Under the NIOSH-sponsored contract, a total of 40 surveys were conducted at 28 manufacturing plants. The industries investigated were the fish, dye, leather, rubber and manufacturers and users of cutting fluids. NDELA, NMOR, NDMA and NDPhA were found in the air of several factories. In a chrome tannery, NDMA was identified at levels as high as 47 micrograms/m3 and NMOR was found at 27 micrograms/m3 in a rubber tire plant. This study has resulted in an increased understanding of man's exposure to exogenous N-nitrosamines. It is conceivable, from the information obtained in this study, that nitrosamine exposure comparable to that in the tire and rubber industry exists in other industries not yet surveyed. NIOSH is continuing its research on nitrosamines in the industrial environment. A full, industry-wide report on the 40 plant surveys is being compiled for publication.