by Brie Zeltner | Flint Journal news service
Sunday November 23, 2008, 2:31 AM

Flint Journal extra: Related article: Scientists divided over cellphone use; One group says cellphones increase cancer risk

We clip them to our belts or slip them in our pockets, manically text until our thumbs require medical attention, and are ditching the landline for them at a steady pace.
 

Statistically speaking, it's almost impossible to escape them.

With 262 million American wireless subscribers, we're very close to a cellphone democracy.

Almost 80 percent of American teens have a mobile device, mostly provided by a parent with safety in mind.

But are they safe?

Two recently released studies, a large one from Sweden of the long-term risk of brain cancer from cellphone use and a pilot study from a Cleveland Clinic fertility specialist, suggest they are not.

But many others, mainly in the better-studied area of brain cancer, have found no such link.

Why the confusion?

And where does all this back and forth leave us?

Cellular phones emit radio-frequency, or RF, energy, a form of electromagnetic radiation, while turned on. The level of energy released is somewhere between that of a television and a microwave oven.

Studies have shown no consistent link between cellular phone use and cancer. But every time a new study is released on the subject, the question of their safety is revisited, and the headlines fly, at least outside the United States.

More research is needed, say the National Cancer Institute, American Cancer Society and U.S. Food and Drug Administration. Most cellphone research is taking place in Europe, where funding is more widely available.

Dozens of studies have made international news the last five years, many drawing attention to the potential increased risk for children from long-term cellphone use.

The most anticipated of these studies, a six-year, $30 million, 13-country international effort called Interphone, ended in 2006. But its final results are yet to be released, and individual countries within the study have put out conflicting results, adding to confusion and concern about the potential health risks associated with cellphone use.

These studies elicited little attention in America until July, when Dr. Ronald Herberman, director of the University of Pittsburgh Cancer Institute and a prominent researcher in his field, urged his 3,000-person staff to limit their cellphone use. His memo, which specifically focused on the risks to children, cited "early, unpublished data" and offered specific suggestions for parents to help limit exposure.

Then in September, Swedish cancer expert Lennart Hardell reported that people who started using a cellphone before age 20 were five times more likely to develop brain cancer. Hardell's results came from his most recent examination of 26 studies on the likelihood of developing different brain cancers from long-term cellphone use and were delivered at the first International Conference on mobile phones and health in London.

Hardell looked at case-control studies, which take a certain number of people with the condition in question, in this case three different types of brain cancer, and compare them with healthy controls for the behavior in question. Included in his 26-study "meta-analysis" were many of the single-country Interphone studies as well as Hardell's own case-control studies using Sweden's meticulous population and cancer registry.

It's too soon to draw any conclusions from Hardell's study or any of the other, more reassuring ones, said Dr. John Letterio, chief of the division of Hematology and Oncology at University Hospitals' Rainbow Babies & Children's Hospital.

"Right now, the reality is that we don't have the kind of data to, in a scientific way, support a link," he said. "Epidemiologic studies that look at this have really only begun, and it's going to take us some time to sort that out."

Letterio, who has four children, does think it is reasonable to exercise some caution when it comes to kids, however. Using a hands-free headset, limiting talk time and using more text messaging are all good ideas, he says.

But he describes his cell use as "too much" and still holds his phone in the conventional way, right up to his ear.

Hardell puts his in a pocket and uses it hands-free.

A lingering question is how the radio-frequency energy emitted during a mobile or cordless phone call could cause cancer. (Cordless phones emit RF energy, too, just not as much as a cellphone.)

Ashok Agarwal, an infertility specialist at the Cleveland Clinic, believes that his team may have found such a mechanism -- at least to explain how RF energy could damage a man's sperm when he carries the phone in his pocket.

Curious about the potential connection between infertility and talking with an earpiece via a phone in the pants pocket, Agarwal and his team at the Glickman Urological Institute surveyed 300 infertility patients about their cellphone use two years ago. They found a tentative positive connection and decided to follow up this year with a pilot study.

The study showed that in 31 sperm samples exposed to only one hour's worth of cellphone radiation, sperm were less mobile and more likely to die, and there was evidence of oxidative stress, an imbalance in the amount of free radicals that can lead to sperm damage.

Agarwal, who still keeps his phone in his pocket when he's using a headset, is following up with a larger study now that he and his team have proven their concept. They are being cautious with their results.

"This certainly is a preliminary and a pilot study," he said. "We feel that the results were striking because semen quality is significantly affected, even for a duration of one hour."

So where do these newest studies leave us?

Many scientists would say they change nothing, that the vast bulk of research points to the safety of the cellphone. Either way, it may take quite a long time for the scientific community to come to any kind of consensus on the matter.

"We may find in certain populations there's elevated risk, but these epidemiology studies take decades to complete," Letterio said.

CTIA, a wireless telecommunications industry group, reassures consumers on its Web site that the technology is safe by pointing to the "scientific evidence and expert review" from the World Health Organization, American Cancer Society and FDA, among others.

But both the FDA and the cancer society, while emphasizing the lack of consensus on the topic, offer tips on their Web sites for ways to reduce RF exposure from cellphones.

Which, in the absence of any definitive answers, seems like the best we can do. Just try escaping them.