
change significantly during a 48-h period after exposure to 837 MHz continuous
microwaves for 2 h at SAR levels of 0.9 or 9.0 W/kg.
·
Li L,
Bisht KS, LaGroye I, Zhang P, Straube WL, Moros EG, Roti Roti JL.
Measurement of DNA damage in mammalian cells exposed in vitro to radiofrequency
fields at sars of 3-5 w/kg. Radiat Res 156:328-332, 2001.
In the present study, we
determined whether exposure of mammalian cells to 3.2-5.1 W/kg specific
absorption rate (SAR) radiofrequency fields could induce DNA damage in murine
C3H 10T(1/2) fibroblasts. Cell cultures were exposed to 847.74 MHz
code-division multiple access (CDMA) and 835.62 frequency-division multiple
access (FDMA) modulated radiations in radial transmission line (RTL)
irradiators in which the temperature was regulated to 37.0 +/- 0.3 degrees C.
Using the alkaline comet assay to measure DNA damage, we found no statistically
significant differences in either comet moment or comet length between
sham-exposed cells and those exposed for 2, 4 or 24 h to CDMA or FDMA
radiations in either exponentially growing or plateau-phase cells. Further, a
4-h incubation after the 2-h exposure resulted in no significant changes in
comet moment or comet length. Our results show that exposure of cultured C3H
10T(1/2) cells at 37 degrees C CDMA or FDMA at SAR values of up to 5.1 W/kg did
not induce measurable DNA damage.
·
Linz,
KW, von Westphalen, C, Streckert, J, Hansen, V, Meyer, R, Membrane potential
and currents of isolated heart muscle cells exposed to pulsed radio frequency
fields. Bioelectromagnetics 20(8):497-511, 1999.
The influence of radio
frequency (RF) fields of 180, 900, and 1800 MHz on the membrane potential,
action potential, L-type Ca(2+) current and potassium currents of isolated
ventricular myocytes was tested. The study is based on 90 guinea-pig myocytes
and 20 rat myocytes. The fields were applied in rectangular waveguides (1800
MHz at 80, 480, 600, 720, or 880 mW/kg and 900 MHz, 250 mW/kg) or in a TEM-cell
(180 MHz, 80 mW/kg and 900 MHz, 15 mW/kg). Fields of 1800 and 900 MHz were
pulsed according to the GSM-standard of cellular phones. The specific
absorption rates were determined from computer simulations of the
electromagnetic fields inside the exposure devices by considering the structure
of the physiological test arrangement. The electrical membrane parameters were
measured by whole cell patch-clamp. None of the tested electrophysiological
parameters was changed significantly by exposure to RF fields. Another physical
stimulus, lowering the temperature from 36 degrees C to 24 degrees C, decreased
the current amplitude almost 50% and shifted the voltage dependence of the
steady state activation parameter d(infinity) and inactivation parameter
f(infinity) of L-type Ca(2+) current by about 5 mV. However, at this lower
temperature RF effects (900 MHz, 250 mW/kg; 1800 MHz, 480 mW/kg) on L-type
Ca(2+) current were also not detected.
·
Litovitz
TA, Krause D, Penafiel M, Elson EC, Mullins JM, The role of coherence time in
the effect of microwaves on ornithine decarboxylase activity.
Bioelectromagnetics 14(5):395-403, 1993.
Previously, we demonstrated the requirements for a minimum coherence time of an
applied, small amplitude (10 microT) ELF magnetic field if the field were to
produce an enhancement of ornithine decarboxylase activity in L929 fibroblasts.
Further investigation has revealed a remarkably similar coherence time
phenomenon for enhancement of ornithine decarboxylase activity by
amplitude-modulated 915 MHz microwaves of large amplitude (SAR 2.5 W/kg).
Microwave fields modulated at 55, 60, or 65 Hz approximately doubled ornithine
decarboxylase activity after 8 h. Switching modulation frequencies from 55 to
65 Hz at coherence times of 1.0 s or less abolished enhancement, while times of
10 s or longer provided full enhancement. Our results show that the microwave
coherence effects are remarkably similar to those observed with ELF fields.
·
Litovitz,
TA, Penafiel, LM, Farrel, JM, Krause, D, Meister, R, Mullins, JM Bioeffects
induced by exposure to microwaves are mitigated by superposition of ELF noise.
Bioelectromagnetics 18(6):422-430, 1997.
We have previously
demonstrated that microwave fields, amplitude modulated (AM) by an extremely
low-frequency (ELF) sine wave, can induce a nearly twofold enhancement in the
activity of ornithine decarboxylase (ODC) in L929 cells at SAR levels of the
order of 2.5 W/kg. Similar, although less pronounced, effects were also
observed from exposure to a typical digital cellular phone test signal of the
same power level, burst modulated at 50 Hz. We have also shown that ODC
enhancement in L929 cells produced by exposure to ELF fields can be inhibited
by superposition of ELF noise. In the present study, we explore the possibility
that similar inhibition techniques can be used to suppress the microwave
response. We concurrently exposed L929 cells to 60 Hz AM microwave fields or a
50 Hz burst-modulated DAMPS (Digital Advanced Mobile Phone System) digital
cellular phone field at levels known to produce ODC enhancement, together with
band-limited 30-100 Hz ELF noise with root mean square amplitude of up to 10
microT. All exposures were carried out for 8 h, which was previously found to
yield the peak microwave response. In both cases, the ODC enhancement was found
to decrease exponentially as a function of the noise root mean square
amplitude. With 60 Hz AM microwaves, complete inhibition was obtained with
noise levels at or above 2 microT. With the DAMPS digital cellular phone
signal, complete inhibition occurred with noise levels at or above 5 microT.
These results suggest a possible practical means to inhibit biological effects
from exposure to both ELF and microwave fields.
· Loscher W, Kas G, Extraordinary behavior disorders in cows in proximity to transmission stations. Der Praktische Tierarz 79:437-444, 1998.
In addition to reduction of
milk yield and increased health problems, behavioral abnormalities were
observed over a period of two years in a herd of diary cows maintained in close
proximity to a TV and cell phone transmitting antenna. Evaluation of possible
factors which could explain the abnormalities in the live stock did not
disclose any factors other than the high-frequency electromagnetic fields. An
experiment in which a cow with abnormal behavior was brought to a stable 20 km
away from the antenna resulted in a complete normalization of the cow within
five days, whereas symptoms returned when the cow was brought back to the
stable nearby the antenna. In view of the previous described effects of
electromagnetic fields, it might be possible that the observed abnormalities in
cows are related to electromagnetic field exposure. (power densities measured
0.02-7 mW/m2).
·
Maes
A, Collier M, Slaets D, Verschaeve L, 954 MHz microwaves enhance the mutagenic
properties of mitomycin C. Environ Mol Mutagen 28(1):26-30, 1996.
This paper focuses on the combined effects of microwaves from mobile
communication frequencies and a chemical DNA damaging agent mitomycin C (MMC).
The investigation was performed in vitro by exposing whole blood samples to a
954 MHz emitting antenna from a GSM (Global System for Mobile Communication)
base station, followed by lymphocyte cultivation in the presence of MMC. A
highly reproducible synergistic effect was observed as based on the frequencies
of sister chromatid exchanges in metaphase figures.
·
Maes
A, Collier M, Van Gorp U, Vandoninck S, Verschaeve L, Cytogenetic effects of
935.2-MHz (GSM) microwaves alone and in combination with mitomycin C. Mutat Res
393(1-2):151-156, 1997.
This paper focuses on the
genetic effects of microwaves from mobile communication frequencies (935.2 MHz)
alone and in combination with a chemical DNA-damaging agent (mitomycin C).
Three cytogenetic endpoints were investigated after in vitro exposure of human
whole blood cells. These endpoints were the 'classical' chromosome aberration
test, the sister chromatid exchange test and the alkaline comet assay. No
direct cytogenetic effect was found. The combined exposure of the cells to the
radiofrequency fields followed by their cultivation in the presence of
mitomycin C revealed a very weak effect when compared to cells exposed to
mitomycin C alone.
·
Maes
A, Collier M, Verschaeve L Cytogenetic effects of 900 MHz (GSM) microwaves on
human lymphocytes. Bioelectromagnetics 22(2):91-96, 2001
The cytogenetic effects of 900 MHz radiofrequency fields were investigated with
the chromosome aberration and sister chromatid exchange frequency methods.
Three different modes of exposure (continuous, pseudo-random and dummy burst)
were studied for different power outputs (0, 2, 8, 15, 25, 50 W). The specific
absorption rates varied between 0 and 10 W/kg. We investigated the possible
effects of the 900 MHz radiation alone as well as of combined exposure to the
chemical or physical mutagens mitomycin C and X-rays. Overall, no indication
was found of a mutagenic, and/or co-mutagenic/synergistic effect of this kind
of nonionizing radiation.
·
Malyapa
RS, Ahern EW, Straube WL, Moros EG, Pickard WF, Roti Roti JL,
Measurement of DNA damage after exposure to electromagnetic radiation in the
cellular phone communication frequency band (835.62 and 847.74 MHz). Radiat Res
148(6):618-627, 1997.
Mouse C3H 10T1/2 fibroblasts and human glioblastoma U87MG cells were exposed to
cellular phone communication frequency radiations to investigate whether such
exposure produces DNA damage in in vitro cultures. Two types of frequency
modulations were studied: frequency-modulated continuous-wave (FMCW), with a
carrier frequency of 835.62 MHz, and code-division multiple-access (CDMA)
centered on 847.74 MHz. Exponentially growing (U87MG and C3H 10T1/2 cells) and
plateau-phase (C3H 10T1/2 cells) cultures were exposed to either FMCW or CDMA
radiation for varying periods up to 24 h in specially designed radial transmission
lines (RTLs) that provided relatively uniform exposure with a specific
absorption rate (SAR) of 0.6 W/kg. Temperatures in the RTLs were monitored
continuously and maintained at 37 +/- 0.3 degrees C. Sham exposure of cultures
in an RTL (negative control) and 137Cs gamma-irradiated samples (positive
control) were included with every experiment. The alkaline comet assay as
described by Olive et al. (Exp. Cell Res. 198, 259-269, 1992) was used to
measure DNA damage. No significant differences were observed between the test
group exposed to FMCW or CDMA radiation and the sham-treated negative controls.
Our results indicate that exposure of cultured mammalian cells to cellular
phone communication frequencies under these conditions at an SAR of 0.6 W/kg
does not cause DNA damage as measured by the alkaline comet assay.
·
Mann,
K, Roschke, J, Effects of pulsed high-frequency electromagnetic fields on human
sleep. Neuropsychobiology 33(1):41-47, 1996.
In the present study we
investigated the influence of pulsed high-frequency electromagnetic fields of
digital mobile radio telephones on sleep in healthy humans. Besides a hypnotic
effect with shortening of sleep onset latency, a REM suppressive effect with
reduction of duration and percentage of REM sleep was found. Moreover, spectral
analysis revealed qualitative alterations of the EEG signal during REM sleep
with an increased spectral power density. Knowing the relevance of REM sleep
for adequate information processing in the brain, especially concerning mnestic
functions and learning processes, the results emphasize the necessity to carry
out further investigations on the interaction of this type of electromagnetic
fields and the human organism.
·
Mann,
K, Roschke, J, Connemann, B, Beta, H, No effects of pulsed high-frequency
electromagnetic fields on heart rate variability during human sleep.
Neuropsychobiology;38(4):251-256, 1998.
The influence of pulsed high-frequency electromagnetic fields emitted by
digital mobile radio telephones on heart rate during sleep in healthy humans
was investigated. Beside mean RR interval and total variability of RR intervals
based on calculation of the standard deviation, heart rate variability was
assessed in the frequency domain by spectral power analysis providing
information about the balance between the two branches of the autonomic nervous
system. For most parameters, significant differences between different sleep
stages were found. In particular, slow-wave sleep was characterized by a low
ratio of low- and high-frequency components, indicating a predominance of the
parasympathetic over the sympathetic tone. In contrast, during REM sleep the
autonomic balance was shifted in favor of the sympathetic activity. For all
heart rate parameters, no significant effects were detected under exposure to
the field compared to placebo condition. Thus, under the given experimental
conditions, autonomic control of heart rate was not affected by weak-pulsed
high-frequency electromagnetic fields.
·
Mann,
K, Wagner, P, Brunn, G, Hassan, F, Hiemke, C, Roschke, J, Effects of pulsed
high-frequency electromagnetic fields on the neuroendocrine system.
Neuroendocrinology 67(2):139-144, 1998.
The influence of pulsed
high-frequency electromagnetic fields emitted from a circularly polarized
antenna on the neuroendocrine system in healthy humans was investigated (900
MHz electromagnetic field, pulsed with 217 Hz, average power density 0.02
mW/cm2). Nocturnal hormone profiles of growth hormone (GH), cortisol,
luteinizing hormone (LH) and melatonin were determined under polysomnographic
control. An alteration in the hypothalamo-pituitary-adrenal axis activity was
found with a slight, transient elevation in the cortisol serum level
immediately after onset of field exposure which persisted for 1 h. For GH, LH
and melatonin, no significant effects were found under exposure to the field
compared to the placebo condition, regarding both total hormone production
during the entire night and dynamic characteristics of the secretion pattern.
Also the evaluation of the sleep EEG data revealed no significant alterations
under field exposure, although there was a trend to an REM suppressive effect.
The results indicate that weak high-frequency electromagnetic fields have no
effects on nocturnal hormone secretion except for a slight elevation in
cortisol production which is transient, pointing to an adaptation of the
organism to the stimulus.
·
Marino
C, Cristalli G, Galloni P, Pasqualetti P, Piscitelli M, Lovisolo GA , Effects
of microwaves (900 MHz) on the cochlear receptor: exposure systems and
preliminary results. Radiat
Environ Biophys 39(2):131-136, 2000.
The purpose of this paper
is to present the experimental device and the work in progress performed in
search for objective organic correlation of damage to hearing, examining
possible acoustic otofunctional effects on the cochlear epithelium of the rat
due to exposure to microwaves (900 MHz). Two experiments using male
Sprague-Dawley rats were carried out with a far-field exposure in a cubic
chamber. No statistically significant evidence was obtained at both specific
absorption rate (SAR) values. The exposure system and the diagnostic apparatus
are extremely useful to investigate a potential effect on the auditory system:
however, with the parameters applied in these experiments, no evidence was
observed.
·
Mashevich
M, Folkman D, Kesar A, Barbul A, Korenstein R, Jerby E, Avivi L, Exposure of
human peripheral blood lymphocytes to electromagnetic fields associated with
cellular phones leads to chromosomal instability. Bioelectromagnetics 24:82-90,
2003.
Whether exposure to
radiation emitted from cellular phones poses a health hazard is at the focus of
current debate. We have examined whether in vitro exposure of human peripheral
blood lymphocytes (PBL) to continuous 830 MHz electromagnetic fields causes
losses and gains of chromosomes (aneuploidy), a major somatic mutation leading
to genomic instability and thereby to cancer. PBL were irradiated at different
average absorption rates (SAR) in the range of 1.6-8.8 W/kg for 72 hr in an
exposure system based on a parallel plate resonator at temperatures ranging
from 34.5-37.5 °C. The averaged SAR and its distribution in the exposed tissue
culture flask were determined by combining measurements and numerical analysis
based on a finite element simulation code. A linear increase in chromosome 17
aneuploidy was observed as a function of the SAR value, demonstrating that this
radiation has a genotoxic effect. The SAR dependent aneuploidy was accompanied
by an abnormal mode of replication of the chromosome 17 region engaged in
segregation (repetitive DNA arrays associated with the centromere), suggesting
that epigenetic alterations are involved in the SAR dependent genetic toxicity.
Control experiments (i.e., without any RF radiation) carried out in the
temperature range of 34.5-38.5 °C showed that elevated temperature is not
associated with either the genetic or epigenetic alterations observed following
RF radiation - the increased levels of aneuploidy and the modification in
replication of the centromeric DNA arrays. These findings indicate that the
genotoxic effect of the electromagnetic radiation is elicited via a non-thermal
pathway. Moreover, the fact that aneuploidy is a phenomenon known to increase
the risk for cancer, should be taken into consideration in future evaluation of
exposure guidelines.
·
Mausset
A, de Seze R, Montpeyroux F, Privat A. Effects of radiofrequency exposure on
the GABAergic system in the rat cerebellum: clues from semi-quantitative
immunohistochemistry. Brain Res 912(1):33-46, 2001.
The widespread use of
cellular phones raises the problem of interaction of electromagnetic fields
with the central nervous system (CNS). In order to measure these effects on
neurotransmitter content in the CNS, we developed a protocol of neurotransmitter
detection based on immunohistochemistry and image analysis. Gamma-vinyl-GABA
(GVG), an inhibitor of the GABA-transaminase was injected in rats to increase
GABA concentration in the CNS. The cellular GABA contents were then revealed by
immunohistochemistry and semi-quantified by image analysis thanks to three
parameters: optical density (O.D.), staining area, and number of positive
cells. The increase in cerebellar GABA content induced by GVG 1200 mg/kg was
reflected in these three parameters in the molecular and the granular layers.
Therefore, control of immunohistochemistry parameters, together with
appropriate image analysis, allowed both the location and the detection of
variations in cellular neurotransmitter content. This protocol was used to
investigate the effects of exposure to 900 MHz radiofrequencies on cerebellar
GABA content. Both pulsed emission with a specific absorption rate (SAR) of 4
W/kg and continuous emission with high SAR (32 W/kg) were tested. We observed a
selective diminution of the stained processes area in the Purkinje cell layer
after exposure to pulsed radiofrequency and, in addition, a decrease in O.D. in
the three cell layers after exposure to continuous waves. Whether this effect
is, at least partly, due to a local heating of the tissues is not known.
Overall, it appears that high energetic radiofrequency exposure induces a
diminution in cellular GABA content in the cerebellum.
·
McNamee
JP, Bellier PV, Gajda GB, Miller SM, Lemay EP, Lavallee BF, Marro L,
Thansandote A. DNA Damage and Micronucleus Induction in Human Leukocytes after
Acute In Vitro Exposure to a 1.9 GHz Continuous-Wave Radiofrequency Field. Radiat Res 158(4):523-533, 2002a.
Human blood cultures were
exposed to a 1.9 GHz continuous-wave (CW) radiofrequency (RF) field for 2 h
using a series of six circularly polarized, cylindrical waveguides. Mean
specific absorption rates (SARs) of 0.0, 0.1, 0.26, 0.92, 2.4 and 10 W/kg were
achieved, and the temperature within the cultures during a 2-h exposure was maintained
at 37.0 +/- 0.5 degrees C. Concurrent negative (incubator) and positive (1.5 Gy
(137)Cs gamma radiation) control cultures were run for each experiment. DNA
damage was quantified immediately after RF-field exposure using the alkaline
comet assay, and four parameters (tail ratio, tail moment, comet length and
tail length) were used to assess DNA damage for each comet. No evidence of
increased primary DNA damage was detected by any parameter for RF-field-exposed
cultures at any SAR tested. The formation of micronuclei in the
RF-field-exposed blood cell cultures was assessed using the cytokinesis-block
micronucleus assay. There was no significant difference in the binucleated cell
frequency, incidence of micronucleated binucleated cells, or total incidence of
micronuclei between any of the RF-field-exposed cultures and the sham-exposed
controls at any SAR tested. These results do not support the hypothesis that
acute, nonthermalizing 1.9 GHz CW RF-field exposure causes DNA damage in
cultured human leukocytes.
·
McNamee
JP, Bellier PV, Gajda GB, Lavallee BF, Lemay EP, Marro L, Thansandote A. DNA
Damage in Human Leukocytes after Acute In Vitro Exposure to a 1.9 GHz
Pulse-Modulated Radiofrequency Field. Radiat Res 158(4):534-537, 2002b.
Blood cultures from human
volunteers were exposed to an acute 1.9 GHz pulse-modulated radiofrequency (RF)
field for 2 h using a series of six circularly polarized, cylindrical
waveguides. Mean specific absorption rates (SARs) ranged from 0 to 10 W/kg, and
the temperature within the cultures during the exposure was maintained at 37.0
+/- 0.5 degrees C. DNA damage was quantified in leukocytes by the alkaline
comet assay and the cytokinesis-block micronucleus assay. When compared to the
sham-treated controls, no evidence of increased primary DNA damage was detected
by any parameter for any of the RF-field-exposed cultures when evaluated using
the alkaline comet assay. Furthermore, no significant differences in the
frequency of binucleated cells, incidence of micronucleated binucleated cells,
or total incidence of micronuclei were detected between any of the
RF-field-exposed cultures and the sham-treated control at any SAR tested. These
results do not support the hypothesis that acute, nonthermalizing 1.9 GHz
pulse-modulated RF-field exposure causes DNA damage in cultured human
leukocytes.
·
Morrissey
JJ, Raney S, Heasley E, Rathinavelu P, Dauphinee M, Fallon JH, IRIDIUM exposure
increases c-fos expression in the mouse brain only at levels which likely
result in tissue heating. Neuroscience 92(4):1539-1546, 1999.
With the rapid development
of wireless communication technology over the last 20 years, there has been
some public concern over possible health effects of
long-term, low-level radiofrequency exposure from cellular telephones. As an initial
step in compiling a database for risk analysis by government agencies,
the effects of 1-h exposure of mice to a 1.6-GHz radiofrequency signal, given as
either a continuous wave or pulse modulated at 11 Hz with a duty cycle of
4:1 and a pulse duration of 9.2 ms IRIDIUM), on c-fos gene expression in the brain
was investigated. The IRIDIUM signal is the operating frequency for a
ground-to-satellite-to-ground cellular communications web which has recently become
fully operational, and was named as such due to the original designed
employment of the same number of low orbiting satellites as there are electrons
orbiting the nucleus of an iridium atom. The expression of c-fos was not
significantly elevated in the brains of mice until exposure levels exceeded six
times the peak dose and 30 times the whole body average dose as maximal
cellular telephone exposure limits in humans. Higher level exposure using
either continuous wave (analog) or IRIDIUM signals elevated c-fos to a similar
extent, suggesting no obvious pulsed modulation-specific effects. The pattern
of c-fos elevation in limbic cortex and subcortex areas at higher exposure
levels is most consistent with a stress response due to thermal perception
coupled with restraint and/or neuron activity near thermoregulatory regions,
and not consistent with any direct interaction of IRIDIUM energy with brain
tissue.
·
Moustafa
YM, Moustafa RM, Belacy A, Abou-El-Ela SH, Ali FM.
Effects of acute exposure to the radiofrequency fields of cellular phones on
plasma lipid peroxide and antioxidase activities in human erythrocytes. J Pharm
Biomed Anal 26(4):605-608, 2001.
Radiofrequency fields of cellular phones may affect biological systems by
increasing free radicals, which appear mainly to enhance lipid peroxidation,
and by changing the antioxidase activities of human blood thus leading to
oxidative stress. To test this, we have investigated the effect of acute
exposure to radiofrequency fields of commercially available cellular phones on
some parameters indicative of oxidative stress in 12 healthy adult male
volunteers. Each volunteer put the phone in his pocket in standby position with
the keypad facing the body. The parameters measured were lipid peroxide and the
activities of superoxide dismutase (SOD), total glutathione peroxidase (GSH-Px)
and catalase. The results obtained showed that the plasma level of lipid
peroxide was significantly increased after 1, 2 and 4 h of exposure to
radiofrequency fields of the cellular phone in standby position. Moreover, the
activities of SOD and GSH-Px in human erythrocytes showed significant reduction
while the activity of catalase in human erythrocytes did not decrease
significantly. These results indicate that acute exposure to radiofrequency
fields of commercially available cellular phones may modulate the oxidative
stress of free radicals by enhancing lipid peroxidation and reducing the
activation of SOD and GSH-Px, which are free radical scavengers. Therefore,
these results support the interaction of radiofrequency fields of cellular
phones with biological systems.
·
Muscat
JE, Malkin MG, Thompson S, Shore RE, Stellman SD, McRee D, Neugut AI, Wynder
EL, Handheld cellular telephone use and risk of brain cancer. JAMA
284(23):3001-3007, 2000.
CONTEXT: A relative paucity
of data exist on the possible health effects of using cellular telephones.
OBJECTIVE: To test the hypothesis that using handheld cellular telephones is
related to the risk of primary brain cancer. DESIGN AND SETTING: Case-control
study conducted in 5 US academic medical centers between 1994 and 1998 using a
structured questionnaire. PATIENTS: A total of 469 men and women aged 18 to 80
years with primary brain cancer and 422 matched controls without brain cancer.
MAIN OUTCOME MEASURE: Risk of brain cancer compared by use of handheld cellular
telephones, in hours per month and years of use. RESULTS: The median monthly
hours of use were 2.5 for cases and 2.2 for controls. Compared with patients
who never used handheld cellular telephones, the multivariate odds ratio (OR) associated
with regular past or current use was 0.85 (95% confidence interval [CI],
0.6-1.2). The OR for infrequent users (<0. 72 h/mo) was 1.0 (95% CI,
0.5-2.0) and for frequent users (>10.1 h/mo) was 0.7 (95% CI, 0.3-1.4). The
mean duration of use was 2.8 years for cases and 2.7 years for controls; no
association with brain cancer was observed according to duration of use (P
=.54). In cases, cerebral tumors occurred more frequently on the same side of
the head where cellular telephones had been used (26 vs 15 cases; P =.06), but
in the cases with temporal lobe cancer a greater proportion of tumors occurred
in the contralateral than ipsilateral side (9 vs 5 cases; P =.33). The OR was
less than 1.0 for all histologic categories of brain cancer except for uncommon
neuroepitheliomatous cancers (OR, 2.1; 95% CI, 0.9-4.7). CONCLUSIONS: Our data
suggest that use of handheld cellular telephones is not associated with risk of
brain cancer, but further studies are needed to account for longer induction
periods, especially for slow-growing tumors with neuronal features.
·
Muscat
JE, Malkin MG, Shore RE,. Thompson S, Neugut AL, Stellman SD, Bruce J. Handheld
cellular telephones and risk of acoustic neuroma. Neurology 58:1304-1306, 2002.
The hypothesis that
intracranial energy deposition from handheld cellular telephones causes
acoustic neuroma was tested in an epidemiologic study of 90 patients and 86
control subjects. The relative risk was 0.9 (p = 0.07) and did not vary
significantly by the frequency, duration, and lifetime hours of use. In
patients who used cellular telephones, the tumor occurred more often on the
contralateral than ipsilateral side of the head. Further efforts should focus
on potentially longer induction periods.
·
Oftedal
G, Wilen J, Sandstrom M, Mild KH, Symptoms experienced in connection with
mobile phone use. Occup Med (Lond) 50(4):237-245, 2000.
Many people in Norway and
Sweden reported headaches, fatigue, and other symptoms experienced in
connection with the use of a mobile phone (MP). Therefore, we initiated a
cross-sectional epidemiological study among 17,000 people, all using an MP in
their job. Thirty-one percent of the respondents in Norway and 13% of those in
Sweden had experienced at least one symptom in connection with MP use. Next to
the sensations of warmth on the ear and behind/around the ear, burning
sensations in the facial skin and headaches were most commonly reported. Most
symptoms usually began during or within half an hour after the call and lasted
for up to 2 h. Relatively few had consulted a physician or been on sick leave
because of the symptoms, but about 45% among those with an MP attributed
symptom had taken steps to reduce the symptom. These results suggest an
awareness of the symptoms, but not necessarily a serious health problem.
·
Pacini
S, Ruggiero M, Sardi I, Aterini S, Gulisano F, Gulisano M. Exposure to global
system for mobile communication (GSM) cellular phone radiofrequency alters gene
expression, proliferation, and morphology of human skin fibroblasts. Oncol Res
13(1):19-24, 2002.
Human skin fibroblasts were
exposed to global system for mobile communication (GSM) cellular phone
radiofrequency for 1 h. GSM exposure induced alterations in cell morphology and
increased the expression of mitogenic signal transduction genes (e.g., MAP
kinase kinase 3, G2/mitotic-specific cyclin G1), cell growth inhibitors (e.g.,
transforming growth factor-beta), and genes controlling apoptosis (e.g., bax).
A significant increase in DNA synthesis and intracellular mitogenic second
messenger formation matched the high expression of MAP kinase family genes.
These findings show that these electromagnetic fields have significant
biological effects on human skin fibroblasts.
·
Paredi
P, Kharitonov SA, Hanazawa T, Barnes PJ, Local vasodilator response to mobile
phones. Laryngoscope 111(1):159-162, 2001.
OBJECTIVES: The use of
mobile phones with the resulting generation of potentially harmful
electromagnetic fields (EMF) is the focus of public interest. Heat generation
and the activation of the inducible form of nitric oxide (NO) synthase may be
possible causes of the biological effects of EMF exposure. We investigated if a
mobile telephone conversation can modify skin temperature, NO, and nasal
resistance. METHODS: We studied the effect of an EMF (900 MHz) generated by a
commercially available cellular phone during a 30-minute telephone conversation
on skin temperature, nasal NO measured by chemiluminescence, and nasal minimal
cross-sectional area (MCA) measured by rhinometry. Eleven normal subjects (mean
age +/- standard error of mean [SEM], 32 +/- 5 y; 10 male) were studied.
RESULTS: There was a similar and significant increase in skin temperature of
the nostril and occipital area on the same side as the telephone (maximal
increase 2.3 +/- 0.2 degrees C at 6 min) as well as a tendency for higher nasal
NO levels (maximal increase 12.9 +/- 4.9% at 10 min), whereas the MCA was
significantly reduced (maximal decrease -27 +/- 6% at 15 min). Such changes
were not recorded when an earpiece was used to avoid the direct exposure to the
electromagnetic field. There were no changes in the skin temperature and nasal
NO measured on the opposite side to the mobile phone, whereas the MCA was
significantly increased (38 +/- 10%). CONCLUSIONS: Exposure to EMF produced by
a mobile phone produces biological effects that can be easily measured.
Microwaves may increase skin temperature and therefore cause vasodilation and
reduce MCA. Further studies are needed to study the long-term effects of mobile
phone use and the relation among NO production, vasodilation, and temperature.
·
Penafiel
LM, Litovitz T, Krause D, Desta A, Mullins JM, Role of modulation on the effect
of microwaves on ornithine decarboxylase activity in L929 cells.
Bioelectromagnetics 18(2):132-141, 1997.
The effect of 835 MHz
microwaves on the activity of ornithine decarboxylase (ODC) in L929 murine cell
was investigated at an SAR of approximately 2.5 W/kg. The results depended upon
the type of modulation employed. AM frequencies of 16 Hz and 60 Hz produced a
transient increase in ODC activity that reached a peak at 8 h of exposure and
returned to control levels after 24 h of exposure. In this case, ODC was
increased by a maximum of 90% relative to control levels. A 40% increase in ODC
activity was also observed after 8 h of exposure with a typical signal from a
TDMA digital cellular telephone operating in the middle of its transmission
frequency range (approximately 840 MHz). This signal was burst modulated at 50
Hz, with approximately 30% duty cycle. By contrast, 8 h exposure with 835 MHz
microwaves amplitude modulated with speech produced no significant change in
ODC activity. Further investigations, with 8 h of exposure to AM microwaves, as
a function of modulation frequency, revealed that the response is frequency
dependent, decreasing sharply at 6 Hz an 600 Hz. Exposure with 835 MHz
microwaves, frequency modulated with a 60 Hz sinusoid, yielded no significant
enhancement in ODC activity for exposure times ranging between 2 and 24 h.
Similarly, exposure with a typical signal from an AMPS analog cellular
telephone, which uses a form of frequency modulation, produced no significant
enhancement in ODC activity. Exposure with 835 MHz continuous wave microwaves
produced no effects for exposure times between 2 and 24 h, except for a small
but statistically significant enhancement in ODC activity after 6 h of
exposure. Comparison of these results suggests that effects are much more
robust when the modulation causes low-frequency periodic changes in the
amplitude of the microwave carrier.
·
Persson
BRR, Salford LG, Brun A, Blood-brain barrier permeability in rats exposed to
electromagnetic fields used in wireless communication. Wireless Network
3:455-461, 1997.
Biological effects of radio
frequency electromagnetic fields (EMF) on the blood-brain barrier (BBB) have
been studied in Fischer 344 rats of both sexes. The rats were not anesthetised
during the exposure. The brains were perfused with saline for 3-4 minutes, and
thereafter perfusion fixed with 4% formaldehyde for 5-6 minutes. Whole coronal
sections of the brains were dehydrated and embedded in paraffin and sectioned
at 5 micrometers. Albumin and fibinogen were demonstrated immunochemically and
classified as normal versus pathological leakage. In the present investigation
we exposed male and female Fischer 344 rats in a Transverse Electromagnetic
Transmission line camber to microwaves of 915 MHz as continuous wave (CW) and
pulse-modulated with different pulse power and at various time intervals. The
CW-pulse power varied from 0.001 W to 10 W and the exposure time from 2 min to
960 min. In each experiment we exposed 4-6 rats with 2-4 controls randomly
placed in excited and non-excited TEM cells, respectively. We have in total
investigated 630 exposed rats at various modulation frequencies and 372
controls. The frequency of pathological rats is significantly increased (P<
0.0001) from 62/372 (ratio 0.17 + 0.02) for control rats to 244/630 (ratio:
0.39 + 0.043) in all exposed rats. Grouping the exposed animals according to the
level or specific absorption energy (J/kg) give significant difference in all
levels above 1.5 J/kg. The exposure was 915 MHz microwaves either pulse
modulated (PW) at 217 Hz with 0.57 ms pulse width, at 50 Hz with 6.6 ms pulse
width or continuous wave (CW). The frequency of pathological rats (0.17) among
controls in the various groups is not significantly different. The frequency of
pathological rats was 170/480 (0.35 + 0.03) among rats exposed to pulse
modulated (PW) and 74/149 (0.50 + 0.07) among rats exposed to continuous wave
exposure (CW). These results are both highly significantly different to their
corresponding controls (p< 0.0001) and the frequency of pathological rats
after exposure to pulsed radiation (PW) is significantly less (p< 0.002) than
after exposure to continuous wave radiation (CW).
·
Phillips,
J.L., Ivaschuk, O., Ishida-Jones, T., Jones, R.A., Campbell-Beachler, M. and
Haggren, W. DNA damage in Molt-4 T- lymphoblastoid cells exposed to cellular
telephone radiofrequency fields in vitro. Bioelectrochem. Bioenerg. 45:103-110,
1998.
Molt-4 T-lymphoblastoid
cells have been exposed to pulsed signals at cellular telephone frequencies of
813.5625 MHz (iDEN signal) and 836.55 MHz (TDMA signal). These studies were
performed at low SAR (average = 2.4 and 24
microwatt/g for iDEN and 2.6 and 26 microwatt/g for TDMA) in studies designed
to look for athermal RF effects. The alkaline comet, or single cell gel
electrophoresis, assay was employed to measure DNA single-strand breaks in cell
cultures exposed to the radiofrequency (RF) signal as compared to concurrent
sham-exposed cultures. Tail moment and comet extent were calculated as
indicators of DNA damage. Statistical differences in the distribution of values
for tail moment and comet extent between exposed and control cell cultures were
evaluated with the Kolmogorov-Smirnoff distribution test. Data points for all
experiments of each exposure condition were pooled and analyzed as single
groups. It was found that: 1) exposure of cells to the iDEN signal at an SAR of
2.4 microwatt/g for 2 h or 21 h significantly decreased DNA damage; 2) exposure
of cells to the TDMA signal at an SAR of 2.6 microwatt/g for 2 h and 21 h
significantly decreased DNA damage; 3) exposure of cells to the iDEN signal at
an SAR of 24 microwatt/g for 2 h and 21 h significantly increased DNA damage;
4) exposure of cells to the TDMA signal at an SAR of 26 microwatt/g for 2 h
significantly decreased DNA damage. The data indicate a need to study the
effects of exposure to RF signals on direct DNA damage and on the rate at which
DNA damage is repaired.
·
Philippova
TM, Novoselov VI, Alekseev SI, Influence of microwaves on different types of
receptors and the role of peroxidation of lipids on receptor-protein shedding.
Bioelectromagnetics 15(3):183-192, 1994.
The effects of a continuous
wave or pulse-modulated, 900 MHz microwave field were studied by in vitro
assays of rat chemoreceptors. The pulsed field was modulated as rectangular
waves at rates of 1, 6, 16, 32, 75, or 100 pps. The pulse-period to
pulse-duration ratio was 5 in all cases, and specific absorption rates (SARs)
ranged from 0.5 to 18 W/kg. Binding of ligands to cell membranes was
differentially affected by exposure to microwaves. For example, binding of
H3-glutamic acid to hippocampal cells was not altered by a 15 min exposure to a
continuous wave field at 1 W/kg, but binding of H3-dihydroalprenolol to
liver-cell membranes of neonates underwent a fivefold decrease under the same
field conditions. This effect was not dependent on modulation or on a change in
the constant of stimulus-receptor binding but depended on a shedding of the
membrane's receptor elements into solution. The magnitude of inhibition
correlated with the oxygen concentration in the exposed suspension. Antioxidants
(dithiothreitol and ionol) inhibited the shedding of receptor elements. The
microwave exposure did not cause an accumulation of products from the
peroxidation of lipids (POL). Ascorbate-dependent or non-enzymatic POL was not
responsible for the inhibition, and POL was not found in other model systems.
However, enzymatic POL mechanisms in localized areas of receptor binding remain
a possibility.
·
Preece,
AW, Iwi, G, Davies-Smith, A, Wesnes, K, Butler, S, Lim, E, Varey, A, Effect of
a 915-MHz simulated mobile phone signal on cognitive function in man. Int J
Radiat Biol 75(4):447-456, 1999.
PURPOSE: To examine whether
a simulated mobile telephone transmission at 915 MHz has an effect on cognitive
function in man. MATERIALS AND METHODS: Thirty-six subjects in two groups were
each given two training sessions and then three test sessions in a randomized
three-way cross-over design. About 1 W mean power at 915 MHz from a
quarter-wave antenna mounted on a physical copy of an analogue phone, as a sine
wave, or modulated at 217 Hz with 12.5% duty cycle, or no power, was applied to
the left squamous temple region of the subjects while they undertook a series
of cognitive function tests lasting approximately 25-30 min. The second group
was investigated for sleep, consumption of alcohol and beverages, and any other
substances that might affect performance. RESULTS: In both groups, the only
test affected was the choice reaction time and this showed as an increase in
speed (a decrease in reaction time). There were no changes in word, number or
picture recall, or in spatial memory. While an effect of visit-order was
evident suggesting a learning effect of repeat tests, the design of the study
allowed for this. Additionally, there was no systematic error introduced as a result
of consumption of substances or sleep time. CONCLUSIONS: There was evidence of
an increase in responsiveness, strongly in the analogue and less in the digital
simulation, in choice reaction time. This could be associated with an effect on
the angular gyrus that acts as an interface between the visual and speech
centres and which lies directly under and on the same side as the antenna. Such
an effect could be consistent with mild localized heating, or possibly a
non-thermal response, which is nevertheless power-dependent.
·
Repacholi,
MH, Basten, A, Gebski, V, Noonan, D, Finnie, J, Harris, AW, Lymphomas in E
mu-Pim1 transgenic mice exposed to pulsed 900 MHZ electromagnetic fields.
Radiat Res 147(5):631-640, 1997.
Whether radiofrequency (RF)
fields are carcinogenic is controversial; epidemiological data have been
inconclusive and animal tests limited. The aim of the present study was to
determine whether long-term exposure to pulse-modulated RF fields similar to
those used in digital mobile telecommunications would increase the incidence of
lymphoma in E mu-Pim1 transgenic mice, which are moderately predisposed to
develop lymphoma spontaneously. One hundred female E mu-Pim1 mice were
sham-exposed and 101 were exposed for two 30-min periods per day for up to 18
months to plane-wave fields of 900 MHz with a pulse repetition frequency of 217
Hz and a pulse width of 0.6 ms. Incident power densities were 2.6-13 W/m2 and
specific absorption rates were 0.008-4.2 W/kg, averaging 0.13-1.4 W/kg.
Lymphoma risk was found to be significantly higher in the exposed mice than in
the controls (OR = 2.4. P = 0.006, 95% CI = 1.3-4.5). Follicular lymphomas were
the major contributor to the increased tumor incidence. Thus long-term
intermittent exposure to RF fields can enhance the probability that mice
carrying a lymphomagenic oncogene will develop lymphomas. We suggest that such
genetically cancer-prone mice provide an experimental system for more detailed
assessment of dose-response relationships for risk of cancer after RF-field
exposure.
·
Roschke,
J, Mann, K, No short-term effects of digital mobile radio telephone on the
awake human electroencephalogram. Bioelectromagnetics 18(2):172-176, 1997.
A recent study reported the
results of an exploratory study of alterations of the quantitative sleep
profile due to the effects of a digital mobile radio telephone. Rapid eye
movement (REM) was suppressed, and the spectral power density in the 8-13 Hz
frequency range during REM sleep was altered. The aim of the present study was
to illuminate the influence of digital mobile radio telephone on the awake
electroencephalogram (EEG) of healthy subjects. For this purpose, we
investigated 34 male subjects in a single-blind cross-over design experiment by
measuring spontaneous EEGs under closed-eyes condition from scalp positions C3
and C4 and comparing the effects of an active (0.05 mW/cm2) and an inactive
digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min
to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a
pulse width of 580 microseconds, we could not detect any difference in the
awake EEGs in terms of spectral power density measures.
·
Roti
Roti JL , Malyapa RS, Bisht KS, Ahern EW, Moros EG, Pickard WF, Straube WL,
Neoplastic Transformation in C3H 10T(1/2) Cells after Exposure to 835.62 MHz
FDMA and 847.74 MHz CDMA Radiations. Radiat Res 155(1):239-247, 2001.
Neoplastic Transformation
in C3H 10T(1/2) Cells after Exposure to 835.62 MHz FDMA and 847.74 MHz CDMA
Radiations. The effect of radiofrequency (RF) radiation in the cellular phone
communication range (835.62 MHz frequency division multiple access, FDMA;
847.74 MHz code division multiple access, CDMA) on neoplastic transformation
frequency was measured using the in vitro C3H 10T(1/2) cell transformation
assay system. To determine if 835.62 MHz FDMA or 847.74 MHz CDMA radiations
have any genotoxic effects that induce neoplastic transformation, C3H 10T(1/2)
cells were exposed at 37 degrees C to either of the above radiations [each at a
specific absorption rate (SAR) of 0.6 W/kg] or sham-exposed at the same time
for 7 days. After the culture medium was changed, the cultures were transferred
to incubators and refed with fresh growth medium every 7 days. After 42 days,
the cells were fixed and stained with Giemsa, and transformed foci were scored.
To determine if exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiation has
any epigenetic effects that can promote neoplastic transformation, cells were
first exposed to 4.5 Gy of X rays to induce the transformation process and then
exposed to the above radiations (SAR = 0.6 W/kg) in temperature-controlled
irradiators with weekly refeeding for 42 days. After both the 7-day RF exposure
and the 42-day RF exposure after X irradiation, no statistically significant
differences in the transformation frequencies were observed between incubator
controls, the sham-exposed (maintained in irradiators without power to the
antenna), and the 835.62 MHz FDMA or 847.74 MHz CDMA-exposed groups
·
Salford
LG, Brun A, Sturesson K, Eberhardt JL, Persson BR Permeability of the
blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous
wave and modulated at 8, 16, 50, and 200 Hz. Microsc Res Tech 27(6):535-542,
1994.
Biological effects of electromagnetic fields (EMF) on the blood-brain barrier
(BBB) can be studied in sensitive and specific models. In a previous
investigation of the permeability of the blood-brain barrier after exposure to
the various EMF-components of proton magnetic resonance imaging (MRI), we found
that the exposure to MRI induced leakage of Evans Blue labeled proteins
normally not passing the BBB of rats [Salford et al. (1992), in: Resonance
Phenomena in Biology, Oxford University Press, pp. 87-91]. In the present
investigation we exposed male and female Fischer 344 rats in a transverse
electromagnetic transmission line chamber to microwaves of 915 MHz as
continuous wave (CW) and pulse-modulated with repetition rates of 8, 16, 50,
and 200 s-1. The specific energy absorption rate (SAR) varied between 0.016 and
5 W/kg. The rats were not anesthetized during the 2-hour exposure. All animals
were sacrificed by perfusion-fixation of the brains under chloral hydrate
anesthesia about 1 hour after the exposure. The brains were perfused with
saline for 3-4 minutes, and thereafter fixed in 4% formaldehyde for 5-6
minutes. Central coronal sections of the brains were dehydrated and embedded in
paraffin and sectioned at 5 microns. Albumin and fibrinogen were demonstrated
immunohistochemically. The results show albumin leakage in 5 of 62 of the
controls and in 56 of 184 of the animals exposed to 915 MHz microwaves.
Continuous wave resulted in 14 positive findings of 35, which differ
significantly from the controls (P = 0.002).
·
Salford
LG, Brun A, Persson BRR, Brain tumour development in rats exposed to
electromagnetic fields used in wireless cellular communication. Wireless
network 3: 463-469, 1997.
It has been suggested that
electromagnetic fields (EMF) act as promoters late in the carcinogenesis
process. To date, however, there is no convincing laboratory evidence that EMFs
cause tumour promotion at non-thermal exposure levels. Therefore the effects of
exposure to electromagnetic fields were investigated in a rat brain glioma
model. Some of the exposures correspond to electromagnetic fields used in
wireless communication. Microwaves at 915 MHz were used both as continuous
waves (1 W), and pulse-modulated at 4, 8, 16 and 217 Hz in 0.57 ms pulses and
50 Hz in 6.67 ms pulses (2 W per pulse). Fischer 344 rats of both sexes were
used in the experiments. By stereotaxic technique rat glioma cells (RG2 and
N32) were injected into the head of the right caudate nucleus in 154 pairs of
rats, exposed and matched controls. Starting on day 5 after inoculation, the
animals were exposed for 7 hours a day, 5 days a week during 2-3 weeks. Exposed
animals were kept unanaesthetized in well-ventilated TEM cells producing 915
MHz continuous or modulated microwaves. Their matched controls were kept in
identical TEM cells without EMF exposure. All brains were examined
histopathologically and the tumour size was estimated as the volume of an
ellipsoid. Our study of 154 matched pairs of rats does not show any significant
difference in tumour size between animals exposed to 915 MHz, and those not
exposed. Thus our results do not support that even an extensive daily exposure
to EMF promotes tumour growth when given from the fifth day after the start of
tumour growth in the rat brain until the sacrifice of the animal after about 16
days.
·
Salford
LG, Brun AR, Eberhardt JL, Malmgren L, Persson BRR, Nerve cell damage in
mammalian brain after exposure to microwaves from GSM mobile phones. Environ
Health Persp Online January 29, 2003.
The possible risks of
radio-frequency electromagnetic fields for the human body is a growing concern
for the society. We have earlier shown that weak pulsed microwaves give rise to
a significant leakage of albumin through the blood-brain barrier (BBB). Now we
have investigated whether a pathological leakage over the BBB might be combined
with damage to the neurons. Three groups of each 8 rats were exposed for 2
hours to GSM mobile phone electromagnetic fields of different strengths. We
found, and present here for the first time, highly significant (p< 0.002)
evidence for neuronal damage in both the cortex, the hippocampus and the basal
ganglia in the brains of exposed rats.
·
Sandstrom
M, Wilen J, Oftedal G, Hansson Mild K, Mobile phone use and subjective
symptoms. Comparison of symptoms experienced by users of analogue and digital
mobile phones. Occup Med (Lond) 51(1):25-35, 2001.
In 1995 many people
reported symptoms such as headaches, feelings of discomfort, warmth
behind/around or on the ear and difficulties concentrating while using mobile
phones. The number of complaints was higher for people using the digital (GSM)
system, i.e. with pulse modulated fields, than for those using the analogue
(NMT) system. Our main hypothesis was that GSM users experience more symptoms
than NMT users. An epidemiological investigation was initiated including 6379
GSM users and 5613 NMT 900 users in Sweden, and 2500 from each category in
Norway. The adjusted odds ratio did not indicate any increased risk for
symptoms for GSM users compared with NMT 900 users. Our hypothesis was
therefore disproved. However, we observed a statistically significant lower
risk for sensations of warmth on the ear for GSM users compared with NMT 900 users.
The same trend was seen in Norway for sensations of warmth behind/around the
ear and in Sweden for headaches and fatigue. Factors distinguishing the two
systems (radio frequency emission, phone temperatures and various ergonomic
factors) may be responsible for these results, as well as for a secondary
finding: a statistically significant association between calling time/number of
calls per day and the prevalence of warmth behind/around or on the ear,
headaches and fatigue.
·
Santini
R, Seigne M, Bonhomme-Faivre L, Bouffet S, Defrasne E, Sage M. Symptoms
experienced by users of digital cellular phones: a pilot study in a French
engineering school. Pathol Biol (Paris) 49(3):222-226, 2001.
A survey study, using
questionnaire, was conducted in 161 students and workers in a French
engineering school on symptoms experienced during use of digital cellular
phones. A significant increase in concentration difficult (p < 0.05) was
reported by users of 1800-MHz (DCS) cellular phones compared to 900-MHz (GSM)
phone users. In users of cellular phones, women significantly (p < 0.05)
complained more often of sleep disturbance than men. This sex difference for
sleep complaint is not observed between women and men non-users of cellular
phone. The use of both cellular phones and VDT significantly (p Ä 0.05)
increased concentration difficulty. Digital cellular phone users also
significantly (p < 0.05) more often complained of discomfort, warmth, and
picking on the ear during phone conversation in relation with calling duration
per day and number of calls per day. The complaint warmth on the ear might be a
signal to users for stopping the call.
·
Santini
R, Santini P, Danze JM, Le Ruz P, Seigne M.Study of the health of people living
in the vicinity of mobile phone base stations: I. Influence of distance and
sex. Pathol Biol (Paris) 50(6):369-373, 2002.
A survey study using questionnaire was conducted in 530 people (270 men, 260
women) living or not in vicinity of cellular phone base stations, on 18 Non
Specific Health Symptoms. Comparisons of complaints frequencies (CHI-SQUARE
test with Yates correction) in relation with distance from base station and
sex, show significant (p < 0.05) increase as compared to people living >
300 m or not exposed to base station, till 300 m for tiredness, 200 m for
headache, sleep disturbance, discomfort, etc. 100 m for irritability,
depression, loss of memory, dizziness, libido decrease, etc. Women
significantly more often than men (p < 0.05) complained of headache, nausea,
loss of appetite, sleep disturbance, depression, discomfort and visual
perturbations. This first study on symptoms experienced by people living in
vicinity of base stations shows that, in view of radioprotection, minimal
distance of people from cellular phone base stations should not be < 300 m.
·
Schirmacher
A, Winters S, Fischer S, Goeke J, Galla H, Kullnick U, Ringelstein EB,
Stogbauer F, Electromagnetic fields (1.8 GHz) increase the permeability to
sucrose of the blood-brain barrier in vitro. Bioelectromagnetics 21(5):338-345,
2000.
We report an investigation
on the influence of high frequency electromagnetic fields (EMF) on the
permeability of an in vitro model of the blood-brain barrier (BBB). Our model
was a co-culture consisting of rat astrocytes and porcine brain capillary
endothelial cells (BCEC). Samples were characterized morphologically by
scanning electron microscopy and immunocytochemistry. The BBB phenotype of the
BCEC was shown by the presence of zona occludens protein (ZO-1) as a marker for
tight junctions and the close contact of the cells together with the absence of
intercellular clefts. Permeability measurements using (14)C-sucrose indicated a
physiological tightness which correlated with the morphological findings and
verified the usefulness of our in vitro model. Samples were exposed to EMF
conforming to the GSM1800-standard used in mobile telephones (1.8 GHz). The
permeability of the samples was monitored over four days and compared with
results of samples that were cultured identically but not exposed to EMF.
Exposure to EMF increased permeability for (14)C-sucrose significantly compared
to unexposed samples. The underlying pathophysiological mechanism remains to be
investigated.
·
Shallom JM,
Di Carlo AL, Ko D, Penafiel LM, Nakai A, Litovitz TA.
Microwave exposure
induces Hsp70 and confers protection against hypoxia in chick embryos. J Cell
Biochem 86(3):490-496, 2002.
To determine if microwave
exposure could elicit a biological effect in the absence of thermal stress,
studies were designed in which chick embryos were exposed to athermal microwave
radiation (915 MHz) to look for induction of Hsp70, a protein produced during
times of cellular stress that aids in the protection of cellular components.
Levels of Hsp70 were found to increase within 2 h, with maximum expression
(approximately 30% higher than controls) typically occurring by 3 h from the
start of exposure. Other embryos were exposed to microwave radiation prior to
being subjected to hypoxic stress, and were found to have significantly higher
survival (P < 0.05) following re-oxygenation than non-exposed controls. The
results of these studies indicate that not only can athermal microwave
exposures activate the stress protein response pathway; they can also enhance
survivability following exposure to a subsequent, potentially lethal stress.
From a public health standpoint, it is important that more studies be performed
to determine if repeated exposures, a condition likely to be found in cell
phone use, are still beneficial.
·
Sienkiewicz
ZJ, Blackwell RP, Haylock RG, Saunders RD, Cobb BL, Low-level exposure to
pulsed 900 MHz microwave radiation does not cause deficits in the performance
of a spatial learning task in mice. Bioelectromagnetics 21(3):151-158, 2000.
There is some concern that
short-term memory loss or other cognitive effects may be associated with the
use of mobile cellular telephones. In this
experiment, the effect of repeated, acute exposure to a low intensity 900 MHz radiofrequency
(RF) field pulsed at 217 Hz was explored using an
appetitively-motivated spatial learning and working memory task. Adult male C57BL/6J
mice were exposed under far field conditions in a GTEM cell for 45 min each day
for 10 days at an average whole-body specific energy absorption rate (SAR) of
0.05 W/kg. Their performance in an 8-arm radial maze was compared to that of
sham-exposed control animals. All behavioral assessments were performed without
handlers having knowledge of the exposure status of the animals. Animals were
tested in the maze immediately following exposure or after a delay of 15 or 30
min. No significant field-dependent effects on performance were observed in
choice accuracy or in total times to complete the task across the experiment.
These results suggest that exposure to RF radiation simulating a digital
wireless telephone (GSM) signal under the conditions of this experiment does
not affect the acquisition of the learned response. Further studies are planned
to explore the effects of other SARs on learned behavior.
·
Singh
B, Bate LA, Responses of pulmonary intravascular macrophages to 915-MHz
microwave radiation: ultrastructural and cytochemical study. Anat Rec
246(3):343-355, 1996.
BACKGROUND: Microwave (MW)
radiation is being increasingly used as a source of heat supplementation during
early postnatal development of pigs. Although MW radiation does not cause
deleterious physiological effects, no specific information exists regarding its
impact on immune cells such as macrophages. Pulmonary intravascular macrophages
(PIMs) are emerging as important inflammatory cells due to their endocytic and
secretory potential. An in vivo study was conducted to evaluate the effects of
infrared, and low and high power MW radiation on the PIMs of pigs. METHODS:
Pigs were exposed to infrared (IR), low MW (LMW; 6.1mW cm-2), and high MW (HMW;
11.4mW cm-2) radiation at 915 MHz (n = 2 for each treatment) for 24 hr. The
controls (n = 2) were exposed to natural light for the same period of time.
Lung tissues were processed for ultrastructural examination and acid
phosphatase (AcPase) cytochemistry. In addition, rough endoplasmic reticulum
(RER) as a fraction of cytosol of the PIMs was counted. RESULTS:
Ultrastructural and numerical data suggested enhanced secretory activity in the
PIMs of LMW-treated pigs as indicated by the increased RER:cytoplasm ratio,
prominent Golgi complex profiles, and accumulation of secretory vesicles in
conjunction with microtubules as compared with the control, IR, and HMW-exposed
pigs. High MW treatment induced some damage to pulmonary interstitium as
deduced from the presence of extracellular AcPase precipitates and disrupted
collagen matrix. Intracellular globules were noticed in the PIMs of IR and
LMW-treated pigs but not in the control and HMW-radiated animals. CONCLUSIONS:
Elaboration of structural signs of secretory activity in the PIMs by LMW
radiation in the absence of pulmonary pathological changes indicates its
potential for cell activation in addition to the already established role of
LMW in heat supplementation. This activation could be due to either increased
core body temperature or initiation of intracellular signaling by the LMW
radiation. This study also shows that the HMW radiation is capable of inducing
pathology in the form of changes in the pulmonary interstitial matrix and may
not be a good source of supplementary heat.
·
Smythe
JW, Costall B. Mobile phone use facilitates memory in male, but not female,
subjects. Neuroreport 14(2):243-246, 2003.
In the present study we
report on the effects of mobile phone exposure on short- and long-term memory
in male and female subjects. Subjects were university undergraduate students,
and consisted of right-handed, males ( = 33) and females ( = 29). Individuals
were randomly assigned to one of three experimental conditions: no phone
exposure; inactive phone exposure; and active phone exposure. They were
provided with a series of words to learn, structured in a two-dimensional
shape, and given 3 min to memorise the words. After a 12 min distraction task,
they were then asked to draw the shape (spatial) and place the correct words
(semantic) into the appropriate boxes. One week later the same subjects were
brought back to again redraw the shape and words. Error scores were determined
and analysed by non-parametric techniques. The results show that males exposed
to an active phone made fewer spatial errors than those exposed to an active
phone condition, while females were largely unaffected. These results further
indicate that mobile phone exposure has functional consequences for human
subjects, and these effects appear to be sex-dependent.
·
Stagg
RB, Thomas WJ, Jones RA, Adey WR, DNA synthesis and cell proliferation in C6
glioma and primary glial cells exposed to a 836.55 MHz modulated radiofrequency
field. Bioelectromagnetics 18(3):230-236, 1997.
We have tested the
hypothesis that modulated radiofrequency (RF) fields may act as a
tumor-promoting agent by altering DNA synthesis, leading to increased cell
proliferation. In vitro tissue cultures of transformed and normal rat glial
cells were exposed to an 836.55 MHz, packet-modulated RF field at three power
densities: 0.09, 0.9, and 9 mW/cm2, resulting in specific absorption rates
(SARs) ranging from 0.15 to 59 muW/g. TEM-mode transmission-line cells were
powered by a prototype time-domain multiple-access (TDMA) transmitter that
conforms to the North American digital cellular telephone standard. One sham
and one energized TEM cell were placed in standard incubators maintained at 37
degrees C and 5% CO2. DNA synthesis experiments at 0.59-59 muW/g SAR were
performed on log-phase and serum-starved semiquiescent cultures after 24 h
exposure. Cell growth at 0.15-15 muW/g SAR was determined by cell counts of
log-phase cultures on days 0, 1, 5, 7, 9, 12, and 14 of a 2 week protocol.
Results from the DNA synthesis assays differed for the two cell types.
Sham-exposed and RF-exposed cultures of primary rat glial cells showed no
significant differences for either log-phase or serum-starved condition. C6
glioma cells exposed to RF at 5.9 muW/g SAR (0.9 mW/cm2) exhibited small
(20-40%) significant increases in 38% of [3H]thymidine incorporation
experiments. Growth curves of sham and RF-exposed cultures showed no
differences in either normal or transformed glial cells at any of the power
densities tested. Cell doubling times of C6 glioma cells [sham (21.9 +/- 1.4 h)
vs. field (22.7 +/- 3.2 h)] also demonstrated no significant differences that
could be attributed to altered DNA synthesis rates. Under these conditions,
this modulated RF field did not increase cell proliferation of normal or
transformed cultures of glial origin.
·
Stagg
RB, Hawel LH III, Pastorian K, Cain C, Adey WR, Byus CV, Effect of
Immobilization and Concurrent Exposure to a Pulse-Modulated Microwave Field on
Core Body Temperature, Plasma ACTH and Corticosteroid, and Brain Ornithine
Decarboxylase, Fos and Jun mRNA. Radiat Res 155(4):584-592, 2001.
Effect of Immobilization
and Concurrent Exposure to a Pulse-Modulated Microwave Field on Core Body
Temperature, Plasma ACTH and Corticosteroid, and Brain Ornithine Decarboxylase,
Fos and Jun mRNA. Exposure of humans and rodents to radiofrequency (RF) cell
phone fields has been reported to alter a number of stress- related parameters.
To study this potential relationship in more detail, tube-restrained
immobilized Fischer 344 rats were exposed in the near field in a dose-dependent
manner to pulse-modulated (11 packets/s) digital cell phone microwave fields at
1.6 GHz in accordance with the Iridium protocol. Core body temperatures, plasma
levels of the stress-induced hormones adrenocorticotrophic hormone (ACTH) and
corticosterone, and brain levels of ornithine decarboxylase (Odc), Fos and Jun
mRNAs were measured as potential markers of stress responses mediated by RF
radiation. We tested the effects of the loose-tube immobilization with and
without prior conditioning throughout a 2-h period (required for near-field
head exposure to RF fields), on core body temperature, plasma ACTH and
corticosteroids. Core body temperature increased transiently (+/-0.3 degrees C)
during the initial 30 min of loose- tube restraint in conditioned animals. When
conditioned/tube- trained animals were followed as a function of time after
immobilization, both the ACTH and corticosterone levels were increased by
nearly 10-fold. For example, within 2-3 min, ACTH increased to 83.2 +/- 31.0
pg/dl, compared to 28.1 +/- 7.7 pg/dl for cage controls, reaching a maximum at
15-30 min (254.6 +/- 46.8 pg/dl) before returning to near resting levels by 120
min (31.2 +/- 10.2 pg/dl). However, when non-tube-trained animals were
submitted to loose-tube immobilization, these animals demonstrated
significantly higher (3-10-fold greater) hormone levels at 120 min than their
tube-trained counterparts (313.5 +/- 54.8 compared to 31.2 +/- 10.2 pg/dl;
corticosterone, 12.2 +/- 6.2 ?g/dl compared to 37.1 +/- 6.4 ?g/dl). Hormone
levels in exposed animals were also compared to those in swim-stressed animals.
Swimming stress also resulted in marked elevation in both ACTH and corticosterone
levels, which were 10-20 fold higher (541.8 compared to 27.2-59.1 pg/dl for
ACTH) and 2-5 fold higher (45.7 compared to 8.4- 20.0 ?g/dl for
corticosteroids) than the cage control animals. Three time-averaged brain SAR
levels of 0.16, 1.6 and 5 W/ kg were tested in a single 2-h RF-field exposure
to the Iridium cell phone field. When RF-exposed and sham-exposed (immobilized)
animals were compared, no differences were seen in core body temperature,
corticosterone or ACTH that could be attributed to near-field RF radiation.
Levels of Odc, Fos and Jun mRNA were also monitored in brains of animals
exposed to the RF field for 2 h, and they showed no differences from
sham-exposed (loose-tube immobilized) animals that were due to RF-field
exposure. These data suggest that a significant stress response, indicated by a
transient increase in core body temperature, ACTH and corticosterone, occurred
in animals placed in even the mild loose-tube immobilization required for
near-field RF exposure employed here and in our other studies. Failure to
adequately characterize and control this immobilization response with
appropriate cage control animals, as described previously, could significantly
mask any potential effects mediated by the RF field on these and other
stress-related parameters. We conclude that the pulse-modulated digital Iridium
RF field at SARs up to 5 W/kg is incapable of altering these stress-related
responses. This conclusion is further supported by our use of an RF-field
exposure apparatus that minimized immobilization stress; the use of
conditioned/tube-trained animals and the measurement of hormonal and molecular
markers after 2 h RF-field exposure when the stress-mediated effects were
complete further support our conclusion.
·
Stang
A, Anastassiou G, Ahrens W, Bromen K, Bornfeld N, Jockel KH,
The possible role of radiofrequency radiation in the development of uveal
melanoma. Epidemiology 12(1):7-12, 2001.
There are few epidemiologic
studies dealing with electromagnetic radiation and uveal melanoma. The majority
of these studies are exploratory and are based on job and industry titles only.
We conducted a hospital-based and population-based case-control study of uveal
melanoma and occupational exposures to different sources of electromagnetic
radiation, including radiofrequency radiation. We then pooled these results. We
interviewed a total of 118 female and male cases with uveal melanoma and 475
controls matching on sex, age, and study regions. Exposure to
radiofrequency-transmitting devices was rated as (a) no radiofrequency
radiation exposure, (b) possible exposure to mobile phones, or (c)
probable/certain exposure to mobile phones. Exposures were rated independently
by two of the authors who did not know case or control status. We used
conditional logistic regression to calculate odds ratios (ORs) and 95%
confidence intervals (95% CIs). We found an elevated risk for exposure to
radiofrequency-transmitting devices (exposure to radio sets, OR = 3.0, 95% CI =
1.4-6.3; probable/certain exposure to mobile phones, OR = 4.2, 95% CI =
1.2-14.5). Other sources of electromagnetic radiation such as high-voltage
lines, electrical machines, complex electrical environments, visual display
terminals, or radar units were not associated with uveal melanoma. This is the
first study describing an association between radiofrequency radiation exposure
and uveal melanoma. Several methodologic limitations prevent our results from
providing clear evidence on the hypothesized association.
·
Sykes
PJ, McCallum BD, Bangay MJ, Hooker AM, Morley AA. Effect of Exposure to 900 MHz
Radiofrequency Radiation on Intrachromosomal Recombination in pKZ1 Mice. Radiat
Res 156(5):495-502, 2001.
Radiofrequency (RF) radiation emitted from mobile phones is not considered to
be directly genotoxic, but it may have downstream effects on cellular DNA. We
studied the effect of 4 W/kg pulsed 900 MHz RF radiation on somatic
intrachromosomal recombination in the spleen in the pKZ1 recombination
mutagenesis model. Somatic intrachromosomal recombination inversion events were
detected in spleen tissue of pKZ1 mice by histochemical staining for E. coli
beta-galactosidase protein in cells in which the lacZ transgene has undergone
an inversion event. pKZ1 mice were exposed daily for 30 min to plane-wave
fields of 900 MHz with a pulse repetition frequency of 217 Hz and a pulse width
of 0.6 ms for 1, 5 or 25 days. Three days after the last exposure, spleen
sections were screened for DNA inversion events. There was no significant
difference between the control and treated groups in the 1- and 5-day exposure
groups, but there was a significant reduction in inversions below the
spontaneous frequency in the 25-day exposure group. This observation suggests
that exposure to RF radiation can lead to a perturbation in recombination frequency
which may have implications for recombination repair of DNA. The biological
significance of a reduction below the spontaneous frequency is not known. The
number of mice in each treatment group in this study was small (n = 10 or n =
20). Therefore, repetition of this study with a larger number of animals is
required to confirm these observations.
·
Takahashi
S, Inaguma S, Cho Y-M, Imaida K, Wang J, Fujiwara O, Shirai T, Lack of Mutation
Induction with Exposure to 1.5 GHz Electromagnetic Near Fields Used for
Cellular Phones in Brains of Big Blue Mice. Cancer Res 62:1956-1960, 2002.
The possible mutagenic
potential of exposure to 1.5 GHz electromagnetic near field (EMF) was
investigated using brain tissues of Big Blue mice (BBM). Male BBM were locally exposed
to EMF in the head region at 2.0, 0.67, and 0 W/kg specific absorption rate for
90 min/day, 5 days/week, for 4 weeks. No gliosis or degenerative lesions were
histopathologically noted in brain tissues, and no obvious differences in Ki-67
labeling and apoptotic indices of glial cells were evident among the groups.
There was no significant variation in the frequency of independent mutations of
the lacI transgene in the brains. G:C to A:T transitions at CpG sites
constituted the most prevalent mutations in all groups and at all time points.
Deletion mutations were slightly increased in both the high and low EMF
exposure groups as compared with the sham-exposed group, but the differences
were not statistically significant. These findings suggest that exposure to 1.5
GHz EMF is not mutagenic to mouse brain cells and does not create any increased
hazard with regard to brain tumor development.
·
Testylier
G , Tonduli L, Malabiau R, Debouzy JC. Effects of exposure to low level
radiofrequency fields on acetylcholine release in hippocampus of freely moving
rats. Bioelectromagnetics 23:249-255, 2002.
Some central cholinergic
effects have been reported in animals after acute exposure to radiofrequency
electromagnetic field at low intensity. We studied acetylcholine (ACh) release
in the brain of freely moving rats exposed for 1 h during the day to a 2.45 GHz
continuous wave radiofrequency field (RF) (2 or 4 mW/cm2) or exposed for 1 or
14 h during the night to a 800 MHz field modulated at 32 Hz (AM 200 mW/cm2).
Measurements were performed by microdialysis using a membrane implanted through
the upper CA1 region of the hippocampus. After irradiation with the 2.45 GHz
RF, rats exposed at 2 mW/cm2 did not show a significant modification of Ach
release, whereas those exposed at 4 mW/cm2 showed a significant 40% decrease in
mean ACh release from hippocampus. This decrease was maximal at 5 h post
exposure. Exposure to the 800 MHz RF for 1 h did not cause any significant
effect, but exposure for 14 hrs induced a significant 43% decrease in ACh
release during the period 11 p.m.-4 a.m. compared to control rats. In the
control group we observed an increase of ACh release at the beginning of the
night, which was linked to the waking period of rats. This normal increase was
disturbed in rats exposed overnight to the 800 MHz RF. This work indicates that
neurochemical modification of the hippocampal cholinergic system can be
observed during and after an exposure to low intensity RF.
·
Tice
RR , Hook GG , Donner M , McRee DI, Guy AW. Genotoxicity of radiofrequency
signals. I. Investigation of DNA damage and micronuclei induction in cultured
human blood cells. Bioelectromagnetics 23:113-126, 2002.
As part of a comprehensive
investigation of the potential genotoxicity of radiofrequency (RF) signals
emitted by cellular telephones, in vitro studies evaluated the induction of DNA
and chromosomal damage in human blood leukocytes and lymphocytes, respectively.
The signals were voice modulated 837 MHz produced by an analog signal generator
or by a time division multiple access (TDMA) cellular telephone, 837 MHz
generated by a code division multiple access (CDMA) cellular telephone (not
voice modulated), and voice modulated 1909.8 MHz generated by a global system
of mobile communication (GSM)-type personal communication systems (PCS)
cellular telephone. DNA damage (strand breaks/alkali labile sites) was assessed
in leukocytes using the alkaline (pH>13) single cell gel electrophoresis
(SCG) assay. Chromosomal damage was evaluated in lymphocytes mitogenically
stimulated to divide postexposure using the cytochalasin B-binucleate cell
micronucleus assay. Cells were exposed at 37±1°C, for 3 or 24 h at average
specific absorption rates (SARs) of 1.0-10.0 W/kg. Exposure for either 3 or 24
h did not induce a significant increase in DNA damage in leukocytes, nor did
exposure for 3 h induce a significant increase in micronucleated cells among
lymphocytes. However, exposure to each of the four RF signal technologies for
24 h at an average SAR of 5.0 or 10.0 W/kg resulted in a significant and
reproducible increase in the frequency of micronucleated lymphocytes. The
magnitude of the response (approximately four fold) was independent of the
technology, the presence or absence of voice modulation, and the frequency (837
vs. 1909.8 MHz). This research demonstrates that, under extended exposure
conditions, RF signals at an average SAR of at least 5.0 W/kg are capable of
inducing chromosomal damage in human lymphocytes.
·
Tsurita
G, Nagawa H, Ueno S, Watanabe S, Taki M, Biological and morphological effects
on the brain after exposure of rats to a 1439 MHz TDMA field.
Bioelectromagnetics 21(5):364-371, 2000.
We investigated the effects
of exposure to a 1439 MHz TDMA (Time Division Multiple Access) field, as used
in cellular phones, on the permeability of the blood-brain barrier (BBB), on
the morphological changes of the brain, and on body-mass fluctuations. Male
Sprague-Dawley (SD) rats were divided into Three groups of eight rats each. The
rats in the EM(+) group, which had their heads arrayed in a circle near the
central antenna of an exposure system, were exposed to a 1439 MHz field for one
hour a day. The rats in EM(-) group were also in the exposure system, however,
without high-frequency electromagnetic wave (HF-EMW) exposure. The animals in
the control group were neither placed in the system nor exposed to HF-EMWs. The
exposure period was two or four weeks. The energy dose rate peaked at 2 W/kg in
the brain; the average over the whole body was 0.25 W/kg. The changes in the
permeability of BBB were investigated by Evans blue injection method and by
immunostaining of serum albumin. HF-EMWs had no effect on the permeability of
BBB. The morphological changes in the cerebellum were investigated by assessing
the degeneration of Purkinje cells and the cell concentration in the granular
layer. No significant changes were observed in the groups of rats exposed to
HF-EMWs for two or four weeks. Averaged body masses were not affected by
HF-EMWs exposure. In conclusion, a 1439 MHz TDMA field did not induce
observable changes in the permeability of the BBB, morphological changes in the
cerebellums, or body mass changes in rats, as evaluated by the conventional
methods.
·
Urban,
P, Lukas, E, Roth, Z, Does acute exposure to the electromagnetic field emitted
by a mobile phone influence visual evoked potentials? A pilot study. Cent Eur J
Public Health 6(4):288-290, 1998.
To search for a potential
negative influence on the central nervous system (CNS) of the electromagnetic
field emitted by a mobile phone, the authors performed a pilot experimental
study of the influence of a single short acute exposure to the GSM mobile phone
Motorola 8700, using visual evoked potentials (VEP) examination as an
electrophysiological marker of CNS dysfunction. The study group consisted of 20
healthy volunteers. The duration of exposure was 5 minutes. The output power of
the device was 1.5 W when the antenna was pulled up. Five parameters of VEP
were evaluated by means of multifactorial ANOVA. Confounding effects of age,
sex, and of the call in itself were taken into consideration. No statistically
significant influence of the above-described exposure to the electromagnetic
field emitted by the mobile phone on latencies or amplitudes of VEP was
observed.
·
Utteridge
TD, Gebski V, Finnie JW, Vernon-Roberts B, Kuchel TR. Long-Term Exposure of
E?-Pim1 Transgenic Mice to 898.4 MHz Microwaves does not Increase Lymphoma
Incidence. Radiat Res 158(3):357-364, 2002.
A total of 120 E?-Pim1
heterozygous mice and 120 wild-type mice were exposed for 1 h/day 5 days/week
at each of the four exposure levels in "Ferris-wheel" exposure
systems for up to 104 weeks to GSM-modulated 898.4 MHz radiation at SARs of
0.25, 1.0, 2.0 and 4.0 W/kg. In addition, 120 heterozygous and 120 wild-type
mice were sham-exposed; there was also an unrestrained negative control group.
Four exposure levels were used to investigate whether a dose-response effect
could be detected. Independent verification confirmed that the exposures in the
current study were nonthermal. There was no significant difference in the
incidence of lymphomas between exposed and sham-exposed groups at any of the
exposure levels. A dose-response effect was not detected. The findings showed
that long-term exposures of lymphoma-prone mice to 898.4 MHz GSM radiofrequency
(RF) radiation at SARs of 0.25, 1.0, 2.0 and 4.0 W/kg had no significant
effects when compared to sham-irradiated animals. A previous study (Repacholi
et al., Radiat. Res. 147, 631-640, 1997) reported that long-term exposure of
lymphoma-prone mice to one exposure level of 900 MHz RF radiation significantly
increased the incidence of non-lymphoblastic lymphomas when compared to
sham-irradiated animals.
·
Velizarov,
S, Raskmark, P, Kwee, S, The effects of radiofrequency fields on cell
proliferation are non-thermal. Bioelectrochem Bioenerg 48(1):177-180, 1999.
The number of reports on
the effects induced by radiofrequency (RF) electromagnetic fields and microwave
(MW) radiation in various cellular systems is still increasing. Until now no
satisfactory mechanism has been proposed to explain the biological effects of
these fields. One of the current theories is that heat generation by RF/MW is
the cause, in spite of the fact that a great number of studies under isothermal
conditions have reported significant cellular changes after exposure to RF/MW.
Therefore, this study was undertaken to investigate which effect MW radiation
from these fields in combination with a significant change of temperature could
have on cell proliferation. The experiments were performed on the same cell
line, and with the same exposure system as in a previous work [S. Kwee, P.
Raskmark, Changes in cell proliferation due to environmental non-ionizing
radiation: 2. Microwave radiation, Bioelectrochem. Bioenerg., 44 (1998), pp.
251-255]. The field was generated by signal simulation of the Global System for
Mobile communications (GSM) of 960 MHz. Cell cultures, growing in microtiter
plates, were exposed in a specially constructed chamber, a Transverse Electromagnetic
(TEM) cell. The Specific Absorption Rate (SAR) value for each cell well was
calculated for this exposure system. However, in this study the cells were
exposed to the field at a higher or lower temperature than the temperature in
the field-free incubator i.e., the temperature in the TEM cell was either 39 or
35 +/- 0.1 degrees C. The corresponding sham experiments were performed under
exactly the same experimental conditions. The results showed that there was a
significant change in cell proliferation in the exposed cells in comparison to
the non-exposed (control) cells at both temperatures. On the other hand, no
significant change in proliferation rate was found in the sham-exposed cells at
both temperatures. This shows that biological effects due to RF/MW cannot be
attributed only to a change of temperature. Since the RF/MW induced changes
were of the same order of magnitude at both temperatures and also comparable to
our previous results under isothermal conditions at 37 degrees C, cellular
stress caused by electromagnetic fields could initiate the changes in cell
cycle reaction rates. It is widely accepted that certain classes of heat-shock
proteins are involved in these stress reactions.
·
Von
Klitzing, L, Low-frequency pulsed electromagnetic fields influence EEG of man.
Phys. Medica 11:77-80, 1995.
New techniques using
low-frequency puled electromagnetic fields (e.g., digital telecommunication)
have raised the question for interference with the biological system of man.
EEG data of man sampled under the influence of these electromagnetic fields are
altered extremely in the range of alpha-activity as well as during after
exposure for some hours. The biological effect is induced by field intensities
lower than the given international limiting values.
·
Vijayalaxmi
, Leal BZ, Meltz ML, Pickard WF, Bisht KS, Roti Roti JL , Straube WL, Moros EG,
Cytogenetic Studies in Human Blood Lymphocytes Exposed In Vitro to
Radiofrequency Radiation at a Cellular Telephone Frequency (835.62 MHz, FDMA).
Radiat Res 155(1):113-121, 2001.
Freshly collected
peripheral blood samples from four healthy human volunteers were diluted with
RPMI 1640 tissue culture medium and exposed in sterile T-75 tissue culture
flasks in vitro for 24 h to 835.62 MHz radiofrequency (RF) radiation, a
frequency employed for customer-to-base station transmission of cellular
telephone communications. An analog signal was used, and the access technology
was frequency division multiple access (FDMA, continuous wave). A nominal net
forward power of 68 W was used, and the nominal power density at the center of
the exposure flask was 860 W/m(2). The mean specific absorption rate in the
exposure flask was 4.4 or 5.0 W/kg. Aliquots of diluted blood that were
sham-exposed or exposed in vitro to an acute dose of 1.50 Gy of gamma radiation
were used as negative or positive controls. Immediately after the exposures,
the lymphocytes were stimulated with a mitogen, phytohemagglutinin, and
cultured for 48 or 72 h to determine the extent of genetic damage, as assessed
from the frequencies of chromosomal aberrations and micronuclei. The extent of
alteration in the kinetics of cell proliferation was determined from the
mitotic indices in 48-h cultures and from the incidence of binucleate cells in
72-h cultures. The data indicated no significant differences between
RF-radiation- and sham-exposed lymphocytes with respect to mitotic indices,
incidence of exchange aberrations, excess fragments, binucleate cells, and
micronuclei. In contrast, the response of the lymphocytes exposed to gamma
radiation was significantly different from both RF-radiation- and sham-exposed
cells for all of these indices. Thus, under the experimental conditions tested,
there is no evidence for the induction of chromosomal aberrations and micronuclei
in human blood lymphocytes exposed in vitro for 24 h to 835.62 MHz RF radiation
at SARs of 4.4 or 5.0 W/kg.
·
Vijayalaxmi,
Bisht KS, Pickard WF, Meltz ML, Roti Roti JL, Moros EG. Chromosome damage and
micronucleus formation in human blood lymphocytes exposed in vitro to
radiofrequency radiation at a cellular telephone frequency (847.74 MHz, CDMA).
Radiat Res 156(4):430-432, 2001.
Peripheral blood samples
collected from four healthy nonsmoking human volunteers were diluted with
tissue culture medium and exposed in vitro for 24 h to 847.74 MHz
radiofrequency (RF) radiation (continuous wave), a frequency employed for
cellular telephone communications. A code division multiple access (CDMA)
technology was used with a nominal net forward power of 75 W and a nominal
power density of 950 W/m(2) (95 mW/cm(2)). The mean specific absorption rate
(SAR) was 4.9 or 5.5 W/kg. Blood aliquots that were sham-exposed or exposed in
vitro to an acute dose of 1.5 Gy of gamma radiation were included in the study
as controls. The temperatures of the medium during RF-radiation and sham
exposures in the Radial Transmission Line facility were controlled at 37 +/-
0.3 degrees C. Immediately after the exposures, lymphocytes were cultured at 37
+/- 1 degrees C for 48 or 72 h. The extent of genetic damage was assessed from
the incidence of chromosome aberrations and micronuclei. The kinetics of cell
proliferation was determined from the mitotic indices in 48-h cultures and from
the incidence of binucleate cells in 72-h cultures. The data indicated no
significant differences between RF-radiation-exposed and sham-exposed
lymphocytes with respect to mitotic indices, frequencies of exchange
aberrations, excess fragments, binucleate cells, and micronuclei. The response
of gamma-irradiated lymphocytes was significantly different from that of both
RF-radiation-exposed and sham-exposed cells for all of these indices. Thus
there was no evidence for induction of chromosome aberrations and micronuclei
in human blood lymphocytes exposed in vitro for 24 h to 847.74 MHz RF radiation
(CDMA) at SARs of 4.9 or 5.5 W/kg.
·
Vijayalaxmi,
Sasser LB, Morris JE, Wilson BW, Anderson LE. Genotoxic Potential of 1.6 GHz Wireless
Communication Signal: In Vivo Two-Year Bioassay. Radiat Res 159(4):558-564,
2003.
Timed-pregnant Fischer 344
rats (from nineteenth day of gestation) and their nursing offspring (until
weaning) were exposed to a far-field 1.6 GHz Iridium wireless communication
signal for 2 h/day, 7 days/week. Far-field whole-body exposures were conducted with
a field intensity of 0.43 mW/cm(2) and whole-body average specific absorption
rate (SAR) of 0.036 to 0.077 W/kg (0.10 to 0.22 W/kg in the brain). This was
followed by chronic, head-only exposures of male and female offspring to a
near-field 1.6 GHz signal for 2 h/day, 5 days/week, over 2 years. Near-field
exposures were conducted at an SAR of 0.16 or 1.6 W/kg in the brain. Concurrent
sham-exposed and cage control rats were also included in the study. At the end
of 2 years, all rats were necropsied. Bone marrow smears were examined for the
extent of genotoxicity, assessed from the presence of micronuclei in
polychromatic erythrocytes. The results indicated that the incidence of
micronuclei/2000 polychromatic erythrocytes were not significantly different between
1.6 GHz-exposed, sham-exposed and cage control rats. The group mean frequencies
were 5.6 +/- 1.8 (130 rats exposed to 1.6 GHz at 0.16 W/kg SAR), 5.4 +/- 1.5
(135 rats exposed to 1.6 GHz at 1.6 W/kg SAR), 5.6 +/- 1.7 (119 sham-exposed
rats), and 5.8 +/- 1.8 (100 cage control rats). In contrast, positive control
rats treated with mitomycin C exhibited significantly elevated incidence of
micronuclei/2000 polychromatic erythrocytes in bone marrow cells; the mean
frequency was 38.2 +/- 7.0 (five rats). Thus there was no evidence for excess
genotoxicity in rats that were chronically exposed to 1.6 GHz compared to
sham-exposed and cage controls.
·
Vollrath
L, Spessert R, Kratzsch T, Keiner M, Hollmann H, No short-term effects of
high-frequency electromagnetic fields on the mammalian pineal gland.
Bioelectromagnetics 18(5):376-387, 1997.
There is ample experimental
evidence that changes of earth-strength static magnetic fields, pulsed magnetic
fields, or alternating electric fields (60 Hz)
depress the nocturnally enhanced melatonin synthesis of the pineal gland of certain
mammals. No data on the effects of high-frequency electromagnetic
fields on melatonin synthesis is available. In the present study, exposure to 900
MHz electromagnetic fields [0.1 to 0.6 mW/cm2, approximately 0.06 to 0.36
W/kg specific absorption rate (SAR) in rats and 0.04 W/kg in Djungarian hamsters;
both continuous and/or pulsed at 217 Hz, for 15 min to 6 hr at day or
night had no notable short-term effect on pineal melatonin synthesis in male and
female Sprague-Dawley rats and Djungarian hamsters. Pineal synaptic ribbon
profile numbers (studied in rats only) were likewise not affected. The 900 MHz electromagnetic
fields, unpulsed or pulsed at 217 Hz, as applied in the present
study, have no short-term effect on the mammalian pineal gland.
·
Wagner,
P, Roschke, J, Mann, K, Hiller, W, Frank, C, Human sleep under the influence of
pulsed radiofrequency electromagnetic fields: a polysomnographic study using
standardized conditions. Bioelectromagnetics 19(3):199-202, 1998.
To investigate the
influence of radiofrequency electromagnetic fields (EMFs) of cellular phone GSM
signals on human sleep electroencephalographic (EEG) pattern, all-night
polysomnographies of 24 healthy male subjects were recorded, both with and
without exposure to a circular polarized EMF (900 MHz, pulsed with a frequency
of 217 Hz, pulse width 577 micros, power flux density 0.2 W/m2. Suppression of
rapid eye movement (REM) sleep as well as a sleep-inducing effect under field
exposure did not reach statistical significance, so that previous results
indicating alterations of these sleep parameters could not be replicated.
Spectral power analysis also did not reveal any alterations of the EEG rhythms
during EMF exposure. The failure to confirm our previous results might be due
to dose-dependent effects of the EMF on the human sleep profile.
·
Wagner
P, Roschke J, Mann K, Fell J, Hiller W, Frank C, Grozinger M, Human sleep EEG
under the influence of pulsed radio frequency electromagnetic fields. results
from polysomnographies using submaximal high power flux densities.
Neuropsychobiology 42(4):207-212, 2000.
Former exploratory
investigations of sleep alterations due to global system for mobile
communications (GSM) signals have shown a hypnotic and REM-suppressive effect
under field exposure. This effect was observed in a first study using a power
flux density of 0.5 W/m(2), and the same trend occurred in a second study with
a power flux density of 0.2 W/m(2). For the present study, we applied a
submaximal power flux density of 50 W/m(2). To investigate putative effects of
radio frequency electromagnetic fields (EMFs) of cellular GSM phones on human
sleep EEG pattern, all-night polysomnographies of 20 healthy male subjects both
with and without exposure to a circularly polarized EMF (900 MHz, pulsed with a
frequency of 217 Hz, pulse duration 577 &mgr;s) were recorded. The results
showed no significant effect of the field application either on conventional
sleep parameters or on sleep EEG power spectra.
·
Warren HG,
Prevatt AA, Daly KA, Antonelli PJ. Cellular telephone use and risk of intratemporal facial nerve tumor.
Laryngoscope 113(4):663-667, 2003. (G-C, H-U, C-P)
OBJECTIVES/HYPOTHESISMicrowave radiation exposure from cellular telephone use
has been implicated in the development of intracranial tumors. The
intratemporal facial nerve (IFN) is exposed to higher levels of cellular
telephone radiation than intracranial tissues. The purpose of the study was to
determine whether cellular telephone use is associated with an increased risk
of IFN tumors. STUDY DESIGNCase-control using a structured telephone survey at
an academic, tertiary-care referral center. METHODS Patients with IFN tumors (n
= 18) were case-matched with patients treated for acoustic neuroma (n = 51),
rhinosinusitis (n = 72), and dysphonia or gastroesophageal reflux disease (n =
69). Risk of facial nerve tumorigenesis was compared by extent of cellular
telephone use and other risk factors.RESULTSThe odds ratio of developing an IFN
tumor was 0.6 (95% CI, 0.2-1.9) with any handheld cellular telephone use and
0.4 (95% CI, 0.1-2.1) with regular cellular telephone use. No factors were
associated with an increased risk for IFN tumor development. CONCLUSIONS
Regular cellular telephone use does not appear to be associated with a higher
risk of IFN tumor development. The short duration of widespread cellular
telephone use precludes definite exclusion as a risk for IFN tumor development.
·
Weisbrot
D, Lin H, Ye L, Blank M, Goodman R. Effects of mobile phone radiation on
reproduction and development in Drosophila melanogaster. J Cell Biochem
89(1):48-55, 2003.
In this report we examined
the effects of a discontinuous radio frequency (RF) signal produced by a GSM
multiband mobile phone (900/1,900 MHz; SAR approximately 1.4 W/kg) on
Drosophila melanogaster, during the 10-day developmental period from egg laying
through pupation. As found earlier with low frequency exposures, the
non-thermal radiation from the GSM mobile phone increased numbers of offspring,
elevated hsp70 levels, increased serum response element (SRE) DNA-binding and
induced the phosphorylation of the nuclear transcription factor, ELK-1. The
rapid induction of hsp70 within minutes, by a non-thermal stress, together with
identified components of signal transduction pathways, provide sensitive and
reliable biomarkers that could serve as the basis for realistic mobile phone
safety guidelines.
·
Wilen
J, Sandstrom M, Hansson Mild K. Subjective symptoms among mobile phone users-A
consequence of absorption of radiofrequency fields? Bioelectromagnetics
24(3):152-159, 2003.
In a previous
epidemiological study, where we studied the prevalence of subjective symptoms
among mobile phone (MP) users, we found as an interesting side finding that the
prevalence of many of the subjective symptoms increased with increasing calling
time and number of calls per day. In this extrapolative study, we have selected
2402 people from the epidemiological study who used any of the four most common
GSM MP. We used the information about the prevalence of symptoms, calling time
per day, and number of calls per day and combined it with measurements of the
Specific Absorption Rate (SAR). We defined three volumes in the head and
measured the maximum SAR averaged over a cube of 1 g tissue (SAR(1g)) in each
volume. Two new exposure parameters Specific Absorption per Day (SAD) and
Specific Absorption per Call (SAC) have been devised and are obtained as
combinations of SAR, calling time per day, and number of calls per day, respectively.
The results indicates that SAR values >0.5 W/kg may be an important factor
for the prevalence of some of the symptoms, especially in combination with long
calling times per day.
·
Wolke S, Neibig U, Elsner R, Gollnick F, Meyer R, Calcium homeostasis of
isolated heart muscle cells exposed to pulsed high-frequency electromagnetic
fields. Bioelectromagnetics 17(2):144-153, 1996.
The intracellular calcium
concentration ([Ca(2+)]i) of isolated ventricular cardiac myocytes of the
guinea pig was measured during the application of
pulsed high-frequency electromagnetic fields. The high-frequency fields were applied
in a transverse electromagnetic cell designed to allow microscopic
observation of the myocytes during the presence of the high-frequency fields. The
[Ca(2+)]i was measured as fura-2 fluorescence by means of digital image
analysis. Both the carrier frequency and the square-wave pulse-modulation pattern
were varied during the experiments (carrier frequencies: 900, 1,300,
and 1,800 MHz pulse modulated at 217Hz with 14 percent duty cycle; pulsation pattern
at 900 MHz: continuous wave, 16 Hz, and 50 Hz modulation with 50
percent duty cycle and 30 kHz modulation with 80 percent duty cycle). The mean specific
absorption rate (SAR) values in the solution were within one order of
magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and
pulse pattern. The experiments were designed in three phases: 500 s of sham
exposure, followed by 500 s of field exposure, then chemical stimulation without
field. The chemical stimulation (K+ -depolarization) indicated the
viability of the cells. The K+ depolarization yielded a significant increase in
[Ca(2+)]i. Significant differences between sham exposure and high-frequency
field exposure were not found except when a very small but statistically significant
difference was detected in the case of 900 MHz/50 Hz. However, this
small difference was not regarded as a relevant effect of the exposure.
·
Yamaguchi
H, Tsurita G, Ueno S, Watanabe S, Wake K, Taki M, Nagawa H. 1439 MHz pulsed
TDMA fields affect performance of rats in a T-maze task only when body
temperature is elevated. Bioelectromagnetics 24(4):223-230, 2003.
This study sought to
clarify the effects of exposure to electromagnetic waves (EMW) used in cellular
phones on learning and memory processes. Sprague-Dawley rats were exposed for
either 1 h daily for 4 days or for 4 weeks to a pulsed 1439 MHz time division
multiple access (TDMA) field in a carousel type exposure system. At the brain,
average specific absorption rate (SAR) was 7.5 W/kg, and the whole body average
SAR was 1.7 W/kg. Other subjects were exposed at the brain average SAR of 25
W/kg and the whole body average SAR of 5.7 W/kg for 45 min daily for 4 days.
Learning and memory were evaluated by reversal learning in a food rewarded
T-maze, in which rats learned the location of food (right or left) by using
environmental cues. The animals exposed to EMW with the brain average SAR of 25
W/kg for 4 days showed statistically significant decreases in the transition in
number of correct choices in the reversal task, compared to sham exposed or
cage control animals. However, rats exposed to the brain average SAR of 7.5
W/kg for either 4 days or for 4 weeks showed no T-maze performance impairments.
Intraperitoneal temperatures, as measured by a fiber optic thermometer,
increased in the rats exposed to the brain average SAR of 25 W/kg but remained
the same for the brain average SAR of 7.5 W/kg. The SAR of a standard cellular
phone is restricted to a maximum of 2 W/kg averaged over 10 g tissue. These
results suggest that the exposure to a TDMA field at levels about four times
stronger than emitted by cellular phones does not affect the learning and
memory processes when there are no thermal effects.
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Zook BC, Simmens SJ, The Effects of 860 MHz Radiofrequency Radiation on the
Induction or Promotion of Brain Tumors and Other Neoplasms in Rats. Radiat Res
155(4):572-583, 2001.
Sprague-Dawley rats were
irradiated with a continuous- wave (CW) or a pulsed-wave (P) radiofrequency
(RF) for 6 h/day, 5 days/week from 2 up to 24 months of age. The RFs emanated from
dipole antennas (1 W average output) 2.0 +/- 0.5 cm from the tip of each rat's
nose. The RFs had an 860 MHz frequency, and the specific absorption rate was
1.0 W/ kg averaged over the brain. Fifteen groups of 60 rats (900 total) were
formed from offspring of females injected i.v. with 0 (groups 1, 2, 9, 10, 13),
2.5 (groups 5, 6, 7, 8, 11, 12, 14) or 10 mg/kg (groups 3, 4, 15)
ethylnitrosourea (ENU) to induce brain tumors. Groups 1, 3, 5 and 7 received
the PRF, and groups 9 and 11 the CWRF; groups 2, 4, 6, 8, 10 and 12 were
sham-irradiated, and groups 13-15 were cage controls. All rats but 2, totaling
898, were necropsied, and major tissues were studied histopathologically. There
was no statistically significant evidence that the PRF or CWRF induced neoplasia
in any tissues. Additionally, there was no significant evidence of promotion of
cranial or spinal nerve or spinal cord tumors. The PRF or CWRF had no
statistically significant effect on the number, volume, location, multiplicity,
histological type, malignancy or fatality of brain tumors. There was a trend
for the group that received a high dose of ENU and was exposed to the PRF to
develop fatal brain tumors at a higher rate than its sham group; however, the
result was not significant using the log-rank test (P = 0.14, 2-tailed). No
statistically significant differences were related to the PRF or CWRF compared
to controls in the low- or zero-dose groups regarding tumors of any kind.