The digest presents in summary form the essential elements of State air pollution control laws to assist in the consideration of State air pollution control legislation, both existing and proposed. It was prepared with the assistance of the Office of the General Counsel, U.S. Department of Health, Education, and Welfare, from an examination of State statutes enacted through the 1963 legislative session. Also included is an introductory section entitled, 'Guiding Principles -- State Air Pollution Legislation.' It deals with the essential elements of air pollution control statutes and should help those charged with the responsibility of preparing new or revised legislation in this area. (Author)