The report describes the accomplishments of the Office of Research and Development (ORD) and its 14 laboratories is fiscal year 1983. During that year, researchers uncovered important and unexpected new information on how some major pollutants affect human health, developed less costly and more accurate tests for environmental toxicity, and assessed potential pollution from, and the cost effectiveness of numerous industrial and municipal sources of pollution. ORD also helped to estimate the cost of air pollution and to reduce the cost of controlling it. In addition, the program improved the methods used to detect hazardous wastes and the means available to destroy them.