Use of pattern recognition techniques to characterize local sources of toxic organics in the atmosphere

Abstract

Pattern recognition techniques are used to characterize local sources of toxic air contaminants. Data collected in the Kanawha Valley, WV, from four sites are used to construct profiles of chemical emissions from nearby chemical industries. A regional profile is also constructed. A chemical mass balance (CMB) model is used to apportion the emission of selected toxic compounds at the sites among the chemical industries and the regional mixed sources. At sites 1 and 2, which are near one chemical industrial complex, the ambient concentrations of toxics are due almost entirely to the local source. At sites 3 and 4, which are near a second chemical industrial complex, more widespread regional sources often contribute to the ambient concentrations of the toxic compounds. The use of pattern recognition to construct source profiles is useful especially for area sources and where source emission data are not available from specific point sources. These techniques allow a distinction to be made between point and area source contributions to toxic air pollutants. 24 references, 6 figures, 5 tables.