Second-hand Smoke, Cotinine Levels, and Risk of Circulatory Mortality in a Large Cohort Study of Never-Smokers

Exposure to second-hand smoke has been shown to be associated with increased cardiovascular mortality in several, but not all, epidemiologic studies. Our aim was to investigate the risk of circulatory death associated with exposure to second-hand smoke in never-smokers in a very large prospective study, the European Prospective Investigation into Cancer and Nutrition. A secondary aim was to use cotinine levels for cross-validating self-reported second-hand smoke exposure.