title: Occurrence and sources of polycyclic aromatic hydrocarbons and n-alkanes in PM(2.5) in the roadside environment of a major city in China.
abstract: Thirty six PM(2.5) samples were collected at a roadside site of the heaviest traffic road in Qingdao, a coastal mega city in North China, from March 2004 to January 2005 to perform a detailed characterization of 16 priority polycyclic aromatic hydrocarbons (PAHs) proposed by the USEPA and n-alkanes. For PAHs, the significant increase in winter was observed with average PAH level of 32.3, 11.5, 48.9 and 263 ng m(-3) for spring, summer, autumn and winter, respectively. The average concentrations of n-alkane in PM(2.5) at ground level were 232, 121, 309 and 369 ng m(-3) in spring, summer, autumn, and winter, respectively. The pyrogenic PAHs were mainly from the coal burning, and the liquid fossil fuel combustion was their second contribution even at the roadside of a busy street with heavy traffic in Qingdao. Petroleum residues were the dominant source for the n-alkanes. Principal component analysis results indicated that all the measured PAHs but naphthalene and those C17-C26 n-alkanes could be attributed to the fossil fuel burning while long-chain n-alkanes (C27-C35) were mainly derived from higher plant waxes. Good correlations between PAHs and n-alkanes in summer, autumn and winter suggested that they were mainly from local sources. The poor correlation of n-alkanes and PAHs in spring could be mainly due to the shift from the space heating season to non-heating season during the sampling period. This work indicated that the roadside environment in Qingdao was more deteriorated compared with non-roadside environment in other mega cities in China.
authors.affiliation: Department of Environmental Science and Engineering, Center for Atmospheric Chemistry Study, Fudan University, Shanghai 200433, China. guozgg@fudan.edu.cn
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Guo
authors.forename: Tian
authors.initials: T
authors.lastname: Lin
authors.forename: Gan
authors.initials: G
authors.lastname: Zhang
authors.forename: Limin
authors.initials: L
authors.lastname: Hu
authors.forename: Mei
authors.initials: M
authors.lastname: Zheng
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D000473:Alkanes / Q000032:analysis*; D002681:China; D004782:Environmental Health; D052638:Particulate Matter / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D025341:Principal Component Analysis; D012621:Seasons; D001335:Vehicle Emissions
chemical_list: D000395:Air Pollutants, Occupational; D000473:Alkanes; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D001335:Vehicle Emissions