By
Lindsey Tanner
AP Medical Writer Washington Post
CHICAGO
A study of people who used cell phones for
an average of less than three years found no evidence the
devices cause brain cancer.
The
research does not answer the question of whether longer-term
use is dangerous.
The
study, funded by the industry group Wireless Technology
Research and the National Cancer Institute, appears in Wednesday's
Journal of the American Medical Association.
The
study of 891 people did find a slightly increased risk for
a rare type of brain cancer, but the researchers said it
was not statistically significant.
While
they acknowledge longer-term studies are needed, the researchers
said the overall results should reassure the more than 86
million cell phone users nationwide.
"We
feel confident that the results reflect that cell phones
don't seem to cause brain cancer," said epidemiologist
Joshua Muscat, a scientist at the American Health Foundation
who helped lead the study.
Unlike
regular telephones, handheld cell phones contain an antenna
inside the receiver, which puts the user's brain close to
the electromagnetic radio waves the antenna emits. Since
cell phones were introduced in the United States in 1984,
conflicting data have emerged from safety studies on animals
and humans.
The
Food and Drug Administration has said there is no evidence
that the phones are unsafe, but it has joined with the wireless
industry in sponsoring research on the devices. Some cell
phone makers have also started disclosing their products'
radiation levels.
The
new study, co-written by Dr. Mark Malkin of Memorial Sloan-Kettering
Cancer Center in New York, involved phone-use questionnaires
given to 469 men and women ages 18 to 80 with brain cancer
and a 422-member cancer-free control group.
Cell-phone
use was slightly more common among the cancer-free participants,
though average cell-phone use for both groups was under
three hours monthly for less than three years.
The
amount and duration of cell-phone use were not related to
an increased brain cancer risk except for a type of neuron-cell
tumors called neuroepitheliomatous cancer. Of the 35 patients
with these rare tumors, 14 40 percent used
cell phones.
"An
isolated result like that can occur entirely due to chance,"
said Russell Owen, chief of the FDA's radiation biology
branch. He said the overall findings are in line with previous
research and "certainly not cause for concern."
Professor
Henry Lai of the University of Washington, whose animal
research linked cellular phone signals with cell damage
in rat brains, called the study "very preliminary and
inconclusive."
"Since
most solid tumors take 10 to 15 years to develop, it is
probably too soon to see an effect," Lai said.
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