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
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 longterm 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 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 dayto- 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.
Safety Guidelines
150