Murbach et al. · 2014
Researchers evaluated three hypotheses about how radiofrequency exposure could affect EEG by using numerical simulations and experimental assessments with phantoms and anatomical human models. They found that induced fields cause less than a 20% increase in 10 g-averaged SAR, that worst-case electrode placement raises skin temperature by at most 0.31 °C and brain temperature by less than 0.1 °C, and that temperature ripples from RF pulses are below 0.001 °C for GSM-like signals and below 0.004 °C for higher pulse energy. These local short-term temperature elevations are unlikely to change brain physiology during the time period from minutes to several hours after exposure. Thus, the mechanism of interaction between RF and changes in the EEG power spectrum remains unknown.
Hsu MH et al. · 2014
Researchers conducted a population-based study using cancer registry data from 2000 to 2009 and cell phone user statistics from the National Communication Commission. The National Cancer Registry recorded 4 incidences and 4 deaths due to malignant neoplasms in Taiwan during 2000-2009. Ten years of observational data showed no significant effect of intensive cell phone use on the incidence rate or mortality of malignant brain tumors in Taiwan. The authors concluded they detected no correlation between cell phone use and malignant brain tumor morbidity or mortality in Taiwan.
Hauri DD et al. · 2014
Researchers conducted a time-to-event analysis of children under 16 living in Switzerland on December 5, 2000, with follow-up until December 31, 2008. They also included an incidence density cohort of all children living in Switzerland for some time between 1985 and 2008. In the time-to-event analysis of 997 cancer cases, the adjusted hazard ratio for the highest exposure category was 1.03 for all cancers, 0.55 for childhood leukemia, and 1.68 for childhood CNS tumors. The incidence density analysis of 4,246 cancer cases showed similar results for all cancers and leukemia but did not indicate a CNS tumor risk, with an incidence rate ratio of 1.03.
Zhang Y, Liu X, Zhang J, Li N. · 2014
Researchers exposed 20 healthy male Sprague Dawley rats to 100 μT/50 Hz ELF-EMF or sham exposure for 12 weeks. The Morris water maze test showed no cognitive or memory impairment in the exposed rats compared to sham-exposed rats. Body weight, Aβ levels, and neuron morphology showed no significant changes between groups.
Li Y, Zhang C, Song T. · 2014
Researchers exposed Sprague-Dawley rats to Morris water maze training, ELF-MF exposure (50 Hz, 100 microT), or combined training and exposure for 90 days, with normal rats as controls. Previous training improved spatial acquisition in the Morris water maze and this effect lasted at least 90 days. However, this improvement was not observed during the probe trial. ELF-MF exposure did not significantly differ from controls and did not interfere with training-related improvements.
de Groot MW, Kock MD, Westerink RH. · 2014
Researchers investigated acute (30 min) and sub-chronic (48 h) exposure to 50 Hz ELF-EMF on naïve and chemically stressed PC12 cells. Acute exposure up to 1000 μT did not affect basal or depolarization-evoked calcium levels in naïve cells. Sub-chronic exposure up to 1000 μT had no consistent effects on calcium homeostasis, ROS production, or membrane integrity in naïve cells. In chemically stressed cells, both acute and sub-chronic exposure also failed to exert consistent effects on calcium homeostasis, ROS production, and membrane integrity. The authors concluded that exposure up to 1000 μT does not induce neurotoxic effects in vitro in either cell type.
Shirai T et al. · 2014
Researchers exposed rats to 2.14 GHz W-CDMA signals for 20 hours a day over three generations. No abnormalities were observed in mother rats or offspring across any biological parameters including neurobehavioral function. The study used three SAR levels: high (<0.24 W/kg), low (<0.08 W/kg), and sham exposure. Pregnant rats were exposed from gestational day 7 to weaning, and offspring were continuously exposed until 6 weeks of age.
Klose M et al. · 2014
Female Wistar rats from 14 days to 19 months were exposed in the head region for 2 hours per day, 5 days per week to a GSM-modulated 900 MHz field at SAR values of 0, 0.7, 2.5, and 10 W/kg. Four behavioral and learning tests (rotarod, Morris water maze, 8-arm radial maze, open field) were performed three times in juvenile, adult, and presenile rats. No profound differences were identified between exposure groups, though rotarod data showed significantly longer holding times for sham-exposed rats on some days, but these findings were not consistent. The results do not indicate harmful effects of long-term RF-EMF exposure begun at an early age on development, learning, and behavior, even at relatively high SAR values.
Kim HS et al. · 2014
Researchers assigned male Sprague-Dawley rats to cage-control, sham-exposed, and CDMA-exposed groups, with six rats per group. The CDMA-exposed rats received whole-body exposure to an 848.5 MHz CDMA signal at 2 W/kg for either 1 or 8 hours daily, five days a week, for two weeks. During the last five exposure days, all rats were injected with BrdU to label dividing cells, and the numbers of BrdU-positive cells in the subventricular zone and dentate gyrus were estimated using an unbiased stereological method. The study found no significant difference in BrdU-positive cell counts in either brain region between CDMA-exposed rats and both control groups.
Zhou H et al. · 2014
Researchers used the finite-difference time-domain method to compute the specific absorption rate (SAR) of radio frequency (RF) waves in the human brain and to investigate the effects of geometry and polarisation on SAR value. The results suggested that high SAR values were found in the brain at approximately 250 MHz for vertical polarisation and 900-1200 MHz for both vertical and horizontal polarisation, which may be the result of head resonance at these frequencies.
Vijayalaxmi, Prihoda TJ. · 2014
The study aimed to investigate whether mobile phone radiofrequency fields and brain cancer show an adaptive response. The authors re-examined all odds ratios from the INTERPHONE study published in 2011. Their analysis showed 24.3% decreased and 0.7% increased risk for meningioma and 22.1% decreased and 6.6% increased risk for glioma. They hypothesized that the overwhelming evidence for decreased risk may be due to induction of an adaptive response.
Varsier N et al. · 2014
Researchers analyzed the influence of pregnancy stage and fetus position on whole-body and brain exposure of the fetus to radiofrequency electromagnetic fields at 2100 MHz. They used semi-homogeneous pregnant woman models between 8 and 32 weeks of amenorrhea. Whole-body and average brain exposures decreased during the first trimester. From the beginning of the second trimester, whole-body and average brain exposures were quite stable. A fetal head-up position produced slightly higher brain exposure than a head-down position, while whole-body exposures were similar.
Trunk A et al. · 2014
Researchers recorded EEG and event-related potentials in an oddball paradigm during four sessions combining caffeine and UMTS mobile phone exposure. Caffeine significantly shortened reaction time and decreased the P300 area under the curve compared to control or mobile phone exposure alone. No effects on reaction time or P300 were observed for UMTS mobile phone exposure alone or combined with caffeine. The authors concluded no interactive or synergistic effects of caffeine and UMTS mobile phone exposure on neural or cognitive measures.
Hardell L, Carlberg M, · 2014
In total, 1498 cases (89% participation) and 3530 controls (87% participation) were included. Mobile phone use increased glioma risk with an overall odds ratio of 1.3 (95% CI 1.1–1.6), rising to 3.0 (95% CI 1.7–5.2) for latency over 25 years. Cordless phone use increased glioma risk with an overall odds ratio of 1.4 (95% CI 1.1–1.7), with highest risk in the >15–20 years latency group (OR 1.7, 95% CI 1.1–2.5). Ipsilateral mobile phone use had an odds ratio of 1.8 (95% CI 1.4–2.2) and ipsilateral cordless phone use had an odds ratio of 1.7 (95% CI 1.3–2.1). The highest risk was for glioma in the temporal lobe, and first use before age 20 gave higher odds ratios than later first use.
Ghanmi A, Varsier N, Hadjem A, Conil E, Picon O, Wiart J. · 2014
Researchers analyzed how phone position affects brain exposure by comparing SAR from two GSM phone models. They tested 80 phone positions selected via Latin hypercube sampling. They estimated SAR10g in the head, SAR1g in the brain, and SAR in brain structures at 900 and 1800 MHz. Results show SAR distributions in the brain are sensitive to phone position. For 5–10% of positions, SAR10g in head and SAR1g in brain were 20% higher than the standard cheek position, and the SAM model was conservative for 95% of positions.
Curcio G, Mazzucchi E, Marca GD, Vollono C, Rossini PM. · 2014
Researchers recorded EEG activity from 12 patients with focal epilepsy under real and sham exposure using a double-blind, crossover, counterbalanced design. Spiking activity tended to be lower during real exposure than during sham exposure. Gamma band power increased significantly during real exposure, mainly in parieto-occipital and temporal areas. Interhemispheric instantaneous coherence in the beta band increased from left temporal to right frontal regions during real exposure relative to baseline. No significant change in lagged coherence was observed.
Chiu CT, Chang YH, Chen CC, Ko MC, Li CY. · 2014
Carlberg M, Hardell L. · 2014
Researchers analyzed survival of 1678 glioma patients from the 1997-2003 and 2007-2009 case-control studies. Wireless phone use with more than 20 years latency showed an increased hazard ratio of 1.7 for glioma overall. For glioblastoma multiforme, mobile phone use had a hazard ratio of 2.0 and cordless phone use a hazard ratio of 3.4 in the same latency category.
Adibzadeh F et al. · 2014
Researchers performed detailed dosimetric simulations for 20 head models to quantify how head morphology affects RF dose in different brain regions. The variation in averaged SAR among heads reached up to 16.4 dB in a 1 cm³ brain cube using the field-sensor method and up to 15.8 dB in the medulla using the Talairach method. Head models were exposed to generic mobile phone fields at 835 and 1900 MHz in tilted and cheek positions. The authors concluded that head morphology is an important uncertainty source and that dosimetric analyses for specific brain regions should use real morphology.
Adachi-Mejia AM et al. · 2014
The study aimed to determine if mobile phones interfere with adolescent sleep, and researchers conducted a pilot test in a pediatric primary care practice with 454 patients aged 12 to 20 years, half female, attending a well-child visit. Adolescents completed paper-and-pencil surveys in the waiting room. More than half took their mobile phone to bed (62.9%) and kept it turned on while sleeping (56.8%). More than one-third texted after going to bed (36.7%), and 7.9% were awakened by a text two or more times per week. Almost half used their phone as their alarm (45.7%).
Ragy MM. · 2014
Researchers exposed male rats to 900-MHz electromagnetic radiation for one hour daily over 60 days, with a withdrawal group that had a 30-day recovery period. Exposure significantly increased malondialdehyde levels and decreased total antioxidant capacity in brain, liver, and kidney tissues. Serum levels of alanine transaminase, aspartate aminotransferase, urea, creatinine, and corticosterone were significantly increased, while catecholamines were not significantly changed. All these alterations were corrected after the withdrawal period.
Liu DD, Ren Z, Yang G, Zhao QR, Mei YA. · 2014
Researchers exposed rat cerebellar granule cells to extremely low-frequency electromagnetic fields for 60 minutes and measured sodium channel currents. ELF-EMF exposure significantly increased Nav current densities by 62.5 percent. Melatonin at 5 μM inhibited this ELF-EMF-induced increase in sodium currents. The protective effect of melatonin involved MT2 receptors and calcium release triggered by calcium influx.
Leone L et al. · 2014
The study used an in vitro model of hippocampal neural stem cells from newborn mice to examine effects of extremely low-frequency electromagnetic fields. ELFEFs enhanced proliferation and neuronal differentiation of these neural stem cells through epigenetic regulation. Exposure increased expression of the pro-proliferative gene Hes1 and neuronal determination genes NeuroD1 and Neurogenin1. These changes were preceded by increased H3K9 acetylation and phosphorylated CREB binding to gene regulatory sequences. The epigenetic modifications were blocked by the Cav1-channel blocker nifedipine and linked to increased CBP occupancy at promoter loci.
Davanipour Z, Tseng C-C, Lee PJ, Markides KS, Sobel E. · 2014
The study included 3050 Mexican Americans aged 65 and older from the H-EPESE study, and severe cognitive dysfunction was defined as an MMSE score below 10. Occupational extremely low frequency magnetic field exposure was classified using a methodology from earlier studies. Univariate odds ratios were 3.4 for high exposure and 1.7 for medium or high exposure, with similar results in multivariate models. Interactions between medium/high or high exposure and smoking history or age group were statistically significant, particularly for those aged 75 and older. The authors concluded that high or medium/high occupational exposure may increase the risk of severe cognitive dysfunction, and that smoking and older age may increase the deleterious effect.
Saikhedkar N et al. · 2014
Researchers exposed 30-day-old rats to 900 MHz radio waves from a mobile handset for 4 hours per day over 15 days. Exposed rats showed more anxiety and poor learning compared to control and sham groups. Antioxidant enzymes and non-enzymatic antioxidants changed significantly and lipid peroxidation increased in exposed rats.
