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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 well within the FCC s compliance limits.
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.
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 proof of a cancer
promoting effect if one exists. Epidemiological studies can provide data that is directly applicable to human
populations, but 10 or more years follow-up may be needed to provide answers about some health effects,
such as cancer. This is because the interval between the time of exposure to a cancer-causing agent and the
time tumors develop - if they do - may be many, many years. The interpretation of epidemiological studies is
hampered by difficulties in measuring actual RF exposure during day-to-day use of wireless phones. Many
factors affect this measurement, such as the angle at which the phone is held, or which model of phone is
used.
