Radiation. Powerful enough to turn Dr. Bruce Banner (Bill Bixby) into The Incredible Hulk (Lou Ferrigno), or meek Peter Parker (Tobey Maguire) into The Amazing Spider-Man (still Tobey Maguire, but more buff and spandexed). It also obliterated two cities in Japan, and continues to contribute to cancers near Chernobyl. It’s sciency, strong, and scary. No wonder it creates so much apprehension.
We’re all living every day surrounded by radiation sources, and bathed in radioactive rays. Cosmic rays are a significant and unavoidable source of radiation from above, and naturally occurring forms of radon, carbon, and many other elements in the earth’s crust bombard us with radiation from below.
Not all radiation is the same. The more-powerful, cell-damaging kind is called “ionizing radiation,” and we know that can strip atoms apart and disrupt DNA. This kind of radiation occurs in cosmic rays and diagnostic x-rays, and that’s why radiology technicians wear lead overcoats. It is a bad idea to be exposed to excessive ionizing radiation, though even that risk should be put in perspective, since you can’t possibly avoid it entirely. For comparison, a single chest x-ray exposes an adult to about the same ionizing radiation that you’d get in three days of living on the earth at sea level. Three days, that doesn’t sound so bad. But an abdominal CT scan? That’s about three extra years. Diagnostic radiology is a wonderful tool, but it should be used carefully.
The other kind of radiation is called “non-ionizing.” You’re swimming in that, too. All light is a form of non-ionizing radiation, as are radio waves and microwaves. Though at very intense, high exposures these kinds of radiation can damage tissue (think about a microwave oven, or spending a day in the sun), the process of damage is by the transfer of heat, not the destruction of DNA or other molecules directly. And it only takes a very thin layer of shielding to protect from even intense non-ionizing radiation. You can get a sunburn, yes, but you won’t burn through a thin piece of clothing or a layer of sunscreen, and a little piece of darkened plastic can make squinting unnecessary even on a bright day. Non-ionizing radiation doesn’t penetrate tissue well, and that’s one reason it’s thought of as generally safe.
Cell phones themselves use non-ionizing radio waves to communicate with their towers, and that radiation can barely penetrate the topmost payer of your skin. The most recent research has found no link between cell phone use and cancer, though good studies of more than ten years exposure have not been done. Certainly, if there is a risk, it’s very small; a large risk effect would be easy to spot in demographic and population trends, and it just isn’t there.
Cell phone towers transmit in both radio waves and microwaves, though the microwaves are directed to travel along lines of sight to the next tower– they don’t point down towards the ground at all. There is no credible evidence that they cause any direct harm. At least not from their radiation.
The real risk, of course, is automobile accidents. Car wrecks kill about 45,000 people in the USA every year. How many of these are caused by drivers distracted by a cell phone?
For a while, high-voltage electric transmission lines, which also emit electromagnetic radiation, were implicated as a cause of cancer and other bad things. After decades of research failed to find real evidence of any harm, the anti-power line crowd seems to have moved on to cell phones as the latest health boogeyman. (For more about the story of epidemiology and the rise and fall of the hysteria over health risks from power lines, read Geoffrey Kabat’s Hyping Health Risks.)
Don’t fall for the hysteria over cell towers. Careful studies have so far been able to rule out any large effect; though tiny effects are still possible, good research is being done to see what the extent of that might be. In the meantime, if you want to be safe around cell phones, don’t use them when you’re driving. That’s a much, much bigger health risk than could possibly be associated from the Scary Rays from The Sky.
Roy Benaroch is a pediatrician who blogs at The Pediatric Insider. He is also the author of Solving Health and Behavioral Problems from Birth through Preschool: A Parent’s Guide and A Guide to Getting the Best Health Care for Your Child.
