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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