Krause CM et al. · 2004
Researchers conducted a double-blind study in which subjects performed a memory task with and without exposure to a digital 902 MHz field. All eight significant EEG changes from the earlier study were not significant in this replication. The effect of EMF on incorrect answers was inconsistent, with a significant increase in errors observed in this study but not in the earlier one.
Martinez-Burdalo M, Martin A, Anguiano M, Villar R · 2004
Peak SAR1g and SAR10g trended downwards as head size decreased. The percentage of energy absorbed in the brain increased with smaller head size. SAR distributions in eyes were very similar between full-size and scaled models.
Capri M et al. · 2004
Researchers exposed human peripheral blood mononuclear cells (PBMCs) from healthy donors in vitro to a 900 MHz GSM or continuous-wave (CW) radiofrequency field for 1 hour per day for 3 days. The researchers studied mitogen-induced proliferation, cell cycle progression, spontaneous and induced apoptosis, and mitochondrial membrane potential. GSM-exposed cells showed a slight decrease in proliferation at the lowest mitogen concentration and a slight increase in cells with altered phosphatidylserine distribution, but cell cycle phases, mitochondrial membrane potential, and susceptibility to apoptosis were unaffected. When cells were exposed to the CW radiofrequency field, no significant modifications were observed for any of the endpoints studied.
Marinelli F et al. · 2004
Nylund R, Leszczynski D · 2004
Researchers exposed the human endothelial cell line EA.hy926 to mobile phone radiation and examined protein expression using two-dimensional electrophoresis. Up to 38 proteins showed statistically significant changes in expression levels after irradiation. Four proteins were identified by mass spectrometry, including two isoforms of the cytoskeletal protein vimentin.
Haarala C et al. · 2004
Researchers studied the effects of a 902 MHz mobile phone EMF on human short term memory using a double blind, multi-centre design. Sixty-four subjects in two laboratories performed an n-back task with memory loads of 0 to 3 items under both EMF and sham exposure. The EMF had no effect on reaction times or accuracy, and performance did not differ between the two laboratories.
Capri M et al. · 2004
Researchers studied whether prolonged in vitro exposure to 1800 MHz radiofrequency could affect human peripheral blood mononuclear cells from young and elderly donors by altering apoptosis, mitochondrial membrane potential, and heat shock protein 70 levels. Three GSM signal modulations (Basic, DTX, and Talk) were applied at specific absorption rates of 1.4 and 2.0 W kg−1. Endpoints were analyzed both with and without the apoptosis-inducing agent 2-deoxy-D-ribose. No significant difference was found between RF-exposed and sham-exposed cells for any endpoint. The 1800 MHz RF did not induce apoptosis on its own, did not alter apoptosis triggered by an agent, and did not change mitochondrial function or HSP 70 expression.
Tahvanainen K et al. · 2004
Researchers conducted a randomized, double-blind, placebo-controlled crossover trial with 32 healthy subjects exposed to 900 MHz (2 W) and 1800 MHz (1 W) cellular phone signals and sham exposure in separate sessions. Arterial blood pressure and heart rate did not change significantly during or after the 35-minute RF exposures at either frequency compared to sham exposure. Blood pressure was measured with an arm cuff and heart rate was recorded during and after each 35-minute exposure session.
Sommer AM, Streckert J, Bitz AK, Hansen VW, Lerchl A · 2004
Survival rate and lymphoma incidence did not differ between exposed and sham-exposed mice. Exposed mice gained more weight than sham-exposed mice. The data do not support the hypothesis that 900 MHz fields are a significant risk factor for lymphoma in this genetically predisposed strain.
Cobb BL, Jauchem JR, Adair ER. · 2004
Researchers exposed rats to 2450 MHz fields at 0.6 W/kg for 45 minutes daily over 10 days in circularly polarized waveguides and gave them a pre-exposure injection of a psychoactive compound or saline. Error rate analysis showed no significant effect of microwave exposure, no drug effect, and no exposure-drug interaction, while performance improved across test days indicating learning. Time to criterion showed no significant exposure effect but a significant drug effect, a significant test day effect, and a significant drug-by-test-day interaction. The authors concluded there is no evidence that microwave radiation exposure under the tested parameters caused decrements in spatial memory learning.
Ayata A et al. · 2004
Thirty Wistar-Albino rats were assigned to control, irradiated, and irradiated-plus-melatonin groups, and the irradiated group received 900 MHz, 2 W radiation for 30 minutes daily over 10 days. The melatonin group received 10 mg/kg/day melatonin in tap water for 10 days before irradiation. Skin samples were analyzed for malondialdehyde, hydroxyproline, superoxide dismutase, glutathione peroxidase, and catalase. Radiation significantly increased MDA, hydroxyproline, CAT, and GSH-Px and decreased SOD; melatonin reversed the increases in MDA, hydroxyproline, CAT, and GSH-Px but did not prevent the SOD decrease. The results suggest that 900 MHz radiation increases fibrosis and lipid peroxidation in rat skin and that melatonin can reduce these effects.
Ayata A et al. · 2004
Researchers exposed rats to 900 MHz mobile phone radiation for 30 minutes daily over 10 days and found significant skin damage, including increased fibrosis (tissue scarring) and oxidative stress markers. When rats were pre-treated with melatonin, a natural antioxidant hormone, most of the radiation-induced skin damage was prevented. This suggests that mobile phone radiation can harm skin tissue through oxidative stress, but protective measures may help reduce this damage.
Curcio G et al. · 2004
Researchers randomly assigned subjects to two groups exposed to 902.40 MHz EMF either before or during testing sessions. Subjects completed four performance tasks under double-blind conditions while tympanic temperature was measured five times per session. Results showed improved simple and choice reaction times and increased local temperature on the exposed region after at least 25 minutes of exposure.
Lagroye I et al. · 2004
The study aimed to investigate the effect of 2450 MHz pulsed-wave microwaves on DNA damage in rat brain cells and whether proteinase K is needed to detect such damage. Rats exposed to γ-rays showed significant DNA damage using both comet assay versions independent of proteinase K. Neither assay version detected any difference in comet length or normalized comet moment between sham-exposed and microwave-exposed rats regardless of proteinase K inclusion. No DNA damage was detected in brain cells after exposure to 2450 MHz pulsed-wave microwaves at 1.2 W kg−1 regardless of proteinase K inclusion. The results support the conclusion that low-level 2450 MHz pulsed-wave microwave exposures do not induce DNA damage detectable by the alkaline comet assay.
Hook et al. · 2004
Researchers exposed mouse immune cells to cell phone radiation at 835-847 MHz for over 20 hours to test whether radiofrequency signals cause oxidative stress (cellular damage from harmful molecules). They found no evidence that either FMCW or CDMA modulated signals at 0.8 W/kg caused oxidative stress, cellular damage, or changes in the cells' natural antioxidant defenses. The study suggests that cell phone-type radiation at these levels does not trigger the cellular stress responses that can lead to health problems.
Hook, G. · 2004
The study measured intracellular oxidants, glutathione disulfide accumulation, antioxidant enzyme activities, nitric oxide production, and cell viability. FMCW- and CDMA-modulated RF radiation did not alter any measured oxidative stress parameters or cell toxicity.
Markkanen A et al. · 2004
Researchers exposed wild-type and cdc48-mutant yeast cells to 900 or 872 MHz RF fields with or without UV radiation at elevated temperature. Amplitude modulated RF exposure significantly enhanced UV-induced apoptosis in cdc48-mutated cells, but unmodulated fields at the same SAR had no effect. Apoptosis was measured using the annexin V-FITC method with flow cytometry.
Ozguner F, Aydin G, Mollaoglu H, Gokalp O, Koyu A, Cesur G. · 2004
Researchers used thirty male Wistar-Albino rats divided into a nontreated control group, an irradiated group, and an irradiated group that also received melatonin. The irradiated group received 900 MHz radiation for 10 days at 30 minutes per day, and skin grafts were taken from the thoraco-abdominal area at the end of the tenth day. In the irradiated group, researchers observed increased thickness of stratum corneum, atrophy of epidermis, papillamatosis, basal cell proliferation, hypergranulosis, capillary proliferation, and impairment in collagen tissue distribution compared to the control group. Most of these changes, except hypergranulosis, were prevented with melatonin treatment.
Koyama S, Isozumi Y, Suzuki Y, Taki M, Miyakoshi J. · 2004
Researchers exposed Chinese hamster ovary CHO-K1 cells to 2.45-GHz electromagnetic fields for 2 hours at SARs of 5, 10, 20, 50, 100, and 200 W/kg to study micronucleus formation. Micronucleus frequency in cells exposed at SARs lower than 50 W/kg did not differ from sham-exposed controls. At SARs of 100 and 200 W/kg, micronucleus frequency was significantly higher than in sham-exposed controls. The researchers also found that micronucleus frequency increased in a temperature-dependent manner when cells were heat-treated at temperatures from 38 to 42 degrees C.
Koyama S, Isozumi Y, Suzuki Y, Taki M, Miyakoshi J · 2004
Japanese researchers exposed Chinese hamster cells to 2.45 GHz radiation (the same frequency as microwave ovens and WiFi) for 2 hours at various power levels. They found that high-intensity exposures (100-200 W/kg) caused significant chromosome damage, while lower levels showed no effect. The damage appeared to be caused by heating rather than the radiation itself.
Sandrini L et al. · 2004
Researchers created a female dielectric anatomical model and compared power absorption in male and female models from 0.1 to 4 GHz. Whole-body-averaged SAR was higher in the female model, mainly due to a thicker subcutaneous fat layer. Maximum 1 g and 10 g averaged SAR did not depend on gender because it occurs in regions without subcutaneous fat.
Papageorgiou CC et al. · 2004
Ten women and nine men performed a short memory task during baseline and during exposure to a 900 MHz signal. Baseline EEG energy was higher in men than in women, and EMF exposure decreased EEG energy in men but increased it in women. Memory performance did not change with EMF exposure or gender.
Aran JM et al. · 2004
In the first experiment, guinea pigs were exposed to GSM microwaves at SARs of 1, 2, and 4 W/kg for 1 hour per day, 5 days per week, for 2 months. In the second experiment, guinea pigs were exposed at 4 W/kg and auditory brainstem response thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or ABR thresholds between exposed and sham-exposed groups. Acute exposure for 1 hour also produced no statistically significant change in ABR thresholds. In vitro, organs of Corti from newborn rats exposed to 1 W/kg for 24-48 hours appeared normal under light microscopy after 2-3 days of culture.
Anderson, L. · 2004
Researchers conducted a two-year chronic bioassay to determine whether long-term exposure to a 1.6 GHz radiofrequency field would affect cancer incidence in Fischer 344 rats. Timed-pregnant rats were assigned to far-field RF Iridium or sham groups, with whole-body exposures starting at 19 days gestation for 2 hours per day, 7 days per week until weaning. Offspring then received near-field head-first exposures 2 hours per day, 5 days per week from 36 days old until 2 years of age at brain SAR levels of 1.6 W/kg, 0.16 W/kg, or sham. No statistically significant differences were seen among groups for live pups per litter, survival index, weaning weights, clinical signs, or neoplastic lesions, and male survival was similar across groups while female cage controls had reduced survival time.
Unknown authors · 2004
Case reports of peripheral neurological effects of radiofrequency radiation describe mainly disturbances of noxious sensation called dysaesthesia. Cases have arisen after exposure to much of the frequency range from low MHz to GHz. After very high intensity exposures nerves may be grossly injured; however, after lower intensity exposures which may result in dysaesthesia, ordinary nerve conduction studies demonstrate no abnormality although current perception threshold studies may. Only a small proportion of similarly exposed persons develop symptoms. Some observations are not consistent with the hypothesis that all health effects of radiofrequency radiation arise from thermal mechanisms.
