Each time a cell phone user makes a call, it emits a low level of radiofrequency energy as the phone’s antenna generates radio waves that ultimately transmit people’s voices from one phone to another. The amount of radiation depends on how long a person stays on the phone, how he holds the phone to his head, and whether he uses it in the city or the country. Though studies are being done to see if there is a link between cell phone use and the development of tumors of the brain, the US National Cancer Institute (NCI) has categorically said that there is no definitive link between the two.
So why does the controversy persist? Studies trying to link a behavior to an outcome are inherently difficult. Researchers typically ask people (who may, in fact, have cognitive impairment as a result of the brain cancer) to recall their cell phone habits. Brain tumor patients who know about the potential risk of cell phones may be more prone to what is known as recall bias, reporting using their cell phones at a higher rate than they actually did. And brain cancer itself is rare: According to the NCI, only one in 165 people are diagnosed during the course of a lifetime with a cancer of the brain or nervous system. To put this into perspective, lung cancer is roughly 10 times more common.
Cause For Concern
On July 21 last year, the head of a prominent US cancer institute issued an unprecedented warning to his faculty and staff: Limit cell phone use because of the potential risk of cancer.
The warning from Dr. Ronald Herberman, director of the University of Pittsburgh Cancer Institute, is contrary to numerous studies that have not found a link between cancer and cell phone use, and a public lack of worry by the US Food and Drug Administration (FDA). Herberman based his alarm on early, unpublished data. He said it takes too long to get answers from science and he thinks people should take action now. David Carpenter, director of the Institute of Health and Environment at the University of Albany, supported Herberman’s move. He said, “Society must not repeat the situation we had with the relationship between smoking and lung cancer where we waited until every “i” was dotted and every “t” was crossed before warnings were issued. He added that like messages that warn of health risks on cigarette packs, cell phones “need a precautionary message.” Added Herberman, “Recalling the 70 years it took to remove lead from paint and gasoline, and the 50 years it took to convincingly establish the link between smoking and lung cancer, I argue that we must learn from our past to do a better job of interpreting evidence of potential risks.”
A driving force behind the Herberman memo was Devra Lee Davis, director of the university’s Center for Environmental Oncology. “The question is, do you want to play Russian roulette with your brain?” she said in interview. “I don’t know that cell phones are dangerous. But I don’t know that they are safe.”
One study that Herberman and Carpenter quote is a paper published last year by the Royal Society in London which found that adolescents who start using cell phones before the age 20 were five times more likely to develop brain cancer at the age of 29 than those who didn’t use a cell phone. “And it only occurs on the side of the head where you use the cell phone,” Carpenter said. However, some experts have...