Federal Communications Commission chair Julius Genachowski has put forward a proposal that the agency review its regulations governing the amount of energy that can be emitted by mobile phones. Although a spokesperson characterized the potential review as “routine,” the possible move has reignited concerns over a potential link between mobile phone usage and some types of brain and head cancers. Any re-examination could have broad effects on the mobile industry, since essentially all mobile phone and portable device makers have to comply with FCC requirements on emissions. There’s even a possibility the FCC could look at different sets of standards: one for adults, and another more-stringent set of guidelines aimed at children, whose developing bodies may be more at risk.

That sounds well and good — after all, looking out for the public’s well-being is part of the agency’s job. However, the vast majority of scientific studies to date have found no relationship between cell phone use and cancer. Why is the FCC opening up this can of worms again?

The FCC’s role

Here’s a funny thing: there are no universal federal standards that layout supposedly-safe levels of exposure to radio frequency (RF) energy — the sort of thing emitted by cell phones and other devices. That said, a bunch of separate federal agencies have their own takes on the issue, including the National Institute for Occupational Safely and Health, the Environmental Protection Agency, the Food and Drug Administration, and (of course) the FCC. The FCC is, of course, concerned with communications devices, while agencies like the FDA are more concerned with devices like microwave ovens, NIOSH tends to look at things like video display terminals in workplaces, and the EPA looks at levels of RF emissions in the general environment, as well as things like RFID tags and so-called “smart meters” that report power usage information back to utilities using wireless technologies.

These federal agencies generally have few (if any) physicians, biologists, or other experts on their staff conducting research to form their guidelines, so they rely on work from non-governmental organizations like the the American National Standards Institute (ANSI) National Council on Radiation Protection and Measurements (NCRP) and the Institute of Electrical and Electronics Engineers (IEEE). But they really don’t look at the standards all that often. The FCC last set regulations covering emissions from mobile phones back in 1996 — the document is old enough that the FCC released it in WordPerfect format. If it’s “routine,” it’s not a very regular routine. But compared to other agencies, the FCC is kind of on the ball: The EPA last looked at RF emissions way back in 1979.

What are the limits?

For mobile phones and other devices designed to be used close to the human body, the FCC and most other agencies deals with RF emissions in terms of specific absorption rate, or SAR. The FCC’s maximum “safe” SAR for RF emissions from a mobile phone or similar device is 1.6 Watts per kilogram, averaged over one gram of tissue. (This is actually a bit more restrictive than similar limits in Europe, which are currently 2 Watts per kilogram averaged over 10 grams of tissue.) As a point of comparison, measured SAR of RF radiation from a microwave oven is about 8 Watts per kilogram if you are literally pressing yourself up against it while its operating. From a distance of just 5 cm — say, peering through the window to see if your macaroni and cheese has exploded — the SAR from that same microwave oven drops to less than 0.3 Watts per kilogram.

That said, the concern with mobile phones is that literally hundreds of millions of people are pressing RF-emitting devices to within a centimeter or so of their brains, sometimes for several hours a day. As yet, even longitudinal scientific studies attempting to track individuals’ health and cell phone use over decades have not linked any known health problems to exposure to RF energy from mobile phones. However, you can’t prove a negative, so studies haven’t disproven any connection either, and there’s enough variation in some studies that researchers and activists aren’t willing to rule out of the possibility of a relationship, however slight. And if there is a connection, we may not be seeing signs yet. Back in 1996, only about 44 million Americans had mobile phones; today, most industry estimates put the figure over 330 million. Given how long it can take cancers like glioma and acoustic nueroma to develop, it may be many years before any long term effects start to become apparent, at which point, it would be too late for a couple generations of mobile phone users to avoid problems.

Mobile phones as a possible carcinogen

Most forms of cancer develop as a result of damage to DNA. Plenty of things can lead to DNA damage: Sometimes it even occurs “naturally” when cells goof up during the complex chemical processes involved in DNA replication. The copying process is near-perfect, but not wholly perfect. That’s one way we get mutations. Sometimes mutations are beneficial; sometimes they’re cancer.

Sometimes substances interfere with the DNA replication process, inserting themselves into the process or preventing certain chemical bondings from taking place. (These substances are “carcinogens.” Sometimes they’re exotic chemicals, sometimes they’re everyday materials like oxygen with a spare electron just waiting to latch on to something convenient.) Ionizing radiation — like x-rays, gamma rays, and radon — can also damage DNA directly. This is an oversimplification, but think of ionizing radiation as bullets smashing into DNA. DNA replication takes place, the original DNA is broken, so the copies are broken too. All these things increase risk of cancer.

Radio frequency (RF) radiation is non-ionizing. Basically, it has no bullets. There is currently no scientific evidence that RF energy increases cancer risk. None.

The only known biological impact of RF energy being absorbed by tissue is heating. This is actually the process by which microwave ovens work, albeit at a much higher power levels than mobile phones. The heating impact of mobile phone use is not enough to raise human body temperature, although it might be enough to slightly raise the temperature of tissue closest to the phone. A 2011 study found preliminary evidence that during long mobile phone calls (50 minutes) brain tissue on the side of users’ heads with the mobile phone metabolized more sugar (glucose) than the opposite side of the brain. But there is as yet no known significance to this finding — assuming it holds up.

So why the worry?

No amount of research will be able to prove there’s no connection between mobile phones and cancer, so there will always be room for doubt. Not all people are created equal — your mileage may vary, as the saying goes. RF energy and heating may not have any known general impact on tissue, but testing cannot have accounted for every substance, medication, or combination thereof that could be floating around a person’s physiology or bloodstream. Who knows: Maybe metabolizing more glucose while on a particular medication can produce a slight uptick in a nucleotide that, rarely, can interfere with normal DNA replication? No one can say. Possibilities like this and inconsistent results from a handful of long-term studies are what led the International Agency for Research on Cancer (part of the World Health Organization) to classify cell phones alongside things like gasoline and DDT as “possible” carcinogens. The agency did not claim there is a connection, but called for more research. However, other organizations like the International Commission on Non-Ionizing Radiation conclude (PDF) that scientific evidence is increasingly against any link between mobile phone use and brain tumors in adults. But there’s still very little data on people who have used cell phones for more than 15 years.

Children, however, might be another matter. Children’s brains are undergoing rapid development and could conceivably be more sensitive to RF energy than healthy adults. The issue of children is usually where the debate about cell phone emissions becomes most forceful, since parents and societies are understandably very sensitive about any issue potentially impacting child welfare. Children are also one area where current scientific research is lacking — longitudinal studies to date don’t have much data to work with on childhood tumors. However, one of the only major studies to date, the CEFALO study conducted in Sweden, Norway, Denmark, and Switzerland, found no connection between brain tumors and cell phone use in children aged 7 to 19.

Upshot

The FCC’s proposed review of RF emission standards can hardly be classified as “routine,” since they basically never seem to do it. However, in light of the current body scientific research, it can only be described as being proposed with an abundance of caution. There is no reason to suspect a problem, but the world has changed since 1996 and another look can’t hurt. After all, not only is mobile technology vastly more common, but it’s changing. Things like directional antennas may warrant some changes to the ways the FCC tests that devices meet emissions requirements.

Coping mechanisms

If you’re concerned about RF energy emitted by a mobile phone, here are a few things you can do:

  • Limit call time. Just don’t talk as much. Consider using text messages or other messaging services for things that don’t require direct interaction.
  • Use a headset or speakerphone. Although wired headsets can conduct a bit of energy to your head and Bluetooth headsets are themselves RF emitters, the levels are far lower than those emitted from mobile phones.
  • Keep your phone a little further away. Folks who carry a cell phone around in a pants pocket may not be pressing it to their head, but they’re pressing it to another part of their body. Consider keeping your phone in a bag or jacket pocket that keeps the device farther away from you.

Cancer cell image via Shutterstock / Robert J. Daveant
Cell tower image via Shutterstock / noolwlee]
Microwave hazard via Shutterstock / XAOC
Children and smartphone via Shutterstock / photo video the same object