Cement Workers Asbestos Fiber Concentrations and Mortality Rates

It has been proven that the inhalation of asbestos fibers can lead to a variety of health problems ranging from asthma to cancer.  Another interesting study that explored mesothelioma rates in an asbestos cement factory is called, "Follow up study of workers manufacturing chrysotile asbestos cement products." By M J Gardner, P D Winter, B Pannett, C A Powell - British Journal of Industrial Medicine 1986;43:726-732.  Here is an excerpt: "A cohort study has been carried out of 2167 subjects employed between 1941 and 1983 at an asbestos cement factory in England. The production process incorporated the use of chrysotile asbestos fibre only, except for a small amount of amosite during four months in 1976. Measured airborne fibre concentrations available since 1970 from personal samplers showed mean levels below 1 fibre/ml, although higher levels had probably occurred previously in certain areas of the factory. No excess of lung cancer was observed in the mortality follow up by comparison with either national or local death rates, and analyses of subgroups of the workforce by job, exposure level, duration of employment, duration since entry, or calendar years of employment gave no real suggestion of an asbestos related excess for this cause of death. There was one death from pleural mesothelioma and one with asbestosis mentioned as an associated cause on the death certificate, but neither is thought to be linked to asbestos exposure at this factory. Other suggested asbestos related cancers, such as laryngeal and gastrointestinal, did not show raised risks. Although the durations of exposure were short in this study, the findings are consistent with two other studies of workers exposed to low concentrations of chrysotile fibre in the manufacture of asbestos cement products which reported no excess mortality."

Another interesting study is called, "Respiratory function changes after asbestos pleurisy." By P H Wright, A Hanson, L Kreel, L H Capel - Thorax 1980;35:31-36.  Here is an excerpt: "Abstract - Six patients with radiographic evidence of diffuse pleural thickening after industrial asbestos exposure are described. Five had computed tomography of the thorax. All the scans showed marked circumferential pleural thickening often with calcification, and four showed no significant evidence of intrapulmonary fibrosis (asbestosis). Lung function testing showed reduction of the inspiratory capacity and the single-breath carbon monoxide transfer factor (TLCO). The transfer coefficient, calculated as the TLCO divided by the alveolar volume determined by helium dilution during the measurement of TLCO, was increased.

Pseudo-static compliance curves showed markedly more negative intrapleural pressures at all lung volumes than found in normal people. These results suggest that the circumferential pleural thickening was preventing normal lung expansion despite abnormally great distending pressures. The pattern of lung function tests is sufficiently distinctive for it to be recognised in clinical practice, and suggests that the lungs are held rigidly within an abnormal pleura. The pleural thickening in our patients may have been related to the condition described as "benign asbestos pleurisy" rather than the interstitial fibrosis of asbestosis."

Another interesting study is called, "Cancer in a Factory Using Amosite Asbestos" by Gardner M J, Winter P D and Bennett C. Cancer in a factory using amosite asbestos. International Journal of Epidemiology 1984; 13: 3–10.   Here is an excerpt: "The paper describes the mortality experience of 5969 men employed in a factory where insulation board was manufactured using amosite asbestos from 1947 to 1979. 422 (7%) of the men were known to have died by the end of 1980. Among the 4820 men engaged in the manufacture of insulation board a doubling of the risk of lung cancer has occurred (57 deaths observed; 29 deaths expected). An excess is present both in men who entered the factory before and after 1960. Among the 2461 for whom smoking information is available a detectable excess risk is limited to current smokers exposed to higher levels of asbestos. Apart from five deaths from mesothelioma no statistically large or significant excesses of mortality from cancers of other sites have occurred, but further follow-up of the cohort is in progress. Nine deaths from asbestosis have been recorded. The results are discussed in the light of other studies of the effects of exposure to amosite asbestos."

If you found any of these excerpts interesting, please read the studies in their entirety.  We all owe a great debt to these researchers for their important work.