5700
United States
Environmental Protection
Agency
Region 5
Office of Public Affairs
230 South Dearborn Street
Chicago, Illinois 60604
905R99100
vvEPA
Toxic Chemicals
What They Are,
How They Affect You
This fact sheet explains
what toxic chemicals are,
what they're used for, and
how they can be harmful.
Although here we examine
just a sampling of the
approximately 60,000
chemicals that are now in
the marketplace, this fact
sheet will shed light on
some of the more common
toxic chemicals EPA
encounters.
What Does Toxic Mean?
A chemical is toxic if it damages living
tissue, impairs the central nervous system,
or causes birth defects, illness, or death
when eaten, drunk, inhaled, or absorbed
through the skin.
How Much Exposure To A
Chemical Causes Harm?
It depends on the chemical. The amount
needed to trigger a toxic reaction varies
with the nature of the substance, the
route of exposure, and the length of
exposure. Acute toxicity refers to an
exposure of short duration. Chronic
toxicity refers to repeated or prolonged
exposures often in tiny doses to
substances that in any single exposure
would cause little or no harm.
Certain chemicals are so toxic that they
are measured in parts per million (ppm) or
even smaller parts per billion (ppb). One
ppb would be one pound of a chemical in
a billion pounds of soil. Or it can be
compared to one silver dollar in a roll of
U.S. Environmental Protection Agency
Region V, Library
230 South Dearborn Street
Chicago, Illinois 60604
Bioaccumulation
People catch and eat fish
containing PCB's Chemicals
like PCB's. that bioaccumulate
collect in the fatty tissue and
organs in humans
Small invertebrate animals
such as aquatic insects,
and crustaceans eat
plants contaminated with
PCB's or absorb PCB's
from the water
Some chemicals {PCB's will be
used in this example) don't
dissolve and don't break down
easily They stick to plants and
particles in the water
Trout and salmon eat small
invertebrates and smaller fish
Fish (both large and small)
absorb PCB's directly from the
water
silver dollars stretching from Detroit to
Salt Lake City.
But Why Are Such Small Doses Of
Some Toxic Chemicals Hazardous?
Besides being poisonous at low levels,
PCB's, lead, and various other chemicals
are also extremely persistent. That is, they
don't break down easily and therefore
remain in the environment for years.
Prolonged exposure to small doses of such
chemicals are thought to cause a variety of
health problems, including cancer.
Bioaccumulation
Bioaccumulation is another reason why
prolonged exposure to low-level doses
can be dangerous. Chemicals such as
PCB's and mercury build up in the tissues
of humans and animals through the
process of bioaccumulation. It works like
this: A chemical spilled into a river or lake
is ingested and stored by small organisms
like plankton; small fish eat the plankton;
and larger fish eat the smaller fish. As the
process works its way up the food chain,
the chemical may become thousands of
times more concentrated in the tissues of
the large fish than in the plankton. That's
why some fish from parts of the Great
Lakes are unsafe to eat.
What Is EPA Doing About
Toxic Wastes?
Three major laws help EPA control toxic
substances. The Toxic Substances Control
Act (TSCA) regulates the production of a
substance that poses an unreasonable risk
to human health or the environment. The
Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA),
commonly called Superfund, enables EPA
to address immediate dangers, long-range
hazards, and spills at old or abandoned
waste sites. The Resource Conservation
and Recovery Act (RCRA) allows the State
and EPA to track hazardous wastes from
generation through final disposal. Other
laws that also help regulate toxics include
the Clean Water Act, Clean Air Act,
Federal Insecticide, Fungicide and
Rodenticide Act, and Hazardous Materials
Transportation Act.
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Most toxic substances can be handled
safely. Depending on the substance,
however, certain methods of manufactur-
ing, use, and disposal are preferable over
others. High-temperature incineration, for
example, is highly effective in destroying
PCB's and other toxic chemicals, but not
toxic metals such as lead and mercury.
Secure, lined landfills are an acceptable
disposal option for toxic substances. Here
are some of the toxic chemicals EPA often
finds when studying or cleaning up a
Superfund site.
Asbestos
Asbestos a building and insulating
material widely used for years because of
its strength and heat-resisting qualities, has
been found to cause asbestosis a severe
lung ailment, certain types of lung cancer,
and other respiratory problems. If not
completely sealed in a product, asbestos
can break into tiny fibers that float almost
indefinitely in air. These fibers are smaller
and more buoyant than ordinary dust
particles and therefore are easily inhaled
or swallowed. In 1972, asbestos was
banned for use in clothing. In subsequent
years it was banned in fire-proofing
materials, in electric hair dryers, and in
many other products. By 1982, of the
22,723 schools in EPA Region 5 that were
inspected for asbestos problems, 4,634
required corrective measures.
Acrylonitrile
Acrylonitrile a chemical used in the
production of synthetic fibers, plastics, and
acrylics. In 1980, 1.8 billion pounds were
produced in the United States, making it
the 42nd highest volume chemical
produced in the Nation. Acute symptoms
of acrylonitrile exposure are similar to
cyanide poisoning: headaches, dizziness,
tremors, and jaundice. Long-term
exposure to acrylonitrile can cause
damage to the liver, the kidneys, and the
central nervous system. It's a suspected
carcinogen in humans.
Arsenic
Arsenic a grayish white element found
naturally in the environment. Arsenic has
been used in the production of boric acid,
pharmaceutical products, and pesticides.
It is a byproduct of copper, zinc, and lead
smelting. Doses taken over long periods
can cause birth defects and genetic
damage in test animals; there is evidence
that it can cause skin and lung cancer in
humans.
Benzene
Benzene used more and more in recent
years in the synthesis\of chemical
compounds and drugs and in the rubber
industry. It is also added to gasoline as an
octane booster. Eight million tons are
produced annually. Benzene is released
into the air primarily through the
distribution and use of petroleum
products. Evidence shows that long-term
exposure in the workplace can cause
leukemia and that high dosages are fatal.
EPA estimates that three-fourths of all
Americans have probably been exposed to
benzene in varying degrees. Much of the
exposure occurs when pumping gas at
gasoline stations.
U,S. Environmental Protection
Cyanide a poison that asphyxiates the
cells in the body. Warning signs of cyanide
poisoning include dizziness, numbness,
rapid pulse, and nausea. A large dose can
cause immediate unconsciousness. It is
primarily used in the extraction of ore, in
electroplating, and in metal treatment. It is
also used in fumigation and in the
manufacturing of pharmaceuticals.
Dioxin
Dioxin a generic term for a group of
75 related compounds known as poly-
chlorinated dibenzo-p-dioxins. The most
toxic compound of this group is 2,3,7,8-
tetrachloro-dibenzo-p-dioxin (2,3,7,8-
TCDD). Nobody produces dioxin on
purpose. It is an unwanted but almost
unavoidable byproduct that comes from
manufacturing several commercial
substances, chiefly the pesticide 2,4,5-TCP.
Dioxin was also a contaminant in Agent
Orange, the defoliant used during the Viet
Nam War. Tests on laboratory animals
indicate that 2,3,7,8-TCDD is one of the
most toxic substances made by man. It is
also a suspected carcinogen in humans,
although scientists are still mystified by
this chemical's effect on the human body.
EPA has now begun a national study to
determine the extent of dioxin in the
environment.
Formaldehyde
Formaldehyde a colorless, pungent gas
used in plastics, plywood, foam insulation
products, textiles, embalming fluids, room
deodorants, and as a preservative in
cosmetics. Prolonged exposure can cause
eye irritation, respiratory problems, and
fatigue. EPA is currently evaluating
formaldehyde and may soon issue
regulations to reduce exposure to this
chemical.
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Leachate
Leachate a common term when talking
about landfills. Leachate is not a specific
chemical itself; it's a liquid that has
percolated through wastes and contains
components of those wastes. For instance,
water may mix with leaking wastes inside a
landfill, become contaminated, and then
seep into the water table, polluting
drinking water wells.
Heavy
Metals
PCB's
Polychlorinated Biphenyls (PCB's) are a
family of organic compounds used since
1926 in electric transformers as insulators
and coolants, in lubricants, carbonless
copy paper, adhesives, and caulking
compounds. They are also produced in
certain combustion processes. PCB's are
extremely persistent in the environment
because they do not break down into new
and less harmful chemicals. PCB's are
stored in the fatty tissues of humans and
animals through the bioaccumulation
process. EPA banned the use of PCB's in
1976. In general, PCB's are not as toxic in
acute short-term doses as some other
chemicals, although acute and chronic
exposure can cause liver damage. PCB's
have also caused cancer in laboratory
animals. When tested, most people show
traces of PCB's in their blood and fatty
tissues.
in electroplating,
in the manufacture of batteries, and
as a pigment. Chronic exposure to
cadmium damages the liver and kidneys. It
also has been associated with hypertension.
Heavy smoking appears to increase the risk
of cummulative toxic effects of cadmium
exposure. Studies on animals have shown
that cadmium can produce tumors and
birth defects.
Cr
Chromium used in electroplat-
ing, in photography, and as a
paint pigment. Acute ingestion of
one form of chromium causes hemor-
rhages of the gastrointestinal tract.
Airborne chromium has caused lung and
other respiratory cancers in workers who
were frequently exposed to it on the job.
Lead a byproduct of metal
smelting, it is used in the
manufacture of batteries and
pigments. It also is added to gasoline to
improve octane ratings, although in
August 1984 EPA proposed to dramatically
reduce the level of lead in gasoline.
Exposure to low levels of lead over long
periods can cause brain, bone, and
neurological damage, and learning
disabilities in children. Studies have shown
a direct correlation between levels of lead
in gasoline and levels of lead in children's
blood.
Mercurya silvery, liquid heavy
metal found primarily in Spain,
Yugoslavia, Mexico, Canada, and
Algeria. Mercury is highly toxic and can
be absorbed through the skin. It is used in
thermometers, batteries, flourescent light
bulbs, pharmaceuticals, and many other
products. Mercury bioaccumulates in the
tissues of fish, making many larger ones
unsafe to eat. Prolonged exposure can
cause kidney, brain, and neurological
damage.
EPA Region 5 has initiated a 10-year testing program
to examine every community's underground water
supply for these and similiar chemicals, including TCE.
Carbon Tetrachloride is a color-
less liquid used in refrigerants,
metal degreasers, agricultural
fumigants, and as a dry-cleaning agent.
Exposure to it can cause damage to the
central nervous system, liver, and kidneys.
Alcohol intensifies the likelihood of these
effects. Studies of workers exposed to
carbon tetrachloride have concluded that
it is a carcinogen.
Dichloroethylene is a clear,
colorless, volatile liquid used in
cement latexes, film coating
lacquers, paper coatings, and certain
fibers. It causes health effects similiar to
carbon tetrachloride.
Dichloroethane (EDC) is used in
the production of vinyl chloride
and as a chemical feedstock. It's
also used as a lead scavenger, a leaded-gas
additive, an extraction agent for caffeine,
and a dry cleaning agent. In high doses,
dichloroethane can cause damage to the
liver, kidneys and lungs.
Tetrachloroethylene (PCE) is used
in dry cleaning, metal degreasing,
textile dyeing, and various
pesticides. It's a central nervous system
depressant that can cause liver and kidney
damage in animals.
S Frtvtrorrmemai- Protection Agency
Region V, Library
230 South Dearborn Street
Chicago, Illinois 60604
Trichloroethylene (TCE) is used as
an industrial degreaser; a solvent
for oils, paints, and varnishes; a
dry-cleaning agent; and an anesthetic. TCE
is most often found in ground water
because of spills at industrial facilities and
other locations where TCE is used as a
cleaning agent. The chemical is a central
nervous-system depressant. People
exposed to high levels of TCE become
sleepy, experience headaches, and may
develop liver or kidney damage. Animals
exposed to high doses of TCE have
developed cancer. Also, drinking alcoholic
beverages tends to make the symptoms of
TCE more severe.
H
H-C=C
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Vinyl Chloride is a gaseous raw
material used in plastics, floor
tiles, food packaging, and as a
propellant in aerosol containers. Studies
have shown that vinyl chloride causes liver
cancer. Lung cancer and cancer of the
lymphatic and nervous systems have also
been reported.
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For more information,
call our toll-free
Environmental Hotline:
800-572-2515 in Illinois and
800-621-8431 in Indiana,
Michigan, Minnesota, Ohio
and Wisconsin any business
day between 8:30 and 4:30
Central Time.
You may also write:
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U.S. EPA Region 5
230 South Dearborn Street
Chicago, Illinois 60604
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Chicago, Illinois 60604
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