In 1992, 11 million Americans subscribed to cellular phones. In January of this year, there was a widespread health scare about a possible link between brain cancer and cellular phone use.
The connection between brain cancer and cellular phones has not been established, but because there were so many concerns, I wanted to talk with an expert. I turned to my colleague Patrick Breysse, Ph.D., associate director of the Center for VDT and Health Research, for more information.
Q: What is the difference between the phone on my desk or in my home and the phone in my car?
A: Most telephones transmit sound electrically across telephone lines. Cellular phones use electromagnetic waves similar to AM or FM radios, except at a slightly higher frequency, to transmit sound via a two-way radio link.
Cellular phones use microwave frequencies to broadcast information. Microwaves have frequencies greater than normal radio waves but lower than infrared frequencies (infrared are the frequencies that generate heat).
The broadcast frequencies used by cellular phones can also be referred to as ultra-high frequency (UHF). Microwave ovens also use microwaves but at a much higher frequency.
In contrast to cellular phones, cordless telephones use broadcast frequencies in the radio frequency band.
Q: Are there different kinds of cellular phones? Is one safer than another?
A: There are three varieties of cellular phones, and each functions a little bit differently.
Car phones have the antenna permanently installed outside the vehicle, away from the user. Transportable units, which can be used in a car or carried around, have the transmitter housed in a briefcase-sized case and the headset does not transmit the radio waves. Hand-held portables have the transmitter and antenna on the headpiece.
The only unit questioned for health safety is the hand-held variety, because the antenna and transmitter are held directly to the ear in close proximity to the head. Most researchers agree, however, that not enough is known about the possible health effects of the radio waves used in cellular phones.
Q: The phone I use in my home is cordless. Would you consider it a health risk?
A: Cordless phones are the types of phones that have a base attached to the wall or placed on another surface in the home. They use very low power radio waves to transmit the short distance to the phone's base. Because of this, these phones are not considered hazardous.
Q: What precautions do you recommend for cellular phone users?
A: The U.S. Food and Drug Administration (FDA) has recommended users of hand-held cellular phones, with the transmitter and antenna on the headpiece, limit the amount of time they spend on the phone. This is because cellular phones do use microwaves.
The debate on electromagnetic fields and cancer is at least 10 years old. Studies to date have not definitively linked microwaves and cancer. We do know that the frequency of brain cancer cases has increased. Since there is no definitive answer, I would recommend that one should use common sense and minimize any risk.
Q: Are cellular phones regulated?
A: Electronic devices are not required to get approval from the FDA, unlike other consumer items. The FDA can take a product off the market if it is shown to be hazardous. Cellular phones are regulated by the Federal Communications Commission for acceptable emission of electromagnetic radiation.
Dr. Genevieve Matanoski is a physician and epidemiologist at the Johns Hopkins School of Hygiene and Public Health. She is a founding director of the school's Institute for Women's Health Research and Policy.