The basis for the school asbestos hazard program of the Environmental Protection Agency (EPA) is reviewed. Risk of disease following asbestos exposure is discussed. For industrial exposures, lung cancer risks cluster between 1 and 10 percent per fiber year per milliliter. For mesothelioma, estimates range from 0.01 to 0.06 percent. For nonoccupational exposure, lung cancer risks range from 2 to 40 per million exposed persons. Mesothelioma risks range from 2 to 100 per million. The indirect quantitative risk assessment of EPA for asbestos associated cancers due to exposures at schools in early life is discussed. As of May, 1982, approximately 8,600 schools contain friable asbestos and approximately 2 to 6 million students and 100,000 to 300,000 teachers, administrators, and other staff are potentially exposed to airborne asbestos in these schools.