1.1 What are mirex and cholordecone? |
1.2 What happens to mirex and cholordecone
when they enter the environment? |
1.3 How might I be exposed to mirex and
cholordecone? |
1.4 How can mirex and cholordecone enter
and leave my body? |
1.5 How can mirex and cholordecone affect
my health? |
1.6 Is there a medical test to determine
whether I have been exposed to mirex and cholordecone? |
1.7 What recommendations has the federal
government made to protect human health? |
1.8 Where can I get more information? |
References |
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August 1995 |
Public Health Statement |
for |
Mirex and Chlordecone |
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CAS#
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Mirex 2385-85-5 |
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Chlordecone 143-50-5 |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for mirex and chlordecone. It is one in a series
of Public Health Statements about hazardous substances and
their health effects. A shorter version, the ToxFAQs™,
is also available. This information is important because this
substance may harm you. The effects of exposure to any hazardous
substance depend on the dose, the duration, how you are exposed,
personal traits and habits, and whether other chemicals are
present. For more information, call the ATSDR Information
Center at 1-888-422-8737.
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This statement was prepared to give you
information about mirex and chlordecone and to emphasize the
human health effects that may result from exposure to them.
The Environmental Protection Agency (EPA) has identified 1,408
hazardous waste sites as the most serious in the nation. These
sites make up the National Priorities List (NPL) and are the
sites targeted for long-term federal clean-up activities.
Mirex has been found in at least 7 of the sites on the NPL.
Chlordecone has been found at 2 of the sites on the NPL. However,
neither mirex or chlordecone are on EPA's list of target chemicals
and the number of NPL sites evaluated for mirex and chlordecone
is not known. As EPA evaluates more sites, the number of sites
at which mirex and chlordecone are found may increase. This
information is important because exposure to mirex and chlordecone
may cause harmful health effects and because these sites are
potential or actual sources of human exposure to mirex and
chlordecone.
When a substance is released from a large
area, such as an industrial plant, or from a container, such
as a drum or bottle, it enters the environment. This release
does not always lead to exposure. You can be exposed to a
substance only when you come in contact with it. You may be
exposed by breathing, eating, or drinking substances containing
the substance or by skin contact with it.
If you are exposed to substances such
as mirex and chlordecone, many factors will determine whether
harmful health effects will occur and what the type and severity
of those health effects will be. These factors include the
dose (how much), the duration (how long), the route or pathway
(breathing, eating, drinking, or skin contact) by which you
are exposed, the other chemicals to which you are exposed,
and your individual characteristics such as age, sex, nutritional
status, family traits, lifestyle, and state of health.
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1.1
What are mirex and cholordecone? |
Mirex and chlordecone are two separate
synthetic insecticides that have similar chemical structures.
They do not occur naturally in the environment. Mirex is a
snow-white crystalline solid and chlordecone is a tan-white
crystalline solid. Both compounds are odorless and neither
burns easily.
Mirex and chlordecone are no longer made
or used in the United States. Mirex and chlordecone were most
commonly used in the 1960s and 1970s. Mirex was used as a
pesticide to control fire ants mostly in the southeastern
part of the United States. It was also used extensively as
a flame retardant additive under the trade name Dechlorane
in plastics, rubber, paint, paper, and electrical goods from
1959 to 1972 because it does burn easily. Chlordecone was
used to control insects that attacked bananas, citrus trees
with no fruits, tobacco, and ornamental shrubs. It was also
used in household products such as ant and roach traps. Chlordecone
is also known by its trade name Kepone . All registered products
containing mirex and chlordecone were canceled in the United
States between 1977 and 1978.
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1.2
What happens to mirex and cholordecone when they enter the environment? |
Mirex and chlordecone contaminated water
and soil while they were being manufactured and used in the
1960s and 1970s. These substances can still enter surface
water through runoff of contaminated soil at facilities that
once manufactured these chemicals or by seeping from waste
disposal sites. Mirex and chlordecone do not evaporate to
any great extent into the air. They also do not dissolve easily
in water. Most of the mirex and chlordecone in water attaches
to soil particles suspended in the water or to sediment. When
they bind to soil particles in water, they can travel long
distances. Both compounds bind strongly to soil. Because they
are not likely to move through the soil, very little will
get into underground water. Mirex and chlordecone can stay
in soil, water, and sediment for years. Both compounds are
slowly broken down in soil, water, and sediment. Mirex is
broken down more quickly than chlordecone. Mirex is broken
down to photomirex, which can also cause harmful health effects.
Photomirex is even more poisonous than mirex. It is produced
when sunlight reacts with mirex in water or in the air. Fish
or animals that live in waters that contain mirex or chlordecone,
or that eat other animals contaminated with mirex or chlordecone,
can build up these substances in their bodies. The amounts
of mirex and chlordecone in their bodies may be several times
greater than the amount in their prey or in the surrounding
water.
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1.3
How might I be exposed to mirex and cholordecone? |
Most people are exposed to very low levels
of mirex and chlordecone. The most likely way for people in
the general population to be exposed to mirex or chlordecone
is by eating food, particularly fish, taken from contaminated
areas. Currently, three states (Ohio, New York, and Pennsylvania)
have issued a warning to the public that fish may contain
mirex. This warning applies mostly to fish caught in Lake
Ontario. The state of Virginia has also issued a warning to
the public about possible chlordecone contamination in fish
and shellfish caught in the lower 113 miles of the James River.
This contamination was caused when chlordecone was manufactured
in one factory in Hopewell, Virginia, polluting the James
River. People who live in areas where these compounds were
used or made have higher levels in their tissues. Mirex was
found in the milk of women who live in these areas, so nursing
infants could be exposed. People who live near hazardous waste
sites may be exposed to mirex or chlordecone by touching or
eating contaminated soil that is on unwashed hands, food containers,
or food itself, since these compounds bind to soil particles.
Because mirex and chlordecone do not dissolve easily in water
or evaporate easily in air, people are not likely to be exposed
to them by drinking water or by inhaling air. Since mirex
and chlordecone are no longer produced, the only people likely
to be exposed through their work are those involved in the
clean-up and removal of contaminated soils and sediments.
Mirex and chlordecone do not occur naturally
in the environment. Although mirex is not usually found in
the air, it was detected at very low levels of up to 10 parts
of mirex per quadrillion (1,000,000,000,000,000) parts of
air in air samples from southern Ontario, Canada. Surface
water concentrations of mirex ranged from 0.06 to 2.6 parts
mirex per one trillion (1,000,000,000,000) parts of water
in the Niagara River between 1981 and 1983. More recent monitoring
data from 1987 show that mirex concentrations are decreasing
in the surface waters of the Great Lakes to about 0.022 parts
per trillion (ppt). In the mid-1980s, mirex was found in sediments
of Lake Ontario at levels ranging from 6.4 parts per billion
(ppb) to 38 ppb. Nationwide, the average level of mirex in
fish was less than 4 ppb in 1986. However, fish from Lake
Ontario had levels as high as 225 ppb. Chlordecone was found
in surface water samples from the James River estuary at levels
less than 10 ppt in 1977. More recent data were not available.
In 1978, chlordecone was detected in sediments from the James
River below its production site at concentrations of less
than one part chlordecone in one million parts of sediment.
In 1981, chlordecone was found in clams from the James River
at levels ranging from 60 to 140 ppb.
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1.4
How can mirex and cholordecone enter and leave my body? |
Studies in animals show that mirex can
be taken into your bloodstream when you breathe in cigarette
smoke containing mirex or eat food contaminated with mirex.
We do not know if mirex can pass through your skin and enter
your body after you touch it. Mirex passes from the stomach
and intestines of animals into their blood. We do not know
how much passes from the stomach and intestines of people
into the bloodstream. Once in the bloodstream, mirex is carried
to many parts of the body where it is stored, mainly in fat.
Mirex is not broken down in the body. Mirex that is not stored
leaves the body unchanged mainly in the feces. Very little
leaves the body in the urine. Most of the mirex that is swallowed
leaves the body in feces within two days. However, the mirex
that enters the bloodstream and is stored in fat leaves the
body very slowly. This process can take from several weeks
to months. Mirex can also enter breast milk from the bloodstream
of nursing mothers who have been exposed.
Animal studies show that chlordecone
can pass into your blood when you eat food contaminated with
it. Animal data show that only a small amount of chlordecone
can pass through the skin into the bloodstream. We do not
know if or how much chlordecone can pass from your lungs into
your blood when you breathe it in. Like mirex, once chlordecone
is taken up by your body, it is carried by the blood throughout
the body and is stored for a long time. Unlike mirex, chlordecone
is found mainly in the liver. Chlordecone is broken down to
chlordecone alcohol, which is a less harmful product. Chlordecone
and its breakdown product slowly leave the body through the
feces. This process can take from several weeks to months.
Very little chlordecone leaves the body in the urine. Chlordecone
has also been found in saliva and human milk.
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1.5
How can mirex and cholordecone affect my health? |
We do not know how mirex directly affects
the health of people. However, animal studies have shown that
eating mirex can cause harmful effects on the stomach, intestines,
liver, and kidneys. Eating mirex can also cause harmful effects
on the eyes, thyroid, nervous system, and reproductive system.
Since these effects occur in animals, they may also occur
in people. Animals that eat large amounts of mirex for a relatively
short time can develop diarrhea. In animals, short-term exposure
(14 days or less) to low and high levels of mirex and intermediate
exposure (15–364 days) to low levels can harm the liver. Trembling,
tiredness, and weakness can also occur after short-term exposure
to large amounts of mirex. Younger animals are more sensitive
to these effects on the nervous system. Intermediate exposures
to low levels of mirex caused tiredness, and exposure to higher
levels caused extreme excitability. Long-term (365 days or
more) exposure to low levels of mirex caused harm to the kidneys.
Short-term and intermediate exposures to moderately low levels
of mirex did not harm kidneys. Exposure to sufficient amounts
of mirex may cause cataracts in animals if they are exposed
before or soon after birth. We do not know whether human infants
may also develop cataracts; it is not likely that mirex will
cause cataracts in adults. Short-term, low-level exposure
to mirex may harm reproduction and development in rodents.
High-level exposures may result in miscarriage.
Studies in workers exposed (intermediate-
or long-term) to chlordecone have shown harmful effects on
the liver, the nervous system, and reproductive systems. Workers
exposed to high levels of chlordecone during its manufacture
experienced trembling, irritability, blurry vision, and headaches.
Studies in rats have shown that pretreatment with some anticonvulsants
or antidepressants increases the seriousness of the tremors
associated with chlordecone exposure. Therefore, people being
treated with these drugs for epilepsy or depression may also
experience more serious tremors if they are exposed to chlordecone.
Male workers experienced some harmful reproductive effects.
However, there was no evidence that the ability to father
children was affected. Some workers exposed to high levels
of chlordecone developed skin rashes and enlarged livers.
Animal studies show effects similar to those seen in humans.
In addition, long-term exposure to small amounts of chlordecone
caused kidney effects in animals. It is possible exposure
to high concentrations of chlordecone for a long time may
also hurt people's kidneys. Animal studies show harmful effects
on the ability of female animals to reproduce. We do not know
if similar effects occur in exposed women. Animal studies
show that chlordecone harms the offspring of exposed animals.
We do not know if similar harmful developmental effects will
occur in people. However, it is possible that if parents are
exposed to enough chlordecone, their children's development
may be harmed. Very young and very old people may be especially
sensitive to chlordecone.
We do not know for sure whether either
mirex or chlordecone causes cancer in humans. The Department
of Health and Human Services (DHHS) has determined that mirex
and chlordecone may reasonably be expected to be carcinogens.
The International Agency for Research on Cancer (IARC) has
determined that mirex and chlordecone are possibly carcinogenic
to humans. The EPA has not classified mirex or chlordecone
as to carcinogenicity. In rodents, mirex causes liver, adrenal,
and blood cancer. Chlordecone also causes liver cancer in
rodents, but because of problems with these animal studies,
more information is necessary to be sure.
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1.6
Is there a medical test to determine whether I have been exposed
to mirex and cholordecone? |
There are medical tests to determine
whether you have been exposed to mirex. Levels of mirex can
be measured in blood, feces, fat, or milk. The tests are not
done in routine medical examinations. However, doctors can
collect tissue and body fluid samples and send them to university
medical centers or medical laboratories where the tests can
be performed. The tests are specific for mirex exposure. Since
mirex is stored in your body for a long time and slowly excreted,
the tests can detect mirex for a long time after exposure
has stopped. However, the tests are unsatisfactory indicators
of the amount of mirex to which you have been exposed. This
is because a long time may have passed since you were exposed
and you cannot be sure how much mirex may have left your body
by the time the test is performed. The tests also cannot be
used to predict whether you will experience any potential
health effects or harmful changes following exposure.
There are medical tests to determine
whether you have been exposed to chlordecone and/or its breakdown
product, chlordecone alcohol. Levels of chlordecone and/or
chlordecone alcohol can be measured in blood, saliva, feces,
or bile. Chlordecone levels in blood are the best indicator
of exposure to chlordecone. Since chlordecone remains in the
blood for a long time, the test is useful for a long time
after exposure has stopped. Chlordecone can be detected in
saliva only within the first 24 hours after exposure; therefore,
this test has limited use. Blood levels of chlordecone are
a good reflection of total body content of chlordecone. However,
the test is an unsatisfactory indicator of the amount of chlordecone
to which you have been exposed because you cannot be sure
how much chlordecone left your body between the time you were
exposed and the time the test is performed. These tests cannot
predict how your health may be affected after exposure. The
tests are not done in routine medical examinations, but doctors
can collect body fluid samples and send them to a university
medical center or a medical laboratory for analysis.
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1.7
What recommendations has the federal government made to protect
human health? |
The federal government has made regulations
to protect individuals from the possible health effects of
mirex and chlordecone. The National Institute for Occupational
Safety and Health (NIOSH) recommends that the average workroom
air levels of chlordecone should not exceed 50 parts per trillion
(ppt) over an 8-hour period. EPA suggests that taking into
your body each day an amount equal to 200 picograms (pg) of
mirex per kilogram (kg) of your body weight is not likely
to cause any significant (noncancer) harmful health effects.
The Food and Drug Administration (FDA) has determined that
concentrations of mirex below 100 ppt in fish and other foods
are not likely to harm people who eat these foods. EPA has
set a limit of 1 ppt in surface waters to protect aquatic
life from the harmful effects of mirex. FDA has determined
that concentrations of chlordecone below 400 ppt in fish,
crabs, and shellfish are not likely to harm people who eat
these foods.
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1.8 Where can I get more information? |
If you have any more questions or concerns, please contact
your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Information line and technical assistance:
Phone: 888-422-8737
FAX: (770)-488-4178
ATSDR can also tell you the location of occupational and environmental health
clinics. These clinics specialize in recognizing, evaluating, and treating illnesses
resulting from exposure to hazardous substances.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1995. Toxicological
profile for mirex and cholordecone. Atlanta, GA: U.S.
Department of Health and Human Services, Public Health Service.
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