Diesel exhaust exposure and lung cancer: adjustment for the effect of smoking in a retrospective cohort study

Am J Ind Med. 2000 Oct;38(4):399-409. doi: 10.1002/1097-0274(200010)38:4<399::aid-ajim5>3.0.co;2-d.


Background: The extent that cigarette smoking may confound the relationship between diesel exhaust exposure and lung cancer was assessed in a retrospective cohort study of 55,395 U.S. railroad workers followed from 1959 to 1976.

Methods: The relative risk (RR) of lung cancer due to diesel exhaust was indirectly adjusted using job-specific smoking data from a case-control study of railroad workers who died between 1981-1982 and from a survey of 514 living workers from an active railroad in 1982. Adjustment factors were developed based on the distribution of job-specific smoking rates.

Results: The unadjusted RR for lung cancer was 1.58 (95% CI = 1.14-2. 20) for workers aged 40-44 in 1959, who experienced the longest possible duration of exposure, and the smoking adjusted RR was 1.44 (1.01-2.05).

Conclusions: After considering differences in smoking rates between workers exposed and unexposed to diesel exhaust in a relatively large blue-collar cohort, there were still elevated risks of lung cancer in workers in jobs with diesel exhaust exposure.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cohort Studies
  • Confounding Factors, Epidemiologic
  • Humans
  • Lung Neoplasms / epidemiology*
  • Occupational Diseases / epidemiology*
  • Railroads*
  • Retrospective Studies
  • Smoking / epidemiology*
  • United States / epidemiology
  • Vehicle Emissions*


  • Vehicle Emissions