Asbestos Disease Epidemiology

The use of asbestos dates back thousands of years and thousands of uses.  Often referred to as the "magic mineral," it is estimated that there have been more than 3,000 uses for asbestos.  It was incorporated into pottery some 4,000 years ago; woven into cloth with vegetable fibers to quiet the sound of falling trees felled as part of construction projects during the Roman empire; wrapping corpses prior to cremation in order to help collect the ashes, referred to as the funeral dress of kings by Pliny; and even mentioned by Marco Polo during his travels to the Far East, where he found it mined from the mountains, extracted, and then crushed into a fibrous wool that was then spun and made into cloth.

The "modern" asbestos industry dates from the 1880s, when asbestos was first used to make heat-resistant fabrics.  Although asbestos was first discovered in the United States around 1824 near Lowell, Vermont, not much interest was shown with regard to industrial use until about 1890.  By 1906 the commercial importance of asbestos had been well-recognized by industry as illustrated by the full page advertisement run by Johns-Manville in the Saturday Evening Post which read that asbestos "serves more people in more ways than any institution of its kind in the World."  The ad included products for the homebuilder, the industrial and commercial builder, and those in the automotive business.  By this time asbestos was also being used by the steel industry for the insulation of large furnaces. 

Asbestos disease also dates back thousands of years, with references by Pliny to the disease of slaves.  In 1899 the British Lady Inspector of Factories wrote that the effects of asbestos dust were found to injurious, and three years later asbestos was included in a publication on dangerous industries in England that listed dusts known to cause injury to humans.  The first recorded case of what is now known as asbestosis was reported in London in 1906, with the initial recorded case  of asbestosis in the United States being reported in 1930.  It was during this period of time that clinical descriptions of the disease asbestosis were becoming common in medical literature.  The sentinel case, which resulted in the naming of the disease asbestosis, is that of Nellie Kershaw, a 33-year-old asbestos factory worker who had worked in textile factories since she was 13 years of age.  Ms. Kershaw died on March 15, 1924.

In early studies of workers exposed to asbestos, asbestosis was also frequently found in conjunction with lung cancer.  In 1955, Sir Richard  Doll published the pivotal study for the causation of asbestos exposure and lung cancer, when he reported on a cohort of 113 men who had worked for more than 20 years in an asbestos textile factory in the United Kingdom.  Asbestos exposure appears to increase the risk for all histological types of lung cancer, an exposed individuals with asbestosis and exposed persons without asbestosis have risks of lung cancer that is higher than the general population that has not been exposed.  It is generally considered more likely that asbestosis is not a precursor to lung cancer, but that both are independent diseases related with a dose-response resulting from asbestos exposure. 

The rarity of mesothelioma and the fact that it is so strongly associated with asbestos exposure make mesothelioma a "signal tumor."  In other words, a diagnosis of mesothelioma is considered an epidemiological marker for exposure to asbestos.  Primary pleural tumors were first reported in the medical literature as early as 1870, but the term mesothelioma was not coined until 1909,.  The modern concepts for diagnosis of the disease followed in 1931.  Mesothelioma is now reported in virtually every major study of persons exposed to asbestos.  It has been estimated that there were over 18,000 malignant mesothelioma deaths among United States residents in the 1999 - 2005 time period, accounting for more than 200,000 years of potential life lost to life expectancy.  It is estimated that in excess of 2,500 cases of mesothelioma are still diagnosed in the United States every year.