Luo Xiao-San, Xue Yan, Wang Yan-Ling, Cang Long, Xu Bo, Ding Jing
Department of Agricultural Resources and Environment, IceMe, Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China; Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Department of Agricultural Resources and Environment, IceMe, Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Chemosphere. 2015 May;127:152-7. doi: 10.1016/j.chemosphere.2015.01.048. Epub 2015 Feb 16.
Because heavy metals (HMs) occurring naturally in soils accumulate continuously due to human activities, identifying and apportioning their sources becomes a challenging task for pollution prevention in urban environments. Besides the enrichment factors (EFs) and principal component analysis (PCA) for source classification, the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) and Pb isotopic mixing model were also developed to quantify the source contribution for typical HMs (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in urban park soils of Xiamen, a representative megacity in southeast China. Furthermore, distribution patterns of their concentrations and sources in 13 soil profiles (top 20 cm) were investigated by different depths (0-5, 5-10, 10-20 cm). Currently the principal anthropogenic source for HMs in urban soil of China is atmospheric deposition from coal combustion rather than vehicle exhaust. Specifically for Pb source by isotopic model ((206)Pb/(207)Pb and (208)Pb/(207)Pb), the average contributions were natural (49%)>coal combustion (45%)≫traffic emissions (6%). Although the urban surface soils are usually more contaminated owing to recent and current human sources, leaching effects and historic vehicle emissions can also make deep soil layer contaminated by HMs.
由于土壤中天然存在的重金属因人类活动而持续积累，识别和划分其来源成为城市环境污染预防中的一项具有挑战性的任务。除了用于源分类的富集因子（EFs）和主成分分析（PCA）外，还开发了受体模型（绝对主成分得分-多元线性回归，APCS-MLR）和铅同位素混合模型，以量化中国东南部典型大城市厦门城市公园土壤中典型重金属（镉、钴、铬、铜、锰、镍、铅、锌）的源贡献。此外，还通过不同深度（0-5厘米、5-10厘米、10-20厘米）研究了其在13个土壤剖面（表层20厘米）中的浓度和来源分布模式。目前，中国城市土壤中重金属的主要人为来源是煤炭燃烧产生的大气沉降，而非汽车尾气排放。具体就铅源的同位素模型（（206）Pb/（207）Pb和（208）Pb/（207）Pb）而言，平均贡献为自然源（49%）>煤炭燃烧（45%）≫交通排放（6%）。尽管城市表层土壤通常因近期和当前的人类源而受污染更严重，但淋溶效应和历史车辆排放也会使深层土壤层受到重金属污染。
