This report provides information about the health effects of passive smoking, the types of policies that are in force in the public and private sectors to control workplace smoking, and the costs and effects of those policies. The executive summary briefly highlights the three major areas of the report: (1) a review of the studies of health effects related to passive smoking; (2) a review of current federal, state, local, and private sector workplace smoking policies; and (3) a discussion of factors to consider in an analysis of the costs and benefits of implementing a workplace smoking policy. A section on characterizing passive exposure to tobacco smoke discusses mainstream, sidestream, and environmental smoke; measurements of specific constituents of environmental tobacco smoke; and biologic markers of passive exposure to tobacco smoke. The section on health effects examines passive smoking and its relationship to lung cancer, lung function, cardiovascular disease, and irritation. Workplace smoking policies for various federal groups are presented, as are state and local smoking laws, and workplace smoking policies in the private sector. Costs and benefits of workplace smoking policies are examined and alternatives are considered. References are included. (NB)