Asbestos is a common building material used for applications like insulation, fireproofing and brake linings. Its relatively high resistance to acid and fire make it ideally suited for such tasks and explains why, despite the hazard it poses to humans, signs of asbestos useage is still found in manufacturing and construction even today.
At its simplest, asbestos is a fiber made of strands of magnesium silicate. Asbestos's incredible strength even in the face of high force comes from its ability to split into smaller and smaller fibers. But this durability is also what makes it so dangerous. The fibers can become so small that they remain airborne for long periods of time and pass into the lungs unhindered by dust-filtering mechanisms.
Asbestos comes in two forms: serpentine and amphibole. The difference between the two comes down to shape. Serpentine asbestos fibers are curly while amphibole are needle-like and resist any bending or curling. Serpentine asbestos comes in one type: chrysotile, which is currently the commercially used asbestos. Amphibole can be classified as amosite, used for insulation, or crocidolite, used for cement.
Asbestos has been around for centuries, but it was not until the 1900s that people began to note the harmful effects and try to limit its use. As early as the 1800s, however, railroads and shipyards started making commercial use of asbestos. Railroads were able to harness the material as lining for refrigeration units, in boxcars, and for insulation. Shipyards used asbestos even more frequently; those who worked aboard ships or in shipyards are still among the most commonly affected sufferers of asbestos-related diseases. Workers in mines, power plants, oil refiners, steel mills, auto repair shops, and construction sites are also at risk.
Regarded as a miraculous material able to withstand a wide array of uses, asbestos found its way into a plethora of products up until about 1980. Things like felt, gloves, and even weatherproof jackets may have contained asbestos. Often it appeared in products used in construction, such as firebrick, cooling towers, roofing, masonry fill, and turbines. Today, asbestos may still be present in homes and workplaces in the form of drywall, insulation, and certain household products, if they were produced before the 1970s.
A key difficulty in protecting against asbestos exposure is that it is not visible when airborne. The best defense is understanding the types of products where asbestos may still be present. Some products are known to have included asbestos, such as roofing and shingles made with asbestos cement, and oil and coal furnaces. Homes built between 1930 and 1950 are at particular risk, as many contain asbestos insulation, as well as hot water and steam pipes that may be affected.
In the workplace, federal agencies have set limits on how much asbestos workers can be exposed to, but employees are also required to monitor their own exposure. Unlike in the past, today businesses must strictly limit the amount of asbestos their employees could potentially inhale. They're also required to provide safe, unexposed eating areas and place signs in any area where work involving asbestos is being conducted.
Despite warnings and improvements, more than 3,000 modern day products still contain asbestos. Building materials in particular remain a hazard to those who handle or come in contact with them. But signs that a product contains asbestos may be difficult or even impossible to notice. The best defense therefore is awareness of which products are likely to contain asbestos.
