3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Attribution of lung cancer to asbestos exposure in miners South Africa.(2006-11-17T11:32:16Z) Chauhan, ShobnaAn autopsy-based case-series of South African miners was used to evaluate the evidence required to attribute a miner’s lung cancer to occupational asbestos exposure for compensation. The slightly different Helsinki (1997) and National Institute for Occupational Health (NIOH) criteria (1988) require that one of four factors (asbestosis, occupational exposure, raised burden of asbestos fibres and/or bodies) be fulfilled for attribution. These criteria were applied to the case-series to determine and compare the proportions of NIOH- and Helsinki-attributable lung cancers. Of 195 lung cancer cases, 47% (91) were Helsinki-attributable and 52% (101) NIOH-attributable: with 72% concordance. Some differences in the details of occupational exposure criteria and methods for assessing the burden of asbestos in the lung were responsible for differences in these proportions. If attribution had taken place using only presence of asbestosis and the occupational exposure history, many cases would not have been attributable to asbestos. Therefore, taking into account burden of asbestos in lung tissue was important. However, it was found that phase contrast microscopy (PCM) for counting asbestos bodies was “sufficient” and that scanning electron microscopy (SEM), advocated by the Helsinki criteria, added <1% of the cases, suggesting that the cost of expensive SEM fibre counts in a developing country may outweigh the benefits. Using the Helsinki criteria as the gold standard, the sensitivity of the NIOH criteria was 75.8% (95% CI: 65.7 – 84.2).