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 is 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.
6. What is the FDA doing to find out more about the possible health effects of
wireless phone RF?
The FDA is working with the U.S. National Toxicology Program and with groups of
investigators around the world to ensure that high priority animal studies are conducted
to address important questions about the effects of exposure to radiofrequency
energy (RF). The FDA has been a leading participant in the World Health Organization
International Electromagnetic Fields (EMF) Project since its inception in 1996. An
influential result of this work has been the development of a detailed agenda of
research needs that has driven the establishment of new research programs around
the world. The project has also helped develop a series of public information documents
on EMF issues. The FDA and the Cellular Telecommunications & Internet Association
(CTIA) have a formal Cooperative Research and Development Agreement (CRADA) to do
research on wireless phone safety. The FDA provides the scientific oversight, obtaining
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