Current Research and Opportunities to Address Environmental Asbestos Exposures

Our plain-English summary of Current Research and Opportunities to Address Environmental Asbestos Exposures, by D.J. Carlin, T.C. Larson, J.C. Pfau, et al (Environmental Health Perspectives, 2015).

The study

• Authors: D.J. Carlin, T.C. Larson, J.C. Pfau, S.H. Gavett, A. Shukla, A. Miller, R. Hines
• Journal: Environmental Health Perspectives
• Published: 2015;123(8):A194-7
• Cited by: 21 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Asbestos-related diseases continue to result in approximately 120,000 deaths every year in the United States and worldwide. Although extensive research has been conducted on health effects of occupational exposures to asbestos, many issues related to environmental asbestos exposures remain unresolved. For example, environmental asbestos exposures associated with a former mine in Libby, Montana, have resulted in high rates of nonoccupational asbestos-related disease. Additionally, other areas with naturally occurring asbestos deposits near communities in the United States and overseas are undergoing investigations to assess exposures and potential health risks. Some of the latest public health, epidemiological, and basic research findings were presented at a workshop on asbestos at the 2014 annual meeting of the Society of Toxicology in Phoenix, Arizona. The following focus areas were discussed: a) mechanisms resulting in fibrosis and/or tumor development; b) relative toxicity of different forms of asbestos and other hazardous elongated mineral particles (EMPs); c) proper dose metrics (e.g., mass, fiber number, or surface area of fibers) when interpreting asbestos toxicity; d) asbestos exposure to susceptible populations; and e) using toxicological findings for risk assessment and remediation efforts. The workshop also featured asbestos research supported by the National Institute of Environmental Health Sciences, the Agency for Toxic Substances and Disease Registry, and the U.S. Environmental Protection Agency. Better protection of individuals from asbestos-related health effects will require stimulation of new multidisciplinary research to further our understanding of what constitutes hazardous exposures and risk factors associated with toxicity of asbestos and other hazardous EMPs (e.g., nanomaterials).

In plain English

This article was a brief report, not a new study. It summarized a workshop, "New Concerns and New Science Addressing Environmental Asbestos Exposures," held at the 2014 Society of Toxicology meeting in Phoenix, Arizona, where scientists from federal agencies and universities presented. The authors described earlier research by others. At Libby, Montana, a former mine produced vermiculite contaminated with winchite, richterite and tremolite asbestos, and cited studies reported elevated asbestos-related disease among residents without occupational exposure. In mouse studies, Libby amphibole and erionite triggered autoimmune responses, but chrysotile did not. In cell studies, the inflammatory markers IL-8 and COX-2 were 4-fold and 10-fold greater for amosite than for Libby amphibole. The report noted that standard workplace microscopy (PCM) counts only fibers longer than 5 micrometers and wider than 0.25 micrometers. The authors called for more research on susceptible groups such as pregnant women, children and patients with underlying diseases, and on other fibers such as erionite.

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: Brief communication reporting on a scientific workshop. It summarizes presentations and earlier published studies by others and presents no new data of its own.
• Who was studied: No study population. The report covers presentations at a workshop at the 2014 annual meeting of the Society of Toxicology in Phoenix, Arizona, given by scientists from NIEHS, the U.S. EPA, ATSDR and universities.
• Exposure: Environmental (non-workplace) exposure to asbestos and other elongated mineral particles (EMPs). The report discusses Libby amphibole, tremolite, chrysotile, amosite, crocidolite and erionite. It covers end-users of asbestos-containing materials, family members of exposed workers, and people living or working in or around contaminated buildings or areas.
• Main results:
  • The report described the former Libby, Montana mine as producing vermiculite contaminated with asbestiform amphiboles, including winchite, richterite and tremolite asbestos.
  • Citing earlier work by Peipins et al. 2003, the report said studies of the Libby population had shown elevated asbestos-related disease among residents without occupational exposures.
  • Citing earlier mouse studies in the C57BL/6 strain, the report said Libby amphibole material increased autoimmune responses, including autoantibodies and Th17 cytokines in serum. Chrysotile did not have this effect.
  • In the mouse studies cited, chrysotile instead showed a somewhat immunosuppressed serum cytokine profile.
  • The authors noted that the evidence linking asbestos to clinically diagnosed autoimmune disease in people is limited. Only a handful of studies have shown an association with rheumatoid arthritis and systemic sclerosis.
  • Citing Duncan et al. 2010, an in vitro (cell) study, the report said the inflammatory mediators IL-8 and COX-2 were 4-fold and 10-fold greater, respectively, for amosite than for Libby amphibole.
  • Citing earlier rat studies using intratracheal exposure, the report said bronchoalveolar lavage protein, a marker of lung injury, correlated strongly with the number of fibers 5 to 10 micrometers long but not with fibers longer than 20 micrometers.
  • Citing Reid et al. 2013, the report said children living and playing around the Wittenoom crocidolite mine in Western Australia developed excess rates of brain, ovarian, prostate and colorectal cancers as adults, in addition to mesothelioma.
  • The report noted that workplace asbestos rules have relied mainly on phase contrast microscopy (PCM), which counts only fibers longer than 5 micrometers and wider than 0.25 micrometers.
• The authors' conclusion: The authors concluded that more research should be done in susceptible populations (pregnant women, children and patients with underlying diseases), on fiber type and dose metrics, and on other hazardous EMPs such as erionite, winchite, antigorite and nanomaterials, using a multidisciplinary approach.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Occupational Exposure, naturally occurring asbestos (NOA), Fibrosis, Dose Metric.

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