Swedish study shows no association between cell phone use and brain tumour
In "What's New", October '04" we reported a study by Lonn and colleagues that reported their findings from a study of acoustic neuroma. The same authors have now published the results of a study of two other brain tumours - glioma and meningioma. These studies are part of the international case-control study of cell phones and cancers of the brain and salivary glands. They obtained information about 371 cases of gliomas, 273 cases of meningioma, and 674 controls. For regular cell phone use the odds ratio (OR) for glioma was 0.8 and for meningioma 0.7. Similar results were obtained for more than 10 years' duration of phone use. No increased risk was found for tumours located in the temporal and parietal lobes, the brain areas with greatest exposure from cell phones.
The authors conclude that the data do not support the hypothesis that mobile phone use is related to an increased risk of glioma or meningioma.
For more, see "Human Research - Epidemiology".
Lonn S, Ahlbom A, Hall P, Feychting M, and the Swedish Interphone study
group. Long-term phone use and brain tumor risk. Am J Epidemiol 2005;161:526-535.
Several experimental studies on the effect of radiofrequency radiation (RFR) on cognitive function have been done, with conflicting results. The cognitive function testing has usually been done during or shortly after one exposure to RFR. Besset and colleagues report on cognitive function testing that was done on subjects who were exposed for 2 hours a day, 5 days per week, for 4 weeks. The subjects held a phone to their ear during the exposure. A matched group was sham-exposed, and neither the subjects nor those conducting the tests were aware of the exposure status of the subjects. There was no difference between the exposed and sham-exposed subjects in their results on cognitive function testing.
For more, see "Research - Clinical Experiments - Cognitive function".
Besset A, Espa F, Dauvilliers Y, Billiard M, et al. No effect on cognitive
function from daily mobile phone use. Bioelectromagnetics 2005;26:102-108.
Christ and colleagues have recently reported the results of testing of different types of human head phantoms that have been used in the compliance testing of handheld devices. Their main emphasis was on the Specific Anthropomorphic Mannequin (SAM), which has been adopted by CENELEC, IEEE, ARIB, and IEC for compliance testing. Their results suggest that the SAR assessments obtained were reasonable and conservative. They also confirmed the findings of Schonborn and colleagues that smaller heads do not result in increased SAR values, and that all differences can be explained by variations in distance and in the anatomy of tissue structures. They comment that these findings contradict those of Gandhi and colleagues.
Christ A, Chavannes N, Nikoloski N, Gerber H-U, et al. A numerical and
experimental comparison of human head phantoms for compliance testing
of mobile phone equipment. Bioelectromagnetics 2005;26:125-137.
Another article compares SAR induced in two child head models and in adult heads when mobile phones are used. Hadjem and colleagues found no important differences for the peak SAR averaged over 10 g between the two adult head models, as well as between the two child head models. The peak SAR averaged over 10 g was slightly higher in the two child head models, compared with the adult one.
Reference: Hadjem A, Lautru D, Dale C, Wong MF, et al. Study of specific absorption rate (SAR) induced in two child head models and in adult heads using mobile phones. IEEE Transactions on Microwave Therapy and Techniques 2005;53:2289-2337.
The Board of the NRPB has produced a document that updates the report published in 2000 by the Independent Expert Group on Mobile Phones and Health (IEGMP), chaired by Sir William Stewart. The latter is now Chair of NRPB.
Like most other reports by expert groups, the NRPB concludes that there is no direct evidence that the health of the public is being adversely affected by mobile phone technologies, but states that uncertainties remain and a continued precautionary approach to their use is recommended in the meantime.
report is available in PDF format at http://www.hpa.org.uk/radiation/publications/documents_of_nrpb/index.htm
A recent NRPB report examines a number of reviews that have been produced by national and international committees, expert groups, and agencies, since the publication of the Stewart Report in 2000.
Reference: ZJ Sienkiewicz and CI Kowalczuk. A summary of recent reports on mobile phones and health (2000-20004). January 2005. http://www.hpa.org.uk/radiation/publications/documents_of_nrpb/index.htm (go to "reports"