Health effects of hazardous waste

Our plain-English summary of Health effects of hazardous waste, by S.M. Dearwent, M.M. Mumtaz, G. Godfrey, et al (Annals of the New York Academy of Sciences, 2006).

The study

• Authors: S.M. Dearwent, M.M. Mumtaz, G. Godfrey, T. Sinks, H. Falk
• Journal: Annals of the New York Academy of Sciences
• Published: 2006;1076:439-48
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Since 1995, the Agency for Toxic Substances and Disease Registry (ATSDR) has evaluated environmental contaminants and human health risks at nearly 3000 sites. Hazardous substances at these sites include newly emerging problems as well as historically identified threats. ATSDR classifies sites according to the degree of hazard they represent to the public. Less than 1% of the sites investigated are considered urgent public health hazards where chemical or physical hazards are at levels that could cause an immediate threat to life or health. Approximately 20% of sites have a potential for long-term human exposures above acceptable risk levels. At almost 40% of sites, hazardous substances do not represent a public health hazard. Completed exposure pathways for contaminants in air, water, and soil have been reported at approximately 30% of evaluated sites. The most common contaminants of concern at these sites include heavy metals, volatile organic compounds, and polychlorinated biphenyls. This article reviews ATSDR's ongoing work by examining the historic hazard of lead, the contemporary hazard of asbestos, and the emerging issue of perchlorate contamination.

In plain English

This article, written by staff of the US Agency for Toxic Substances and Disease Registry (ATSDR), was a review of the agency's own work, not a new study. It described 2948 site evaluations from 1995 to 2004 and then gave case studies on lead, asbestos and perchlorate. Completed exposure pathways, meaning exposure to a contaminant had occurred at some time, were found at about 30% (880/2948) of sites. Lead and arsenic were the most frequent contaminants. For asbestos, it summarized earlier ATSDR work in Libby, Montana, where vermiculite ore was contaminated with tremolite asbestos. A death-certificate analysis for 1979 to 1998 reported asbestosis mortality rates 40 to 80 times higher than in Montana and the United States, respectively, and a 20 to 30% excess of lung cancer deaths. Mesothelioma deaths were increased but hard to quantify. Medical screening found pleural abnormalities in 18% (1186/6668). A review of the first 28 plants that processed Libby ore found former workers at highest risk. The authors concluded that asbestos, lead and emerging threats will require agency responses for many years.

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 the agency's own site evaluations (descriptive statistics for 1995–2004) plus illustrative case studies (lead, asbestos, perchlorate) drawn from earlier ATSDR reports and studies
• Who was studied: 2948 ATSDR site evaluations of US hazardous waste sites, 1995–2004; the asbestos case study concerned residents and former vermiculite workers of Libby, Montana, and facilities that processed Libby ore
• Exposure: Hazardous waste site contaminants generally; for asbestos, vermiculite ore mined and processed in Libby from the 1920s until 1990 that was contaminated with tremolite asbestos
• Main results:
  • Across ATSDR site evaluations 1995–2004, about 30% (880/2948) of sites had completed exposure pathways, meaning all five pathway elements were present and exposure to a contaminant had occurred at some time.
  • Lead (12%) and arsenic (10%) were the most frequent contaminants at sites with completed exposure pathways.
  • Approximately 25% of site evaluations in the decade were classified as public health hazards. In 1995–2004, 46% of sites were classified as no apparent public health hazard.
  • ATSDR's earlier death-certificate analysis for Libby, 1979–1998, reported asbestosis standardized mortality rates 40–80 times higher than in Montana and the United States, respectively.
  • In the same Libby mortality analysis, lung cancer mortality was significantly elevated, with a 20–30% excess.
  • Mesothelioma mortality in Libby was increased but could not be quantified.
  • In the Libby medical testing program (7307 participants in 2000–2001), pleural abnormalities were found in 18% (1186/6668). Risk rose with increasing age and increasing length of residence in the Libby area.
  • A follow-up ATSDR study of exposed Libby residents indicated that low-dose, high-resolution CT can help screen people with indeterminate chest X-rays.
  • Evaluations of the first 28 facilities that processed Libby vermiculite indicated that former workers were at highest risk. Household contacts and former residents were also at high but unquantifiable risk.
  • Of 14 perchlorate sites evaluated, 12 (85.7%) were classified as no apparent public health hazard or no public health hazard.
• The authors' conclusion: The authors concluded that well-known hazards such as asbestos and lead, together with emerging threats such as perchlorate and perfluorocarbons, will require agency responses for many years.
• Limitations the authors state:
  • ATSDR often does not collect environmental sampling data itself but reviews data from others.
  • A completed exposure pathway does not mean that a health effect occurred.
  • Mesothelioma mortality in Libby could not be quantified because reliable state and national statistics on it are not available.

Topics

Medical terms in this study, explained in our Lexicon: ATSDR.

Related studies

• Leaching behaviour of hazardous demolition waste — N. Roussat, J. Méhu, et al. (2008)
• Human exposure to trace elements and PCDD/Fs around a hazardous waste landfill in Catalonia (Spain) — M. Herrero, J. Rovira, et al. (2020)
• The export of hazardous industries in 2015 — B. Castleman (2016)
• Investigative studies for the use of an inactive asbestos mine as a disposal site for asbestos wastes — E. Gidarakos, K. Anastasiadou, et al. (2008)
• Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy — T. Yamamoto, A. Kida, et al. (2014)
• Community exposure to asbestos from a vermiculite exfoliation plant in NE Minneapolis — J. Kelly, G.C. Pratt, et al. (2006)

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