Washington, USA
26 June 2002 08:31
Cellphones do not seem to cause cancer, according to a US
study that exposed rats to strong doses of radiation similar to those emitted by
cellphones.
Four hundred and eighty rats were subjected to two kinds of radiation for four
hours each day, five days a week for two years by researchers at Washington
University medical school in St Louis, Missouri.
The results were presented on Wednesday in Quebec City at a meeting of the
Bioelectromagnetic Society.
"We tried to mimic a high level of exposure that humans might experience," said
Dr Joseph Roti, study leader and professor of radiation oncology, biochemistry,
molecular biophysics, cell biology and physiology.
"We found no statistically significant increases in any tumour type, including
brain, liver, lung or kidney, compared to the control group," Roti said.
"As far as I can tell from the work so far, the greatest hazard with cellphones
is driving a car while talking on one."
The study, financed by the cellular phone industry, is one of many in the past
few years seeking to resolve the ongoing controversy over whether users have
increased rates of cancer.
It exposed one group of rodents to an intense dosage of the frequency 835.62
megahertz, which is used in analog cellular phones, a second group to 847.74
megahertz which is used in digital phones, and a third to nothing.
After two years, or 505 days of exposure, the rats were dissected and each brain
and spinal cord was inspected under a microscope for signs of cancer. About 20
to 25 samples from each brain were examined, as well as 30-odd samples from
elsewhere in each body.
"We looked specifically for brain and spinal cord tumours," said Marie La
Regina, a veterinary pathologist with the Washington University's division of
comparative medicine, and co-author of the study.
Weight difference and life span on the rats were not taken into account in the
study.
According to the Washington-based Cellular Telecommunications Industry
Association there are currently 137 458 902 wireless subscribers in the United
States.
