Brain & Nervous System

Long-term mobile phone use and brain tumor risk.

Lonn S, Ahlbom A, Hall P, Feychting M. · 2005

Lack of effects of 1439 MHz electromagnetic near field exposure on the blood-brain barrier in immature and young rats.

Kuribayashi M et al. · 2005

Researchers investigated possible effects of 1439 MHz electromagnetic near field exposure on the blood-brain barrier in immature (4 weeks old) and young (10 weeks old) rats. Expression of the three genes was not pathologically changed by EMF at any exposure level or age, and vascular permeability measured with FITC-dextran FD20 was not affected. The findings suggest that local head exposure to 1439 MHz EMF exerts no adverse effects on the BBB in immature and young rats.

No effects of 900 MHz and 1800 MHz electromagnetic field emitted from cellular phone on nocturnal serum melatonin levels in rats.

Koyu A et al. · 2005

Researchers studied the effects of 900 MHz and 1800 MHz EMF on nocturnal serum melatonin in adult male Sprague-Dawley rats exposed for 30 minutes per day, five days per week for four weeks. Serum melatonin concentrations were measured at 12:00 pm using a radioimmunoassay method. No statistically significant differences in melatonin levels were found between the 900 MHz exposed group and the sham group, nor between the 1800 MHz exposed group and the sham group.

Effects of prolonged wakefulness combined with alcohol and hands-free cell phone divided attention tasks on simulated driving.

Iudice A et al. · 2005

Twenty-three young healthy participants completed a 10 km simulated drive under four counterbalanced conditions: alcohol alone, alcohol with 19 h wakefulness, alcohol with 24 h wakefulness, and sober. The combination of alcohol and 24 h wakefulness produced the highest driving impairment, significantly greater than alcohol alone. Alcohol with 19 h wakefulness significantly affected only the time-to-collision measure, while alcohol alone in rested conditions did not significantly change any study measure.

Electromagnetic field emitted by 902 MHz mobile phones shows no effects on children's cognitive function.

Haarala C et al. · 2005

Researchers exposed 32 children aged 10-14 to a 902 MHz GSM mobile phone in active and inactive conditions while they performed cognitive tests. Statistical analysis showed no significant differences in reaction times or accuracy between the phone-on and phone-off conditions across all tests. The authors concluded that a standard mobile phone has no effect on children's cognitive function as measured by response speed and accuracy.

An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes.

Green AC et al. · 2005

Intracellular calcium concentration ([Ca(2 +) ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW x kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Exposure to TETRA (50 or 400 mW x kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.

Electromagnetic Fields from mobile phones do not affect the inner auditory system of Sprague-Dawley Rats.

Galloni P et al. · 2005

Researchers divided 48 Sprague-Dawley rats into exposed and sham-exposed groups. The rats were exposed 2 h/day, 5 days/week for 4 weeks at a local SAR of 2 W/kg in the ear. Distortion product otoacoustic emissions tests were carried out before, during, and after the exposure. The analysis showed no statistically significant differences in audiological signals between the different groups.

Effects of 900 MHz electromagnetic fields exposure on cochlear cells' functionality in rats: Evaluation of distortion product otoacoustic emissions.

Galloni P et al. · 2005

Researchers evaluated possible effects of cellular phone-like electromagnetic fields on the functionality of the rat cochlea. Distortion product otoacoustic emission amplitude was used as an indicator of outer hair cell status, and multiple exposure protocols with varying frequencies, intensities, and durations were tested before, during, and after exposure. No significant variation due to microwave exposure was evidenced.

Effects of universal mobile telecommunications system (UMTS) electromagnetic fields on the blood-brain barrier In Vitro.

Franke H et al. · 2005

Researchers investigated the influence of a generic UMTS signal on barrier tightness, transport processes, and morphology of porcine brain microvascular endothelial cell cultures serving as an in vitro blood-brain barrier model. The cells were exposed continuously for up to 84 hours at an average electric-field strength of 3.4-34 V/m with a maximum of 1.8 W/kg under athermal conditions. Barrier tightness measured by 14C-sucrose and serum albumin permeation and by transendothelial electrical resistance remained unchanged compared to sham-exposed cultures. Permeation of transporter substrates and the localization and integrity of the tight-junction proteins occludin and ZO1 were also unaffected.

Whole-body exposure to 2.45GHz electromagnetic fields does not alter 12-arm radial-maze with reduced access to spatial cues in rats.

Cosquer B, Kuster N, Cassel JC. · 2005

Researchers investigated whether whole-body exposure to 2.45GHz electromagnetic fields alters performance in a 12-arm radial-maze with reduced access to spatial cues in rats. The results showed that microwave exposure as used in the study did not alter spatial working memory when access to spatial cues was reduced. In a replication attempt using a maze apparatus bordered by 30 cm high opaque walls, the performance of exposed rats was normal.

Whole-body exposure to 2.45 GHz electromagnetic fields does not alter anxiety responses in rats: a plus-maze study including test validation.

Cosquer B, Galani R, Kuster N, Cassel JC. · 2005

In a first phase, researchers validated the elevated plus-maze apparatus in male Sprague-Dawley rats. They tested anxiety responses at light intensities of 200, 30, 10, and 2.5 lux and with diazepam doses of 0.5 and 1.0 mg/kg. Anxiety responses decreased with decreasing light intensity and were attenuated by diazepam. A separate group of rats was then exposed to 2.45 GHz EMFs with a whole-body SAR of 0.6 W/kg and brain-averaged SAR of 0.9 W/kg for 45 min. EMF exposure did not significantly affect anxiety responses at either low or high ambient light intensity.

Cellular telephones and risk for brain tumors: A population-based, incident case-control study.

Christensen et al. · 2005

Researchers conducted a nationwide population-based case-control study in Denmark. Cellular telephone use was associated with lower risk for high-grade glioma (OR 0.58, 95% CI 0.37-0.90). Risk estimates were near unity for low-grade glioma (OR 1.08) and meningioma (OR 1.00). The results did not support an association between cellular telephone use and risk for glioma or meningioma.

Differences in RF energy absorption in the heads of adults and children.

Christ A, Kuster N. · 2005

The study investigates differences in RF energy absorption in the heads of adults and children. It discusses absorption mechanisms, tissue parameters, the effect of the pinna, and uncertainties in head models based on spheroids, scaled adult heads, and MRI data of children. The review concludes that energy exposure does not increase due to smaller heads, but identifies open issues regarding dielectric tissue parameters and pinna thickness.

No effect on cognitive function from daily mobile phone use.

Besset A, Espa F, Dauvilliers Y, Billiard M, de Seze R. · 2005

The study investigated the effects of daily exposure to GSM 900 type MP on cognitive function. Fifty-five subjects were divided into two groups matched for age, gender, and IQ. The double-blind study lasted 45 days with baseline, exposure, and recovery periods.

[Subjective symptoms related to mobile phone use--a pilot study]

Szyjkowska A et al. · 2005

A survey using a self-reported questionnaire was conducted among randomly selected university students in Lodz, Central Poland. Out of 160 questionnaires distributed, 140 were completed and 117 were analyzed after excluding respondents with pre-existing health problems. The participants were 61 males and 56 females, with most rating their health as good or very good. Seventy percent of students reported headache, 20% reported dizziness, 56% reported impaired concentration, and 11% reported facial dermatitis. Only 8 of 82 students with headache and 10 of 65 with impaired concentration attributed these symptoms to mobile phone use, and the authors concluded that further experimental and epidemiologic studies are needed.

Role of mobile phones in motor vehicle crashes resulting in hospital attendance: a case-crossover study.

McEvoy SP et al. · 2005

Driver mobile phone use up to 10 minutes before a crash was associated with a fourfold increased likelihood of crashing (odds ratio 4.1, 95% CI 2.2 to 7.7). Risk was raised irrespective of whether a hands-free device was used, with hands-free odds ratio 3.8 and hand-held odds ratio 4.9. Increased risk was similar in men and women and in drivers aged 30 years or older and younger than 30 years. A third of calls before crashes and on trips during the previous week were reportedly on hand-held phones (n = 21).

Effects of practice, age, and task demands, on interference from a phone task while driving.

Shinar D, Tractinsky N, Compton R · 2005

The study used a simulated driving environment with two different hands-free phone tasks. The experiment consisted of five sessions of driving while using the phone. A learning effect occurred on most driving measures across the sessions. Interference from the phone task on many driving tasks diminished over time. Interference was greater with an artificial math operations task than with an emotionally involving conversation, with greater driving demands, and with older drivers.

Inhibited head movements: A risk of combining phoning with other activities?

Oommen BS, Stahl JS · 2005

Previous studies attributed impaired driving performance to the distractions of conversation. The researchers determined that holding an inactive phone to the ear reduces the probability of eccentric head positions. This reduction potentially indicates a reduced ability to monitor the visual surround.

Influence of (460 MHz) electromagnetic fields on the induced lipid peroxidation in the structures of visual analyzer and hypothalamus in experimental animals

Musaev AV, Ismailova LF, Gadzhiev AM. · 2005

Researchers studied changes in ascorbate- and NADPN2-dependent induced lipid peroxidation in the visual analyzer and hypothalamus of 3- and 12-month-old rats exposed to high- and low-intensity microwaves. High-intensity exposure stimulated basal LPO but suppressed LPO-inducing systems. Low-intensity exposure activated induced LPO systems accompanied by synchronous antioxidant defense activity maintaining redox balance. The authors concluded that microwaves can be either beneficial or a factor of oxidative stress depending on intensity.

Mobile phone related-hazards and subjective hearing and vision symptoms in the Saudi population

Meo SA, Al-Drees AM · 2005

Researchers invited 873 mobile phone users (57.04% males, 39.86% females) to complete a structured questionnaire and used chi-square tests to examine call duration and symptoms. The study found an association between mobile phone use and hearing and vision complaints, with 34.59% reporting hearing issues like impaired hearing, ear ache, or warmth, and 5.04% reporting decreased or blurred vision. The authors concluded that mobile phone use is a health risk factor and suggested avoiding excessive use while increasing social awareness through health promotion.

Effects of GSM signals on auditory evoked responses.

Maby E, Jeannes RL, Faucon G, Liegeois-Chauvel C, De Seze R. · 2005

Researchers investigated correlation coefficients between auditory evoked potentials and their spectra to detect a possible difference due to RFs. A difference in correlation coefficients between control and experimental sessions was observed, but the effect of RFs on human health could not be deduced.

The effect of electromagnetic fields emitted by mobile phones on human sleep.

Loughran SP et al. · 2005

Researchers examined whether sleep architecture is sensitive to electromagnetic fields from digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 minutes before sleep. Exposure decreased rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz range during the initial part of sleep. The authors concluded that mobile phone exposure before sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.

Hands-free mobile phone conversation impairs the peripheral visual system to an extent comparable to an alcohol level of 4-5 g 100 ml.

Langer P, Holzner B, Magnet W, Kopp M. · 2005

The study investigated how low-dose alcohol and conversation while driving affect the peripheral visual system and driving ability. Holding a conversation while driving reduces the peripheral visual field, an effect also seen with low-dose alcohol. Peripheral vision reaction time was measured in 60 persons using the Schuhfried test.

Selection bias due to differential participation in a case-control study of mobile phone use and brain tumors.

Lahkola A, Salminen T, Auvinen A. · 2005

Researchers evaluated selection bias in a Finnish case-control study of mobile phone use and brain tumors by comparing full and incomplete participants. Among controls, 83% of full participants and 73% of incomplete participants regularly used a mobile phone, while among cases the figures were 76% and 64%. The odds ratio for brain tumor based on the combined group was slightly closer to unity than that based only on full participants. Selection bias tends to distort effect estimates below unity, while analyses based on more comprehensive material gave results close to unity.

Study of subgridding in SAR computation for the cochlea.

Kopecky R, Hamnerius Y, Persson M. · 2005

A 3D subgridding technique was used to model the specific absorption rate (SAR) distribution in the isolated cochlea exposed to mobile phone radiation at 1750 MHz using the FDTD method. The cochlea was modeled at spatial resolutions of 1, 1/3, 1/5, and 1/7 mm. First simulations used 1 mm spatial resolution, then numerical resolution was increased to 1/3, 1/5, and 1/7 using subgridding without changing spatial resolution. A second set of simulations increased both spatial and numerical resolution together. The researchers concluded that subgridding is important only when both numerical and spatial resolution are increased together.