What is asbestos?
Asbestos is categorized into two forms: serpentine and amphibole asbestos. Both are resistant to high temperatures and are extremely durable. In their raw states both are formed from fibrous strands that can be split and divided into smaller and smaller fibers eventually becoming microscopic. Individual fibers can be 700 times smaller than a human hair. Characteristically, the serpentines fibers are curly in shape – much like wool. These fibers can be bent and twisted. Amphibole fibers are brittle shards more like man-made fiberglass in quality. These fibers cannot be bent or curled and are more like tiny slivers of broken glass. Because the fibers are so small, they can be suspended in the air for hours or even days. It is these invisible fibers of both types that create a hazard to human health. When inhaled, the fibers permanently lodge in the lungs impairing the lung's ability to function properly.
Uses and Products
Canada is by far the largest producer of asbestos, supplying 75% of the total world’s supply. Because of its cloth-like qualities, asbestos was in high demand. It could be woven into fireproof garments for firefighters and others who worked in high heat environments. Asbestos was also used in gas masks and woven into sheets to act as insulation and thermal proofing for pipes, boilers, and electrical products. It could be spray applied as fireproofing. As well, it was a perfect coating material for brake linings and clutch pads where friction created high heat.
Other uses include:
-
Building exteriors - siding panels, shingles, soffits, roofing felts, mastics, thermal spray, stucco, mortar, loose fill insulation
-
Flooring - vinyl tile, vinyl sheet flooring, floor leveling compound
-
Ceilings - ceiling tile, plaster or drywall jointing materials
-
Walls - stippled finishes, thermal spray, asbestos cement panels
-
Insulation - boilers, vessels, pipes, ducts, incinerators, floors, ceilings, walls, chillers
-
Structural - fireproofing spray on beams, decks, joints, columns and other structural members
-
Other miscellaneous uses - incandescent light fixture backing, wire insulation, fume hoods, lab counters, elevator brake shoes, heating cabinet panels, fire dampers, emergency generators – thermal insulation and exhaust manifolds, theater curtains, welding blankets, incinerators
Asbestos Related Disease
In the early twentieth century, as worker health started to become more of a concern, research began to reveal unusually high numbers of lung problems and related deaths among asbestos miners.
Despite the fact that many materials (such as fiberglass insulation) were created to replace asbestos, companies that used asbestos ignored the safer alternatives. It has only been recently (since the 1980's) that a concerted effort has been made to regulate asbestos use and protect workers from the effects of the material.
Prolonged exposure to asbestos creates a serious risk for lung disease. Asbestos inhalation is the known cause of pleural plaques, asbestosis, mesothelioma, and causes cancers of the lung, esophagus, and colon. One of the difficulties of diagnosing asbestos related diseases is that they can have a long latency period – it can take between ten to forty years before symptoms are evident.
Asbestos Removal
With the recognition of the serious health risk posed by asbestos, and the fact that it was so widely used, asbestos removal became a new industry of the 1980’s. The removal of asbestos in public buildings such as government offices and schools became a priority. Unfortunately, the removal work was often done by inexperienced contractors who created a bigger risk by disturbing the material than if it had been just left alone.
Working with asbestos has become a highly regulated activity and its removal is a difficult and often expensive undertaking. Not only do the workers need to be protected while they are engaged in the removal process, but the working environment must be sealed to protect against airborne asbestos escaping into adjoining parts of the building or into the general atmosphere around the building.
Workers require full respiration equipment and proper protective clothing to prevent contamination. Adequate ventilation and filtering of ambient air is paramount to the proper removal and abatement of further contamination of surrounding areas.
Sources & Further Information
Asbestos Resource Centre
Mesothelioma Awareness