| Summary: | 碩士 === 國立中山大學 === 海洋環境及工程學系研究所 === 106 === In this study, spatiotemporal variation and potential sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were investigated for four sampling sites located close to air-polluting industrial area in Kaohsiung City, southern Taiwan. The sampling sites included Daliao (DL), Fongshan (FS), Renwu (RW) and Ciaotou District (CT). A total of 90 PM2.5 samples with 16 PAHs collected from September 2016 to August 2017 were analyzed. The concentrations of 16 PAHs were determined through gas chromatography–mass spectrometry. Diagnostic ratios, principle components analysis (PCA) and hierarchical cluster analysis (HCA) were applied to identify potential PAHs sources. The results revealed the annual mean PM2.5 concentrations were 45.8 ± 16.3, 47.6 ± 21.0, 48.3 ± 17.2 and 51.4 ± 14.3 μg m-3 for DL, FS, RW and CT sites, respectively, while their corresponding PAHs concentrations were 1.52 ± 0.79, 1.48 ± 1.03, 1.11 ± 0.68 and 1.35 ± 1.13 ng m-3. According to the component pattern of PM2.5-bound PAHs, the high molecular weight (HMW) PAHs were dominant on PM2.5 compared to the lower molecular weight (LMW) PAHs. The annual average benzo[a]pyrene equivalent (BaPeq) concentrations in PM2.5 at DL, FS, RW and CT sites were 0.215 ± 0.116, 0.217 ± 0.145, 0.161 ± 0.094 and 0.179 ± 0.130 ng m-3, respectively. BaP was found accounted for 49% to 52% of BaPeq concentrations in PM2.5 at four sites. In the present study, PM2.5, PM2.5-bound PAHs and BaPeq showed seasonal variations, the higher concentrations were found in winter while the lower ones were found in summer. There was a negative correlation between concentrations and atmospheric temperatures. The results of diagnostic ratios, PCA and HCA illustrated two major sources of PM2.5-bound PAHs in different seasons, including stationary emissions, such as coal combustion and petroleum burning, and vehicular emissions from gasoline and diesel engines. The annual average incremental lifetime cancer risk (ILCR) from inhaling exposure to PM2.5-bound PAHs at FS site was quantified as 0.262×10-6, which was lower than the criterion specified in the United States Environmental Protection Agency guidelines (10-6).
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