An updated review on asbestos and related diseases in China

Our plain-English summary of An updated review on asbestos and related diseases in China, by M.N. Courtice, S. Lin, X. Wang (International Journal of Occupational and Environmental Health, 2012).

The study

• Authors: M.N. Courtice, S. Lin, X. Wang
• Journal: International Journal of Occupational and Environmental Health
• Published: 2012;18(3):247-53
• Type of article: Review
• Cited by: 35 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Asbestos is an industrial mineral that can cause diseases such as asbestosis, lung cancer, and mesothelioma. Asbestos consumption in China has increased steadily since the 1960s and is currently at half a million tonnes per year. Work conditions in the asbestos-related industries are poor and exposure levels frequently exceed the occupational exposure limit.

Objective: To provide an updated overview on asbestos production and consumption in China and discuss what is known about the resulting burden of asbestos-related diseases.

Findings: China is the world's top chrysotile consumer and second largest producer. Over a million people may be occupationally exposed, yet reliable disease statistics are unavailable and the national burden of asbestos-related disease (ARD) is not well known. Nevertheless, ARD prevalence, incidence, and mortality are expected to be high and will increase for many decades due to the volume of asbestos consumed historically, and a long latency period.

Conclusions: Government policies to prevent ARD have been implemented but more actions are necessary to ensure compliance and ultimately, the complete elimination of asbestos to prevent a heavy future disease burden.

In plain English

This article was a review, not a new study. The authors summarized published research, trade statistics and government sources on asbestos production, use and related disease in China. They reported that chrysotile was the only type of asbestos being mined there. China mined 448 900 t in 2009, which was 20% of world production, and it was the world's top chrysotile consumer. More than a million people were estimated to work in asbestos-related industries. Measured airborne levels had fallen over time but often still exceeded the national limit of 0.8 fibers/ml. Reliable national disease statistics were not available. Only 8237 asbestosis cases had been reported nationwide by the end of 2004. Using prevalence figures from earlier studies, the authors estimated there were about 100 000 current cases. Several Chinese worker studies they reviewed found excess lung cancer risk linked to chrysotile exposure. In the city of Qingdao, 94 mesothelioma cases were documented from 2000 to 2007. The authors concluded that asbestos-related disease in China is expected to rise for decades, and that China must eliminate asbestos to reduce a heavier future disease burden.

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 published studies, trade statistics and government sources on asbestos and asbestos-related diseases in China
• Who was studied: China as a whole, including workers in asbestos-related industries, estimated at over a million people
• Exposure: Chrysotile asbestos, mined in China and imported (mostly from Russia). Most of it was used in asbestos cement, followed by friction, sealing/gasket, heat-insulating and textile products.
• Main results:
  • China mined 448 900 t of chrysotile in 2009, 20% of world production.
  • China was the world's top consumer of chrysotile.
  • In one asbestos products factory, a cited study reported geometric mean airborne fiber concentrations of 0.1 to 12.6 fibers/ml across five departments. The Chinese occupational exposure limit is 0.8 fibers/ml, and workplace levels often still exceed it.
  • Only 8237 cumulative asbestosis cases had been reported nationwide by the end of 2004.
  • Studies of Chinese asbestos workers gave asbestosis prevalence estimates of 10 to 30%. Applying 10% to one million exposed workers, the authors estimated about 100 000 current asbestosis cases.
  • Several Chinese cohort studies reviewed (listed in the article's Table 1) observed excess lung cancer risks attributable to chrysotile exposure.
  • In the Chongqing study, the relative risk of lung cancer was compared against non-exposed non-smokers. It was 6.03 for non-exposed smokers, 7.52 for chrysotile-exposed non-smokers, and 17.35 for chrysotile-exposed smokers.
  • Qingdao's health data system documented 94 mesothelioma cases from 2000 to 2007, about 1.57 cases per million per year. Of these, 65.6% were in females, and one case was reportedly a 12-year-old. The authors called that diagnosis questionable.
• The authors' conclusion: The authors concluded that asbestos-related disease in China is expected to rise over the next few decades, and that China must eliminate asbestos now to reduce a heavier future disease burden.
• Limitations the authors state:
  • Reliable national statistics on asbestos-related cancers were not available. China has no centralized national cancer registry or large-scale surveillance system for asbestos-related disease.
  • Asbestosis data suffer from under-reporting and under-diagnosis. This is partly because China uses its own diagnostic standard instead of the ILO classification.
  • Many mesothelioma cases may be misdiagnosed as lung cancer.

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: Lung Cancer, Mesothelioma, Occupational Exposure, Chrysotile, Latency.

Related studies

• Epidemiology of occupational asbestos-related diseases in China — S.X. Cai, C.H. Zhang, et al. (2001)
• 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)
• Mortality in chrysotile asbestos workers in China — X. Wang, M.N. Courtice, et al. (2013)
• Analysis of mortality in chrysotile asbestos miners in China — L. Du, X. Wang, et al. (2012)
• Size- and type-specific exposure assessment of an asbestos products factory in China — M.N. Courtice, D.W. Berman, et al. (2016)
• A comparative study of the disease burden attributable to asbestos in Brazil, China, Kazakhstan, and Russia between 1990 and 2019 — J. Chen, C. Wang, et al. (2022)

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