Researchers say that asbestos exposure is responsible for 70% to 80% of all cases of mesothelioma, a malignant cancer that attacks the pleura and other cell linings of the body’s serous cavities. Asbestos is also implicated in some forms of lung cancer as well as a chronic, progressively debilitating inflammation of the lungs called asbestosis.
Asbestos exposure is actually commonplace: the mineral occurs naturally in every state except Hawaii, and traces of it are present in air, soil and water. However, prolonged exposure to asbestos fibers and particulate – preconditions for disease – is connected almost exclusively to asbestos mining, processing plants and factories where asbestos containing products are made and to those industries that made intensive use of asbestos either as an insulator or as a fire retardant. These include the construction trades, oil refineries, shipyards, power plants, steel mills, textile mills, chemical plants, and auto parts manufacturers and repair shops, to name just a few. One study estimates that over 27 million men and women were exposed to asbestos through their jobs between 1940 and 1980.
Nor were the employees who worked directly with asbestos the only ones at risk; significant secondary exposure occurred among workers tasked to perform duties within the asbestos contaminated environment. That risk extended to people living in close proximity to asbestos-using industries as contaminants were released into the air and soil. Secondary exposure went home with workers too: family members could be exposed to asbestos and contract asbestos-related diseases from their loved one’s skin, hair and clothing.
Asbestos use in industrial applications leveraged the mineral’s unique properties as a non-conductive heat shield and natural insulator. By the middle of the 20th century, its use was commonplace in flame retardant coatings, fireproof dry wall and cement, roofing, flooring, pipe and boiler linings, gaskets, and automotive brake pads, shoes and clutches.
The health risks of occupational asbestos exposure were recognized early on. The first successful workman’s comp claim for asbestosis in the United States was filed in 1927. Three years later, a comprehensive public health study identified the characteristic latency period associated with asbestos disease for the first time: the Merewether Report found that a quarter of 360 workers at a British textile mill were suffering from asbestosis, and concluded that the disease could be avoided through the adaptation of safety measures in the workplace. By 1943 when the first mesothelioma-like tumor was identified, there were over 200 references to asbestos as an environmental hazard in the medical literature.
If the health dangers of asbestos were known, why did asbestos continue to be so widely used? The quick answer is World War II: the dangers of asbestos paled before threats to national security, and better products were simply unavailable or prohibitively expensive. The Armed Forces, particularly the Navy, found hundreds of uses for asbestos, and it has been estimated that fully 30% of mesothelioma sufferers are military veterans.
Similarly asbestos use in the post war period can be attributed to a nation fearful of regulations that might push the economy back into pre-War depression. Whatever the reason, it is reflected in a spike in the number of mesothelioma deaths. Mesothelioma has a long incubation period, typically manifesting 40 or so years after initial asbestos exposure; the death rate from mesothelioma in the United States increased from 2,000 annually to 3,000 annually in the period of time between 1980 and the late 1990s.