The US Environmental Protection Agency report released in January 1993, Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders, has stirred considerable discussion and interest in the issues surrounding tobacco and health. The report addresses major health effects of environmental tobacco smoke (ETS), concluding (1) that ETS is causally associated with lung cancer in nonsmoking adults and should be classified as a group A, or known human carcinogen, with approximately 3000 excess deaths yearly; (2) that ETS produces an increased risk of development of acute lower respiratory tract irritation, asthma, and acute lower respiratory tract infections in children exposed in the home; and (3) that ETS is associated with an increase risk of sudden infant death syndrome. Other studies implicate ETS in between 35,000 and 40,000 premature deaths each year from cardiovascular disease. The Council on Scientific Affairs (CSA) agrees that ETS should be classified as a human carcinogen, and strongly supports the findings of other groups concerning both lung cancer and ETS-induced respiratory tract illnesses in children. The CSA concludes that exposure to passive smoke, whether in utero or during infancy, is associated with an increased risk of sudden infant death syndrome. The CSA agrees that the available evidence suggests that ETS exposure leads to increased risk for cardiovascular disease. It is clear that these morbidity and mortality estimates represent a significant public health threat that demands attention from the health community as well as government regulatory agencies involved with health protection.