Also known as TCE, trichloroethylene is an industrial solvent
and suspected human carcinogen commonly found as a pollutant in urban
groundwater. It is the chemical at the heart of the lawsuit in the
Woburn, Massachusetts tragedy told in the book and movie, A Civil
Action.
What is TCE?
TCE is a nonflammable, colorless liquid with a somewhat sweet odor
and a sweet, burning taste. It is used mainly as a solvent to remove
grease from metal parts, but it is also an ingredient in adhesives,
paint removers, typewriter correction fluids, and spot removers.
TCE is not thought to
occur naturally in the environment. However, it is present in most
underground water sources and many surface waters as a result of
the manufacture, use, and disposal of the chemical.
What happens to TCE
when it enters the environment?
¡¤ TCE easily dissolves in water, and it remains there
for a long time.
¡¤ It quickly evaporates from surface water, so it
is commonly found as a vapor in the air.
¡¤ It evaporates less easily from the soil, where it
may stick to particles and remain for a long time.
¡¤ It may stick to particles in water, which will cause
it to eventually settle to the bottom sediment.
¡¤ It does not build up significantly in plants and
animals.
How might I be exposed
to TCE?
¡¤ Breathing air in and around the home which has been
contaminated with TCE vapors from shower water or household products
such as spot removers and typewriter correction fluid
¡¤ Drinking, swimming, or showering in water that has
been contaminated with TCE
¡¤ Contact with soil contaminated with TCE, such as
near a hazardous waste site
¡¤ Contact with the skin or breathing contaminated
air while manufacturing TCE or using it at work to wash paint or
grease from skin or equipment
How can TCE affect
my health?
Breathing large amounts of TCE may cause impaired heart function,
coma, and death. Breathing it for long periods may cause nerve,
lung, kidney, and liver damage. Breathing small amounts for short
periods of time may cause headaches, lung irritation, dizziness,
poor coordination, and difficulty in concentrating.
Drinking large amounts
of TCE may cause nausea, liver, kidney damage, convulsions, impaired
heart function, coma, or death.
Drinking small amounts
of TCE for long periods may cause liver and kidney damage, nervous
system effects, impaired immune system function, and impaired fetal
development in pregnant women, although the extent of some of these
effects is not yet clear.
Skin contact with TCE
for short periods may cause skin rashes.
How likely is TCE
to cause cancer?
Some studies with mice and rats have suggested that high levels
of TCE may cause liver or lung cancer. Some studies of people exposed
over long periods to high levels of TCE in drinking water or in
workplace air have found evidence of increased cancer. However,
these results are inconclusive because other chemicals could have
caused the cancer.
The International Agency
for Research on Cancer (IARC) has determined that TCE is not classifiable
as to human carcinogenicity.
Is there a medical test
to show whether I've been exposed to TCE?
If you have recently been exposed to TCE, it can be detected in
your breath, blood, or urine. With recent exposure, a breath test
is a good enough indicator to determine if you have been exposed
to even a small amount.
Exposure to larger amounts
is assessed by blood and urine tests, which can detect TCE and many
of its breakdown products for up to a week after exposure. However,
exposure to other similar chemicals can produce the same breakdown
products, so their detection is not absolute proof of exposure to
TCE. This test isn't available at most doctors' offices, but can
be done at special laboratories that have the right equipment.
Has the federal government
made recommendations to protect human health?
¡¤ The EPA
has set a maximum contaminant level for TCE in drinking water at
0.005 milligrams per liter (0.005 mg/L).
¡¤ The EPA has also developed regulations for the handling
and disposal of TCE.
¡¤ The Occupational Safety and Health Administration
(OSHA) has set an exposure limit of 100 parts of TCE per million
parts of air (100 ppm) for an 8-hour workday, 40-hour workweek.
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