A volume consisting of a collection of reports dealing with a number of investigations conducted in the Soviet Union at its various public health institutes and in university departments of public health is presented. The results of the investigations provide a basis for the establishment of a new series of maximum permissible concentrations for new toxic substances in the atmospheric air, and constitute the scientific criteria for assessing the degree of pollution. The material included in this volume deals with the response of the organism: (1) to low concentrations of chemical air pollutants around major petrochemical complexes that are now under intensive development; (2) to low concentrations of air pollutants around chemical plants manufacturing as raw material for nylon production, the salts of adipic acid and hexamethylenediamine and also salts of sebacic acid and hexamethylenediamine; and (3) to the various concentrations of air pollutants around organic synthesis plants and other facilities of the new chemical industry. Methods of determination of low concentrations of various substances in the atmosphere air are also described in some of these papers. (APCO abstract)