In their efforts to learn why the incidence of cancer and other fatal and serious diseases is on the rise, researchers are concentrating more and more on the health effects of products and waste products of modern industrial society. One such product, vinyl chloride, the principal ingredient of the second most widely used plastic, has recently been shown to cause cancer in humans. Gasoline combustion products have been linked to chronic respiratory difficulties. It has been estimated¹ that up to 90 percent of the incidence of cancer in the general population may be caused by environmental factors (including cigarette smoke).

Protection of the public from threats to public health and safety caused by the release of harmful substances into the environment is accomplished in large part through decisions of the regulatory agencies of the federal government. The agency decisions are made within a framework of laws which express congressional intent as to the extent to and means by which agencies shall act to protect the public against air or water pollution, toxic chemicals, radiation, or other potentially harmful factors. The agency decisions, and through them, the congressionally enacted laws, are reviewed by the courts, institutions which have had and continue to have difficulties in dealing with the complex scientific and public policy issues raised by regulation in the public health area.