Cell phones and acoustic neuroma
Editor: So, can cell phones cause cancer or not? I don't think the
issue is really decided yet, but here's a report on a study that finds a
link between cell phone use and acoustic neuromas. (The article explains
a bit about acoustic neuromas; more information is available at http://anausa.org/
Reprinted with permission from the South Florida Sun-Sentinel.
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Study finds cell phones could cause noncancerous tumors
By Nancy McVicar Health Writer
People who have used cell phones for at least 10 years might have an
increased risk of developing a rare brain tumor, according to a study
published Wednesday in the international journal Epidemiology.
A team of researchers at Institute of Environmental Medicine at the
Karolinska Institute in Stockholm, Sweden, found almost a fourfold
increase of the tumors, known as acoustic neuromas, on the side of the
head where the phone was most often held.
The work was done as part of the World Health Organization's cell
phone research agenda, and experts in the field said it must be taken
seriously and is likely to rekindle consumer worries about the risks of
using the phones.
"The Karolinska researchers are respected around the world, and
this study will force health agencies to take a fresh look at mobile
phone risks," said Louis Slesin, publisher of Microwave News, who
has been covering the industry since its early days. "This study
should put an end to the industry's call to stop mobile phone health
research."
At least one past study conducted for the cell phone industry also
had suggested a link between the phones and this type of tumor. But cell
phone industry officials on Wednesday said the Swedish research is only
one study and that no conclusions can be drawn from it.
The study, involving 150 acoustic neuroma patients and 600 healthy
people, is one of at least six studies of possible links between cell
phone use and acoustic neuromas. Most of those studies had fewer
long-term users than the Karolinska study.
Acoustic neuromas are slow-growing noncancerous tumors that develop
on a nerve linking the brain and the inner ear. The most common first
symptom is hearing loss, but as the tumor grows it can push against
brain tissue. If not treated, it can be life threatening. Such tumors
are very rare, occurring in about one person per 100,000 in the general
population.
"It's a natural place to look [for a problem] because this is
the area of the head that is exposed," said Anders Ahlbom, director
of the Institute of Environmental Medicine at the Karolinska Institute
in Stockholm. When a cell phone is in use, it emits radio-frequency
radiation, some of which is absorbed in areas of the head closest to the
handset.
To conduct the three-year study, the Karolinska researchers
interviewed people who had developed the tumors -- asking about their
cell phone use, how many different phones they had used, the makes and
models, duration of calls, whether they used a hands-free set and on
which side of the head they held the phone.
Researchers said they found no association between the tumors and the
amount of use measured in hours or cumulative number of calls, but
rather on the length of time those in the study had been regular users
of cell phones. Regular use was defined as an average of at least once a
week during six months or more.
Ahlbom said in a phone interview that the data are strong and
statistically significant, but the findings must be confirmed by
follow-up studies. He said the mechanism by which cell-phone radiation
might cause tumors remains unknown.
Dr. David Savitz, chairman of the department of epidemiology at the
University of North Carolina School of Public Health, Chapel Hill, said
the new findings "suggest something a little bit troublesome."
"It is significant in the sense that it is the first
well-designed study to show this," Savitz said. "There was an
earlier study that came out, but it didn't have as many people with
long-term use."
Dr. Henry Lai, research professor of bioengineering at the University
of Washington in Seattle, also said the Karolinska study is not the
first to show a link between cell phones and acoustic neuromas.
"Another Swedish researcher, Dr. [Lennart] Hardell found similar
results in 2002," Lai said, "so this is, in effect, a
replication. I think the data are quite solid and are cause for concern
on long-term cell phone use."
Lai's own research found DNA breaks in the brain cells of animals
exposed to radio-frequency radiation, results that were first published
in 1994, and have been repeated by others, he said.
"We looked at DNA damage in animals, not in humans, and found
that cell phone radiation can damage DNA," he said. The body's
immune system has the ability to repair DNA breaks, but sometimes it can
make a mistake and cause a mutation, which could be the first step
toward cancer, Lai said.
Sam Milham of Olympia, Wash., an epidemiologist and pioneer in
studying the effects of electromagnetic radiation on humans, said it
usually takes 20 years or more for solid tumors to develop.
"I'm actually astonished that they found anything like this
early," Milham said. "If that energy can do that to normal
nerve tissue cells, what can it do to adjacent brain cells? I think it's
the tip of a big iceberg, and the peak could be at 25 years past
exposure.
"What's really alarming is that in the last five years an
enormous number of people started using cell phones, including kids, so
I think this is just the beginning of it. I hope I'm wrong."
According to the Cellular Telecommunications and Internet
Association's Web site, updated daily, there are more than 170 million
wireless subscribers in the United States.
The safety of cell phones was first called into question by the death
of a Florida woman, Susan Reynard of Madeira Beach, from a brain tumor.
In January 1993, the South Florida Sun-Sentinel published a story about
a lawsuit filed by her husband, David, alleging that the cellular phone
he bought her while she was pregnant caused or accelerated the growth of
the tumor that killed her. The case was later dismissed for lack of
scientific evidence.
At the time the suit was filed, the cell phone industry association,
the CTIA, said thousands of studies had been done showing the phones
were safe, but then was not able to provide any. The industry pledged to
spend $25 million on research to prove the phones are safe.
At least three federal agencies -- the Food and Drug Administration,
the Federal Communications Commission, and the Environmental Protection
Agency -- have roles in regulating radio-frequency radiation, but only
recently has the federal government committed funds to studying the cell
phone issue. Those studies are not expected to be completed for five to
seven years.
Dr. George Carlo, an epidemiologist then working at George Washington
University School of Medicine, coordinated the industry-supported
project, which began in the mid-1990s. When the money ran out in 2000,
Carlo said, more research was needed because one study showed the risk
of acoustic neuroma was 50 percent higher in people who used cell phones
for six years or more, and that there appeared to be a correlation
between brain tumors on the right side of the head and the use of the
phones on that side.
Carlo could not be reached on Wednesday, but the CTIA issued a
statement on the Karolinska findings.
"This is just one study on this particular subject and no
conclusions can be drawn from it," said spokesman John Walls.
"The wireless industry agrees that more research is needed in this
area to provide definitive answers to any questions that might still
exist. Numerous independent scientific bodies have conducted research on
possible health effects from using wireless phones and it is widely
accepted that no conclusive link can be made."
Mays Swicord, director of electromagnetic energy research at Motorola
in Plantation, one of the world's largest manufacturers of wireless
products, said the Karolinska study has to be taken in context alongside
1,300 other peer-reviewed publications on radio frequency radiation and
health. No consistent evidence has been observed for an increased risk
of cancer, he said.
Swicord said the Swedish study findings eventually will be pooled
with similar studies under way in 12 other countries as part of the
so-called INTERPHONE study, an international collaboration coordinated
by WHO's International Agency for Research on Cancer.
Nancy McVicar can be reached at nmcvicar@sun-sentinel.com or
954-356-4593.
