October 12, 2004
Mobile Phones Again Linked to Cancer
Mobile phones may present a cancer risk after all.
Epidemiologists at the Karolinska Institute in Stockholm have found
that the phones can increase the incidence of acoustic neuromas, benign
tumors of the auditory nerve. The nerve is exposed to radiation during
the normal use of a cell phone.
Those who used mobile phones for at
least ten years, had close to twice the risk of developing acoustic
neuromas, according to a team led by Prof. Anders Ahlbom, the deputy
director of the Karolinska’s Institute of Environmental Medicine.
For those acoustic neuromas that were
on the same side of the head as the phone was used, the risk was even
higher —approximately a fourfold increase compared to controls, a
statistically significant finding.
“These are strong data,” Ahlbom told Microwave
News in a telephone interview. “Just how strong will be determined
in the upcoming post-publication assessment,” he added. The new study, which appears
in the November issue of Epidemiology, is part of the
13-nation Interphone study coordinated by the International Agency for
Research on Cancer (IARC) in Lyon, France.
These findings will be formally
announced at a press conference in Stockholm tomorrow, Wednesday,
Acoustic neuromas account for less
than 10% of all brain tumors. Approximately 1 in 100,000 people develop
this type of cancer. All the Interphone study teams, including
Ahlbom’s, will also report on the risk of the most common types of
brain tumors —for instance, astrocytomas and meningiomas.
Ahlbom declined to reveal his results
for the other types of brain cancer, but he did say that, “If acoustic
neuromas are possible, then the argument that effects are biologically
implausible does not apply, and we don’t know what is possible.”
“This is just the tip of the
iceberg,” said Dr. Sam Milham, an epidemiologist who has worked on
electromagnetic radiation effects for over 20 years. “If cell phones
can cause acoustic neuromas, they can also cause all the other types of
brain tumors,” he told Microwave News.
The new Swedish findings support
earlier work by Prof. Lennart Hardell and Kjell Hansson Mild of
Sweden’s Öreboro University. In a paper published two
years in the European Journal of Cancer Prevention, Hardell
and Mild reported a close to doubling of all types of brain tumors
among those who had used a mobile phone for more than ten years, a
statistically significant result. The highest risk was for acoustic
neuromas, which was three and a half times the rate among controls,
very similar to the 3.9-fold increased risk reported by Ahlbom.
“This is a replication of our
finding” Hardell told Microwave News. “We regard acoustic
neuroma to be a signal tumor for the increased cancer risk from mobile
phones. The results may predict an increased risk for other types of
brain tumors,” he added. (See also MWN, M/A02).
When Hardell’s results appeared in
2002, they were sharply criticized by many others, including Prof.
Magnus Ingelman-Sundberg, the vice-chair of the Karolinska’s Institute
of Environmental Medicine, where Ahlbom leads the department of
epidemiology. Ingelman-Sundberg called Hardell’s paper “alarmist” and
“irresponsible” (see MWN, S/OO2).
Ahlbom’s is the second report on
acoustic neuromas to appear from the Interphone study. In February, a
Danish group led by Christoffer Johansen of the Danish Cancer Society
in Copenhagen found no increased risk, but this study only had two
cases of acoustic neuroma who had used a mobile phone for more than ten
years. Ahlbom’s has 12 such cases.
In an editorial accompanying the
Ahlbom paper, Dr. David Savitz of the University of Carolina, Chapel
Hill, tries to put a positive spin on the new results. Calling the
neuroma risk “still highly unlikely,” Savitz writes: “This uncertainty
regarding long-term use should not distract from the growing evidence,
enhanced by this study, that neither acoustic neuroma nor brain tumors
is associated with cell phone use of less than ten years.”
But, in his paper, Ahlbom notes that
there may in fact still be a risk from the short-term use of cell
phones. “We cannot exclude the possibility that short-term exposure has
an effect that can be detected only after a long latency period,” he
And others, like Milham never thought
that an increased tumor risk would become apparent so soon. “From what
we know about the latency of solid tumors, you would not expect to see
an increase for at least 10 years and it would more likely be 20
years,” he said.
Hardell predicts that the new
findings will “have an impact on how cell phones are used, especially
by young people.”
In the U.S., the American Cancer
Society (ACS) has dismissed the possibility of a brain tumor risk from
cell phones. Last year, for instance, the ACS announced that any such
link was a “cancer myth” (see MWN, M/J03).
Dr. Eugenia Calle, the ACS’ director
of analytical epidemiology in Altanta, testified at a brain tumor
hearing held in Baltimore in 2002 that, “My conclusion based on the
epidemiological studies...and...the input of the larger scientific
community is...that there’s no association [between cell phone] use and
brain cancer.” Calle was testifying on behalf of the cell phone
Similarly at the same hearing, Dr.
Meir Stampfer, an epidemiologist at the Harvard School of Public
Health, said on behalf of the industry, “There is no credible basis to
support a causation claim between wirelss phone use and brain cancers.”
In the last couple of years, the
mobile phone companies have argued that enough research has been
carried out to be confident that there are no health effects from the
use of cell phones. Dr. Mays Swicord of Motorola, speaking on behalf of
the Mobile Manufacturers Forum (MMF) made this case, most recently, at
a seminar held in
Brussels last month.
The lead author of the new Karolinka
paper is Stefan Lönn, who did the study as part of his doctoral