Source apportionment of polycyclic aromatic hydrocarbons in PM2.5 using positive matrix factorization modeling in Shanghai, China

Environmental Science: Processes & Impacts Pub Date: 2014-12-10 DOI: 10.1039/C4EM00570H

Abstract

Providing quantitative information on the sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in urban regions is vital to establish effective abatement strategies for air pollution in a megacity. In this study, based on a year data set from October 2011 to August 2012, the sources of PM2.5-bound 16 USEPA priority PAHs (16 PAHs) in Shanghai, a megacity in China, were apportioned by positive matrix factorization (PMF) modeling. The average concentrations (in ng m?3) of 16 PAHs in PM2.5 in the fall, winter, spring and summer were 20.5 ± 18.2, 27.2 ± 24.0, 13.7 ± 7.7 and 6.4 ± 8.1, respectively, with an annual average of 16.9 ± 9.0. The source apportionment by PMF indicated that coal burning (30.5%) and gasoline engine emission (29.0%) were the two major sources of PAHs in the PM2.5 in Shanghai, followed by diesel engine emission (17.5%), air-surface exchange (11.9%) and biomass burning (11.1%). The highest source contributor for PAHs in the fall and winter was gasoline engine emission (36.7%) and coal burning (41.9%), respectively; while in the spring and summer, it was diesel engine emission that contributed the most (52.1% and 43.5%, respectively). It was suggested that there was a higher contribution of PAHs from engine emissions in 2011–2012 compared with those in 2002–2003. The major sources apportioned by PMF complemented well with this of using diagnostic ratios, suggesting a convincing identification of sources for the PM2.5-bound 16 PAHs in a megacity.

Graphical abstract: Source apportionment of polycyclic aromatic hydrocarbons in PM2.5 using positive matrix factorization modeling in Shanghai, China
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