Lung cancer after employment in shipyards during World War II

Our plain-English summary of Lung cancer after employment in shipyards during World War II, by W.J. Blot, J.M. Harrington, A. Toledo, et al (The New England Journal of Medicine, 1978).

The study

• Authors: W.J. Blot, J.M. Harrington, A. Toledo, R. Hoover, C.W. Heath, J.F. Fraumeni
• Journal: The New England Journal of Medicine
• Published: 1978;299(12):620-4
• Cited by: 171 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002113).

Abstract

A case-control study, undertaken to identify reasons for the exceptionally high rate of lung cancer among male residents of coastal Georgia, revealed a significantly increased risk associated with employment in area shipyards during World War II. The summary relative-risk estimate, adjusted for smoking, other occupations, age, race and county of residence was 1.6 (95 per cent confidence limits = 1.1 to 2.3). A synergistic relation was found between shipyard employment and cigarette smoking. These findings suggest that asbestos and possible other shipyard exposures during wartime employment account for part of the excess mortality from lung cancer in certain coastal areas of the United States.

In plain English

This case-control study sought reasons for high lung cancer death rates among men in coastal Georgia. The authors compared 458 men with lung cancer and 553 controls from an 11-county coastal area. Cases came from hospitals in Brunswick and Savannah and from death certificates. Most interviews (76 per cent) were with next of kin. Men employed in shipyards for six months or more, mostly for a few years during World War II, had a higher lung cancer risk. After adjustment for smoking, residence, age, race and usual industry, the relative risk was 1.6 (95 per cent confidence limits 1.1 to 2.3). The raised risk appeared in white and black men, in all age groups and areas, and in each smoking category. It grew with heavier smoking, which the authors called a strong synergism, though differences between smoking categories were not statistically significant. Only 10 of 175 shipyard workers reported handling asbestos. The authors concluded that the findings suggest asbestos and possibly other wartime shipyard exposures account for part of the excess lung cancer deaths in certain coastal areas.

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: case-control study using personal interviews of patients, controls or their next of kin
• Who was studied: 458 male lung-cancer cases and 553 controls who were residents of an 11-county coastal Georgia area. They were identified from the Brunswick hospital (diagnoses since 1970), three Savannah hospitals (1975-76) and death certificates (1970-74). Most had lived in the area a long time (median 41 years).
• Exposure: Ever employment (six months or more) in shipyards (the shipbuilding industry), mostly for a few years during World War II. Asbestos exposure was assessed only through self-reported materials handled.
• Main results:
  • 95 cases and 80 controls had ever been employed in shipbuilding.
  • The summary relative risk for shipbuilding, adjusted for cigarette smoking by the Mantel-Haenszel method, was 1.6 (P = 0.006).
  • The summary relative risk was adjusted at the same time for smoking, residence, age, race and usual industry in a logistic model. It was 1.6 (P = 0.01), with 95 per cent confidence limits of 1.1 to 2.3.
  • Relative risks for shipbuilding were elevated in each of the three cigarette-smoking categories.
  • The relative risks rose with heavier smoking, but the differences between smoking categories were not statistically significant (P greater than 0.10). The authors described the sharp increase in excess risk with smoking as indicating a strong synergism.
  • Higher relative risks for shipbuilding were seen in whites and blacks, in all age categories, and in Glynn, Chatham and the rural coastal counties.
  • No excess risk was seen for welders or riggers. An excess was apparent for other shipyard job groups, including some where direct asbestos exposure would not be likely.
  • Of the 175 respondents who had worked in shipbuilding, only 10 (four cases and six controls) reported contact with asbestos.
  • A search of hospital medical records and pathology files since 1960 found only five cases with mesothelioma and two with asbestosis. The authors said this was not higher than the national incidence.
  • Assuming 14 per cent of the area population had worked in shipyards at 1.6 times the usual risk, the authors estimated the coastal lung-cancer rate would exceed the usual rate by about 8 per cent. Rates among white men in the area exceed the national rate by about 30 per cent.
• The authors' conclusion: The authors concluded that the findings suggest asbestos, and possibly other shipyard exposures during wartime employment, account for part of the excess mortality from lung cancer in certain coastal areas of the United States.
• Limitations the authors state:
  • Most interviews were with next of kin. Some inaccuracies may have come from second-party reporting or from difficulty recalling events 30 or more years before the interview.
  • The survey provided few data on asbestos exposure.
  • Diagnostic ascertainment of mesothelioma in the area may be incomplete.
  • The maximum effect of wartime exposures may have occurred before the 1970-76 study period, so the risks presented may be underestimates.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Shipyards and maritime work.

Medical terms in this study, explained in our Lexicon: Lung Cancer, Case-Control Study, Shipyard Exposure.

Related studies

• Cancer mortality in U.S. counties with shipyard industries during World War II — W.J. Blot, B.J. Stone, et al. (1979)
• Lung cancer mortality in the United States: shipyard correlations — W.J. Blot, J.F. Fraumeni (1979)
• Lung cancer in shipyard workers: a plea for prevention — E.L. Wynder (1978)
• Historical perspective on asbestos: policies and protective measures in World War II shipbuilding — J.K. Corn, J. Starr (1987)
• Incidence of bronchial carcinoma in shipyard workers with pleural plaques — J.R. Edge (1979)
• Mortality among shipyard Coast Guard workers: a retrospective cohort study — S. Krstev, P. Stewart, et al. (2007)

Browse more research in The New England Journal of Medicine, or return to medical research.