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FDA CONSUMER UPDATE
3. What kinds of phones are the subject of this update?
The term “wireless phone” refers here to hand-held wireless phones with built-in antennas,
often called “cell,” “mobile,” or “PCS” phones.
These types of wireless phones can expose the user to measurable radiofrequency energy
(RF) because of the short distance between the phone and the user’s head. These RF
exposures are limited by Federal Communications Commission safety guidelines that were
developed with the advice of FDA and other federal health and safety agencies. When
the phone is located at greater distances from the user, the exposure to RF is drastically
lower because a person’s RF exposure decreases rapidly with increasing distance from
the source. The so-called “cordless phones,” which have a base unit connected to the
telephone wiring in a house, typically operate at far lower power levels, and thus produce
RF exposures far below the FCC safety limits.
The term “wireless phone” refers here to hand-held wireless phones with built-in antennas,
often called “cell,” “mobile,” or “PCS” phones.
These types of wireless phones can expose the user to measurable radiofrequency energy
(RF) because of the short distance between the phone and the user’s head. These RF
exposures are limited by Federal Communications Commission safety guidelines that were
developed with the advice of FDA and other federal health and safety agencies. When
the phone is located at greater distances from the user, the exposure to RF is drastically
lower because a person’s RF exposure decreases rapidly with increasing distance from
the source. The so-called “cordless phones,” which have a base unit connected to the
telephone wiring in a house, typically operate at far lower power levels, and thus produce
RF exposures far below the FCC safety limits.
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 long-term exposures, since the average period of
phone use in these studies was around three years.
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 long-term 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 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.
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 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. 6. 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 radiofrequency 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.
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). 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.