Estimating the relationship between exposure to tar volatiles and the incidence of bladder cancer in aluminum smelter workers

Scand J Work Environ Health. 1986 Oct;12(5):486-93. doi: 10.5271/sjweh.2109.


A previously reported case-referent study of 85 incident cases of bladder cancer among aluminum smelter workers and 255 matched referents revealed an excess risk among workers exposed to coal-tar pitch volatiles. For the study reported in the present investigation these data have been augmented by estimates of past workplace exposure to total tar (benzene-soluble matter) and to benzo-a-pyrene (BaP). From these new data, exposure-response relationships have been estimated by maximum likelihood. A linear relationship between cumulative exposure and relative risk and a minimum latency period of ten years were assumed on a priori grounds and found compatible with the data. Under these assumptions, relative risk increased for each year of exposure to benzene-soluble matter at a concentration of 1 mg/m3 by 13%, the 95% confidence interval being 5-31. The corresponding figure for BaP (as micrograms/m3 X year) was 2.3%. On the basis of these estimates, 40 years of exposure to benzene-soluble matter at the current exposure limit of 0.2 mg/m3 would lead to a relative risk of 2.4. There was suggestive but not conclusive evidence that relative risks due to exposure to tar volatiles and to cigarette smoke combined multiplicatively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants, Occupational / adverse effects*
  • Aluminum / adverse effects*
  • Benzene Derivatives / adverse effects
  • Humans
  • Male
  • Middle Aged
  • Occupational Diseases / chemically induced*
  • Polycyclic Compounds / adverse effects
  • Risk
  • Tars / adverse effects*
  • Urinary Bladder Neoplasms / chemically induced*
  • Welding*


  • Air Pollutants, Occupational
  • Benzene Derivatives
  • Polycyclic Compounds
  • Tars
  • Aluminum