Source apportionment of suspended particulate matter at two traffic junctions in Mumbai, India

Very high concentration of suspended particulate matter (SPM) is observed a t traffic junctions in India. Factor analysis-multiple regression (FA-MR), a receptor modelling technique has been used for quantitative apportionment of the sources contributing to the SPM at two traffic junctions (Sakinaka and Gandhinagar) in Mumbai, India. Varimax rotated factor analysis identifi ed (qualitative) five possible sources: road dust, vehicular emissions, mar ine aerosols, metal industries and coal combustion. A quantitative estimati on by FA-MR model indicated that road dust contributed to 41%, vehicular em issions to 15%. marine aerosols to 15%, metal industries to 6% and coal com bustion to 6% of the SPM observed at Sakinaka traffic junction. The corresp onding figures for Gandhinagar traffic junction are 33%, 18%. 15% 8% and 11 %, respectively. Due to limitation in source marker elements analysed about 16% of the remaining SPM at these two traffic junctions could not be appor tioned to any possible sources by this technique. Of the observed lead in t he SPM, FA-MR apportioned 62% to vehicular emissions, 17% to road dust, 11% to metal industries, 7% to coal combustion and 3% to marine aerosols at Ga ndhinagar traffic junction and about a similar apportionment for lead in SP M at Sakinaka traffic junction. (C) 2001 Elsevier Science Ltd. All rights r eserved.