Can Cell Phone Radiation Cause Brain Cancer?
Researchers investigating that question have gone back and forth on this subject and it has divided the medical community and cell-phone users into two camps: those who think we shouldn’t worry so much about cell-phone radiation, and those who think that there is enough evidence to warrant following the cautionary principle. Unfortunately most Americans don’t seem to be worried.
In a recent national Consumer Reports survey of 1,000 adults, only 5 percent said they were very concerned about the radiation from cell phones, and less than half took steps to limit their exposure to it. Many respected scientists also share that same opinion. “We found no evidence of an increased risk of brain tumors or any other form of cancer” from cell-phone radiation, says John Boice Jr., Sc.D., president of the National Council on Radiation Protection & Measurements and a professor of medicine at the Vanderbilt University School of Medicine in Nashville, Tenn. The U.S. government doesn’t seem very troubled, either. The Food and Drug Administration says on its website that research generally doesn’t link cell phones to any health problem. And although the Federal Communications Commission requires manufacturers to include information in user manuals about cell-phone handling, but that is often buried in the fine print.
But not everyone feels unconcerned. In May 2015, a group of 190 independent scientists from 39 countries called on the United Nations, the World Health Organization, and our national governments to develop stricter controls on cell-phone radiation exposure. They point to growing research as well as the classification of cell-phone radiation as a possible carcinogen by the International Agency for Research on Cancer which suggested that low levels of radiation from cell phones could have potentially cancer-causing effects. “I think the overall evidence that wireless radiation might cause adverse health effects is now strong enough that it’s almost unjustifiable for government agencies and scientists not to be alerting the public to the potential hazards,” says David O. Carpenter, M.D., director of the Institute for Health and the Environment at the University at Albany in New York and one of the authors of the recent letter to the U.N. and WHO. Some countries have taken steps to protect children. For example, France, Russia, the U.K., and Zambia have either banned ads that promote the sale of a cell phone to a child, or they have issued precautions when phones are to be used by children.
The city council of Berkeley, Calif., has also acted on this issue earlier this year. In May 2015, it approved a “Right to Know” law that requires electronics retailers to notify consumers about the proper handling of cell phones. CTIA-The Wireless Association, a trade group, is trying to block that law from going into effect, as it did after San Francisco passed similar laws five years ago. Scientific seesawing like that doesn’t provide a lot of clarity or confidence for the 90 percent of American adults and roughly 80 percent of teens who reportedly have a cell phone.
What Is Cell-Phone Radiation?
Your phone sends radio frequency (or RF) waves from its antenna to nearby cell towers, and it also receives RF waves back to its antenna from the cell towers whenever you make a call, text, or use data. The frequency of a cell phone’s RF waves falls somewhere between those emitted by FM radios and those from microwave ovens. All of these are considered “non-ionizing” forms of radiation. That means that, unlike radiation from a nuclear explosion, a CT scan, or a standard X-ray, the radiation from your phone does not carry enough energy to directly break or alter your DNA, which is one way that cancer can occur. FM radios and microwaves don’t raise alarms because they aren’t held close to your head when you use them and because microwave ovens have shields that offers the consumer some protection.
How Can Cell Phone Radiation Cause Cancer?
At high power levels, RF waves can heat up water molecules (this is how microwaves heat up food). Scientists used to worry about the possibility that this method of heating may also have the potential to heat human tissues since our cells are also composed of water, and therefore this might be damaging to our cells.
But most experts aren’t concerned about tissues heating caused by RF waves, but they are worried that the exposure to cell-phone radiation might still have a biological effect without raising temperature. In 2011, researchers at the National Institutes of Health revealed that low-level radiation from an activated cell phone that was held close to a human head could change the way certain brain cells functioned, even though it did not raise the body’s temperature. The study did not prove that the effect on brain cells was dangerous, only that radiation from cell phones could have a direct effect on human tissue.
RF waves from cell phones have also been shown to produce “stress” proteins in human cells. This is according to research from Martin Blank, Ph.D., a special lecturer in the department of physiology and cellular biophysics at Columbia University and another one of the concerned scientist who signed the recent letter to the WHO and U.N. “These proteins are used for protection,” Blank says. “The cell is saying that RF is bad for me and it has to do something about it.”
Also this year, a German study found that RF waves promoted the growth of brain tumors in mice, again this was at radiation levels supposedly too low to raise body temperature. The U.S. National Toxicology Program is now running an animal study of its own by exposing rats and mice to low-dose radiation. Results are expected to be released in 2016.
What Do the Studies with Cell Phones Reveal?
The research above describes lab and animal studies that looked at how cell-phone radiation might cause cancer or affect the body in other ways. But we also reviewed studies that investigated whether cell phones increased brain-cancer risk in humans. For this we focused on five large population studies, plus follow-ups to those studies that investigated that question. Together the studies included more than a million people worldwide, comparing cell-phone users with nonusers.
Though some findings were reassuring, others raised concerns. Specifically, three of the studies—one from Sweden, another from France, and a third that combined data from 13 countries—suggest a connection between heavy cell-phone use and gliomas (tumors that are usually cancerous and often deadly). One of those studies hinted at a link between cell phones and acoustic neuromas (or noncancerous tumors), and two studies hinted at meningiomas (a relatively common but usually not a deadly brain tumor). Although these findings are worrisome, none of the studies can prove that there is a connection between cell phones and brain cancer for several reasons.
- Because cell-phone use in certain studies was self-reported so it may not be accurate.
- Because some of the study subjects owned cell phones that were manufactured two decades ago. The way we use cell phones and the networks they’re operated on have changed since then.
- Most brain cancers develop slowly, and these studies only analyzed data spanning five-20 years.
Are Newer Phones Safer?
Cell-phone designs have changed a lot since the studies described above were completed. For example, the antennas which is where most of the radiation is emitted from are no longer located at the top of the phones, but are now inside towards the bottom. As a result, the antenna may not be held against your head when you’re on the phone. That’s important because when it comes to cell-phone radiation, every millimeter counts: The strength of exposure drops dramatically as the distance from your body increases.
Perhaps our best protection is that more people are using their cell phones to text instead of talk, and the use of headphones and earbuds are growing in popularity. On the other hand, many of us are using our cell phones much more than we used to, so our overall exposure may be greater.
Should I Stop Using My Cell Phone?
“The evidence so far doesn’t prove that cell phones cause cancer, and we definitely need more and better research,” says Michael Hansen, Ph.D., a senior scientist at Consumer Reports. “But we feel that the research does raise enough questions that taking some common-sense precautions when using your cell phone can make sense.” Specifically, Consumer Reports recommends these steps (and I added a few to this list as well):
- Try to keep the phone away from your head and body. That is particularly important when the cellular signal is weak—when your phone has only one bar, for example—because phones may increase their power then to compensate.
- Don’t allow children under 12 to use a cell-phone except in emergencies. Their organs are still developing and are more sensitive to the possible influence of exposure to electromagnetic fields.
- Text or video call whenever possible.
- Use the speaker phone on your device or a hands-free headset or earbuds which helps keep the phone away from your body.
- Don’t stow your phone in your pants, shirt pocket, or bra. Instead, carry it in a bag or purse away from your body.
- Avoid using a cell phone in a vehicle as your phone has an automatic increase in power when the phone is trying to pick up a new or distant signal.
- Choose the phone with the lowest possible Specific Absorption Rate (SAR). This measures the quantity of radio frequency energy absorbed by your body. Classifications of the SAR values of phones from various manufacturers are available on a number of websites.
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This is an adapted version from Consumer Reports Magazine, November 2015 issue, Can You Hear Me Now?