Mortality of Aircraft Maintenance Workers Exposed to Trichloroethylene and Other Hydrocarbons and Chemicals: Extended Follow-Up

Global Outcomes Research Department, Merck and Co, Inc, NJ 08889, USA.
Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine (Impact Factor: 1.63). 12/2008; 50(11):1306-19. DOI: 10.1097/JOM.0b013e3181845f7f
Source: PubMed


To extend follow-up of 14,455 workers from 1990 to 2000, and evaluate mortality risk from exposure to trichloroethylene (TCE) and other chemicals.
Multivariable Cox models were used to estimate relative risk (RR) for exposed versus unexposed workers based on previously developed exposure surrogates.
Among TCE-exposed workers, there was no statistically significant increased risk of all-cause mortality (RR = 1.04) or death from all cancers (RR = 1.03). Exposure-response gradients for TCE were relatively flat and did not materially change since 1990. Statistically significant excesses were found for several chemical exposure subgroups and causes and were generally consistent with the previous follow-up.
Patterns of mortality have not changed substantially since 1990. Although positive associations with several cancers were observed, and are consistent with the published literature, interpretation is limited due to the small numbers of events for specific exposures.

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Available from: Aaron Blair, Oct 04, 2015
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    • "Twenty-four studies in which there was a high likelihood of TCE exposure in individual study subjects (e.g., based on job-exposure matrices or biomarker monitoring) and which were judged to have met, to a sufficient degree, the standards of epidemiologic design and analysis were identified in a systematic review of the epidemiologic literature. Of the 15 of these 24 studies reporting the risk of kidney cancer (Zhao et al., 2005; Charbotel et al., 2006; Radican et al., 2008; Moore et al., 2010), most estimated Relative Risks (RRs) between 1.1 and 1.9 for overall exposure to TCE. Six of these 15 studies reported statistically significantly increased risks for either overall exposure to TCE (Brüning et al., 2003; Moore et al., 2010; Raaschou-Nielsen et al., 2003) or for one of the highest TCE exposure groups (Raaschou-Nielsen et al., 2003; Zhao et al., 2005; Charbotel et al., 2006; Moore et al., 2010). "
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    ABSTRACT: This study investigated the human health risks of trichloroethylene from Industrial Complex A. The excessive carcinogenic risks for central tendency exposure were 1.40 × 10(?5) for male and female residents in the vicinity of Industrial Complex A. The excessive cancers risk for reasonable maximum exposure were 2.88 × 10(?5) and 1.97 × 10(?5) for males and females, respectively. These values indicate that there are potential cancer risks for exposure to these concentrations. The hazard index for central tendency exposure to trichloroethylene was 1.71 for male and female residents. The hazard indexes for reasonable maximum exposure were 3.27 and 2.41 for males and females, respectively. These values were over one, which is equivalent to the threshold value. This result showed that adverse cancer and non-cancer health effects may occur and that some risk management of trichloroethylene from Industrial Complex A was needed.
    Toxicological Research 09/2012; 28(3):173-178. DOI:10.5487/TR.2012.28.3.173
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    ABSTRACT: Occupational cohort and case-control studies suggest that trichloroethylene (TCE) exposure may be associated with non-Hodgkin lymphoma (NHL) but findings are not consistent. There is a need for mechanistic studies to evaluate the biologic plausibility of this association. We carried out a cross-sectional molecular epidemiology study of 80 healthy workers that used TCE and 96 comparable unexposed controls in Guangdong, China. Personal exposure measurements were taken over a three-week period before blood collection. Ninety-six percent of workers were exposed to TCE below the current US Occupational Safety and Health Administration Permissible Exposure Limit (100 p.p.m. 8 h time-weighted average), with a mean (SD) of 22.2 (36.0) p.p.m. The total lymphocyte count and each of the major lymphocyte subsets including CD4+ T cells, CD8+ T cells, natural killer (NK) cells and B cells were significantly decreased among the TCE-exposed workers compared with controls (P < 0.05), with evidence of a dose-dependent decline. Further, there was a striking 61% decline in sCD27 plasma level and a 34% decline in sCD30 plasma level among TCE-exposed workers compared with controls. This is the first report that TCE exposure under the current Occupational Safety and Health Administration workplace standard is associated with a decline in all major lymphocyte subsets and sCD27 and sCD30, which play an important role in regulating cellular activity in subsets of T, B and NK cells and are associated with lymphocyte activation. Given that altered immunity is an established risk factor for NHL, these results add to the biologic plausibility that TCE is a possible lymphomagen.
  • Academic Medicine 12/1964; 40(1):69. · 2.93 Impact Factor
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