Keshvari J, Lang S. · 2005
Researchers used the finite-difference time-domain (FDTD) computational method to calculate specific absorption rate (SAR) in anatomically correct adult and child head models exposed to a half-wave dipole at 900, 1800, and 2450 MHz. The ear and eye regions were studied because they represent realistic exposure scenarios for mobile wireless communication devices.
Kerekhanjanarong V et al. · 2005
The study aimed to investigate the effect of mobile phone use on the audiologic system in 98 subjects. Hearing was evaluated using audiometry, tympanometry, otoacoustic emission, and auditory brain stem evoked response. Comparison of audiograms between dominant and non-dominant ears showed no significant difference overall. In eight subjects who used mobile phones more than 60 minutes per day, the dominant ear had worse hearing thresholds than the non-dominant ear.
Hunton J, Rose JM. · 2005
The study used an experiment where drivers with and without communication training completed a simulated driving course under three conversation conditions. Cellular telephone conversations consumed more attention and interfered more with driving than passenger conversations. Cell phone conversations lack nonverbal cues available in close-contact conversations, leading participants to expend significant cognitive resources to compensate. Communication training may reduce the hazardous effects of cell phone conversations on driving performance.
Hardell L, Carlberg M, Hansson Mild K. · 2005
Researchers conducted a case-control study of benign brain tumors with 413 cases and 692 controls. For meningioma, analogue phone use yielded an odds ratio of 1.7 (95% CI 0.97-3.0), which increased to 2.1 (95% CI 1.1-4.3) with a latency period greater than 10 years. For acoustic neuroma, analogue phone use gave an odds ratio of 4.2 (95% CI 1.8-10) that rose to 8.4 (95% CI 1.6-45) with a latency period greater than 15 years, though based on low numbers. Digital phone use was associated with an odds ratio of 2.0 (95% CI 1.05-3.8) for acoustic neuroma, while cordless phone use did not show a significant increase. In multivariate analysis, analogue phones were a significant risk factor for acoustic neuroma.
Hardell L, Carlberg M, Hansson Mild K. · 2005
Researchers investigated the association between cellular or cordless telephone use and brain tumour risk in urban and rural areas of Sweden. The study included 1429 cases and 1470 controls aged 20 to 80 years diagnosed between 1997 and 2000. Use of different phone types was assessed by questionnaire with one control matched for sex and age per case. Rural residence with digital phone use showed an odds ratio of 1.4 increasing to 3.2 with longer latency, while urban residence showed odds ratios of 0.9. The effect was most obvious for malignant brain tumours.
Garcia Callejo FJ et al. · 2005
Researchers evaluated a group of healthy mobile phone users and a control group of non-users with audiometry at baseline and after three years. Mobile phone users made an average of 24.3 active contacts and accumulated 50.4 days of phone use over three years. After the follow-up, users had a 1 to 5 dB HL greater increase in hearing threshold at speech tones than controls (p<0.001). A trend linked longer phone use to greater hearing loss but was not statistically significant. The authors concluded that frequent mobile phone use over a middle period of time allows to detect a mild hearing loss, but the cause remains unclear.
Curcio G et al. · 2005
Researchers recorded resting EEG from 20 healthy subjects to study the effect of mobile phone EMF on waking brain activity. Subjects were randomly assigned to two groups and exposed double-blind to a 902.40 MHz signal modulated at 217 Hz with 0.25 W average power before or during EEG recording. Real exposure influenced alpha band spectral power in some bins compared to baseline and sham, with a greater effect when the EMF was on during recording. The authors concluded that pulsed high-frequency EMF can affect normal brain functioning, but no health effect conclusions were drawn.
Bit-Babik et al. · 2005
The study used FDTD computations to calculate locally averaged SAR in anatomically correct adult and child head models with the IEEE standard averaging algorithm. Peak local average SAR over 1 g and 10 g of tissue and electromagnetic energy penetration depths were about the same across all head models under the same exposure conditions. Child head models were created by linear scaling of the adult model and by transforming adult models based on children's external head shapes, with tissue properties kept the same. Modeling and experimental measurements also used three spheres filled with tissue-equivalent mixture to approximate heads of increasing size.
Barcal J, Cendelín J, Vozeh F, Zalud V. · 2005
Researchers performed direct registration of brain cortical and hippocampal activity during high-frequency electromagnetic field exposure. Experiments used urethane anaesthesia in Lurcher mutant mice with wild type littermates as controls. Animals were exposed to HF EMF with frequency corresponding to cellular phones. ECoG evaluation showed a distinct shift to lower frequency components in healthy mice but only gentle differences in Lurcher mutant mice. Hippocampal rhythmicity showed gentle changes with increase of higher frequencies and changes in theta oscillations in both animal types.
Balikci K, Cem Ozcan I, Turgut-Balik D, Balik HH. · 2005
Wang Q, Cao ZJ, Bai XT. · 2005
Researchers exposed cerebral cortical neurons from postnatal rats to 900 MHz continuous microwave EMF with a SAR of 1.15 to 3.22 mW/g for 2 hours per day over 6 consecutive days and for 12 hours at one time. GABA receptor was selected as the biological endpoint. Significant changes in GABA receptor expression were observed in exposed neurons (P < 0.01), and the expression was significantly regulated by the microwave with a power window effect.
Seaman RL, Phelix CF. · 2005
3-NP significantly increased ER intracisternal width, ER area density, and nuclear envelope thickness. Microwave exposure at 6 W/kg alone also significantly increased these measures. Exposure of 3-NP-treated animals at 0.6 W/kg reduced the effects of 3-NP.
Janssen T, Boege P, von Mikusch-Buchberg J, Raczek J. · 2005
Researchers investigated potential effects of electromagnetic fields from GSM cellular phones on outer hair cells by measuring distortion product otoacoustic emissions (DPOAEs) in 28 normally hearing subjects. No significant change in DPOAE level was found in response to EMF exposure. After compensating for undesired side effects, an extremely small exposure-correlated change of less than 1 dB was observed in some subjects, which the researchers suggested was physiologically irrelevant given the very large dynamic range of hearing in humans.
Huber R et al. · 2005
Researchers investigated the effects of radio frequency electromagnetic fields similar to those emitted by mobile phones on waking regional cerebral blood flow in 12 healthy young men. Positron emission tomography scans were taken after 30 min unilateral head exposure to pulse-modulated 900 MHz RF EMF, and a sham control condition was also included. Only the 'handset-like' signal, which had stronger low-frequency components, increased relative cerebral blood flow in the dorsolateral prefrontal cortex on the side of exposure; the 'base-station-like' signal did not.
Finnie JW. · 2005
Researchers exposed mice to 900 MHz radiofrequency fields using a purpose-designed exposure system, giving each animal a single, far-field, whole body exposure at a specific absorption rate of 4 W/kg. The study measured activation of the immediate early gene c-fos in mouse brain tissue after this acute exposure. Activation of c-fos in exposed and sham-exposed brains was comparable, but was greatly increased compared with freely moving controls. The results suggest that the majority of the acute genomic response detected by c-fos expression was due to immobilisation.
Cosquer B, Vasconcelos AP, Frohlich J, Cassel JC. · 2005
Bachmann M, Kalda J, Lass J, Tuulik V, Säkki M, Hinrikus H. · 2005
Researchers exposed 23 healthy volunteers to a 450 MHz microwave field with 7 Hz frequency on-off modulation, with a field power density of 0.16 mW cm(-2) at the scalp. The study compared traditional spectral analysis and a new non-linear method called analysis of the length distribution of low-variability periods to detect EEG changes from microwave exposure. The non-linear method detected a significant effect in six exposed subjects, while spectral analysis found a significant result for only one subject.
Lai H, Singh NP · 2005
Researchers studied four groups of rats: one exposed to 2450-MHz microwaves at 1 mW/cm2, one to magnetic field noise at 45 mG, one to both simultaneously, and a sham-exposed group. Brain cells of microwave-exposed rats had significantly higher levels of DNA single- and double-strand breaks compared with sham-exposed animals. Noise exposure alone did not significantly affect DNA strand break levels, but simultaneous noise exposure blocked the microwave-induced increases.
Ono T et al. · 2004
A possible mutagenic effect of 2.45 GHz radiofrequency exposure was examined using lacZ-transgenic MutaTM mice. Offspring were exposed in utero for 16 hours a day from embryonic day 0 to 15 and examined at 10 weeks of age. Mutation frequencies at the lacZ gene in spleen, liver, brain, and testis were similar to those in non-exposed mice. Sequencing of mutant DNAs showed no appreciable difference in mutation quality between exposed and non-exposed samples.
Monnery PM, Srouji EI, Bartlett J · 2004
Researchers recruited 12 volunteers with normal hearing and measured their otoacoustic emissions. The volunteers were exposed to a mobile telephone placed over the mastoid process during receive and transmit modes. There was no change in the trace signature and no statistically significant change in trace figures. The researchers concluded that PEMF from mobile phones has no measurable effect on outer hair cell function during use.
Lonn S, Ahlbom A, Hall P, Feychting M. · 2004
In this population-based case-control study, researchers identified all cases aged 20 to 69 years diagnosed with acoustic neuroma during 1999 to 2002 in certain parts of Sweden. Controls were randomly selected from the study base, stratified on age, sex, and residential area. The overall odds ratio for acoustic neuroma associated with regular mobile phone use was 1.0 with a 95% confidence interval of 0.6 to 1.5. Ten years after the start of mobile phone use the relative risk increased to 1.9 (0.9-4.1), and for tumors on the same side of the head as the phone was normally used, the relative risk was 3.9 (1.6-9.5). The researchers concluded that there was no increased risk for short-term use but suggested an increased risk for at least 10 years' duration.
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.
Hinrichs H, Heinze HJ. · 2004
Researchers investigated potential effects of GSM 1800 electromagnetic fields on verbal memory encoding by recording event-related magnetic fields from the brain during subsequent memory retrieval. Twelve normal subjects each completed two experimental sessions, one with EMF exposure during the study phase and one without. Exposure to EMF changed an early (350-400 ms) task-specific component of the event-related magnetic field, indicating interference with item encoding. Behavioral measures were not significantly affected.
Christensen HC et al. · 2004
Researchers ascertained 106 incident acoustic neuroma cases and matched them with 212 population-based controls between 2000 and 2002. Data came from personal interviews, medical records, radiologic examinations, and socioeconomic records. The overall relative risk of acoustic neuroma was 0.90 with a 95% confidence interval of 0.51 to 1.57. Using a cell phone for 10 years or more did not increase risk compared with short-term use. Tumors were not more frequent on the side of the head where the phone was typically used, and tumor size did not correlate with use patterns.
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.
