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".
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.
No effect of microwaves on a rat model of multiple
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.
on the mice lymphoma controversy
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
can be found at www.ursi.org/RSB.htm
national reviews of cell phones and health
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.