A new study in the journal 'BMJ' says there's no evidence of a link between cell phone use and the development of brain tumors. But some previous studies suggest otherwise. Who's right?:v Good news: There is no link between long-term use of cell phones and increased risk of brain tumors - at least according to research just published in the British journal BMJ. In what is being described as the “biggest ever” study on the subject, scientists in Denmark reviewed data on the entire Danish population age 30 and older and born in the country after 1925, which included nearly 360,000 cell phone users, over an 18-year period. After comparing rates of cancer of the brain and central nervous system between long-term cell phone users and non-users, they found no evidence of increased cancer risk, even among people who had been using their phones for more than 13 years.
The results are certainly reassuring, but are they right?
The Debate Over Cell Phones and Cancer
This new study is just the latest loop in the cell phone-cancer roller coaster: Previous research on the subject is extensive - and conflicting. In 2006, for example, Swedish scientists announced that an hour of daily cell phone use over the course of a decade could increase a person’s risk for developing brain cancer by as much as 240 percent. But earlier that same year, British researchers who collected data on cell phone users found no such link - to any type of cancer.That’s just one example of the mixed messages we’re getting from cell phone-cancer research. In the last nine months alone, there have been at least five studies or reports related to the effects of cell radiation on brain tumor growth, each contradicting or complicating the results of a study that came before.
In February, British researchers at the University of Manchester released data that found that mobile phones were not likely to increase the risk of brain tumors, as there had been no significant change in the number of cancer cases diagnosed since cell phones were introduced. Four days later, scientists at the U.S. National Institutes of Health published a study in the Journal of the American Medical Association, which found that brain activity was higher in the areas closest to a phone’s antenna, although whether the effect was good or bad was unclear.
Then, in May, a World Health Organization (WHO) panel officially classified cell phones as “possibly carcinogenic” - the same category that includes the pesticide DDT and gasoline engine exhaust. That announcement was followed by a June report in the journal Occupational and Environmental Medicine, which suggested that people who used their phones often and for 10 years or more were at higher risk for developing gliomas (a type of brain tumor). But a month later, in July, Swiss researchers released results of a study that found that cell phone use did not pose a cancer threat to children, who are generally thought to be most at risk.
Confused? You’re not alone.
Cell Phones and Cancer: Should You Be Concerned?
The fact is, even experts can’t seem to come to any definitive conclusions. In each of the aforementioned studies, the authors noted that although their results were accurate, their conclusions were not likely to end the debate over whether cell phones cause brain tumors. In fact, the only thing everyone can agree on is that more research is needed. “[The results] must be put into the context of the 15 or so previous studies on mobile telephones and cancer,” Anders Alhbom, PhD, and Maria Feychting, PhD, MD, professors at the Institute of Environmental Medicine in Sweden, write in an accompanying editorial for the latest Danish study. “Evidence is reassuring, but continued monitoring of health registers is still warranted.”“You have to look at a wide range of patients and people,” says Rahul Jandial, MD, PhD, a neurosurgeon at City of Hope in Duarte, Calif. “When you’re looking at statistics, you don’t always find conclusive results right away.” Complicating matters, he adds, is the fact that a lot of these studies are looking at different types of tumors (not just cancerous growths in the brain), so results are bound to be mixed. His personal belief, however, is that cell phones are safe - an idea which he says science seems increasingly to support.
Cell phones emit radiofrequency energy (radio waves), a form of non-ionizing radiation similar to the kind microwave ovens give off - but different from the ionizing type emitted by X-rays and CT scans, which is known to be dangerous. Evidence shows that prolonged or frequent exposure to ionizing radiation causes DNA damage in cells, which can eventually lead to cancer, but research is not as conclusive about whether non-ionizing radiation has the same effect.
“I think only time will tell,” says Ann Louise Gittleman, author of the book Zapped: Why Your Cell Phone Shouldn't Be Your Alarm Clock and 1,268 Ways to Outsmart the Hazards of Electronic Pollution. “And when we do have the definitive data, it probably will be too late.”
Gittleman, a former “cell phone junkie” who changed her habits after she developed a benign tumor in her parotid (salivary) gland, acknowledges the impressive size of the Danish study, but says what we really need is long-term data about the biological effects of chronic and cumulative radiation, particularly as this new generation of cell phone-exposed children and teens transitions into adulthood. The majority of the evidence we have now says that cell phones are not a risk - but just 60 years ago, Gittleman points out, people believed that cigarettes were safe too.
Dr. Jandial, for one, isn’t concerned. In fact, he thinks future research will only reinforce the idea that cell phones are harmless. “We haven’t seen any effect over the last two decades,” he explains. “The total number of brain tumors has remained basically the same as cell phone use has skyrocketed.”
What You Can Do About Cell Phone Radiation
In any case, both Jandial and Gittleman say that you should view all research on the subject cautiously. They also note that it can’t hurt to take steps to minimize your exposure to radiation. Which is not to say that you should abandon your phone or that you should live in constant fear of using it. Cell phones are a major part of modern life: A recent survey of more than 500 people in the U.S. found that many users would rather give up sex, exercise, caffeine, and even toothbrushes than not have their phones for a week. It’s unrealistic — and unnecessary — to try to eliminate your cell phone use completely. But there are steps you can take to make your current usage safer.Easy Ways to Reduce Your Cell Phone Cancer Risk
“People are not going to go without technology,” Gittleman says. “We’re not going to go backward. But in order to go forward, we need to be proactive about protecting ourselves.”Here, 10 tips from Gittleman and Jandial to minimize exposure to radiation from your cell phone:
- Limit the frequency and length of calls. Keep cell phone calls as short as possible. If the conversation starts to drag on, hang up and call back from a landline.
- Don’t have a landline? Get one. If you know you’re going to be having a lot of hours-long heart-to-hearts with your mom or your best friend, use a landline — preferably one that isn’t cordless. Gittleman says that there’s some research that indicates cordless phones may be emit even more radiation than cell phones. “It’s almost like having a mini cell phone tower in your home,” she explains. “One study showed that cordless phones caused heart rate and arrhythmias to increase.”
- Don’t chat in cars, trains, or elevators. Your phone has to work a lot harder to get signal out through the metal, so it emits stronger electromagnetic radiation, Gittleman explains. Also, if you’re using your phone in a metal container, the frequency waves it emits have nowhere to go and instead bounce back and forth in the space around you, exposing you to more-than-usual radiation. Going at high speeds (such as in a train) also automatically boosts the power of the signal to maximize the phone’s attempts to connect to a new relay antennae, Gittleman explains. More power equals more radiation.
- Only use your phone when you have a full signal. When you have poor reception, your phone has to work harder to connect, which increases the strength of the electromagnetic radiation it gives off. Don’t try to make calls when your bars are low, and if the signal goes bad mid-conversation, hang up and try again later.
- Use a headset or speaker mode. Gittleman suggests using an air tube headset, which is less conductive of radio frequency than regular wired headsets and also keeps the phone further away from your head.
- Get text savvy. Take a cue from your kids. “Younger people tend to text more, which is a good habit,” Dr. Jandial says. Texting requires less battery power and less signal strength to connect, so your phone doesn’t emit as much radiation as when you’re talking. Plus, any radiation that is released is further away from your brain.
- Hold the phone away from your head. Putting a phone up to your ear is “almost like using a mini microwave oven on your brain,” Gittleman says. Whenever possible, keep the phone at least 6 to 7 inches from your skull — including when it’s on but not in use. (Don’t sleep with it next to your pillow if you use it as an alarm clock.)
- Keep your battery charged. Low battery power makes it difficult for your phone to find a signal, so you’re likely to have poor reception and be exposed to more radiation.
- Switch sides regularly during conversation. Spread out your exposure to any radiation by alternating which side of your head is closest to your phone. This helps to ensure that no one part of your brain gets an unusually high dose.
