Risk of lung cancer from exposure to dusts and fibers in leningrad province, Russia

Abstract

Several dusts and fibers have been classified by the International Agency for Research on Cancer (IARC) as carcinogens to humans. Others have been indicated as risk factors for lung cancer, but with no conclusive demonstration. We conducted an autopsy-based case–control study in Leningrad Province, Russia, to investigate the association of lung cancer risk with the exposure to 58 different dusts and fibers. We identified 540 pathologically diagnosed lung cancer cases (474 males, 66 females) and 582 controls (453 males, 129 females) among subjects who had died in hospitals of Leningrad Province between 1993 and 1998. We retrieved subject-specific quantitative measurements of 15 organic, 15 synthetic and 28 natural inorganic dusts and fibers performed since 1950 in each work facility of the study area. We used unconditional logistic regression to compute sex-specific odds ratios (OR) and 95% confidence intervals (CI) for lung cancer adjusted for age, smoking, and residence. Nearly 90% of the study subjects had been exposed to one or more of the 58 dusts and fibers evaluated. Exposure above the specific maximum allowable concentrations (MACs) was frequent in this population, with average exposure intensity higher than MACs for 16% of the subjects. In males, lung cancer risk was increased among workers exposed to linen dust (OR = 3.68, 95% CI = 1.00–13.6) or unspecified dusts and fibers (OR = 1.44, 95% CI = 1.07–1.94). A nonsignificant increased risk, correlated with exposure intensity, was observed in males exposed to synthetic vitreous fibers (OR = 1.82, 95% CI = 0.88–3.75). Male subjects exposed to quartz dust had OR = 1.27 (95% CI = 0.83–1.93). In female subjects, a nonsignificant excess risk, which tended to increase with cumulative exposure, was observed for paper dust (OR = 1.77, 95% CI = 0.74–4.20) and for unspecified dusts and fibers (OR = 1.52, 95% CI = 0.77–3.03). Most study subjects were exposed to dusts and fibers, often above the maximum allowable concentrations. We observed increased lung cancer risks for specific categories of dusts and fibers.