Environmental Tobacco Smoke and Lung Cancer Following several
reports of the Surgeon General on the consequences of
involuntary smoking, the U.S. Environmental Protection Agency
(EPA) released a report in 1993 in which environmental tobacco
smoke (ETS) was labeled a human carcinogen. The report was based
on 30 epidemiologic studies from around the world, including a
large multicenter case-control study involving SEER registries.
The study used a questionnaire specifically designed to evaluate
the role of ETS exposure in the development of lung cancer among
lifetime nonsmokers. The study revealed that any exposure from a
spouse who smoked was associated with at least a 30 percent
excess risk. Findings from the first 3 years of the study
contributed the greatest individual study weight to the relative
risk estimates for lung cancer in the EPA report. After
completion of 2 additional years of subject accrual in 1994, the
investigators confirmed excess risk among women exposed to ETS
in the household, in the work