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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
phones themselves, the RF exposures that people get from these base stations are
typically thousands of times lower than those they can get from wireless phones.
Base stations are thus not the subject of the safety questions discussed in this
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. 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 exposures 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
wireless phones have yielded conflicting results that often cannot be repeated in
other laboratories. A few animal studies, however, 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 development used animals
that had been genetically engineered or treated with cancer-causing chemicals
so as to be predisposed 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 exposure from wireless
phones poses a health risk?
A combination of laboratory studies and epidemiological studies of people
actually using wireless phones would provide some of the data that are needed.
