We have no clear evidence that cell phones pose health risks, but that doesn't mean there's no cause for concern. The latest on this subject comes from Britain, where a six-year study published in September, 2007, by the UK Mobile Telecommunications and Health Research (MTHR) Programme found that cell phone use had no adverse effects on brain function, memory and reaction times and no evidence that it can lead to brain cancer.
But the scientist who headed the $17.9 million study emphasized that research so far has included few participants who have used cell phones for 10 years or longer. An ongoing study involving 200,000 people in Denmark, Finland, Sweden and Britain may tell us more about possible long-term health risks.
In 2006, a Swedish study showed that the risk of developing a malignant tumor on the side of the head where a cell phone is typically used was 240 percent greater than normal. But the findings, published in 2006 in the International Archives of Occupational and Environmental Health, contradicted the results of a number of large clinical trials, none of which found any such evidence. The latest from Sweden, an analysis of earlier studies, concluded that using a cell phone for more than a decade can double the risks of benign brain tumors called acoustic neuroma and malignant brain and nervous system tumors called gliomas.
Brain tumors can take 30 to 40 years to develop, so it could be many years before we know for sure whether cell phone use is safe or, if not, how great the risks may be. Until then, the big worry is that children may be more vulnerable than adults (just as they're more susceptible to risks posed by exposure to cigarette smoke, lead and radiation). For this reason, experts in the United States and Britain have advised limiting youngsters' cell phone use.
It also makes sense for adults take precautions:
- Save long conversations for conventional phones.
- In your car, use a cell phone that has a remote antenna outside the vehicle.
- Always use a headset and keep the phone itself away from your body.
- Find out how much radiofrequency energy your cell phone emits. (This measurement is called the Specific Absorption Rate or SAR; find the SAR for your cell phone via the FCC at http://www.fcc.gov/oet/rfsafety/sar.html. The SAR permitted in the United States is 1.6 watts per kilogram.)
And to avoid auto accidents, the biggest known risk, stay off the phone while driving, and pull over when you have to make or take a call.
Andrew Weil, M.D.