September 1995 |
ToxFAQs™ |
for |
Chlorodibenzofurans (CDFs) |
(Dibenzofuranos
Policlorados (DFPCs)) |
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This fact sheet answers the most frequently
asked health questions about chlorodibenzofurans (CDFs). For
more information, you may call the ATSDR Information Center
at 1-888-422-8737. This fact sheet is one in a series of summaries
about hazardous substances and their health effects. 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.
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SUMMARY: Exposure to chlorodibenzofurans
(CDFs) occurs mainly by eating certain contaminated foods.
In people, exposure to CDFs is most likely to cause skin
and eye irritation, and increased vulnerability to respiratory
infection and nervous system effects. This chemical has
been found in at least 51 of 1,416 National Priorities
List sites identified by the Environmental Protection
Agency. |
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What
are chlorodibenzofurans (CDFs)? |
Chlorinated dibenzofurans, or CDFs, are
a family of chemicals that contain one to eight chlorine atoms
attached to the carbon atoms of the parent chemical, dibenzofuran.
There are 135 different types of CDFs with varying harmful
health and environmental effects. The compounds that contain
chlorine atoms at the 2,3,7,8-positions of the dibenzofuran
molecule are known to be especially harmful.
Not all of the different types have been
found in large enough quantities to study the physical properties.
However, of those that have been studied, they do not dissolve
in water easily and appear to be in the form of colorless
solids.
There is no known use for these chemicals.
Other than for research purposes, they are not deliberately
produced by industry. Most CDFs are produced in small amounts
as undesirable by-products of certain processes, such as manufacturing
other chemicals or bleaching at paper and pulp mills. CDFs
can also be released from incinerators.
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What
happens to CDFs when they enter the environment? |
- CDFs exist in the air as solid particles and sometimes
vapors.
- They can enter the environment from car exhausts or from
burning coal, wood, or oil for home heating, and the production
of electricity.
- Vaporized CDFs are broken down by other chemicals in the
atmosphere.
- They can be removed from the air in snow and rain.
- They attach to soil and sediment in lakes and rivers.
- They are not likely to move into groundwater from soil.
- They accumulate in fish to tens of thousands times higher
levels than in the water or sediment.
- They also build up in other animals, birds, and people
that are exposed to CDFs in their food.
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How
might I be exposed to CDFs? |
- Eating contaminated foods, such as meat, fish, and milk
(90% of daily exposure, which is only a few picograms [pg],
results from eating contaminated food).
- Breathing air or drinking water that is contaminated,
or coming in contact with contaminated soil.
- Using products such as milk cartons, coffee filters, and
tampons could result in very low exposures.
- Breathing contaminated workplace air.
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How
can CDFs affect my health? |
Very little is known about the health
effects in people or animals from breathing or touching CDFs.
A study in mice showed that skin exposure to low levels over
several weeks produced effects similar to those from ingesting
CDFs.
Most of the information on the adverse
health effects comes from studies in people who were accidentally
exposed to food contaminated with CDFs. The amounts that these
people were exposed to were much higher than are likely from
environmental exposures or from a normal diet.
CDFs caused skin and eye irritations,
including severe acne, darkened skin color, and swollen eyelids
with discharge from the eyes. CDF poisoning also caused vomiting
and diarrhea, anemia, more frequent lung infections, numbness,
effects on the nervous system, and mild changes in the liver.
Children born to exposed mothers had skin irritation and more
difficulty learning.
Many of the same effects that occurred
in people also occurred in laboratory animals that ate CDFs.
Animals also had severe weight loss, and their stomachs, livers,
kidneys, and immune systems were seriously injured. Some animals
had birth defects and testicular damage, and in severe cases,
some animals died. These effects in animals were seen when
they were fed large amounts of CDFs over a short time, or
small amounts over several weeks or months.
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How
likely are CDFs to cause cancer? |
The Department of Health and Human Services,
the International Agency for Research on Cancer, and the Environmental
Protection Agency (EPA) have not classified CDFs for carcinogenicity.
It is not definitely known if CDFs cause
cancer in people. There are no cancer studies in animals that
ate or breathed CDFs. One study found that when CDFs were
applied to the skin of animals, they did not cause cancer,
but when they were applied with another compound called MNNG,
which is known to initiate tumors, cancer did develop.
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Is
there a medical test to show whether I've been exposed to CDFs? |
There are tests available to measure
CDFs in your blood, body fat, and breast milk. The tests can
tell you if you have been exposed, but they can't tell you
the exact amount of CDFs or for how long you were exposed.
The tests also cannot predict whether you will experience
harmful health effects. Nearly everyone in the United States
and other industrialized countries has been exposed to low
levels of CDFs because they are in the environment.
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Has the federal government made recommendations to protect human health? |
There are no federal guidelines or recommendations
for protecting human health or the environment from exposure
to CDFs.
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Glossary |
Anemia: A decreased ability of the blood
to transport oxygen.
Carcinogenicity: Ability to cause cancer.
Picogram (pg): One trillionth of a gram.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1994. Toxicological Profile for chlorodibenzofurans (CDFs). Atlanta, GA: U.S.
Department of Health and Human Services, Public Health Service.
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Where can I get more information? |
ATSDR can tell you where to find occupational
and environmental health clinics. Their specialists can recognize,
evaluate, and treat illnesses resulting from exposure to hazardous
substances. You can also contact your community or state health
or environmental quality department if you have any more questions
or concerns. For more information, contact:
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Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Phone: 1-888-42-ATSDR (1-888-422-8737)
FAX: (770)-488-4178
Email: ATSDRIC@cdc.gov
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