Recent Scientific Evidence Regarding Asbestos Use and Health Consequences of Asbestos Exposure

Our plain-English summary of Recent Scientific Evidence Regarding Asbestos Use and Health Consequences of Asbestos Exposure, by M. Valenzuela, M. Giraldo, S. Gallo-Murcia, et al (Current Environmental Health Reports, 2016).

The study

• Authors: M. Valenzuela, M. Giraldo, S. Gallo-Murcia, J. Pineda, L. Santos, J.P. Ramos-Bonilla
• Journal: Current Environmental Health Reports
• Published: 2016;3(4):335-347
• Type of article: Review
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

To justify the continuous use of two million tons of asbestos every year, it has been argued that a safe/controlled use can be achieved. The aim of this review was to identify recent scientific studies that present empirical evidence of: 1) health consequences resulting from past asbestos exposures and 2) current asbestos exposures resulting from asbestos use. Articles with evidence that could support or reject the safe/controlled use argument were also identified. A total of 155 articles were included in the review, and 87 % showed adverse asbestos health consequences or high asbestos exposures. Regarding the safe/controlled use, 44 articles were identified, and 82 % had evidence suggesting that the safe/controlled use is not being achieved. A large percentage of articles with evidence that support the safe/controlled use argument have a conflict of interest declared. Most of the evidence was developed in high-income countries and in countries that have already banned asbestos.

In plain English

This was a review of published studies, not a new study of people. The authors searched PubMed for English-language articles published between January 2010 and July 2015. They looked for articles that gave empirical evidence on the health effects of asbestos exposure, or on exposure levels from using asbestos or asbestos-containing products. Of 1516 articles found, 155 were included. The authors reported that 134 (87 %) showed adverse health effects or extremely high exposures, 11 (7 %) showed no or reduced health effects or low exposures, and 10 were ambiguous. Of 44 studies that could show whether a safe/controlled use of asbestos is being achieved, 36 (82 %) had evidence against it and 8 (18 %) supported it. Four of those eight declared a conflict of interest. Among the 123 non-ambiguous single-country studies, 91 came from high-income countries and 65 came from countries that had banned asbestos. The authors noted that they may have missed or misclassified articles, and that they left out articles they could not access for free. They concluded that the literature does not seem to support the safe/controlled use concept, and they called for a global ban.

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 scientific literature (PubMed search), classifying studies by whether they showed adverse health effects or high exposures, and by conflict of interest and country income level
• Who was studied: Published articles, not people: 1516 articles identified in PubMed, of which 155 English-language articles published between 1 January 2010 and 31 July 2015 were included
• Exposure: Asbestos of all types (amphiboles or chrysotile) from use of asbestos or asbestos-containing products. The review included epidemiological studies of mesothelioma, asbestosis, pleural plaques, lung opacities and thickening, and cancer of the lung, larynx and ovaries, plus exposure assessment studies. Studies of naturally occurring asbestos or contaminated materials such as talc were excluded.
• Main results:
  • Of the 155 included articles, 134 (87 %) presented evidence of adverse health consequences from asbestos exposure or extremely high exposures
  • Of the 155 included articles, 11 (7 %) presented evidence of no or reduced health consequences or low asbestos concentrations, and 10 were classified as ambiguous
  • Among the 134 studies showing adverse effects or high exposures, 69 % reported no conflict of interest, 8 % declared one, and 23 % did not report
  • Among the 11 studies showing no health effect or compliant exposures, the text reports 70 % had a conflict of interest, 10 % reported none, and 20 % did not report (Table 1 prints 64 %, 9 % and 27 %)
  • After excluding ambiguous studies, 145 studies remained. Of these, 22 were regional or global, which left 123 single-country studies.
  • Of these 123 non-ambiguous single-country studies, 91 (74 %) were in high-income countries, 31 (25 %) in upper-middle-income countries, one (1 %) in a lower-middle-income country, and none in low-income countries
  • 65 of the 123 non-ambiguous single-country studies (53 %) were conducted in countries that had already banned asbestos
  • Of 44 studies with evidence on the safe/controlled use argument, 36 (82 %) had evidence against it and 8 (18 %) supported it
  • Of the 8 studies supporting safe/controlled use, four (50 %) had a conflict of interest, one (12 %) had none, and three (38 %) did not report
  • Among recent exposure studies, 15 (79 %) found extremely high exposures and 4 (21 %) found low or no exposure. Of the 15, one reported a conflict of interest, seven had none, and seven did not report. None of the 4 low-exposure studies reported having no conflict of interest.
  • All studies supporting safe/controlled use were conducted in high-income countries (six; 75 %) or in multiple countries (two; 25 %)
  • 38 of the 155 articles did not report whether a conflict of interest existed. In 4 studies the authors declared no conflict of interest but acknowledged funding that the review authors considered a financial conflict of interest.
• The authors' conclusion: The authors concluded that the recent scientific literature does not seem to support the safe/controlled use concept, and they joined other authors in calling for a global ban of asbestos
• Limitations the authors state:
  • Because of budget constraints, articles that could not be accessed for free were not included (44 articles, 3 % of those initially identified)
  • Only articles written in English were considered
  • The authors acknowledged possible human error: articles may have been missed or misclassified
  • Some included studies estimated exposure using surrogates such as asbestos consumption or industry location, which the authors said could lead to an ecological fallacy
  • Exposures judged compliant under local regulations might have been non-compliant under the international standard of 0.1 f/cc
  • Conflict of interest was classified only from what the study authors themselves reported
  • Very few included articles came from upper-middle, lower-middle and low-income countries, so exposures there may be underestimated

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Controlled Use.

Related studies

• The health effects of chrysotile: current perspective based upon recent data — D.M. Bernstein, J.A. Hoskins (2006)
• Canadian hypocrisy regarding chrysotile — J. Bridle, J. Hoskins (2011)
• Malignant mesothelioma and asbestos exposure among auto mechanics: appraisal of scientific evidence — O. Wong (2001)
• Adverse health effects of asbestos: solving mysteries regarding asbestos carcinogenicity based on follow-up survey of a Chinese factory — E. Yano (2018)
• Health and environmental consequences of the world trade center disaster — P.J. Landrigan, P.J. Lioy, et al. (2004)
• Health consequences of the September 11 World Trade Center attacks: a review — J. Moline, R. Herbert, et al. (2006)

Browse more research in Current Environmental Health Reports, or return to medical research.