Asbestos is the name for a group of naturally occurring silicate minerals that can be separated
into fibers. The fibers are strong, durable, and resistant to heat and fire. They are also long, thin
and flexible. Asbestos fibers can be molded or woven into various fabrics. Because it is
nonflammable and a poor heat conductor, asbestos has been widely used to make fireproof
products such as safety clothing for fire fighters and insulation products such as hot-water
piping. Asbestos has also been used in building-construction materials, textiles, missile and jet
parts, asphalt and caulking compounds and paints, and in friction products such as brake linings.
Since the 1960s, asbestos has been recognized as a potent carcinogen and serious health
hazard. Inhalation of airborne asbestos fibers has been established as the cause of asbestosis
(thickening and scarring of lung tissue) and as a cause of mesothelioma (a highly lethal tumor of
the pleura) as well as of cancers of the lung, intestines, and liver.
The main symptoms include
shortness of breath on exertion, a persistent cough, chest pain or tightening of the chest, nail
abnormalities (such as ridges developing on the nails or white streaks on the nails) and
thickening of the fingers and toes. There is no cure for asbestos diseases, but, as severity depends
on the length of exposure and amount of asbestos dust inhaled, early identification through chest
x-ray can prevent further exposure and worsening of conditions.
Asbestos is obtainable by various underground mining methods, but the most common
method is open-pit mining. Only about 6 percent of the mined ore contains usable fibers. For
many years mining companies have known about the connection between mesothelioma and
asbestos, but choose not to inform their employees. Moreover, while many employees became
sick and suffered lung disease, some companies had...