CERTAIN REGULARITIES IN THE COMPOSITION OF VOLATILE ORGANIC POLLUTANTS IN THE URBAN ATMOSPHERE

Data are reported for a detailed comparative analysis of organic compounds in the atmosphere of six large cities in the USSR, in different geographic and climatic zones using a uniform methodology to eliminate methodological differences between the sampling sites. Organics were concentrated on hydrophobic carbonaceous sorbents and subsequently analyzed by GC and GC/MS. The qualitative composition of the hydrocarbons collected was relatively constant. Atmospheric C4-C13 hydrocarbons were comprised of paraffins (~50%), aromatic compounds (~30%), and alkenes (~10-20%), regardless of geographic location. Divergencies in the quantitative group composition are found in cities with specific additional sources of pollution (e.g., increased levels of naphthenes and olefins were observed near deposits of naphthenic oil and large petrochemical plants, respectively). It is suggested that the toluene/benzene ratio in air cannot serve as a reliable criterion for the significance of exhaust gases as a source of atmospheric hydrocarbon pollutants; instead of this, the ratio of the sum of aromatic hydrocarbons to the sum of paraffins is suggested as a more reliable value. It is also shown that the direct evaporation of automobile fuel can represent an important source of hydrocarbon pollutants in air. © 1979, American Chemical Society. All rights reserved.