Mary McBride: Do cell phones cause brain cancer?

Mary McBride explains some of the basics about how cell phones interact with the body, and about how much cell phone use could be too much.

Mary McBride led the Canadian component of a multinational, decade-long study – released in May of 2010 – that tracked the cell phone use and incidence of brain tumors of about 13,000 people over 13 countries. The International Agency for Research on Cancer (IARC) and the Canadian Institutes for Health Research conducted the study. EarthSky originally published this interview on May 31, 2010. We release it again here in light of the World Health Organization listing of cell phones on its category 2B list of things possibly carcinogenic to humans.

How could cell phone use 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 cause 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.

What did your study find?

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. 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.

Your study found that moderate cell phone use – defined in the study as under a half hour a day – was not linked to brain cancer. However, your study was less conclusive about heavier use of cell phones. Tell us about that.

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 headset or texting reduce exposure to the individual for any individual call, given that the actual main source of exposure, the cell phone antenna, is farther away from the body.

Can using your cell phone give you brain cancer?

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.

Jorge Salazar