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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 pre-disposed 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 neuroma, 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.