Public health risks from asbestos cement roofing

Our plain-English summary of Public health risks from asbestos cement roofing, by M. Kottek, M.L. Yuen (American Journal of Industrial Medicine, 2022).

The study

• Authors: M. Kottek, M.L. Yuen
• Journal: American Journal of Industrial Medicine
• Published: 2022;65(3):157-161
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

There is no identified risk-free threshold exposure to asbestos. Based on epidemiology and toxicology, asbestos fiber dimensions have been implicated in causing asbestos-related diseases. Phase-contrast microscopy provides only a limited index of exposure to fiber dimensions implicated in mesothelioma induction. Installed asbestos-containing materials (ACMs) create an ongoing risk of intense exposure during natural disasters and remodeling, along with low-level exposure arising from the continual emission of airborne asbestos into the environment arising from weathering of installed ACM. Epidemiological studies have demonstrated a risk of disease associated with proximity to asbestos cement roofing (ACR), while ongoing environmental emissions of asbestos from installed ACR have also been demonstrated. Owing to the limitations of the available data, a precautionary approach is warranted; asbestos-free roofing materials should be used in new construction and existing ACR should be removed at the earliest opportunity.

© 2021 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals LLC.

In plain English

This article was a commentary. It reviewed published research on asbestos cement roofing and collected no new data. The authors explained that phase-contrast optical microscopy, the usual workplace measurement method, does not count fibers shorter than 5 µm and only resolves fibers wider than about 0.25 µm. As a result, none of the fibers that a cited review linked to mesothelioma are counted. They summarized earlier work showing that weathering roofs release asbestos, including wind-erosion emission rates of up to 14,000,000 fibers per square meter per hour for fibers longer than 5 µm. They cited earlier studies reporting increased mesothelioma risk for people living in buildings with asbestos cement roofs. They noted that all three studies took place in regions that once had asbestos cement plants, and that another cited study did not control for confounders. The authors concluded it is biologically plausible that asbestos roofing can cause asbestos-related disease in the general public. Citing the precautionary principle, they called for asbestos-free roofing in new construction and controlled removal of existing roofs at the earliest opportunity.

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: Commentary reviewing published epidemiological, toxicological and exposure-measurement studies; no new data collected
• Who was studied: No study population of its own; the commentary concerns workers and members of the public who live or work around asbestos-containing materials, especially asbestos cement roofing
• Exposure: Asbestos from installed asbestos cement roofing (ACR) and other asbestos-containing materials: passive emission from weathering, plus intense exposure during remodeling and after natural disasters; chrysotile fibers released by weathering are discussed
• Main results:
  • The authors stated that phase-contrast optical microscopy (PCOM) resolves fibers with diameters greater than about 0.25 µm and does not count fibers shorter than 5 µm, so none of the fibers that a cited review (Lippmann) linked to mesothelioma (diameter under 0.1 µm, length 5 µm or more) are counted
  • Citing earlier work by Spurny, the authors reported wind-erosion emission rates from asbestos cement of up to 14,000,000 fibers per square meter per hour for fibers longer than 5 µm, most of which would not have been visible by PCOM
  • Citing a Sri Lankan screening study (Wickramatillake et al.) of 230 self-selected asbestos-exposed workers, the authors reported lung fibrosis in 6 of 8 tsunami debris workers and 6 of 12 building demolition workers
  • Citing studies by Magnani (2000, 2001) and Ferrante, the authors reported increased mesothelioma risk for living in a home or building with asbestos cement roofing. The risk was statistically significant in Magnani 2000 and Ferrante, and approached significance in Magnani 2001. The authors noted that all three studies were in regions that previously had asbestos cement manufacturing plants
• The authors' conclusion: The authors concluded that it is biologically plausible that asbestos roofing can cause asbestos-related disease in the general public. Based on the precautionary principle, they stated that asbestos-free roofing should be used for new construction and that existing asbestos cement roofing should be removed under controlled conditions at the earliest opportunity
• Limitations the authors state:
  • The authors stated that the implications of the increased mesothelioma risks reported in the cited roofing studies are somewhat unclear, because those studies took place in regions with former asbestos cement plants
  • The authors noted that a cited study (Kang et al., 2018) linking high-density asbestos roofing areas to lower lung fibrosis and pleural disease was not controlled for potential confounders
  • The authors noted that the cited studies on proximity to asbestos cement roofing make no reference to the condition or disturbance of the roofing material
  • The authors acknowledged that some studies are complicated by other potential sources of exposure

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos-Cement, Epidemiology, Fiber Dimensions, Mesothelioma, Asbestos-Containing Material (ACM).

Related studies

• Asbestos in High-Risk Communities: Public Health Implications — E.A. Emmett (2021)
• Asbestos in the air of public buildings: a public health risk? — J. Whysner, V.T. Covello, et al. (1994)
• Public Health and Independent Risk Assessment — P. Vineis (2019)
• Mapping asbestos-cement roofing with hyperspectral remote sensing over a large mountain region of the Italian Western Alps — F. Frassy, G. Candiani, et al. (2014)
• Estimation of the amount of asbestos-cement roofing in Poland — E. Wilk, M. Krówczyńska, et al. (2017)
• Asbestos as a public health risk: disease and policy — H. Weill, J.M. Hughes (1986)

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