FDA CONSUMER UPDATE
U.S. Food and Drug Administration -Center for Devices and
Radiological Health Consumer Update on Wireless Phones
1. Do wireless phones pose a health hazard?
The available scientific evidence does not show that any health problems are associated with using wireless phones. There is no proof, however, that wireless phones are absolutely safe. Wireless phones emit low levels of radiofrequency energy (RF) in the microwave range while being used. They also emit very low levels of RF when in the stand-by mode. Whereas high levels of RF can produce health effects (by heating tissue), exposure to low level RF that does not produce heating ef-fects causes no known adverse health effects. Many studies of low level RF exposures have not found any biological ef-fects. Some studies have suggested that some biological ef-fects may occur, but such findings have not been confirmed by additional research. In some cases, other researchers have had difficulty in reproducing those studies, or in determining the reasons for inconsistent results.
2. What is FDA’s role concerning the safety of wireless phones?
Under the law, FDA does not review the safety of radiation-emitting consumer products such as wireless phones before they can be sold, as it does with new drugs or medical de-vices. However, the agency has authority to take action if wire-less phones are shown to emit radiofrequency energy (RF) at a level that is hazardous to the user. In such a case, FDA could require the manufacturers of wireless phones to notify users of the health hazard and to repair, replace or recall the phones so that the hazard no longer exists. Although the existing scientific data do not justify FDA regula-tory actions, FDA has urged the wireless phone industry to take a number of steps, including the following:
•Support needed research into possible biological effects of RF of the type emitted by wireless phones;
•Design wireless phones in a way that minimizes any RF ex-posure to the user
that is not necessary for device function; and
•Cooperate in providing users of wireless phones with the best possible information on possible effects of wireless phone use on human health.
FDA belongs to an interagency working group of the federal agencies that have responsibility for different aspects of RF safety to ensure coordinated efforts at the federal level. The following agencies belong to this working group:
•National Institute for Occupational Safety and Health
•Environmental Protection Agency
•Federal Communications Commission
•Occupational Safety and Health Administration
•National Telecommunications and Information Administration
The National Institutes of Health participates in some inter-agency working group activities, as well. FDA shares regulatory responsibilities for wireless phones with the Federal Communications Commission (FCC). All phones that are sold in the United States must comply with FCC safety guidelines that limit RF exposure. FCC relies on FDA and other health agencies for safety questions about wireless phones. FCC also regulates the base stations that the wireless phone networks rely upon. While these base stations operate at higher power than do the wireless
Cphones themselves, the RF expo-sures that people get from these base stations
Hare typically thousands of times lower than those they can get from wire-less phones. Base stations are thus not the subject of the safety questions discussed in
8this document.
3. What kinds of phones are the subject of this update?
The term “wireless phone” refers here to hand-held wireless phones with built-in antennas, often called “cell,” “mobile,” or “PCS” phones.
FDA CONSUMER UPDATE
These types of wireless phones can expose the user to measurable radiofrequency energy (RF) because of the short distance between the phone and the user’s head. These RF exposures are limited by Federal Communications Commission safety guidelines that were developed with the advice of FDA and other federal health and safety agencies. When the phone is located at greater distances from the user, the exposure to RF is drastically lower because a person’s RF exposure decreases rapidly with increasing distance from the source. The so-called “cordless phones,” which have a base unit connected to the telephone wiring in a house, typically operate at far lower power levels, and thus produce RF expo-sures far below the FCC safety limits.
4. What are the results of the research done already?
The research done thus far has produced conflicting results, and many studies have suffered from flaws in their research methods. Animal experiments investigating the effects of radiofrequency energy (RF) exposures characteristic of wire-less phones have yielded conflicting results that often cannot be repeated in other laboratories. A few animal studies, how-ever, have suggested that low levels of RF could accelerate the development of cancer in laboratory animals. However, many of the studies that showed increased tumor develop-ment used animals that had been genetically engineered or treated with cancer-causing chemicals so as to be pre-dis-posed to develop cancer in the absence of RF exposure. Other studies exposed the animals to RF for up to 22 hours per day. These conditions are not similar to the conditions under which people use wireless phones, so we don’t know with certainty what the results of such studies mean for human health. Three large epidemiology studies have been published since December 2000. Between them, the studies investigated any possible association between the use of wireless phones and primary brain cancer, glioma, meningioma, or acoustic neu- roma, tumors of the brain or salivary gland, leukemia, or other cancers. None of the studies demonstrated the existence of any harmful health effects from wireless phone RF exposures. However, none of the studies can answer questions about long-term exposures, since the average period of phone use in these studies was around three years.
5.What research is needed to decide whether RF expo-sure from wireless
phones poses a health risk?
A combination of laboratory studies and epidemiological stud-ies of people actually using wireless phones would provide some of the data that are needed. Lifetime animal exposure studies could be completed in a few years. However, very large numbers of animals would be needed to provide reliable proof of a cancer promoting effect if one exists. Epidemiological stud-ies can provide data that is directly applicable to human popu-lations, but 10 or more years’ follow-up may be needed to pro-vide answers about some health effects, such as cancer. This is because the interval between the time of exposure to a can-cer- causing agent and the time tumors develop - if they do -may be many, many years. The interpretation of epidemiologi-cal studies is hampered by difficulties in measuring actual RF exposure during day-to-day use of wireless phones. Many fac-tors affect this measurement, such as the angle at which the phone is held, or which model of phone is used.
6.What is FDA doing to find out more about the possible health effects of wireless phone RF?
FDA is working with the U.S. National Toxicology Program and with groups of investigators around the world to ensure that high priority animal studies are conducted to address impor-tant questions about the effects of exposure to radiofrequency energy (RF). FDA has been a leading participant in the World Health Orga-nization International Electromagnetic Fields (EMF) Project since its inception in 1996. An influential result of this work has been the development of a detailed agenda of research needs that has driven the establishment of new research pro- grams around the world.
