Epidemiology of occupational asbestos-related diseases in China

Our plain-English summary of Epidemiology of occupational asbestos-related diseases in China, by S.X. Cai, C.H. Zhang, X. Zhang, et al (Industrial Health, 2001).

The study

• Authors: S.X. Cai, C.H. Zhang, X. Zhang, K. Morinaga
• Journal: Industrial Health
• Published: 2001;39(2):75-83
• Type of article: Review
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In 1950s and 60s, asbestosis had been a major health hazard for asbestos exposed workers. In the late 1970s, lung cancers with or without asbestosis were found among asbestos workers. All cohort studies on asbestos workers and on chrysotile miners in China showed excess deaths from lung cancer. In a large scale of cohort study on asbestos workers, a synergistic effect was found between cigarette smoking and asbestos exposure in the production of lung cancer. There have been not so many cases of malignant mesotheliomas reported, so far. In the cohort of chrysotile miners, 4 cases of pleural mesothelioma were observed. In the large scale of cohort study on asbestos workers in 9 factories using only chrysotile only one case of pleural mesothelioma was detected for 10 years' observation. In another 2 cohort studies, 2 cases of peritoneal mesotheliomas were found, one in Shanghai asbestos factory where a small amount of crocidolite had been used in 1960s, and one in Anqing asbestos factory that was located near tremolite mine. Further study is needed especially for the relationship between exposure to Chinese chrysotile and malignant mesotheliomas.

In plain English

This article reviewed epidemiological studies on asbestos-related diseases among workers in China, where most asbestos mined and used is chrysotile. The authors reported that asbestosis prevalence was high in the 1950s and 1960s and fell after the 1980s as dust control improved. In a national cohort of 9,950 workers in 9 asbestos factories followed from 1972 to 1981, lung cancer deaths were 2.78 times those expected for men and 4.79 times for women (standardized mortality ratios). One male pleural mesothelioma was found in that cohort. Among 6,198 chrysotile miners in 5 mines, the lung cancer ratio for men was 3.46. Three pleural mesotheliomas occurred among the miners, all at Laiyuan, and one more was found later in a Sichuan mine. An extended follow-up of 8 factories showed a synergistic effect of smoking and asbestos on lung cancer. Two peritoneal mesotheliomas were reported: one in a Shanghai factory that had used some crocidolite in the 1960s, and one in an Anqing factory near a tremolite mine. The authors noted that mesothelioma may be missed in China and concluded that more research on it is needed.

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 of Chinese epidemiological studies, including conference abstracts
• Who was studied: asbestos-exposed workers in China (factories, household industries, mines), in studies published between 1960 and 1999
• Exposure: mainly chrysotile asbestos, mined and used in China; a small amount of crocidolite at one Shanghai factory; possible tremolite at an Anqing factory
• Main results:
  • A national survey counted 4,289 cases of asbestosis in China between 1949 and 1986
  • Asbestosis prevalence decreased after the 1980s as dust control improved
  • National cohort of 9,950 workers in 9 asbestos factories, followed 1972 to 1981: lung cancer SMR 2.78 for males and 4.79 for females
  • One male case of pleural mesothelioma in the 9-factory cohort
  • 6,198 miners in 5 chrysotile mines: lung cancer SMR 3.46 for males
  • 3 pleural mesotheliomas among the miners over 10 years, all among 1,227 Laiyuan miners; 1 pleural mesothelioma among 1,470 Sichuan chrysotile miners over 15 years
  • Extended follow-up of the 8-factory cohort showed a synergistic effect between asbestos exposure and smoking on lung cancer
  • Two peritoneal mesotheliomas reported: one in a Shanghai factory that used a small amount of crocidolite in the 1960s, and one in an Anqing factory located near a tremolite mine
• The authors' conclusion: The authors concluded that further research is needed, especially on mesothelioma, because most asbestos mined and used in China is chrysotile
• Limitations the authors state:
  • Pathological and postmortem examination for cancer diagnosis had not been done well in China, so mesothelioma cases may have been missed
  • China has no mesothelioma panels

Topics

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

Medical terms in this study, explained in our Lexicon: Epidemiology, Lung Cancer, Chrysotile, Cohort Study, Synergistic Effect, Asbestos Exposure, Malignant Mesothelioma, Pleural Mesothelioma.

Related studies

• An updated review on asbestos and related diseases in China — M.N. Courtice, S. Lin, et al. (2012)
• Asbestos related diseases from environmental exposure to crocidolite in Da-yao, China. I. Review of exposure and epidemiological data — S. Luo, X. Liu, et al. (2003)
• The Status of Occupational Burnout and Its Influence on the Psychological Health of Factory Workers and Miners in Wulumuqi, China — Y. Lu, Z. Zhang, et al. (2020)
• Hand-spinning chrysotile exposure and risk of malignant mesothelioma: A case-control study in Southeastern China — Z. Jiang, T. Chen, et al. (2018)
• Study of occupational lung cancer in asbestos factories in China — H. Zhu, Z. Wang (1993)
• Occupational and environmental cancer incidence and mortality in China — P. Li, S.S. Deng, et al. (2012)

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