Document KkaNGp3eEaqpQ56YREvez8J0
the larynx arc anribiitnblc to asbestos. Altliough the use * and Canada.) The 11 angiosarcoma deaths detected in
of. and exposure to, asbestos is being reduced in this * the study were all linked to heavy exposure to vinyl
country, the related cancer rate is not expected to decline * chloride. The NIOSH study also found that the chances
until the 21st century, because of the latency period. * of cancer developing in vinyl chloride workers increased
As with other carcinogens, the greater the amount and duration of the exposure to asbestos, the greater
*
with each passing year after the initial exposure. In another study, NIOSH examined death certificates
the apparent chances for cancer to develop. But research
for 29,139 former workers at three chemical plants in
indicates even relatively brief exposures to asbestos can
West Virginia. Twelve liver cancer deaths were reported
cause cancer. Occupational mortality studies show high * in those working routinely with vinyl chloride--10 times
slung-cancer rates in those who worked with asbestos * the number expected in the general population. The
only a few years--and some only a few months--while
survey also found a high correlation between years of
building ships during World War II,
exposure and the disease.
Usually, the latency period for asbestos-induced lung *
Altogether, 1974-84 research on more than 10,000
cancer is 20 or more years; for mesothelioma it is longer. But latency periods of less than five years have been
*
workers from the United States, Canada, Great Britain and Scandinavia found liver cancer occurring among
recorded, particularly with heavy exposures to
vinyl chloride workers at nearly five times the expected
crocidolite, considered more carcinogenic than other * rate for the general population. Thirty-seven cases were
asbestos fibers.
* observed, while only seven were expected.
sAsbestos, from the Greek word for "incombustible," *
Other studies show elevated cancer rates in those
has more than 3,000 commercial uses in this country,
living within a mile of vinyl chloride plants. In a 1970-
primarily for insulation. Asbestos-cement pipe covers * 73 survey of Ohioans (age 45 and older) living in the
more than 200,000 miles across the 50 states. Though
vicinity of a vinyl chloride plant, the cancer rate among
use is declining, about 35,000 American workers in the
males was nearly twice the expected rate. Twenty-seven
sasbestos manufacturing sector still risk direct exposure, * were observed with only 14 expected. The same survey
while another 2.5 million are potentially exposed in
also found an increase of congenital abnormalities,
other occupations, according to NIOSH. Asbestos exposure is the most hazardous during operations that
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especially pertaining to the central nervous system, in babies bom in that area.
circulate the fibers into the immediate air, as in asbestos *
Vinyl chloride, also known as chloroethylene, is a
sremoval, mining, drilling, cutting, spraying, or when * colorless, pleasant-smelling gas, usually in the form of
materials containing asbestos begin to decompose.
a cool liquid. It functions as a chemical intermediate
Along with asbestos manufacturers and fabricators,
and a solvent, and is used primarily in the manufacture
insulators, asbestos-cement workers, shipbuilders,
ofplastics, polyvinyl chloride and other resins. Industries
construction workers performing demolition and
where exposure is likely to be highest include plastics,
renovation w'ork, and auto workers servicing brakes and clutches all are at high risk for contracting asbestosrelated cancer. Also, high rates of asbestos-related
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rubber, polyvinyl-resin manufacture and organic chemical synthesis.
Both the U.S. Environmental Protection Agency
!cancer among families of asbestos workers indicate that
even work clothing or other asbestos-contaminated material routinely brought into the home may be
(EPA) and the Food and Drug Administration have banned vinyl chloride as an aerosol propellant, eliminating exposure to as many as 5 million Americans.
\hazardous. Further recognizing the risks posed by asbestos, in 1986 OSHA reduced the 8-hour time-weighted-average
But roughly 3.5 million U.S. workers remain potentially exposed. The OSHA PEL is 1.0 part per million (ppm) for an 8-hour TWA not to exceed 5 ppm for any 15-
(TWA) PEL from 2 fibers per cubic centimeter (f/cc)
minute period. Though cancer risk appears highest with
to 0.2 f/cc. Late last year, OSHA reinforced asbestos
heavy exposures to vinyl chloride, there is as yet no
protection by mandating that even within the 0.2 TWA,
evidence of an exposure level below which no increased
asbestos exposures should not exceed 1 f/cc for any
cancer risk would occur, according to the IARC.
given 30-minute period.
Exposure occurs mainly through inhaladon. Effects
Vinyl Chloride
Angiosarcoma of the liver is an extremely rare affliction. That is why the heads of medical researchers turned so fast when three cases arose from the same vinyl chloride plant in Kentucky 15 years ago.
Subsequently, NIOSH performed follow-up studies on 1,294 workers with five or more years' vinyl chloride exposure from four separate plants. Along with "higherthan-expected" rates for liver cancer, NIOSH also detected high rates ofleukemia, and cancers of the brain, central nervous system and respiratory system. (These
of overexposure may resemble mild alcohol
intoxification, including symptoms of lightheadedness
\ and nausea. Vinyl chloride can also be absorbed through
s the skin. It is a skin irritant and may cause frostbite s after evaporation. Vinyl chloride is especially hazardous
s to the eyes.
s*
Benzene
Benzene, a clear, colorless and highly flammable
*
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liquid, is derived from petroleum and is commonly used as a gasoline additive, a chemical intermediate, and
s formerly was used as a solvent for rubber, plastics, inks,
findings were backed up by similar studies in Europe * oils, paints and adhesives. It is also used in the
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GENC 003173
Ohio Monitor/October 1989