Cancer Following Occupational Exposure To Asbestos And Vinyl Chloride

Our plain-English summary of Cancer Following Occupational Exposure To Asbestos And Vinyl Chloride, by W.J. Nicholson (1977).

The study

• Author: W.J. Nicholson
• Published: Cancer 39(Supplement 4):1792-1801, April (1977)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 002246. The article is still under copyright, so we describe it here rather than post it.

In plain English

This 1977 article was a review of cancer following work with asbestos and with vinyl chloride. Drawing largely on earlier studies, it reported that among 17,800 asbestos insulation workers, one in five deaths was from lung cancer and nearly 40% of deaths were attributed to asbestos exposure. Lung cancer deaths in this group peaked 30 years or more after first exposure, and lung cancer was far more frequent among cigarette smokers than non-smokers. The review also covered asbestos factory workers, shipyard workers, people living near asbestos factories, and household members of asbestos workers. The author's own measurements, which identified chrysotile fibers, found that air supplies of buildings fireproofed with dry-spray asbestos were often contaminated, while no contamination was demonstrated in buildings where cementitious spray was used. For vinyl chloride, the review described liver hemangiosarcoma among polymerization workers. The author concluded that asbestos controls had been much less successful than vinyl chloride controls. The author also wrote that adopting and following a proposed 0.1 fiber per cubic centimeter standard would do much to eliminate the risk from asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Review article covering asbestos-related and vinyl chloride-related disease. It draws mainly on previously published or reported studies and includes the author's group's measurements of asbestos in building air.
• Who was studied: No single study population. The review discusses 17,800 asbestos insulation workers in the United States and Canada, workers at a large U.S. asbestos products factory, British shipyard workers, people living near asbestos operations, household contacts of asbestos workers, air in office buildings, and vinyl chloride and PVC workers.
• Exposure: Asbestos exposure in insulation work, asbestos manufacturing, shipyards, households and neighborhoods, and from spray fireproofing in buildings. Chrysotile was the fiber identified in the building air samples. The review also covers vinyl chloride exposure in polymerization and PVC processing.
• Main results:
  • Among the 17,800 insulation workers studied by Selikoff, Hammond and Seidman, one in five of those who died had died of lung cancer.
  • Comparing these workers with the general population, nearly 40% of deaths among the insulation workers were attributed to their occupational asbestos exposure.
  • Among the insulation workers, both the number of lung cancer deaths and the ratio of observed to expected lung cancer deaths peaked after 30 years from onset of exposure.
  • Among the insulation workers whose smoking habits were known, 2 lung cancer deaths were seen in 2066 non-cigarette smokers over a 6-year period, compared with 179 in 9590 men with a history of cigarette smoking.
  • For New York and New Jersey insulators, the article gives an estimate that the lung cancer death risk of smoking asbestos workers was 92 times that of a person who neither smokes nor works with asbestos.
  • Among 689 long-term production employees of the largest U.S. asbestos products factory, about 134 deaths were expected and 199 occurred. About 28 cancers were expected and 72 were observed.
  • In the same factory, deaths from asbestosis fell as estimated job dustiness fell, but cancer deaths did not.
  • In a reviewed study of former shipyard workers in Barrow whose x-rays showed pleural plaques and who later died, deaths from bronchogenic carcinoma were 21 times the number expected.
  • In the Newhouse and Thompson study of mesothelioma at the London Hospital, 31 of 76 cases were of occupational origin. Of the remaining 45, 11 were in people living within half a mile of an asbestos factory and nine in household members of asbestos workers.
  • In a study by Henry Anderson of 326 family contacts of former factory workers, four cases of mesothelioma had already been identified among family members.
  • The author's building-air measurements found that air supplies of buildings with dry-spray asbestos fireproofing were often contaminated. No contamination was demonstrated in buildings with cementitious spray.
  • In a vinyl chloride cohort of 257 workers at a single polymerization plant (Nicholson et al.), three of 24 deaths were from hemangiosarcoma.
  • The author reported that efforts to control asbestos began earlier than those for vinyl chloride but had been much less successful.
• The authors' conclusion: The author concluded that if the proposed lower asbestos standard of 0.1 fiber per cubic centimeter were adopted and followed, much would be done to eliminate the human risk from asbestos exposure.
• Limitations the authors state:
  • For the factory study, disease could not be linked to known dust concentrations. Only a qualitative dose-response relationship was possible, based on job dustiness as ranked by workers and union officials.
  • The smoking data were too scant to measure the lung cancer risk of non-smoking asbestos insulators.
  • No definitive data yet linked hemangiosarcoma to non-occupational vinyl chloride exposure.

Topics

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Insulator, Lung Cancer, Asbestos Exposure, Chrysotile.

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