Identifying and estimating the relative importance of sources of airborne particulates

A regression model was developed for apportioning the relative contributions of several sources to total suspended particulate matter (TSP) based on trace substance concentrations in aerosol samples. The model when applied to data from New York City indicates that about 40% of the TSP is due to natural or secondary sources. In 1972 to 1975, about 20 to 25% of the TSP is related to automobile emissions, while fuel oil burning for heat and power contributes about 10%, and incineration about 5%. The model was tested on data collected over several years at urban and nonurban sites. Predicted and observed TSP values agreed usually to within better than 20%.