Julio 2006

Health effects from mobile phones

Hutter and colleagues did a cross-sectional study of 365 randomly selected inhabitants living near to 10 selected base stations in urban and rural areas of Austria. General health symptoms were evaluated and cognitive tests performed. There was a significant relation of headache and of cold hands and feet with increase in power density. Perceptual speed increased.

In an accompanying commentary, Coggon points out that, given the large number of health outcomes examined in the study, there is a possibility that some associations occurred by chance.

References: Hutter H-P, Moshammer H, Wallner P, Kundi M. Subjective symptoms, sleeping problems, and cognitive performance in subjects living near mobile phone base stations. Occup Environ Med 2006;63:307-313.
Coggon D. Health risks from mobile phone base stations. Occup Environ Med 2006;63:298-299.

Brain activity from cell phone exposure

Two recent papers report findings from studies of event-related potentials (ERPs) on electroencephalography (EEG) during auditory tasks.

Hamblin and colleagues from Melbourne, Australia, have previously reported that RFR from cell phones can affect brain activity as measured by EEG. They have now repeated their study using a much larger group of volunteers (120 as opposed to 12), and an improved study design. This time the volunteers, who performed an auditory and a visual task while the recordings were made, showed no significant differences between the RFR and sham exposures in the N100 and P300 components of ERPs. The authors concluded that there is currently no evidence that acute cell phone exposure affects auditory or visual event related potentials or reaction time.

Papageorgiou and colleagues from Athens, Greece, on the other hand, found an increase in the P50 component of ERPs with low frequency stimuli and a decrease with high frequency stimuli. Their study was much smaller (19 subjects) and appears to have been single blind.

For more, see “Research – Clinical– EEG”.

References: Hamblin D, Croft RJ, Wood AW, Stough C, et al. The sensitivity of human event-related potentials and reaction time to mobile phone emitted electromagnetic fields. Bioelectromagnetics 2006;27:265-273.

Papageorgiou CC, Nanou ED, Tsiafakis VG, Kapareliotis E, et al. Acute mobile phone effects on pre-attentive operation. Neuroscience Letters 2006;397:99-103.

RFR does not affect tumour promotion in offspring of ENU-treated rats.

There have been numerous studies of tumour promotion in lab animals exposed to RFR. Another study has examined the effect of RFR on rats whose mothers were injected intravenously with ethylnitrourea (ENU) while pregnant. ENU induces tumours of the central nervous system. Equal numbers of rats were divided into RF-exposed (860 MHz frequency), sham and cage-control groups. There was no evidence that exposure to the RF signal affected the incidence, malignancy, volume, multiplicity, latency or fatality associated with any kind of neurogenic tumor.

For more, see “Research – Toxicological – Cancer studies”.

Reference: Zook B, Simmens SJ. The effects of pulsed 860 MHz radiofrequency radiation on the promotion of neurogenic tumors in rats. Radiation Research 2006;165:608-615.

More on genotoxicity

Two recent articles have further explored the issue of RFR effects on genotoxicity.
Belyaev and colleagues from Stockholm, Sweden, investigated whether exposure of rat brain to RFR of the GSM signal type (915 MHz frequency) induces DNA breaks, changes in chromatin conformation and in gene expression.

No changes were seen in chromatin conformation or DNA double-strand breaks. Out of 8800 genes tested, 12 showed significant changes. The authors caution that the statistical power of the study was limited by the number of gene arrays and also by the fact that the brain normally shows small changes in gene expression.

Reference: Belyaev IY, Koch CB, Terenius O, Roxstrom-Lindquist K, et al. Exposure of rat brain to 915 MHz GSM microwaves induces changes in gene expression but not double stranded DNA breaks or effects on chromatin conformation. Bioelectromagnetics 2006;27:295-306.

Verschaeve and colleagues studied the effect of exposure to RFR in rats that were also exposed to 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in their drinking water. MX is a multi-site carcinogen in Wistar rats when given continuously in their drinking water. There was no evidence of genotoxic activity of MX in blood and liver cells, but there was in brain cells. Co-exposures to MX and RFR did not significantly increase the response of blood, liver, and brain cells compared to MX exposure.

Reference: Verschaeve L, Heikkinen P, Verheyen G, van Gorp U, et al. Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo. Radiation Research 2006;165:598-607.

For more, see “Research – Toxicological – Cancer studies”.

Children and cell phones

In his latest review in Radio Science Bulletin, James Lin discusses the question of whether cell phones are potentially harmful to children. He discusses the results of two recent studies (mentioned in “What’s New” of January ’06).

Reference: Lin JC. Mental process of children and mobile-phone electromagnetic fields. Radio Science Bulletin #316 (March ’06). This can be found at www.ursi.org

For more, see “What’s New” September ’03, March ’04, April, July, and December’05.