Key Laboratory of Geographic Information Science (Ministry of Education), East China Normal University, Shanghai, 200241, China.
Environ Sci Process Impacts. 2018 Mar 1;20(3):531-543. doi: 10.1039/c7em00580f. Epub 2018 Feb 14.
Spatial-temporal distributions, source identification, and possible effects of land use patterns on PAHs were studied in overlying water and surface sediments in Yangtze estuarine and nearby coastal areas. The concentrations of PAHs ranged from 172.6 ± 9.3 to 5603.7 ± 548.7 ng L, 841.0 ± 36.6 to 31 190.5 ± 3711.5 ng g and 312.3 ± 7.6 to 9081.1 ± 862.3 ng g, with mean contents of 1042.9 ng L, 8922.9 ng g and 2400.2 ng g in water, suspended particulate matter (SPM) and sediments. PAH concentrations in three phases were higher in dry seasons (January and April) than in rainy seasons (July and October), and showed a distribution pattern as freshwater area > transition area > seawater area. Water and urban (especially for industrial) land uses contributed significantly to the PAH content in water and sediments. Urban and agricultural land uses were identified as important factors for regulating PAH concentrations in the SPM. TOC and BC were crucial controlling factors for the sorption and distribution of PAHs. The stable carbon isotope signatures of TOC and BC indicated the terrestrial origin of PAHs. Multivariate statistical and toxicity assessments revealed that LHK and SDK were contamination hotspots. Traffic emissions contributed 63% of PAH loadings in the three phases, yet biomass/coal combustion contributed over 85% of the toxicity caused by PAHs. Potential ecological and health risks of PAHs were low. We thus conclude that PAH pollution in the study area was primarily of terrestrial origin. BC and TOC were important predictors for PAH fate in the estuary. Urban and agricultural land use and river systems along the estuary were the major input pathways for the PAH loadings.
本研究调查了长江口及其邻近海域水体和表层沉积物中多环芳烃（PAHs）的时空分布、来源识别及其与土地利用模式的可能相互作用。结果表明，PAHs 在水体、悬浮颗粒物（SPM）和沉积物中的浓度范围分别为 172.6±9.3 至 5603.7±548.7ng/L、841.0±36.6 至 31190.5±3711.5ng/g 和 312.3±7.6 至 9081.1±862.3ng/g，平均值分别为 1042.9ng/L、8922.9ng/g 和 2400.2ng/g。三个相中的 PAH 浓度在旱季（1 月和 4 月）高于雨季（7 月和 10 月），分布模式为淡水区>过渡区>海水区。水相和城市（特别是工业）土地利用对水相和沉积物中 PAH 含量的贡献显著。城市和农业土地利用被确定为调节 SPM 中 PAH 浓度的重要因素。TOC 和 BC 是控制 PAHs 吸附和分布的关键因素。TOC 和 BC 的稳定碳同位素特征表明 PAHs 具有陆源特征。多元统计和毒性评估表明，LHK 和 SDK 是污染热点。在三个阶段，交通排放贡献了 PAH 负荷的 63%，而生物质/煤炭燃烧对 PAHs 毒性的贡献超过 85%。PAHs 的潜在生态和健康风险较低。因此，我们得出结论，研究区的 PAH 污染主要来源于陆地。BC 和 TOC 是河口区 PAH 命运的重要预测因子。城市和农业土地利用以及沿河口的河流系统是 PAH 负荷的主要输入途径。
