Study: Cell Phones Are Safe
Friday, February 9th 2001, 12:00 am
By: News On 6
WASHINGTON (AP) â€” A study of 420,000 cell phone users in Denmark concluded callers are no more likely than anyone else to suffer cancer â€” but even this huge study, the latest to provide reassurance about the phones' safety, won't end the debate.
The study, published in Wednesday's Journal of the National Cancer Institute, found no increased risk for brain or nervous system cancers, leukemia or salivary gland tumors among cell phone users, the types of malignancies that worry critics.
``Every which way we looked at it, we could not find any suggestive evidence for elevated risks,'' said John Boice of the International Epidemiology Institute in Rockville, Md., who co-authored the study with Christoffer Johansen of Copenhagen's Danish Cancer Society.
Taken together with two recent, smaller U.S. studies that found no cancer risk, the research should ``minimize the concern and fears that the public has with regard to the use of these phones,'' he said.
But the study didn't last long enough to completely settle the issue. Several thousand Danes had used their phones for more than 10 years, the time it can take a slow-growing brain tumor to appear, but the majority had used them for only about three years.
Consequently, ``this study ... should not be taken as the final answer,'' said University of Washington professor Henry Lai, whose laboratory research linked cell phone signals with damage to rat brain cells.
``It's reassuring ... but not enough that it closes the book on this question,'' added Boston University epidemiology professor Kenneth Rothman.
Federal health officials insist there's no real evidence that cell phones used by 97 million Americans cause health hazards beyond car crashes that result from people talking while driving.
Yet no health or government agency gives the popular gadgets a definitively clean bill of health, either. Unable to give a clear answer, the Food and Drug Administration tells worried consumers they can simply use an earphone device that keeps the phone's antenna away from the head.
Cellular phones work by beaming radio-frequency energy, low-powered radiation. Most research â€” including two recent U.S. studies that examined 2,400 people, some who had used cell phones for five years â€” has found no risk.
But a few small studies have raised concern. They include Lai's rat data and a Swedish study that found brain tumors more likely on the side of the head on which cell phones were used.
Denmark provides a strong look at the issue thanks to the unique Danish Cancer Registry that tracks every citizen who gets cancer, using personal identification numbers assigned to each Dane at birth.
Johansen used cell phone company records to identify Danes who began using the phones between 1982 and 1995. Using those personal ID numbers, he matched phone users with the registry's cancer records through the end of 1996, to determine if cell callers suffered cancer at the same rate as other Danes.
Based on national cancer rates, 161 of the cell phone users should have suffered brain or nervous system cancer, and 154 of them did. Similarly, there were 84 leukemia cases instead of an expected 86, and seven salivary gland tumors instead of the expected nine.
Phone use didn't affect which side of the brain a tumor was on, nor did the study find any increase in very rare tumors, called neuroepitheliomas and acoustic neuromas, that some studies have linked to cell phones.
The study couldn't track how long all 420,000 Danish callers actually spent on the phone. But Boice said people who began using the phones about three years ago were spending 30 to 60 minutes a day talking, and that duration of use showed no risk.
The ``beautifully designed'' study and ``rock-solid database make it difficult to take issue with the report's conclusion,'' Robert Park of the American Physical Society wrote in an accompanying editorial.
On the Net: FDA: http://www.fda.gov/cdrh/radhealth.html
National Cancer Institute: http://www.cancer.gov
Danish Cancer Society: http://www.cancer.dk/index.asp?language1&tekst/english/intro.htm