Asbestos exposure and mesothelioma mortality among atomic veterans

Our plain-English summary of Asbestos exposure and mesothelioma mortality among atomic veterans, by J.E. Till, H.L. Beck, J.D. Boice, et al (International Journal of Radiation Biology, 2022).

The study

• Authors: J.E. Till, H.L. Beck, J.D. Boice, H.J. Mohler, M.T. Mumma, J.W. Aanenson, H.A. Grogan
• Journal: International Journal of Radiation Biology
• Published: 2022;98(4):781-785
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: The United States (U.S.) conducted 230 above-ground atmospheric nuclear weapons tests between 1945 and 1962 involving over 250,000 military personnel. This is the first quantitative assessment of asbestos-related mesothelioma, including cancers of the pleura and peritoneum, among military personnel who participated in above-ground nuclear weapons testing.

Methods: Approximately 114,000 atomic veterans were selected for an epidemiological study because they were in one of eight series of weapons tests that were associated with somewhat higher personnel exposures than the other tests and because they have been previously studied. We were able to categorize specific jobs into potential for asbestos exposure based on a detailed database of the military activities of the atomic veterans. Standardized mortality ratios (SMR) were calculated by service, rank (officer/enlisted) and ratings (occupation code and work location aboard ship) after 65 years of follow-up.

Results: Mesothelioma deaths were significantly increased overall (SMR 1.56; 95% CI 1.32-1.82; n = 153). This increase was seen only among those serving in the PPG (SMR 1.97; 95% CI 1.65-2.34; n = 134), enlisted men (SMR 1.81; 95% CI 1.53-2.13; n = 145), and the 70,309 navy personnel (SMR 2.15; 95% CI 1.80-2.56; n = 130). No increased mortality rates were seen among the other services: army (SMR 0.45), air force (SMR 0.85), or marines (SMR 0.75). Job categories with the highest potential for asbestos exposure (machinist's mates, boiler technicians, water tender, pipe fitters, and fireman) had an of SMR 6.47. Job categories with lower potential (SMR =1.35) or no potential (SMR =1.28) for asbestos exposure had non-significantly elevated mesothelioma mortality.

Conclusions: The large excess of mesothelioma deaths seen among atomic veterans was explained by asbestos exposure among enlisted naval personnel. The sources of exposure were determined to be on navy ships in areas (or with materials) with known asbestos content. No excess of mesothelioma was observed in other services or among naval personnel with minimal exposure to asbestos in this low-dose radiation exposed cohort.

In plain English

This study examined mesothelioma deaths among 114,270 U.S. service members from eight above-ground nuclear weapons test series. Deaths through 2010 were compared with those expected from U.S. general population rates. Enlisted sailors' exposure was judged from Navy job titles ("ratings") and pay grades; officers were classed by rank. Before 1999, cancers of the pleura and peritoneum were counted as probable mesothelioma. Overall there were 153 mesothelioma deaths, 1.56 times the expected number (95% CI 1.32-1.82). The excess was in the Navy (130 deaths; SMR 2.15, 95% CI 1.80-2.56), especially among enlisted sailors. Non-Navy participants (Army, Air Force, Marines and 19 veterans in no listed branch) had fewer deaths than expected (23 deaths; SMR 0.61, 95% CI 0.38-0.91). Machinist's mates, boiler technicians, water tenders, pipe fitters and firemen (SMR 6.47 together) were 20% of enlisted sailors but had 55% of their mesothelioma deaths. Sailors with minimal exposure potential had a non-significant SMR of 1.28 (95% CI 0.87-1.83). Estimated whole-body radiation doses for sailors who died of mesothelioma were all below 10 mSv. The authors concluded that asbestos, not low-dose radiation, explained the excess.

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: Retrospective cohort mortality study comparing observed mesothelioma deaths with those expected from U.S. general population rates (standardized mortality ratios), with Navy jobs grouped by potential for asbestos exposure
• Who was studied: 114,270 U.S. military participants in eight atmospheric nuclear weapons test series. Five were held at the Pacific Proving Grounds (CASTLE, CROSSROADS, GREENHOUSE, REDWING, HARDTACK I), two at the Nevada Test Site (UPSHOT-KNOTHOLE, PLUMBBOB), and TRINITY in New Mexico. The cohort included 70,309 Navy personnel, of whom 63,815 were enlisted. Follow-up ran to death, the 95th birthday, or December 31, 2010.
• Exposure: Asbestos used aboard Navy ships (boilers, steam pipe insulation, hull insulation, floors, gaskets, cables, fireproofing), especially in engineering spaces. For enlisted personnel, exposure potential was assigned by Navy rating, rate and shipboard work location; officers were classed by rank. Fiber types were not named. Estimated whole-body radiation doses for sailors who died of mesothelioma were low (under 10 mSv).
• Main results:
  • Whole cohort: 153 mesothelioma deaths, SMR 1.56 (95% CI 1.32-1.82), a statistically significant excess
  • Navy personnel (70,309): 130 deaths, SMR 2.15 (95% CI 1.80-2.56). Table 1 also shows enlisted Navy personnel (63,815): 126 deaths, SMR 2.34 (95% CI 1.95-2.79). Navy officers (6,494) had 4 deaths, SMR 0.61 (95% CI 0.16-1.56).
  • Those who served at the Pacific Proving Ground: 134 deaths, SMR 1.97 (95% CI 1.65-2.34). All enlisted men: 145 deaths, SMR 1.81 (95% CI 1.53-2.13).
  • Statistically significant deficits were found among all officers (SMR 0.44; 8 deaths), Army personnel (SMR 0.45; 10 deaths) and those who served at the Nevada Test Site (SMR 0.57; 14 deaths)
  • All other services combined (43,961 veterans: Army, Air Force, Marines, plus 19 veterans not in any of the four branches) had a significant deficit: SMR 0.61 (95% CI 0.38 to 0.91; 23 deaths). The Air Force SMR of 0.85 and the Marines SMR of 0.75 were not significantly different from expected.
  • Navy job categories with the highest asbestos exposure potential (machinist's mates, boiler technicians, water tender, pipe fitters, fireman) had an SMR of 6.47 as a group
  • Among enlisted Navy personnel, boiler technicians, pipe fitters and machinist's mates each had SMRs above 9, and firemen had an SMR of nearly 5
  • High-exposure-potential jobs were held by 20% of the enlisted naval population but accounted for 55% of mesothelioma deaths among them
  • Navy personnel with minimal asbestos exposure potential: SMR 1.28 (95% CI 0.87-1.83). Those with lower potential: SMR 1.35. Both were non-significantly elevated.
  • Estimated whole-body radiation doses for the sailors who died from mesothelioma were all low (under 10 mSv). Doses for the high-risk asbestos rating groups did not differ significantly from those of other Navy groups.
• The authors' conclusion: The authors concluded that the mesothelioma excess among Navy personnel at the Pacific Proving Grounds was related to high potential for asbestos exposure among enlisted sailors in certain ratings. They stated that their investigation rules in asbestos and rules out low-dose radiation as the cause of the excess.
• Limitations the authors state:
  • Because no specific code for mesothelioma existed before ICD-10 (1999), earlier deaths were counted as probable mesothelioma using codes for cancers of the pleura and peritoneum
  • Officers were harder to assign to a specific shipboard location than enlisted personnel

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Mesothelioma, Pleura, Peritoneum, standardized mortality ratio (SMR), Machinist's Mate, Boiler Technician.

Related studies

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• A principal factor analysis to characterize agricultural exposures among Nebraska veterans — L. Weissenburger-Moser, J. Meza, et al. (2017)
• Asbestos plaques in a typical Veteran's hospital population — J.A. Miller, J.V. Zurlo (1996)
• Living with mesothelioma: A qualitative study of the experiences of male military veterans in the UK — S. Ejegi-Memeh, L. Darlison, et al. (2021)
• Mortality of employees of the United Kingdom Atomic Energy Authority, 1946-97 — W.D. Atkinson, D.V. Law, et al. (2004)
• Solid cancer mortality associated with chronic external radiation exposure at the French atomic energy commission and nuclear fuel company — C. Metz-Flamant, E. Samson, et al. (2011)

Browse more research in International Journal of Radiation Biology, or return to medical research.