Can using your cell phone give you brain cancer? We posed that question to Mary McBride, a senior scientist with the British Columbia Cancer Agency.
Mary McBride: We don't exactly know. We're reassured that for the casual user, there is no conclusive evidence that cell phones do cause cancer. We still do not know about heavy users, long-term users, or children as users.
Ms. McBride is a co-investigator of the largest study of its kind that looked at the risk of cancer from cell phone use by adults. The decade-long study, released in May of 2010, tracked the cell phone use and incidence of brain tumors of about 13,000 people over 13 countries.
What we have found is that there doesn't appear to be any large risk of brain tumors from cell phone use. And there doesn't seem to be any short-term risk from cell phones. And again, given that we know that there's some uncertainty in our calculations. We looked to previous studies and the lab studies to be consistent with that. So I think that's a very important conclusion.
In other words, there was no smoking gun found that links moderate cell phone use, defined in the study as under a half hour a day, with brain cancer. However, the study was less conclusive about heavier use of cell phones, said McBride. She said that there's been a dramatic increase in the use of cell phones in the last ten years or more.
It's probably useful to point out that although more people are using them, and they're probably using them for longer, cell phone technology has also changed, so that the newer technology phones, digital versus the older analog phones produce lower emissions of radio frequency fields.Also, practices such as using a handset or texting reduce exposure to the individual for any individual call, given that the actual main source of exposure, cell phone antenna, is farther away from the body.
McBride described the way cell phone use could possibly interact with the body to elevate cancer risk.
Cancer is considered a two-stage process. The first step is a change to the DNA, to the genetic material. That's called the initiation step. And that can occur if there is a genetic mutation, for example, or if something like x-rays damages the DNA. The second type of step, what's called the promoting step, there's various mechanisms that can promote an already susceptible cell and change it further into a cancer cell. So the question of whether radio frequency fields could actually DNA damage was looked at extremely closely. It's probably more likely that if these radio frequency fields cause cancer, it'll be more at the later stages of development, at the promoting stages, which is why we think our information for users of ten years or less is definitely relevant to individuals and to the population.
Mary McBride is a research scientist with the British Columbia Research Center, part of the government-run British Columbia Cancer Agency which oversees much of the research and nearly all of the radiation and chemotherapy of the Canadian province. McBride is co-investigator of the Canadian component of a multinational case-control study of the use of cell phones and risk of brain tumors, sponsored by the International Agency for Research on Cancer and funded by the Canadian Institutes for Health Research. Previously, she has conducted a large epidemiologic investigation into risk factors, including power-frequency electric and magnetic fields, for development of childhood leukemia, and co-authored a number of publications on second cancer risk.