Cancer mortality in Chinese chrysotile asbestos miners: exposure-response relationships

Our plain-English summary of Cancer mortality in Chinese chrysotile asbestos miners: exposure-response relationships, by X. Wang, E. Yano, S. Lin, et al (PloS One, 2013).

The study

• Authors: X. Wang, E. Yano, S. Lin, I.T. Yu, Y. Lan, L.A. Tse, H. Qiu, D.C. Christiani
• Journal: PloS One
• Published: 2013;8(8):e71899
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: This study was conducted to assess the relationship of mortality from lung cancer and other selected causes to asbestos exposure levels.

Methods: A cohort of 1539 male workers from a chrysotile mine in China was followed for 26 years. Data on vital status, occupation and smoking were collected from the mine records and individual contacts. Causes and dates of death were further verified from the local death registry. Individual cumulative fibre exposures (f-yr/ml) were estimated based on converted dust measurements and working years at specific workshops. Standardized mortality ratios (SMRs) for lung cancer, gastrointestinal (GI) cancer, all cancers and nonmalignant respiratory diseases (NMRD) stratified by employment years, estimated cumulative fibre exposures, and smoking, were calculated. Poisson models were fitted to determine exposure-response relationships between estimated fibre exposures and cause-specific mortality, adjusting for age and smoking.

Results: SMRs for lung cancer increased with employment years at entry to the study, by 3.5-fold in ≥ 10 years and 5.3-fold in ≥ 20 years compared with <10 years. A similar trend was seen for NMRD. Smokers had greater mortality from all causes than nonsmokers, but the latter also had slightly increased SMR for lung cancer. No excess lung cancer mortality was observed in cumulative exposures of <20 f-yrs/ml. However, significantly increased mortality was observed in smokers at the levels of ≥ 20 f-yrs/ml and above, and in nonsmokers at ≥ 100 f-yrs/ml and above. A similarly clear gradient was also displayed for NMRD. The exposure-response relationships with lung cancer and NMRD persisted in multivariate analysis. Moreover, a clear gradient was shown in GI cancer mortality when age and smoking were adjusted for.

Conclusion: There were clear exposure-response relationships in this cohort, which imply a causal link between chrysotile asbestos exposure and lung cancer and nonmalignant respiratory diseases, and possibly to gastrointestinal cancer, at least for smokers.

In plain English

No summary of this study can be given from the material supplied. The citation is for a 2013 PLoS ONE article on cancer deaths among Chinese chrysotile asbestos miners. The full text provided with it is a different article from the same journal: a laboratory study of how parathyroid hormone and a protein called Runx1 affect cartilage formation in mouse embryo cells (PLoS ONE 8(9): e74255). That article does not concern asbestos, mining, cancer or human workers. None of the miners' study's methods, numbers or conclusions appear in the text provided, so none of them can be checked against the article itself. To avoid giving workers, families or lawyers any figures that cannot be checked against the source, this entry has been left without findings. The correct full text of the chrysotile miners' article is needed before a summary can be written.

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.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile, Lung cancer.

Medical terms in this study, explained in our Lexicon: Chrysotile, Lung Cancer, Asbestos Exposure, standardized mortality ratio (SMR), Cumulative Exposure, Multivariate Analysis.

Related studies

• Mortality in a Chinese chrysotile miner cohort — X. Wang, S. Lin, et al. (2012)
• Exposure to chrysotile mining dust and digestive cancer mortality in a Chinese miner/miller cohort — S. Lin, X. Wang, et al. (2014)
• Cause-specific mortality in relation to chrysotile-asbestos exposure in a Chinese cohort — S. Lin, X. Wang, et al. (2012)
• Cause-specific mortality in a Chinese chrysotile textile worker cohort — X. Wang, S. Lin, et al. (2013)
• Analysis of mortality in chrysotile asbestos miners in China — L. Du, X. Wang, et al. (2012)
• A 37-year observation of mortality in Chinese chrysotile asbestos workers — X. Wang, E. Yano, et al. (2012)

Browse more research in PloS One, or return to medical research.