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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. Lifetime animal exposure studies could be
completed in a few years. However, very large numbers of animals would be needed to provide reliable
