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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 ten 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.
What is FDA doing to find out more
about the possible health effects of
wireless phone RF?
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 radio
frequency energy (RF).
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.
FDA and Cellular Telecommunications &
Internet Association (CTIA) have a formal
Cooperative Research and Development
Agreement (CRADA) to do research on
wireless phone safety. FDA provides the
scientific oversight, obtaining input from
experts in government, industry, and
academic organizations. CTIA-funded
research is conducted through contracts to
independent investigators. The initial
research will include both laboratory studies
and studies of wireless phone users. The
CRADA will also include a broad assessment
of additional research needs in the context
