Diesel exhaust exposure and lung cancer: adjustment for the effect of smoking in a retrospective cohort study.
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.
Larkin
E K
EK
Medical and Research Service, VA Boston Healthcare System, Boston, MA 02132, USA.
Smith
T J
TJ
Stayner
L
L
Rosner
B
B
Speizer
F E
FE
Garshick
E
E
D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology*; D009784:Occupational Diseases / Q000453:epidemiology*; D011890:Railroads; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology; D001335:Vehicle Emissions
D001335:Vehicle Emissions