Health and Safety Information 176
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 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
