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answer questions about long-term exposures, since 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 threat?
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 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. 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 tis work has been the development of a detailed agenda
of research needs that has driven the establishment of new research programs
