This book is a report designed to be used by scientists in a wide variety of disciplines and by interested laymen. Thus, the readability of the material was maintained without sacrificing scientific accuracy. The document consisted of three parts. Part 1, Air Conservation and Public Policy, was written to be of interest to the broadest possible readership. Part 2, Summary of the Facts, is a concise report on the state of scientific knowledge about air conservation. Part 3, Background Reports, is primarily directed to scientists and specialists in other disciplines. Part 3 constitutes eighty-five percent of the total report. Nearly half of this section is devoted to pollutants and their effects of which chemical and radioactive pollutants received strong emphasis. (RR)