Epidemiologic evidence for workplace ETS as a risk factor for lung cancer among nonsmokers: specific risk estimates.

Exposure to environmental tobacco smoke (ETS) among individuals who have never smoked tobacco products has been well established as a risk factor for lung cancer. Most of the epidemiologic evidence for this association has come from studies of exposure to a spouse who smokes. Fewer studies have explicitly evaluated this risk relationship for workplace sources of ETS exposure. These are reviewed here in the context of study design issues and their contributions to the overall evidence for risks of ETS exposure in the workplace. Although most studies have low power to detect workplace risk estimates in the modest range suggested by the larger studies, risk estimates tend to be consistent with those for exposure from a smoking spouse.