Unknown authors · 2011
Standards stipulate a 6-min averaging interval for radiofrequency electromagnetic field measurements to assess human exposure. That interval noticeably limits the number of measuring points in practical base station surveys. Measurements near a multisystem GSM, DCS, and UMTS base station showed that shorter averaging intervals of 15 s, 30 s, and 1 min significantly accelerated the measurement process. Results from the shorter intervals differed from the 6-min root-mean-square mean by 10.5%, 15.9%, and 19%, while measurement uncertainty increased by 3.0%, 3.8%, and 4.4% respectively. The authors concluded that shorter intervals would reduce total survey duration without compromising measurement quality too much.
Unknown authors · 2011
Researchers exposed Spirostomum ambiguum infusoria to 1 GHz radiofrequency at energy flow densities of 5 μW/cm(2) and 50 μW/cm(2). Both exposure levels caused a reduction in motor activity that appeared in a jump-wise manner after a certain exposure duration and did not increase with longer exposure. The safe exposure duration was 8-9 h and 10 min at 5 and 50 μW, respectively.
Unknown authors · 2011
The authors used two Danish nationwide cohort studies covering 2.9 million adults and followed them for vestibular schwannoma up to 2006. A subscription of 11 years or more was not associated with higher risk in men (relative risk 0.87, 95% CI 0.52–1.46), and no cases occurred in long-term female subscribers versus 1.6 expected. Tumors did not appear more often on the right side of the head, nor were they larger in long-term male subscribers.
Unknown authors · 2011
The algorithm was applied to Interphone Study subjects in five countries. The main determinants of cumulative RF energy were communication system, frequency band, brain location, and amount and duration of phone use. Categorization by cumulative RF energy agreed substantially with cumulative call time, but misclassification was non-negligible, especially at higher frequency bands. Factors such as adaptive power control (except in CDMA networks), discontinuous transmission, and conditions of phone use had relatively minor influence.
Unknown authors · 2011
Researchers analyzed brain tumor patients from five countries in the Interphone study, with tumors localized by neuroradiologists, and matched controls on age, sex, and region. The study included 553 glioma and 676 meningioma cases with 1762 and 1911 controls, respectively, and estimated RF dose as total cumulative specific energy (TCSE) absorbed at the tumor's estimated centre. Ever regular mobile phone use showed odds ratios of 0.93 (95% CI 0.73 to 1.18) for glioma and 0.80 (95% CI 0.66 to 0.96) for meningioma. For glioma, odds ratios were below 1 in the first four TCSE quintiles but rose to 1.35 (95% CI 0.96 to 1.90) in the highest quintile, and increased with TCSE 7+ years before diagnosis (p-trend 0.01; OR 1.91, 95% CI 1.05 to 3.47 in highest quintile).
Unknown authors · 2011
Researchers conducted a case-control study of 1105 acoustic neuroma patients and 2145 controls across 13 countries, assessing past mobile phone use by personal interview. In the primary analysis, the odds ratio for ever regular mobile phone use was 0.85 (95% CI 0.69-1.04), and for use beginning 10 or more years before the reference date it was 0.76 (0.52-1.11). There was no trend of increasing risk with greater cumulative call time; the highest decile (≥1640 hours) showed an odds ratio of 1.32 (0.88-1.97) with implausible reported use, and with five-year censoring the odds ratio for that decile rose to 2.79 (1.51-5.16).
Unknown authors · 2011
Researchers performed power level measurements of transmitted and received signals using a mobile handset in home and office environments. They also measured radiofrequency electric field strength and frequency selective measurements near the femtocell access point with a radiation meter. The cumulative distribution functions showed that in 90% of measurement points the mobile phone transmit power was at least 7 dB lower during femtocell operation. At about 1 meter from the femtocell in its main beam, power flux density measurements showed very little difference between femtocell on and off.
Unknown authors · 2011
The existing certification process uses a plastic head model called SAM that represents the top 10% of U.S. military recruits from 1989 and greatly underestimates SAR for typical users, especially children. A superior computer simulation certification process has been approved by the FCC but is not used to certify phones. When electrical properties are considered, a child's head absorption can be over two times greater and skull bone marrow absorption ten times greater than adults. The authors recommend a new certification process incorporating different modes of use, head sizes, and tissue properties using anatomically based models.
Repacholi MH et al · 2011
Unknown authors · 2011
The authors reviewed evidence on whether mobile phone use raises the risk of glioma and meningioma, focusing on the 13-country Interphone Study. Methodological deficits limit conclusions from the Interphone study, but its results combined with other studies and incidence trends suggest that within about 10–15 years after first use of mobile phones there is unlikely to be a material increase in the risk of brain tumors in adults. Data for childhood tumors and for periods beyond 15 years are lacking, and the evidence trend is increasingly against the hypothesis that mobile phone use causes brain tumors in adults.
Unknown authors · 2011
Researchers studied mitotic spindle disturbances and apoptosis activation in V79 Chinese hamster cells exposed to continuous 2.45 GHz microwaves to investigate non-thermal cell damage. Exposure for 15 minutes significantly increased the proportion of aberrant spindles and apoptotic cells and decreased the mitotic index compared with untreated cells. Control heating experiments showed that spindle assembly was unaffected up to 41°C and apoptosis occurred only at 40°C, a temperature higher than that reached during microwave exposure.
Unknown authors · 2011
In vitro studies used several cell types from both humans and rodents, including primary cells, embryonic cell lines, undifferentiated cancer cell lines, and stem cells. Gene and protein expression were not significantly changed by exposure in nine out of 15 studies. Genotoxicity was evaluated in 13 papers and in most of these studies no DNA damage was detected; eight studies failed to demonstrate induction of apoptosis and three reported lack of oxidative stress induction by RF exposures. Few papers have been published on low level exposure of immature animals and the available results are very limited, but the evidence does not indicate that prenatal or early postnatal exposures are associated with acute adverse responses or long-term detrimental changes.
Unknown authors · 2011
The review noted that in 2004 very few studies on radiofrequency fields and children were available, and WHO later identified this as a high priority research area. It described a few cross-sectional studies on well-being, cognitive effects, and behavioral problems, plus some cohort studies mainly on maternal mobile phone use during pregnancy. The review highlighted methodological limitations including cross-sectional designs that cannot determine temporal sequence, potential reversed causality, recall errors in self-reported use, and lack of confounding control.
Unknown authors · 2011
Case-control studies on adults point to an increased risk of brain tumours (glioma and acoustic neuroma) associated with the long-term use of mobile phones. The CEFALO study was the first to examine mobile phone use and brain tumour risk in children and adolescents. It has been claimed that this relatively small study yielded reassuring results of no increased risk. The commentary authors do not agree and consider that the data contain several indications of increased risk despite low exposure, short latency period, and study limitations.
Valentini E, Ferrara M, Presaghi F, De Gennaro L, Curcio G. · 2011
Sambucci M et al. · 2011
Newborn mice were exposed to WiFi signals at SAR of 0.08 or 4 W/kg, 2 hours per day, 5 days per week, for 5 weeks starting the day after birth. No effects were seen on most immune parameters in either sex, but male mice exposed at 4 W/kg showed reduced IFN-γ production in spleen cells. The researchers concluded that early post-natal WiFi exposure does not induce detrimental effects on the developing immune system. The study used a blind procedure with sham controls and found no differences in body weight or development between groups.
Roux D et al. · 2011
Redmayne M, Smith E, Abramson MJ. · 2011
Researchers explored school cellphone rules and adolescent exposure to cellphone microwave emissions during school using a census and survey. All schools banned private use of cellphones in class, but 43% of student participants admitted breaking this rule. A high-exposure group of risk-takers was identified for whom prohibited in-school use was positively associated with high texting rates, carrying the phone switched-on >10h/day, and in-pocket use. The authors reviewed reproductive bio-effect papers and concluded there is sufficient evidence and expert opinion to warrant an enforced school policy removing cellphones from students during the day.
Peyman A et al. · 2011
Researchers measured radiofrequency power densities and total emitted powers from Wi-Fi devices used in UK schools. A 20 MHz bandwidth signal analyzer captured the whole Wi-Fi signal, unlike previous studies. Laptop radiation patterns showed a minimum toward the user's torso and two maxima symmetrically opposed across a vertical plane bisecting the screen and keyboard. Spherically-integrated radiated power for laptops ranged from 5 to 17 mW at 2.45 GHz and from 1 to 16 mW at 5 GHz, while hemispherically-integrated power for access points ranged from 3 to 28 mW at 2.4 GHz and from 3 to 29 mW at 5 GHz, and power densities at 0.5 m and greater were all much lower than the ICNIRP reference level.
Mahfouz Z, Gati A, Lautru D, Wong MF, Wiart J, Hanna VF. · 2011
Researchers measured temporal variations and traffic distributions of broadcast signals and GSM or UMTS mobile telephone signals at indoor sites in urban and rural zones over a day. Broadcast signals remained constant over the day and were best fitted with a Normal distribution, while mobile telephone signals depended on traffic demand and fit a three-Gaussian distribution model. The study compared real exposure to maximum theoretical values and constructed a general mask for maximum equivalent active traffic. Extrapolation factors were provided for each system to estimate maximum values from instantaneous measurements and for broadband measurements to estimate maximum potential exposure during the day.
Lindholm H et al. · 2011
Each exposure and sham period lasted 15 minutes and took place in a climatic chamber under controlled thermoneutral conditions. They measured ear canal temperature, skin temperature at multiple sites, local cerebral blood flow via near-infrared spectroscopy, and autonomic nervous system function via ECG and continuous blood pressure. During the short-term RF exposure, local cerebral blood flow did not change, ear canal temperature did not increase significantly, and autonomic nervous system function was not interfered with.
Lee HJ et al. · 2011
Researchers examined the effects of combined exposure to radiofrequency electromagnetic fields on rat testicular function, specifically spermatogenesis. Male rats were exposed to CDMA and WCDMA RF signals for 12 weeks at 45 minutes per day, 5 days per week, with a whole-body average SAR of 2.0 W/kg each or 4.0 W/kg total. They investigated sperm count, testosterone concentration, malondialdehyde concentrations, spermatogenesis stages, and apoptotic cells in the testes.
Lee HJ et al. · 2011
Six-week-old AKR/J mice were simultaneously exposed to CDMA and WCDMA RF-EMFs for 45 minutes per day, five days per week, for 42 weeks. The whole-body average SAR was 2.0 W/kg for each signal, totaling 4.0 W/kg. No differences were found in final survival, lymphoma incidence, or splenomegaly incidence between sham- and RF-exposed mice. However, brain metastasis infiltration in lymphoma-bearing mice was significantly different in RF-exposed mice compared to sham-exposed mice, with no consistent correlation between sexes. Infiltration to liver, lung, and spleen did not differ between groups.
Kwon MK, Nam KC, Lee da S, Jang KH, Kim DW. · 2011
Researchers conducted a double-blind provocation study with 10 self-reported electromagnetic hypersensitivity and 10 non-hypersensitivity volunteers. Participants were exposed to WCDMA RF fields at 1950 MHz with 24 dBm output and a specific absorption rate of 1.57 W/kg for 30 minutes. The 30-minute exposure did not produce any physiological changes in either group.
Kayabasoglu G et al. · 2011
Forty Wistar Albino rats, twenty newborn and twenty adult, were divided into exposed and control groups of ten each. The rats were exposed to the electromagnetic field for 6 hours per day for 30 consecutive days. Distortion product otoacoustic emissions were measured before and after the 30 day exposure period and a signal-to-noise ratio was calculated for statistical analysis. No significant difference in distortion product otoacoustic emissions was found before and after exposure in either newborn or adult rats (p>0.05).
