Opinion ID: 3134558
Heading Depth: 2
Heading Rank: 1

Heading: Medical and Scientific Literature

Text: As circumstantial evidence of defendants’ alleged knowledge of the health hazards of asbestos, plaintiffs presented evidence of the information about these hazards contained in medical and scientific publications during the relevant time periods. Prior to 1930, there were approximately 12 case reports linking asbestos and disease in Britain, the United States, and Europe. In 1930, the first epidemiological study relating asbestos exposure to disease was published. This study, which was published in Britain and the United States, showed that approximately 25% of the asbestos industry workers studied had lung scarring and that the scarring was more severe in individuals who worked in dustier areas and had been exposed to asbestos for longer amounts of time. To prevent such lung damage, the author recommended dust control, respiratory protection, periodic health examinations of the workers, and education of workers concerning the risks of asbestos. In 1938, a bulletin issued by the United States Public Health Service reported the results of a study on asbestos textile manufacturing employees. The study connected asbestosis, which is irreversible lung scarring caused by asbestos fibers, to exposure to asbestos dust in concentrations greater than five million particles per cubic foot. The bulletin contained a recommendation that dust levels be kept below this threshold in order to prevent asbestosis. In the 1940s and 1950s, the five million particles per cubic foot threshold limit value for asbestos was adopted by the American Conference of Governmental and Industrial Hygienists and by many states, including Ohio and New Jersey. In the 1950s, however, the five million particles per cubic foot asbestos dust limit was criticized in the medical and scientific literature because it was designed only to prevent asbestosis and did not account for the cancer risk associated with asbestos exposure. Nevertheless, the threshold limit value for asbestos remained the same until 1969, when it was lowered. Beginning in the 1930s, case reports linking asbestos to lung cancer were published in the medical and scientific literature. In 1955, an epidemiological study involving asbestos and lung cancer was published in the British Journal of Industrial Medicine. This study found that asbestos manufacturing workers with asbestosis had 10 times the rate of lung cancer as the general population. In 1960, an epidemiological study linking asbestos exposure to mesothelioma, a cancer of the membrane surrounding the lungs, was published in the British Journal of Industrial Medicine. In the 1960s, Dr. Irving Selikoff began a large scale epidemiological study of asbestos and disease. Selikoff became one of the leading authorities on asbestos and disease. Throughout the 1960s , 1970s, and 1980s, Selikoff published the results of an ongoing health survey of members of the International Association of Heat and Frost Insulators and Asbestos Workers Union. In a 1964 article published in the Journal of the American Medical Association, Selikoff stated that, although many researchers had questioned the link between lung cancer and asbestosis, the results of his study proved that there was a connection. He found that asbestos exposure put insulation workers at greater risk for diseases such as asbestosis, lung cancer, and mesothelioma. These diseases were most apparent in workers with more than 20 years since the date of their first exposure.