Mesothelioma and Occupational Cancers in Retired Workers

The overwhelming majority of asbestos exposure comes from the workplace.  Exposure to hazardous asbestos can be an impetus for disease development such as lung cancer and mesothelioma.  One interesting study is called, "Respiratory cancer in relation to occupational exposures among retired asbestos workers" by Philip Enterline, Pierre De Coufle, and Vivian Henderson - Br J Ind Med 1973;30.  Here is an excerpt: "Abstract - A cohort of 1 348 men who completed their working lifetime in the asbestos industry and retired with an industry pension during the period 1941-67 was observed through 1969 for deaths. The average length of employment in the asbestos industry for these men was 25 years and all had exposures to asbestos dust. In some instances these exposures were very high and continued for many years. Mortality for this cohort of men after age 65 was 14•7% higher than for the entire population of United States white men living at the same ages and time periods. This excess was due almost entirely to cancer and respiratory disease. The cancer excess was chiefly due to respiratory cancer where mortality was 2-7 times the expected. The respiratory disease excess was entirely due to asbestosis.

A time-weighted measure of asbestos dust exposure at the time of retirement was calculated for each man. This was made up of the summed products of dust levels for each job (expressed in mppcf) and years at each level. This measure was directly related to the respiratory cancer excess at ages 65 and over, ranging from 1•7 times expected for men with less than 125 mppcf-years exposure to 5•6 times expected for men with 750 or more mppcf-years exposure. There appeared to be no direct relationship between asbestos dust exposure and respiratory cancer below 125 mppcf-years. Important increments in respiratory cancer mortality apparently occurred somewhere between 100 and 200 mppcf-years exposure.

Separation of the effects of time from the effects of average dust level on respiratory cancer mortality showed that the contribution of each was about the same and that a time-weighted measure of asbestos dust appears to be an appropriate method for predicting respiratory cancer effects."

Another interesting study is called, "Asbestos exposure during brake lining maintenance and repair" by Arthur N. Rohl, Arthur M. Langer, Mary S. Wolff and Irving Weisman -
Environmental Sciences Laboratory, Mount Sinai School of Medicine of the City University of New York - Environmental Research Volume 12, Issue 1, August 1976, Pages 110-128.  Here is an excerpt: "Abstract - Data obtained on asbestos exposure of garage mechanics during brake lining maintenance and repair work show that fiber concentrations frequently in excess of regulated limits are common. The presence of chrysotile, ranging from 2 to 15%, in brake drum dusts, was demonstrated by X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and electron microprobe analyses. Unaltered chrysotile was found, both in fiber and fibril form, in air and brake drum dust samples. The chrysotile asbestos content of personal air samples, taken during automobile brake repair work, was measured both by optical and electron microscopic techniques. While a positive correlation exists between the types of measurements, the present technique of optically counting asbestos fibers may considerably underestimate the levels of total asbestos exposure."

If you found any of these excerpts interesting, please read the studies in their entirety.