UK report on mobile phone radiation shields
The UK's Department
of Trade and Industry (DTI) released a report in May 2002 on mobile
phone radiation shields. Four different types of RF shields were tested
- shielded cases, earpiece pads and shields, antenna clips and caps,
and absorbing buttons. The report concluded that although shields can
reduce the maximum Specific Absorption Rate from the handset, they also
reduce the effectiveness of the phone. The power of the phone is decreased,
which compromises quality of service and shortens the battery life.
A full copy of the report can be found at www.dti.gov.uk/cii/docs/R500016att.pdf
There have been a number of studies in the past decade that have looked at the effect of RF radiation exposure on the production of micronucleated cells, which are a sign of chromosomal damage. The March edition of "What's New" reported two studies that showed an increase in these cells after radiation exposure. Now another study has shown no increase in micronucleated cells after exposure to 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiation. The authors postulate that the difference in their results from those of Tice that were reported in the March update could be due to differences in the biological systems used or in the irradiation facilities. For more on this, see "Toxicological Experiments - cancer studies - genotoxicity".
Bisht KS, Moros EG, Straube WL, Baty JD, Roti Roti JL (2002): The effect
of 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiofrequency radiation
on the induction of micronuclei in C3H 10T½ cells. Radiation
In "What's New" in July 2000 and November 2001 we discussed possible effects of RF radiation on the production of heat-shock proteins. These proteins are formed in response to various stresses in the body and help to repair damaged proteins. A new study has reported that exposure of human endothelial cells (that line blood vessels) to 900 MHz radiation for 1 hour (average SAR 2 W/kg) can cause changes in the status of a variety of proteins in the cells. One of these was a heat-shock protein, hsp 27. The observed changes were thought to be non-thermal. The authors hypothesize that repeated RF exposure may create a health hazard by altering normal pathways of cell death or by interrupting the blood-brain barrier. The authors emphasize that further investigation is required. For more on this, see "Toxicological - Others - Heat-shock response".
Leszcynski D, Joenvaara S, Reivinen J, Kuokka R (2002): Non-thermal
activation of the hsp27/p38MAPK stress pathway by mobile phone radiation
in human endothelial cells: Molecular mechanism for cancer- and blood-brain
barrier-related effects. Differentiation 70:120-129.