Table 4.

Risk of specific histologic types of lung cancer among males associated with occupational exposure to crystalline silica, studies I and II pooled

ExposureSquamous cellSmall cellAdenocarcinoma
Ca/CoOR (95% CI)*Ca/CoOR (95% CI)*Ca/CoOR (95% CI)*
Unexposed434/1,5651213/1,5651324/1,5651
Any level of exposure186/4001.49 (1.17-1.90)73/4001.37 (0.97-1.92)84/4001.07 (0.79-1.46)
Nonsubstantial exposure132/3021.41 (1.08-1.84)54/3021.31 (0.90-1.90)63/3021.03 (0.74-1.45)
Substantial exposure54/981.77 (1.18-2.65)19/981.57 (0.87-2.82)21/981.22 (0.71-2.09)
  • *Adjusted for several covariates determined a priori, including original study (i.e., study I or II), age, ethnicity, proxy respondent, education level, natural logarithm of median postal code region income, cigarette ever smoking, natural logarithm of cigarette-years, years since quitting smoking, and occupational exposure to respirable asbestos, benzo(a)pyrene, chromium VI, and diesel emissions.