Zhao Liang, Liang Yun-Ping, Chen Qian, Xu Qian, Jing Hong-Wei
Beijing Municipal Ecological and Environmental Monitoring Center, Beijing 100048, China.
Beijing Radiation Safety Technology Center, Beijing 100089, China.
Huan Jing Ke Xue. 2020 Dec 8;41(12):5552-5561. doi: 10.13227/j.hjkx.202004277.
To study the condition of urban green space soils in the central parts of a city in North China, the spatial distribution, sources, and pollution levels of heavy metals (Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni) within green space soils in the central urban districts of the city were investigated. The results showed that the soil quality was high overall. The mean concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni were 0.172, 0.202, 9.02, 34.7, 57.0, 31.2, 85.7, and 26.3 mg·kg, respectively. The mean concentrations of Cd, Hg, Pb, and Zn in urban soils exceeded the background value of the Beijing-Tianjin-Tangshan region. All of the samples' heavy metal concentrations were lower than the risk screening values for soil contamination of development land in the national soil environment quality standards. With respect to the spatial distribution, the concentrations of As, Cr, and Ni were higher in the northwest of the study area, the concentrations of Cd and Zn were higher in the northeast, and the concentrations of Hg, Pb, and Cu were higher in the urban core area. As for the different land use types of the soils, the concentrations of Cd, Zn, and Ni were higher in the enterprise soils, while the concentrations of Hg, Pb, and Cu were higher in park and residential soils. Assessments of soil quality showed that 97.2% of soil samples' Nemerow integrated indices were less than 1, indicating that the soils were clean. Indices of potential ecological risk for all soil samples were less than 80, indicating that they posed a slight ecological risk. Multivariate statistical analysis (correlation and principle component analyses) showed that Cu, Pb, and Hg may originate from an anthropogenic source via the painting of ancient buildings and pesticides used to protect ancient trees. Chromium may originate from natural sources via geochemical activity and soil parent material; Cr, Zn, Ni, and As were derived from mixed sources through human and geochemical activities. The receptor model was used for identification and apportionment of pollution sources of elements over the standard. The contribution rates of sources were as follows:source 2(46.1%), source 3(33.1%), source 1(17.7%), and others (3.1%) for Cd, source 1(93.0%) for Cu, source 1(52.4%), source 3(24.2%), source 2(20.0%), and others (3.4%) for Zn, source 1(56.3%), source 2(37.8%), and source 3(5.8%) for Ni. Sources 1 and 3 were anthropogenic, while source 2 was natural.
为研究华北某市中心城区城市绿地土壤状况，对该市中心城区绿地土壤中重金属（镉、汞、砷、铅、铬、铜、锌和镍）的空间分布、来源及污染水平进行了调查。结果表明，土壤质量总体较高。镉、汞、砷、铅、铬、铜、锌和镍的平均含量分别为0.172、0.202、9.02、34.7、57.0、31.2、85.7和26.3mg·kg。城市土壤中镉、汞、铅和锌的平均含量超过了京津冀地区的背景值。所有样品的重金属含量均低于国家土壤环境质量标准中建设用地土壤污染风险筛选值。在空间分布方面，研究区域西北部的砷、铬和镍含量较高，东北部的镉和锌含量较高，城市核心区域的汞、铅和铜含量较高。对于不同土地利用类型的土壤，企业土壤中的镉、锌和镍含量较高，公园和住宅土壤中的汞、铅和铜含量较高。土壤质量评价表明，97.2%的土壤样品内梅罗综合指数小于1，表明土壤清洁。所有土壤样品的潜在生态风险指数均小于80，表明它们构成的生态风险较小。多元统计分析（相关性分析和主成分分析）表明，铜、铅和汞可能通过古建筑油漆和古树保护用农药等人为来源产生。铬可能通过地球化学活动和土壤母质等自然来源产生；铬、锌、镍和砷是通过人类活动和地球化学活动混合来源产生的。采用受体模型对超标元素的污染源进行识别和分配。各污染源的贡献率如下：镉的污染源2（46.1%）、污染源3（33.1%）、污染源1（17.7%）和其他（3.1%），铜的污染源1（93.0%），锌的污染源1（52.4%）、污染源3（24.2%）、污染源2（20.0%）和其他（3.4%），镍的污染源1（56.3%）、污染源2（37.8%）和污染源3（5.8%）。污染源1和3是人为源，污染源2是自然源。
