No Causal Evidence for Mobile Phone - Brain Cancer Link

Could your mobile phone be hazardous to your health? Probably not, unless you're using it while driving and raise your risk of a car accident, says John E. Moulder, PhD, Medical College of Wisconsin Professor of Radiation Oncology.

Dr. Moulder, a radiation biologist and an authority on electromagnetic fields and human health, has published numerous articles over the past five years in international professional publications exploring possible health risks posed by the use of mobile phones* - including fears that such phones could cause brain cancer because they emit radiofrequency (RF) energy.

In an article in IEEE Spectrum (August, 2000), a publication of the Institute of Electrical and Electronics Engineers, he and another scientist, Kenneth R. Foster of the University of Pennsylvania, traced the origins of the phone-cancer link speculation. The authors wrote that research into health concerns over the use of mobile phones grew out of a 1992 Florida lawsuit that alleged that a woman's fatal brain cancer had been caused by her use of a mobile phone.

"The suit was dismissed by a federal court in 1995 for lack of valid scientific evidence," they wrote, "and similar suits since have been no more successful. But they … raised questions for which no entirely satisfactory answers existed at the time. Driven in part by these disturbing allegations, a new wave of research in the United States and elsewhere is exploring possible links between cell phone radiation and cancer."

'No Consistent Evidence'
Since then, researchers have reached a broad consensus, Dr. Moulder says: "Multiple studies have looked for excess brain cancer in users of mobile phones, and these studies have found no consistent evidence for any such increase."

The US Food and Drug Administration agrees. In a 2003 update, the FDA said: "The available scientific evidence does not show that any health problems are associated with using wireless phones."

But both Dr. Moulder and the FDA caution that the absence of increased cases of brain cancer by mobile phone users does not necessarily mean that wireless phones are perfectly safe, either.

"It is impossible to prove that anything is 'absolutely safe,' " Dr. Moulder says. "The controversy about RF radiation and cancer reflects difficulties inherent in cancer risk assessment. It is relatively easy to identify strong human carcinogenic risks (for example, cigarette smoking and lung cancer), but proving the absolute absence of a carcinogenic risk is both practically and theoretically impossible."

The FDA, noting that the low levels of RF energy in wireless phones in use or on standby are similar to that of a microwave oven, says: "Many studies of low level RF exposures have not found any biological effects. Some studies have suggested that some biological effects may occur, but such findings have not been confirmed by additional research. In some cases, other researchers have had difficulty in reproducing those studies, or in determining the reasons for inconsistent results."

So, do mobile phones cause brain cancer? Dr Moulder would argue that that is the wrong question.

"Better questions to ask," Dr. Moulder says, are 'How hard have scientists looked for evidence that RF radiation causes cancer?' and 'How strong is the overall evidence linking RF radiation and cancer?' "

"Scientists have looked very hard for human, animal and cellular evidence that RF radiation from mobile phones could cause cancer," says Dr. Moulder. "And they have found no strong or consistent evidence for a such causal link."

Currently, he adds, there is diminishing scientific interest in the subject. "The obvious studies have been done and have found no consistent evidence for carcinogenic potential. Most scientists have very little interest in trying to prove that something does not cause cancer when almost no one thinks that it does."

So if wireless phones are not likely to cause brain cancer, but cannot be called "absolutely safe," what should the user think?

Newer Phones, Less RF Power
"In general," Dr. Moulder says, "the newer mobile phones have lower maximum power than the older ones. Also, the newer phones have 'adaptive power control,' so that they decrease their power when they are near a base station. Since the base stations are more common than they used to be, the actual power produced by the handsets is generally lower than it used to be," he says.

"The issue is whether the benefits of the technology are sufficient that the remaining uncertainty is acceptable. If readers are worried about exposure to RF radiation from mobile phones, they can do three things to reduce exposure:
# talk less
# when possible, avoid using the phone where the signal strength is weak, since the weaker the signal you are getting the stronger the phone has to respond
# use a headset and keep the body of the phone away from you."

And don't use a mobile phone while driving, Dr. Moulder adds, noting that the problem isn't limited to motorists. "I have also seen people here in Milwaukee talking on mobile phones while on bicycles, motorcycles, and roller-blades, so it is not just cars."

"Operating a vehicle while using a mobile phone is clearly hazardous to the user and the rest of us (e.g., other drivers, cyclists, pedestrians). That is the only known hazard from the use of mobile phones, although discourteous use of a phone where it offends other people may be a hazard to the user."