Asbestos: A tiny but lethal fiber
By The Virginian-Pilot, May 6, 2001
A miracle mineral
Asbestos is the generic term for a mineral that separates into long,
threadlike fibers. Though fragile in appearance, the fibers resist heat,
electricity, acid, corrosion and decay. The term ''asbestos'' is derived
from a Greek word meaning ''inextinguishable'' or ''unquenchable.'' Asbestos
can be spun like cotton, making it the only mineral that can be woven
into cloth. Asbestos' unusual qualities have been known for thousands
of years. It was first mined commercially in the 1870s.
A minuscle menace
An inch of chrysotile asbestos contains about 1 million individual fibrils
lying side by side. The tiniest fibrils are so small that when airborne,
they settle to the ground at a rate of about a foot per hour. And just
one fiber can cause cancer, most medical experts believe.
A multitude of industry uses
Asbestos has numerous commercial purposes. Before its health risks were
publicized in the 1970s, one of the key uses was ship insulation.
It also was used widely in construction products. Other common uses included
rail car and refinery insulation; theater curtains; brake pads; and clutch
linings. In 1942 alone, the War Production Board allocated to the nation's
shipyards 40 percent of the estimated 36.8 million pounds of the asbes-tos-containing
pipe insulation produced domestically. About 20 countries have banned
commercial use of asbestos. It is not banned in the United States, but
its use has been discontinued in virtually all consumer products. Most
asbestos today is mined in Canada, Russia and Africa. The primary markets
are developing nations, where in some cases usage is increasing.
Diseases related to asbestos
When inhaled, asbestos fibers can lodge in the lungs and cause disease.
Because of their virtual indestructibility, the fibers can remain in the
lungs indefinitely. Three lung diseases are most commonly associated with
asbestos exposure. They don't usually occur until years, sometimes decades,
later. Gastrointestinal diseases are also associated with asbestos exposure,
but are not as common.
Asbestosis is a fibrosis, or scarring, of the lungs that causes difficulty
breathing. It is the disease most commonly caused by asbestos exposure.
Symptoms include ''rales,'' a rattling in the lungs, and clubbing, or
swelling, of fingers and toes. It is a progressive disease for which there
is no cure. The longer and more intensive the exposure to asbestos, the
more severe the disease is likely to be.
Lung cancer caused by asbestos exposure is often fatal and increases
exponentially in people who also smoke cigarettes. Other cancers associated
with asbes-tos exposure, but which are reported less frequently than lung
cancer, include larynx and gastrointes-tinal tract cancers.
Mesothelioma is a cancer of the lining of the lung and abdomen. It is
distinguished by a fast-growing, sheetlike tumor that can cause the victim
to suffocate. It is almost always fatal. Cigarette smokers are not more
likely to be stricken with mesothelioma.
Impact on Hampton Roads
Most local victims worked in area shipyards. Others include sailors
and merchant seamen who served aboard ships insulated with asbestos, and
railroad, refinery and construction workers. Family members exposed to
asbestos brought home on the clothes of workers and sailors can also be
affected. Here is a look at the local impact:
- At least 9,000 people in Hampton Roads have suffered asbestos disease,
based on settlements of legal claims. About 2,000 of those have been
cancer victims, the rest asbestosis victims.
- The rate for mesothelioma here is seven times higher than the national
average. Between 1982 and 2000, an average of at least one local person
was diagnosed with the cancer every 10 days.
- About 4,200 current or former shipyard workers can be expected to
die of asbestos-related cancer before the epidemic subsides in about
30 years, based on data compiled by occupational health experts.
Death toll in U.S. shipyards
Medical researchers have projected that, nationwide, deaths from malignancies
among shipyard workers peaked at about 2,700 in 1987. About 1,700 are
projected to die this year.