The legacy of weapons grade plutonium production: Health status of Hanford complex workers who manage the waste

Our plain-English summary of The legacy of weapons grade plutonium production: Health status of Hanford complex workers who manage the waste, by D. Cherry, E. Friedman, M. Vincent, et al (Toxicology and Industrial Health, 2021).

The study

• Authors: D. Cherry, E. Friedman, M. Vincent, A. Maier
• Journal: Toxicology and Industrial Health
• Published: 2021;37(5):260-269
• Type of article: Review
• Read it: PubMed · Publisher

Abstract

The extent and etiology of health effects in workers who maintain underground storage tanks at the Hanford Nuclear Reservation (Hanford) have been subjects of controversy and concern for several decades. Hanford is a decommissioned nuclear production complex managed by the US Department of Energy in southeast Washington State. This integration-of-evidence review evaluates the relationship between exposure to vapors from mixed chemical and radioactive waste stored in underground storage tanks at Hanford and worker health. Hanford workers' health information was gathered from technical reports, media reports, and published literature, including the systematic search of seven databases. This review describes the health status and health concerns of Hanford tank farm workers based on the integration of the available health effects data from disparate sources. In interviews with external groups, Hanford workers reported both irritant-type symptoms and diseases that they believe are attributable to tank farm vapors. However, the results of this integration-of-evidence review indicated that no pervasive pattern of occupational disease was identified that can be associated with exposure to tank farm vapors. Inhalation exposure to asbestos and beryllium is associated with lung disease from various types of nuclear industry work but not from work on tank farms. This review concluded that while irritant-type symptoms and isolated cases of occupational disease are plausible under certain conditions, the currently available data do not support a pervasive pattern of occupational disease associated with vapor exposure.

In plain English

This was a review, which the authors called an integration-of-evidence review, of the health of workers who maintain underground tanks of mixed chemical and radioactive waste at the Hanford Nuclear Reservation. It drew on worker interviews, media reports, surveillance reports and one cohort mortality study from 2006 to 2019. Interviewed workers reported cough, sore throat, nausea and headaches linked to tank odors. Surveillance reports did not find tank farm work to be a risk factor for abnormal lung, liver, kidney or mercury tests. A screening program for former Department of Energy workers, which did not separate out tank farm workers, found asbestos-related lung disease on chest X-ray in 9565 of 81,465 workers at all sites (11.7%) and in 859 of 3572 former Hanford construction workers (24.0%). A pooled study of nuclear workers at five sites, which did not assess tank farm work, found 96 mesothelioma and pleural cancer deaths. That was a standard mortality ratio of 2.80 (confidence interval 2.27 to 3.42). The authors concluded that current data do not support a pervasive pattern of occupational disease from tank vapors. They tied asbestos-related lung disease to other nuclear industry work, not tank farm work.

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: Integration-of-evidence review of worker interviews, media reports, surveillance reports and a cohort mortality study
• Who was studied: Hanford tank farm workers (about 2000 as of 2019), plus wider groups of Hanford and Department of Energy workers in the included reports. Reports published or released 2006 to 2019 were included.
• Exposure: Inhalation of vapors from mixed chemical and radioactive waste stored in underground tanks. Asbestos, beryllium and noise exposure were described as features of past production and construction work, not tank farm work.
• Main results:
  • In interviews and focus groups, tank farm workers reported acute irritant symptoms associated with chemical odors.
  • In the 2018 surveillance report covering 2012 to 2017, enrollment as a tank farm worker was not associated with abnormal kidney or liver tests, lung function deficits or elevated mercury.
  • In a 2006 case-control analysis of tank farm workers, high exposure to tank farm vapors was not a risk factor for pulmonary obstruction (OR 1.19 [0.88, 1.59]). Current smoking was a risk factor (OR 1.83 [1.52, 2.20]).
  • Among former Department of Energy workers screened from 1997 to 2017, asbestos-related lung disease on chest X-ray was found in 9565/81,465 (11.7%) at all sites, in 859/3572 (24.0%) former Hanford construction workers, and in 1041/5332 (19.5%) former Hanford production workers. Tank farm workers were not separated out.
  • In the pooled cohort of US nuclear workers (Schubauer-Berigan et al., 2015), overall mortality was below that of the US population (SMR 0.85, 0.84 to 0.86). There were 96 mesothelioma and pleural cancer deaths, with an SMR of 2.80 (2.27 to 3.42). The lung cancer SMR was 0.84 (0.81 to 0.87). Tank farm work was not assessed.
• The authors' conclusion: The authors concluded that asbestos and beryllium exposure is associated with lung disease from various types of nuclear industry work but not from tank farm work. They also concluded that irritant symptoms and isolated cases of occupational disease are plausible, but the currently available data do not support a pervasive pattern of occupational disease from vapor exposure.
• Limitations the authors state:
  • Most of the sources were technical reports and media, which were not independently peer-reviewed.
  • In the surveillance studies, exposure was classified crudely by enrollment in the tank farm surveillance program.
  • Survivor bias may occur if the sickest workers leave employment and are lost to follow-up.
  • The cohort study's exposure assessment was not specific to tank farm workers, and their mortality was not assessed separately.

Topics

Medical terms in this study, explained in our Lexicon: Etiology, Occupational Disease.

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