John Spengler is the Akira Yamaguchi Professor of Environmental Health and Human Habitation in the Department of Environmental Health at the Harvard School of Public Health. His research activities are directed at the assessment of population exposures to environmental contaminants that occur in homes, offices, schools, and during transit as well as in the outdoor environment. Although he is investigating the effects of pollutants of outdoor origin (ozone, acidic particles, PCBs), he is particularly interested in pollutants of indoor origin (fungi, dust mites, nitrogen dioxide, tobacco smoke, radon, and others). He is also investigating ways to promote improved air quality through sustainable development strategies. Dr. Spengler's objective is to construct the framework for linking zoning, purchases and practices, construction and appliance specifications, and pricing and tax strategies to energy and pollution consequences. He believes that the concepts of pollution prevention, environmental cost accounting, risk-reducing based decision making and life-cycle analysis have to mature from academic concerns to functional activities within the public and private sectors of a market-driven economy.