This series includes: (1) both special and short term studies to determine industrial compliance with state and federal ambient air standards; (2) miscellaneous ambient files which include correspondence, memorandums, program plans, progress reports, technical surveys, sampling data and budget proposals; (3) source tests conducted by consultants and private industries; (4) air quality evaluation source tests. It is important to note that this series spans the government reorganization of 1972 at which time the agency was transferred from the Department of Public Health to the Environmental Protection Division of the Department of Natural Resources (Record Group 88). For all subsequent records, see that record group.