Warnings that cell phones cause brain tumors and that chatting contributes to car crashes have not stopped more than 134 million Americans from enjoying tetherless links to friends, family, and business associates.

The all-too-familiar chirp of a cellular phone shatters the peace at the beach, breaks up conversations, and intrudes just about everywhere. But such encroachments on privacy may be the least of our concerns.

Health Problems?

For years, people have voiced concern about the dangers of radiofrequency (RF) energy from cell phones. After reviewing the results of multiple studies, though, scientists have not found definite evidence of harm from wireless cellular radiation

Science Searches for Answers

A few animal studies showed that low levels of RF accelerated cancer development in mice exposed to high doses. Others didn't.

"The scientific and medical information is in a gray area," says George L. Carlo, PhD, who headed up a six-year, cellular industry-funded study about wireless health risks. "We can't say clearly that these things are safe. We have a hint that they are dangerous. [But] we don't know how dangerous. What we do know is that in the four different epidemiologic studies we've done, there are hints of health risks."

Dr. Joachim Schz, from the Danish Cancer Society in Copenhagen, and his associates first reported in 2001 that cancer incidence had not increased among residents who had used cell phones up until 1996. He reported in 2006 that fears of brain cancer resulting from the electromagnetic fields generated by cellular telephones could be laid to rest, based on a study of more than 400,000 residents of Denmark who had used cell phones for up to 21 years. However, some cancer experts who reviewed the study did not concur with his results.

Playing it Safe

Jeffrey Nelson, spokesperson for the Cellular Telecommunications Industry Association (CTIA), says, "Obviously there has been a wealth of science done, and some issues [are still] out there. We have long supported scientific inquiry in cellular phone use and public health, and there's no reason to believe they are not safe."

Nelson says his organization is working with the US Food and Drug Administration (FDA) to determine the need for additional research. FDA considers the risk small but has recommended the industry design mobile phones to minimize RF exposure and suggests several steps consumers can take to lower risk:

  • Hold longer calls on a conventional phone, restricting cell phone use to shorter calls and situations where traditional phones are not available.
  • Switch to a phone with an antenna mounted outside the car.
  • Use speaker mode or a headset to place more distance between your head and the cell phone.

Dr. Carlo adds that callers should hold the antenna away from the body and suggests that parents give children pagers rather than cell phones.

Traffic Talk

Radiation risk may be subject to debate, but few dispute the pitfalls of driving while conversing. In 1999, the Center for Urban Transportation Research at the University of South Florida (USF) in Tampa reported that several factors influenced safe phone use in the car, including the type of phone and the conversation.

"The use of mobile phones when driving was found to have a distractive effect, caused primarily by the additional mental workload imposed on the driver and, to a lesser extent, by the physical restrictions imposed by hand-held phone use," says Alasdair Cain, co-author of the center's report.

The National Highway Traffic Safety Administration (NHTSA) knows that driver inattention, from a variety of distractions, plays a role in half of US accidents and reports more instances of inattention, erratic/reckless driving, and running off the road in fatal crashes involving cellular phones than in other fatal auto accidents.

"Distraction is a big problem," says Tim Hurd of the NHTSA. "Our recommendation is to park in a safe place [before you make or receive a call]."

Driven to Distraction

Dr. Donald A. Redelmeier reported in the New England Journal of Medicine that talking on a cellular phone quadrupled the risk of a collision. His research showed people of all ages and driving experiences shared the same relative risk and that hands-free phones offered no safety benefit over handheld units.

A recent Spanish study offers insight into why. Psychologists discovered that thinking about something other than driving can decrease a person's ability to assess surroundings and notice changes in traffic.

"The potential hazard of using a cellular phone is one thing," says L.M. Nunes, PhD. "But add in-depth conversation that requires a considerable amount of mental effort, like recalling a route on a map, performing a mathematical computation, or discussing an emotionally charged subject, and you compound an already risky behavior."

Road Rules for Cell Phone Users

To decrease the risk of accidents, the CTIA and the National Safety Council recommend that drivers:

  • Understand and use special phone features, like speed dial.
  • Use a hands-free speakerphone, even though some studies concluded that holding the phone is not the problem.
  • Keep the phone within easy reach.
  • Don't talk during hazardous conditions, such as inclement weather or heavy traffic. Call the person later.
  • Don't take notes while talking.
  • Don't look up phone numbers.
  • Don't use the texting feature while driving.
  • Make calls when stopped at a traffic light or pull off the road.
  • Avoid making or participating in stressful conversations. "The logic is if you're having an intense call, you're not paying as much attention to driving, and driving becomes a secondary task," says USF's Cain.

Good News

Cellular phones also offer opportunities to improve safety by making it easier to report road conditions and accidents. More than one-third of calls placed to 9-1-1 emergency centers originate from cell phone callers.