Lung cancer risk and workplace exposure to environmental tobacco smoke

Objectives. We sought to quantitatively evaluate the association between workplace environmental tobacco smoke exposure and lung cancer. Methods. We performed a meta-analysis in 2003 of data from 22 studies from multiple locations worldwide of workplace environmental tobacco smoke exposure and lung cancer risk. Estimates of relative risk from these studies were analyzed by fitting the data to fixed and mixed effects models. Analyses of highly exposed workers and of the relationship between duration of exposure and lung cancer were also performed. Results. The meta-analysis indicated a 24% increase in lung cancer risk (relative risk [RR] = 1.24; 95% confidence interval [Cl] = 1.18, 1.29) among workers exposed to environmental tobacco smoke. A 2-fold increased risk (RR=2.01; 95% 0=133, 2.60) was observed for workers classified as being highly exposed to environmental tobacco smoke. A strong relationship was observed between lung cancer and duration of exposure to environmental tobacco smoke. Conclusions. The findings from this investigation provide the strongest evidence to date that exposure to environmental tobacco smoke in the workplace is associated with an increased risk of lung cancer.