Long-term RF exposure has no effect on blood-brain barrier
This study by Finnie and colleagues was part of the study reported by Utteridge and colleagues (2002) (see "Toxicologic Experiments - Cancer studies"), which attempted to replicate Repacholi's 1997 study in mice prone to lymphoma. The authors used the wild-type control mice that were part of the larger study. The mice were exposed to 900 MHz fields (pulse-modulated at 217 Hz) for 1 hour per day, five days per week, for two years. There were four groups of mice at increasing energy absorption levels - 0.25, 1.0, 2.0, and 4.0 W/kg. The authors examined the brains of all the mice who survived to the end of the 2-year study for evidence of albumin leakage from blood vessels into brain tissue. Minor leakage of albumin was found in all exposed and non-exposed groups. There was no trend to increased leakage with increasing exposure. For more details, see "Toxicological Experiments - brain function".
Reference: Finnie JW, Blumberg PC, Manavis J, Utteridge TD, et al. (2002): Effect of long-term mobile communication microwave exposure on vascular permeability in mouse brain. Pathology 34:344-347.
Experimental allergic encephalomyelitis (EAE) is widely used as an animal model for multiple sclerosis. In this study EAE was induced in rats, who were then exposed to radiofrequency radiation at a frequency of 900 MHz for 2 hours per day for 21 days. The SAR was 1.5 or 6.0 W/kg, averaged over the brain. There was no effect of the RF exposure on the onset, duration, and termination of the EAE crisis. The authors plan to extend their experiments to another EAE model, which is more chronic than the acute one used in the present study.
Anane R, Geffard M, Taxile M, Bodet D, et al. (2003): Effects of GSM-900
microwaves on the experimental allergic encephalomyelitis (EAE) rat
model of multiple sclerosis. Bioelectromagnetics 24:211-213.
In the February 2003 edition of "What's New" we mentioned that the Radio Science Bulletin is now on-line. In the latest issue (March 2003) Dr. James Lin of the University of Illinois writes about the controversies associated with two studies that examined the effect of RF radiation on mice that were genetically prone to develop lymphomas. He reviews the studies in detail. Some of the points that he raises are addressed in correspondence in "Radiation Research" - as we discussed in last month's "What's New".
The Bulletin can
be found at www.ursi.org/RSB.htm
Two more reviews of cell phones and health have been released recently.
One was from the Norwegian Radiation Protection Authority. The committee concluded that population studies have failed to show any link between cell phones or base stations and health risks. It is also suggested that some laboratory experiments have suggested that weak electromagnetic fields may have some biological effects on cells, although in most cases the effects have not been independently replicated, and they have not been shown to produce adverse health outcomes. The committee members cautioned that more time is needed to assess long-term effects of exposure to the electromagnetic fields associated with cell phones, and state that more research is needed. The report is available, in Norwegian, at www.nrpa.no/fpinternet/Mobiltelefon_sluttrapport.pdf
The other report was by the French Environmental Health Safety Agency (AFSSE), and is available in French at www.afsse.fr This report also did not find a link between exposure to cell phones or base stations and health risk, although the agency recommended adopting the precautionary principle.