shields for mobile phones again shown to be ineffective
In the July
2002 edition of "What's New"
and in FAQ #21, we discuss
the ineffectiveness of shields that are promoted to block radiofrequency
radiation (RFR) emitted from mobile phones. Oliver and colleagues
at Motorola Research Laboratories have tested nine such devices
and found that they did not reduce the location of the peak SAR
or the 1g. peak spatial average SAR.
Reference: Oliver JP, Chou CK, Balzano Q (2003):
Testing the effectiveness of small radiation shields for mobile
phones. Bioelectromagnetics 24:66-69.
phones in enclosed areas
In the June
2002 "What's New" we discussed the subject of simultaneous
use of multiple cell phones in enclosed areas such as trains. Hondou
had suggested that this could create a level of exposure to electromagnetic
fields that could exceed the guidelines of the International Commission
on Non-ionizing Radiation Protection (ICNIRP). Now Toropainen from
the Nokia Research Center in Finland refutes that suggestion with
calculations that show that it would be "highly improbable"
that the exposure from simultaneous use of cell phones in enclosed
spaces, such as trains, elevators, or cars, could exceed the guidelines.
Reference: Toropainen A (2003): Human exposure
by mobile phones in enclosed areas. Bioelectromagnetics 24:63-65.
Science Bulletin on-line
The Radio Science
Bulletin is now on-line and is found at www.ursi.org/RSB.htm
. It is published by URSI (Union Radio-Scientifique Internationale),
which is a non-governmental and non-profit agency under the International
Council for Science. URSI is responsible for stimulating and coordinating
studies, research, applications, scientific exchange, and communication
in the fields of radio science. The September and December 2002
issues contain articles by Dr. James Lin of the University of Illinois.
The September paper deals with "Health and Safety associated
with personal wireless telecommunications base stations", and
the December one with "The auditory perception and hearing
of mobile phones and the nervous system
2003 issue of Bioelectromagnetics contains a review of the effects
of EM radiation of mobile phones on the central nervous system.
It is an update by Hossmann and Hermann of an earlier review in
1997. They state:
of the reported effects are small as long as the radiation intensity
remains in the nonthermal range, and none of the research reviewed
gives an indication of the mechanisms involved at this range".
Hossmann K-A, Hermann DM (2003): Effects of electromagnetic radiation
of mobile phones on the central nervous system. Bioelectromagnetics
from mobile phones alter cerebral blood flow and EEG tracings
In the February
2000 and November 2000 editions of "What's New" we discussed
studies from a Swiss group that examined the effect of RF radiation
on EEG tracings. This
group has now reported a further study. They again found some EEG
changes in the exposed group compared with sham-exposed individuals,
but only when pulse modulated electromagnetic fields were used.
The changes were not seen with continuous wave exposure. The authors
also found increase in regional blood flow in the cerebral cortex
on the same side as the EMF exposure. As with the EEG findings,
the blood flow increase was only seen with pulse modulated EMF.
For more on this study, see "Research
- Clinical Experiments - EEG, and Cognitive
Reference: Huber R, Treyer V, Borbely AA,
Schuderer J, et al. (2002): Electromagnetic fields, such as those
from mobile phones, alter regional cerebral blood flow and sleep
and waking EEG. J Sleep Res 11:289-235.
Report of nerve cell damage in rats
after RF radiation exposure
A group of Swedish
researchers have reported that exposure to microwaves from a GSM
mobile phone caused nerve damage in rats. The rats were exposed
for 2 hours to electromagnetic fields of varying strength. The whole-body
SARs were said to range from 2 to 200 mW/kg. The brains of the rats
were examined 50 days after exposure and there was evidence of leakage
of albumin through the blood-brain barrier and of nerve cell damage.
details of the experiment are lacking. For more, see "Toxicological
Experiments - brain function". It will be important for
this study to be replicated.
Brun AE, Eberhardt JL, Malmgren L, et al. Nerve cell damage in mammalian
brain after exposure to microwaves from GSM mobile phones. Environmental
Health Perspectives, Online January 29, 2003 (www.ehponline.org)