A 37-year observation of mortality in Chinese chrysotile asbestos workers

Abstract

Objectives This 37-year prospective cohort study was undertaken to provide additional evidence for mortality risks associated with exposure to chrysotile asbestos. Methods 577 asbestos workers and 435 control workers in original cohorts were followed from 1972 to 2008, achieving a follow-up rate of 99% and 73%, respectively. Morality rates were determined based on person-years of observation. Cox proportional hazard models were constructed to estimate HRs of causespecific mortality, while taking into account age, smoking and asbestos exposure level. Results There were 259 (45%) deaths identified in the asbestos cohort, and 96 died of all cancers. Lung cancer (n¼53) and non-malignant respiratory diseases (n¼81) were major cause-specific deaths, in contrast to nine lung cancers and 11 respiratory diseases in the controls. Age and smoking-adjusted HRs for mortality by all causes and all cancers in asbestos workers were 2.05 (95% CI 1.56 to 2.68) and 1.89 (1.25 to 2.87), respectively. The risks for lung cancer and respiratory disease deaths in asbestos workers were over threefold that in the controls (HR 3.31 (95% CI 1.60 to 6.87); HR 3.23 (95% CI 1.68 to 6.22), respectively). There was a clear exposureeresponse trend with asbestos exposure level and lung cancer mortality in both smokers and non-smokers. Conclusion Data from this prospective cohort provide strong evidence for increased mortality risks, particularly from lung cancer and non-malignant respiratory diseases, associated with exposure to chrysotile asbestos, while taking into account of the smoking effect.Asbestos, a recognised hazard in both occupational and environmental settings, has been responsible for millions of deaths worldwide.

Occupational exposure to asbestos is associated with increased mortality in men recruited for a population-based study in Germany

“…The significant association of the duration of occupational exposure to asbestos with all-cause mortality and benign lung disease mortality, respectively, underline the validity of our findings. Although we did not observe a statistically significant association between occupational exposure to asbestos and mortality from all cancers or lung cancer, in particular we observed positive non-significant trends that were in line with previous findings [9,15,21,23]. A borderline significant association of the duration of occupational exposure to asbestos with lung cancer mortality may support the assumption of causality between exposure to asbestos dust and lung cancer.…”

“…All-cause mortality and respiratory mortality As in SHIP, significantly increased risks for all-cause mortality [6,9,20,21] and benign lung disease mortality [7,22,23] had previously been observed. The significant association of the duration of occupational exposure to asbestos with all-cause mortality and benign lung disease mortality, respectively, underline the validity of our findings.…”

Personal exposure to asbestos and respiratory health of heavy vehicle brake mechanics

“…15 Although some studies have suggested that chrysotile is less harmful compared with amphiboles, 14 there is robust evidence showing an excess mortality risk because of lung cancer, all cancers, and nonmalignant respiratory diseases in chrysotile-exposed workers, even for those exposed to low concentrations. 16 Asbestos-containing brake pads, brake linings, and brake blocks are still commercialized in Colombia. Brake linings are used for both passenger and heavy vehicles (i.e., with important differences in size and thickness), whereas brake blocks are exclusively used for heavy vehicles.…”

The Rough Path to the Compensation of Asbestos Damages in China

“…clearly attributable to chrysotile exposure in Chinese studies than in mostly of the western studies with a prevalence of male smoker cohorts [5] (p. 250) and [30].…”