title: Characterization and source apportionment of PM2.5-bound polycyclic aromatic hydrocarbons from Shanghai city, China.
abstract: Polycyclic aromatic hydrocarbons (PAHs) were studied in 230 daily fine particulate matter (PM2.5) samples collected in four seasons at urban and suburban sites of Shanghai, China. This study focused on the emission sources of PAHs and its dynamic results under different weather conditions and pollution levels and also emphasized on the spatial sources of PM2.5 and PAHs at a regional level. Annual concentrations of PM2.5 and 16 EPA priority PAHs were 53 μg/m3and 6.9 ng/m3, respectively, with highest levels in winter. Positive matrix factorization (PMF) modeling identified four sources of PAHs: coal combustion, traffic, volatilization and biomass combustion, and coking, with contributions of 34.9%, 27.5%, 21.1% and 16.5%, respectively. The contribution of traffic, a local-indicative source, increased from 17.4% to 28.7% when wind speed changed from >2m/s to <2m/s, and increased from 18.3% to 31.3% when daily PAH concentrations changed from below to above the annual mean values. This indicated that local sources may have larger contributions under stagnant weather when poorer dispersion conditions and lower wind speed led to the accumulation of local-emitted pollutants. The trajectory clustering and potential source contribution function (PSCF) and concentration weighted trajectory (CWT) models showed clearly that air parcels moved from west had highest concentrations of PM2.5, total PAHs and high molecular weight (HMW) PAHs. While small differences were found among all five clusters in low molecular weight (LMW) PAHs. Sector analyses determined that regional transport source contributed 39.8% to annual PM2.5 and 52.5% to PAHs, mainly from western regions and varying with seasons. This work may make contribution to a better understanding and control of the increasingly severe air pollution in China as well as other developing Asian countries.
authors.affiliation: Department of Geography, Key Laboratory of Geo-information of the Ministry of Education, East China Normal University, Shanghai 200062, China; Anhui Key Laboratory of Natural Disasters Process and Prevention, College of Territorial Resource and Tourism, Anhui Normal University, Wuhu 241003, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Geography, Key Laboratory of Geo-information of the Ministry of Education, East China Normal University, Shanghai 200062, China. Electronic address: mliu@geo.ecnu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Geography, Key Laboratory of Geo-information of the Ministry of Education, East China Normal University, Shanghai 200062, China; College of Urban and Environmental Sciences, Yancheng Teachers University, Yancheng 224051, China.
authors.forename: Yingpeng
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Geography, Key Laboratory of Geo-information of the Ministry of Education, East China Normal University, Shanghai 200062, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D002681:China / Q000453:epidemiology; D002947:Cities; D003031:Coal / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005163:Factor Analysis, Statistical; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008962:Models, Theoretical; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry; D012621:Seasons; D014919:Wind
chemical_list: D000393:Air Pollutants; D003031:Coal; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons
keywords: Emission source; PAHs; PMF; Seasonal perspective; Sector analysis; Spatial source