Unknown authors · 2009
Researchers exposed sixty-four male F344 rats to a 915 MHz electromagnetic field at whole-body average specific absorption rates of 0, 0.02, 0.2 and 2.0 W/kg for 2 hours. The brains were examined 14 and 50 days after exposure using histological and immunohistochemical methods. No albumin immunoreactivity was observed in any exposed group. Dark neurons were rare and did not differ significantly between exposed and sham-exposed animals. The authors concluded that the study did not confirm the earlier findings of Salford et al.
Unknown authors · 2009
The effects of radiofrequency electromagnetic fields from mobile telephones on the human nervous system have been the subject of a large number of experimental studies in recent years. Some evidence indicates that GSM-type signals affect spontaneous EEG, but this is not corroborated by evoked potentials studies. No consistent significant effects on cognitive performance in adults were observed, and any effect appears small with exposure possibly improving performance. Short-term exposure to mobile phone signals does not influence hearing or balance, and provocation studies have not demonstrated a causal link between EMF exposure and subjective symptoms.
Marino AA, Carrubba S · 2009
The authors analyzed 55 reports that compared human brain electrical activity with and without mobile-phone electromagnetic fields or before and after exposure. Positive reports failed to adequately address family-wise error rates, spike artifacts, and the confounding influence of two different EMFs, while negative reports lacked positive controls and power analyses. The reviewers concluded that the crucial question of how mobile-phone EMFs affect brain activity remains unanswered and essentially unaddressed.
Ahlbom A et al. · 2009
The review summarizes epidemiologic evidence on whether radiofrequency fields from mobile phones cause tumors. Studies to date do not show an increased risk of any brain or head tumor within roughly 10 years of use. Data do not suggest a causal link for fast-growing tumors like malignant glioma, but conclusions for slow-growing tumors and long-term use are less certain due to short observation periods.
Aldinucci C et al. · 2009
Researchers exposed synaptosomes to a peak magnetic field of 2 mT for 2 hours. They evaluated mitochondrial respiration rate, ATP production, membrane potential, intrasynaptosomal calcium concentration, and release of free iron and F2-isoprostanes. Oxygen consumption and ATP production remained unchanged in exposed synaptosomes. Intrasynaptosomal calcium concentration decreased slowly with no membrane depolarization detected, and free iron and F2-isoprostane release remained unchanged.
Rağbetli MC, Aydinlioğlu A, Koyun N, Rağbetli C, Karayel M. · 2009
The study examined the effect of mobile phone exposure on the developing hippocampus in Swiss albino mice. Pregnant mice were exposed to a mobile phone in an exposure system room. Pyramidal cells in the hippocampus were counted using the optical fractionator method with Axiovision software. No significant difference in pyramidal cell numbers was found between exposed and control groups.
Lipping T et al. · 2009
Eleven pigs were anaesthetized to a burst-suppression EEG level and exposed to a GSM mobile phone signal at 890 MHz. In phase I, EMF stimulation was randomly switched on and off to study the relation between EEG bursts and EMF onsets and endpoints. In phase II, continuous RF stimulation at 31 W/kg was applied for 10 minutes while ECG, EEG, and subcutaneous temperature were recorded. No correlation between exposure and EEG burst occurrences was observed in phase I, and no significant EEG changes were found in phase II. Subcutaneous temperature increased by 1.6°C and heart rate by 14.2 bpm on average during the 10-minute exposure periods.
Kwon MS et al. · 2009
Researchers recorded mismatch negativity responses to duration, intensity, frequency, and gap changes in 17 healthy young adults while a GSM phone was placed on either ear with the field on or off. The mismatch negativity was elicited by all deviant types, but its amplitude and latency showed no significant differences due to EMF exposure for any deviant type. The authors concluded there was no conclusive evidence that acute GSM mobile phone EMF exposure affects cortical auditory change detection processing reflected by the mismatch negativity.
Finnie JW, Chidlow G, Blumbergs PC, Manavis J, Cai Z · 2009
Researchers exposed pregnant mice to 900 MHz radiofrequency fields at 4 W/kg for 60 minutes daily throughout gestation. Fetal brains were examined for heat shock proteins HSP25, HSP32, and HSP70. No induction of HSP32 or HSP70 was found in any brains, and HSP25 expression was similar in exposed and control groups. The study concluded that whole-gestation exposure did not produce a stress response detectable by HSPs.
Finnie JW, Blumbergs PC, Cai Z, Manavis J · 2009
Researchers exposed mice to 900 MHz radiofrequency fields at a specific absorption rate of 4 W/kg for 60 minutes or for 5 days per week over 104 weeks. Control mice were sham-exposed or freely moving to account for restraint stress, and a positive control group received a clostridial toxin that upregulates aquaporin-4. No immunohistochemically detectable up-regulation of aquaporin-4 was observed in exposed mouse brains after either short or long exposure durations.
Eltiti S et al. · 2009
Researchers exposed 44 sensitive and 44 matched-control participants to GSM, UMTS, and sham signals for 50 minutes at 10 mW/m2 under double-blind conditions. Participants performed digit symbol substitution, digit span, and mental arithmetic tasks during exposure. Cognitive functioning and physiological measures including blood volume pulse, heart rate, and skin conductance were not affected by exposure.
de Gannes FP et al. · 2009
In the study, 16 Fischer 344 rats (14 weeks old) were exposed head-only to the GSM-900 signal for 2 h at various brain-averaged SARs (0, 0.14 and 2.0 W/kg) or were used as cage or positive controls. Albumin leakage and neuron degeneration were evaluated 14 and 50 days after exposure. No statistically significant albumin leakage was observed. Neuronal degeneration assessed using cresyl violet or Fluoro-Jade B was not significantly different among the tested groups. No apoptotic neurons were found 14 days after the last exposure using the TUNEL method.
Wake K et al. · 2009
Compliance testing data are measured only on the surface near the device and in a small 3D region around the maximum on a homogeneous phantom. Validation confirmed the method provided good estimation of 3D SAR distribution in the head, especially in the brain. The method has been used in several studies in the INTERPHONE.
Vrijheid M et al. · 2009
The study aimed to quantify selection bias from nonparticipation in a multinational case-control study of mobile phone use and brain tumor. Regular mobile phone use was reported less often by nonparticipants who completed the non-response questionnaire than by participants who completed the full interview. Bias factors ranged from 0.87 to 0.92, indicating roughly a 10% downward bias in odds ratios.
Hardell L, Carlberg M. · 2009
Researchers conducted two case-control studies from 1997 to 2003 assessing mobile and cordless phone use in relation to brain tumors. They analyzed 905 malignant brain tumor cases, 1,254 benign cases, and 2,162 population-based controls. Ipsilateral mobile phone use for over 10 years showed an odds ratio of 3.3 for astrocytoma, while cordless phone use showed an odds ratio of 5.0. For acoustic neuroma, ipsilateral mobile phone use with >10 year latency had an odds ratio of 3.0, and cordless phone use had an odds ratio of 2.3. The annual age-adjusted incidence of astrocytoma increased significantly by 2.16% from 2000 to 2007 in Sweden.
Han YY, Kano H, Davis DL, Niranjan A, Lunsford LD. · 2009
The authors conducted a PubMed search and reviewed 10 case-control studies, one cohort study, and a meta-analysis on cell phone use and acoustic neuroma risk. Most studies did not find an association between cell phone use and acoustic neuroma, but some studies with 10 years or more of follow-up showed an association. The meta-analysis of three case-control studies found a 2.4-fold greater risk of ipsilateral acoustic neuroma for those who used cell phones for at least 10 years.
Abramson MJ et al. · 2009
Capone F et al. · 2009
Researchers used transcranial brain stimulation to study the effect of PEMFs on cortical excitability in 22 healthy volunteers. After 45 minutes of PEMF exposure, intracortical facilitation increased by about 20% while other cortical excitability parameters remained unchanged. Sham field exposure produced no effects. The increase in paired-pulse facilitation suggests PEMFs may enhance cortical excitatory neurotransmission.
Narayanan SN, Kumar RS, Potu BK, Nayak S, Mailankot M · 2009
Researchers exposed male Wistar rats to 50 missed calls per day for four weeks from a GSM mobile phone in vibratory mode. After exposure, the rats were tested for spatial memory using the Morris water maze test. Both exposed and control rats decreased their escape time with training. Phone-exposed rats had about three times higher mean latency to reach the target quadrant and spent about two times less time in it than controls.
Luria R, Eliyahu I, Hareuveny R, Margaliot M, Meiran N. · 2009
The study examined time-dependent effects of GSM phone radiation on human cognitive function. Forty-eight healthy right-handed men performed a spatial working memory task while exposed to phones on the left, right, or sham. Right-hand responses were slower during left-side exposure in the first two blocks compared to right-side and sham. Researchers concluded exposure duration, responding hand, and exposure side may affect detectability of RFR effects.
Li X et al. · 2009
Researchers exposed 70 male rats to microwave radiation at average power densities of 0, 10, 30, and 100 mW/cm(2). Rats were sacrificed at 6 hours, 1 day, 3 days, and 7 days after exposure. Protein levels of AQP4 increased initially and then recovered at 10 and 30 mW/cm(2), but increased progressively at 100 mW/cm(2) within 14 days. Gene expression of AQP4 increased at 6 hours after 10 mW/cm(2) exposure and returned to baseline, while at 30 and 100 mW/cm(2) it peaked at 7 days and did not return.
Amara S et al. · 2009
Researchers exposed male rats to a static magnetic field at 128 mT for one hour per day over 30 consecutive days and then measured antioxidant enzyme activity, malondialdehyde concentration, and DNA oxidation in the brain. In the frontal cortex, exposure decreased glutathione peroxidase activity by 39%, CuZn superoxide dismutase activity by 35%, and catalase activity by 59%. In the hippocampus, exposure decreased CuZn-SOD activity by 51% and Mn-SOD activity by 13%, and increased malondialdehyde concentration by 32%. DNA oxidation was not detected, and the researchers suggested that an increase in metallothioneins in the frontal cortex may have protected DNA from oxidative damage.
Varró P, Szemerszky R, Bárdos G, Világi I. · 2009
Researchers exposed whole rats or excised rat brain slices to a 50 Hz electromagnetic field at 250–500 µT to examine effects on synaptic efficacy in the central nervous system. Slices treated directly ex vivo showed a decrease in basic synaptic activity, observed as a diminution in amplitude of evoked potentials. Following whole-body exposure, enhanced short- and long-term synaptic facilitation in hippocampal slices and increased seizure susceptibility in neocortical slices were observed. The researchers noted that the overall changes may strongly depend on the synaptic structure and neuronal network of the affected region, together with the specific spatial parameters and constancy of the EMF.
Strasák L, Bártová E, Krejci J, Fojt L, Vetterl V. · 2009
Researchers exposed female and male laboratory mice for 4 days to a 50 Hz magnetic field at 2 mT inside a cylindrical coil. After exposure, levels of the proteins c-Jun and c-Fos in different parts of the brain were measured using Western-blot techniques. The expression of c-Jun decreased after magnetic field exposure, while c-Fos expression was not affected, and neither result depended on the sex of the mice.
Janać B, Tovilović G, Tomić M, Prolić Z, Radenović L. · 2009
Researchers exposed adult Wistar rats continuously to an extremely low frequency magnetic field (50 Hz, 0.5 mT) for 1, 3, and 7 days. The study examined serotonin 5-HT(2A) receptors in the prefrontal cortex and dopamine D(1) and D(2) receptors in the striatum, considering their involvement in motor behavior regulation. Serotonin 5-HT(2A) receptor affinity decreased and density increased in the prefrontal cortex, with the affinity effect being most prominent after 7 days of exposure. Dopamine D(1) and D(2) receptors in the striatum showed no significant effect on either affinity or density.
