Update: In the fall of 2014, the Berkeley City Council is considering an ordinance that would make it the only city in the nation to require cell phone warning stickers. We explore whether, based on the latest science, the proposal is a proper precaution, or paranoia, here.
You, me, and everyone we know probably has a radio emitter close to our bodies, blasting off radiation almost constantly. Teens keep it under their pillow so they can hear it at night. Babies play with it. It’s a cell phone, and while it’s revolutionized how we interact with one another, scientists have been debating for years about its possible harmful effects.
Is all that radiation harmful? Can mobile phones cause brain cancer?
Joel Moskowitz, Ph.D., directs a research center in the School of Public Health. He participated in a meta-analysis led by Seung-Kwon Myung, an epidemiologist from South Korea. The researchers looked at 23 recent studies of cell phones and their potential link to tumor risk. What Moskowitz had to say might change your mind about your iPhone or Blackberry.
California: What did your analysis find?
Joel Moskowitz: When you look across all 23 studies, you find no increased cancer risk. However, when you break the studies down in terms of the quality of the research, you find two distinctly different patterns of results.
The methodological quality was rated according to the appropriate use of control groups, blinding of study participants and researchers, etc. In the lower-quality studies you find what would actually appear to be a reduced risk of cancer. That accounts for 13 of the studies.
In the other ten studies, the higher-quality studies, we found an elevated cancer risk: approximately 10 percent higher than the general population. These tumors are mostly of the head and neck: gliomas, acoustic neuromas, meningiomas, and tumors of the salivary gland.
One of the interesting things we found with our meta-analysis is, when looking at a subset of people who used mobile phones for ten or more years, and there were eight of these studies, overall there was a significant risk of brain tumors. There is now evidence from two major studies that the risk of glioma, a common brain cancer, is doubled after ten years of cell phone use.
C: Did you find any connection among the lower-quality studies, the ones that found no risk?
JM: Well, almost all of the low-quality studies, most were part of a consortium called Interphone, were funded all or in part by the cell phone industry. Interphone is underwritten by the WHO [World Health Organization] in part, but also has supplemental funding from the cell phone industry.
C: Have you found any other outside influences on the research?
JM: I’m cautious in reading this literature, because so many biased studies have been published. In the past there have been a few attempts by editors to rewrite results, and by funding agencies to suppress research. Some early pioneers who found biologic reactivity lost funding for their laboratories. There was outright suppression by the military of some of the earliest research, particularly around radar, which is similar to the radiation emitted by cell phones and cordless phones.
The industry, by and large, has not been cooperative with supplying data for research. In the U.S., they have not been forthcoming at all.
C: Did you identify any other negative effects from cell phone or low-level radiation?
JM: One study found evidence of increased risk of salivary gland tumors. We’re hearing from a few physicians about breast cancer in women who keep the cell phone in their breast pocket. We’ve also heard of bone marrow disease in men who keep the phone in their hip pocket. However, these are isolated reports, so it’s hard to know if these effects are due to cell phone use.
C: What can we do to lower these risks?
JM: With electromagnetic radiation, the intensity is a function of the square of the distance, so the difference between 1 inch from your brain and 10 inches from your brain is a factor of 100. You get a substantial reduction of exposure just by keeping it away from your body. So, use a headset, especially a corded device.
[Of] particular concern is the proximity of the phone to sensitive bodily organs, especially your head and neck, but also your reproductive organs. You also have to be concerned if you’re not using the phone but it is turned on, because you’re exposing that part of your body to the radiation.
Another important piece of advice—and by my count about a dozen nations have already issued precautionary health warnings—focuses on children. The concern is that their developing brains are much more vulnerable, and they’re going to have much longer durations of exposure if they start using phones as children. Because it generally takes decades to see brain tumors, and their exposures are starting at a much younger age, they may start having tumors as middle-aged adults. You want to reduce use among children as much as you can.