Long-term cell phone use increases brain tumor risk

http://www.nlm.nih.gov/medlineplus/news/fullstory_55570.html

Tuesday, October 2, 2007

NEW YORK (Reuters Health) - Using a cell phone for more than a
decade can double the risk of some brain tumors, according to a new
analysis of previous studies.

The findings "give a consistent pattern of increased risk for
acoustic neuroma and glioma," Dr. Lennart Hardell of University
Hospital in Orebro, Sweden and colleagues write, with the greatest
risk seen on the side of the head where the mobile phone was held.

Acoustic neuromas are benign growths on the nerve linking the ear to
the brain, while gliomas are malignant, difficult-to-treat tumors of
the brain and nervous system.

Concerns have been raised that mobile phones could boost brain tumor
risk by exposing the brain to electromagnetic energy, but early
studies did not have a long enough follow-up time to fully account
for long-term risk, Hardell and his team report in Occupational
Environmental Medicine.

Enough time has now passed since mobile phones were introduced to
analyze risks of cell phone use for 10 years or longer, which they
believe is a "reasonable minimum period" to estimate risk.

Hardell and his team identified 18 studies of brain tumor risk among
long-term cell phone users, 11 of which provided data for 10 years
or longer. When the findings were analyzed collectively, the
researchers found people who used cell phones for at least a decade
had a 2.4-fold greater risk of acoustic neuromas and were twice as
likely to develop gliomas.

One study found no increased tumor risk with cell phone use, but it
did show that mobile phone users who developed brain tumors had
larger tumors than non-cell phone users.

"These results are certainly of biological relevance." The greatest
risk was for tumors located in the area of the brain with the most
exposure and the study periods allowed enough time for tumors to
develop, the researchers note.

They add that "longer follow-up is needed, however, as an increased
risk for other types of brain tumors cannot be ruled out."

SOURCE: Occupational Environmental Medicine, September 2007.