Diciembre 2006

Cell phones and non-Hodgkin lymphoma

A US case-control study has examined the role of cell phone use in the occurrence of non-Hodgkin lymphoma (NHL). There were 551 cases (79% participation) and 462 controls (55% participation). There was little evidence of an increased risk of NHL with use of cell phones. One non-statistically significant increased odds ratio was seen in men who used cell phones for 6 years or more, but this was based on 7 cases, there was no dose-response trend, and there was no similar result in women. The authors suggested that this was likely to be a chance finding.

For more, see "Research - Epidemiology".

Reference: Linet MS, Taggart T, Severson RK, Cerham JR, et al. Cellular telephones and non-Hodgkin lymphoma. Int J Cancer 2006;119:2382-2388.

RFR has no effect on cell death or p53 gene expression

Hirose and colleagues exposed two types of human cells to RFR similar to that used in the International Mobile Telecommunication 2000 (IMT-2000) cellular system. They were exposed to W-CDMA radiation and CW radiation at SARs up to 800 mW/kg for 48 hours. No significant differences were seen in the percentage of apoptotic cells that were RFR-exposed or sham-exposed, or in expression of phosphorylated p53 gene or total p53.

For more, see "Research - Toxicological - Cancer studies and - Others- cell death".

Reference: Hirose H, Sakuma N, Kaji N, Suhara T, et al. Phosphorylation and gene
expression of p53 are not affected in human cells exposed to 2.1425 GHz band CW or
W-CDMA modulated radiation allocated to mobile hone radio base stations.
Bioelectromagnetics 2006;27:494-504.

Assessment of health effects of EMF by WHO, IARC, and ICNIRP

In the September issue of the Radio Science Bulletin, Vecchia reviews the different roles of WHO, IARC, and ICNIRP in the assessment of health effects associated with electromagnetic fields. The article is based on the invited Commission K lecture at the XXVIIth General Assembly of URSI in October, 2005, at New Dehli. The Bulletin can be accessed at www.ursi.org .

Two studies of RFR and oxidative stress in rats

Two recent studies have examined the effect of exposure to RFR on the production of oxidative stress in rats. Yurekli and colleagues simulated far-field exposure from base stations, and found significant changes in blood levels of markers of oxidative stress.
Ferreira et al. however, found no evidence of oxidative stress in the brains of rats exposed at a higher SAR level.

For more, see "Research - Toxicological - others- Free oxygen radicals".

References: Yurekli AI, Ozkan M, Kalkan T, Saybasili H, et al. GSM base station electromagnetic radiation and oxidative stress in rats. Electromagnetic Biology and Medicine 2006;25:177-188.

Ferreira AR, Bonatto F, Pasquali MA, Polydoro M, et al. Oxidative stress effects on the central nervous system of rats after acute exposure to ultra high frequency electromagnetic fields. Bioelectromagnetics 2006;27:487-493.

Proton magnetic resonance spectroscopy in evaluating brain function in cell phone users

Khiat and colleagues from Montreal, Canada, used the technique of proton magnetic resonance spectroscopy (MRS) that, they claimed, had never been used before to study the possible effects of cell phones on brain function. MRS allows the non-invasive examination of the brain by measuring the levels of certain metabolites that reflect the condition of neurons and glial cells, as well as membrane metabolism and energy status.
Twenty-one individuals who extensively used cell phones and 15 controls took part in the study. The cell phone users had been using their phones for an average of 5.5 years and 2.4 hours per day. The controls had never used a cell phone. The authors examined brain areas that are among those most irradiated by the antenna of the cell phone - the temporal lobe on the side of phone use, and the pontobulbar area. They also examined the contralateral temporal area as a control. There were no significant differences between the users and the non-users. Also, there were no differences between the ipsi- and contra- lateral sides of the users.

For more, see “Research - Clinical - cognitive function”.

Reference: Khiat A, Boulanger Y, Breton G. Monitoring the effect of mobile phone use on the brain by proton magnetic resonance spectroscopy. International Journal of Radiation Biology 2006;82:681-685.

RFR exposure associated with decreased skin resistance

Nam and colleagues from Korea have reported a study of 21 teenagers and 21 adults who were RFR- or sham-exposed. The RFR was from a CDMA phone (835 MHz, SAR 1.6 W/g). The exposure was 30 minutes. There were no differences in pulse or respiratory rates or in blood pressure between the RFR and sham exposures in the teenagers, the adults or between the combined male and female groups. However, skin resistance, caused by increased sweat secretion, was decreased in the teenagers, and in the combined male group, when exposed to RFR. The study was double blind, but can be criticized for the lack of randomization of the sequence of exposure. The sham exposure was always first.

For more, see “Research - Clinical – cardiovascular effects”.

Reference: Nam KC, Kim SW, Kim SC, Kim DW. Effects of RF exposure of teenagers and adults by CDMA cellular phones. Bioelectromagnetics 2006;27:509-514.