Zou Jianmei, Dai Wei, Gong Shengxuan, Ma Zeyu
College of Forestry, Beijing Forestry University, No. 35, Qing Hua East Road, Hai Dian District, Beijing, 100083, China.
PLoS One. 2015 Feb 6;10(2):e0118082. doi: 10.1371/journal.pone.0118082. eCollection 2015.
To understand the effect of intense human activities in suburbs on environmental quality, we obtained 758 measurements of the heavy metals in certain farmland soils of the Beijing suburbs. Multivariate statistical analysis and geostatistical analysis were used to conduct a basic analysis of the heavy metal concentrations, the distribution characteristics and the sources of pollution of the farmland soils in these suburbs. The results showed the presence of eight heavy metals in the agricultural soils at levels exceeding the background values for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. In particular, all the measured Cr concentrations exceeded the background value, while As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were present at 1.13, 1.68, 1.95, 1.43, 1.63, 0.79, 0.92 and 1.36 times their background values, respectively. The results of correlation, factor and spatial structure analyses showed that Cd, Cu, Pb and Zn were strongly homologous, whereas Cr and Hg showed a degree of heterogeneity. The analysis further indicated that in addition to natural factors, Cd, Cu, Pb and Zn in the soil were mainly associated with distribution from road traffic and land use status. Different agricultural production measures in the various areas were also important factors that affected the spatial distribution of the soil Cr concentration. The major sources of Hg pollution were landfills for industrial waste and urban domestic garbage, while the spatial distribution of As was more likely to be a result of composite pollution. The regional distribution of the heavy metals indicated that except for Cr and Hg, the high heavy metal levels occurred in districts and counties with higher organic matter concentrations, such as the northwestern and southeastern suburbs of Beijing. There was no significant Ni pollution in the agricultural soils of the Beijing suburbs.
为了解北京郊区人类高强度活动对环境质量的影响，我们获取了北京郊区部分农田土壤中758份重金属含量测定数据。采用多元统计分析和地统计分析方法，对这些郊区农田土壤中重金属的含量、分布特征及污染源进行了基础分析。结果表明，农业土壤中存在8种重金属，其含量超过了砷、镉、铬、铜、汞、镍、铅和锌的背景值。特别是，所有测得的铬含量均超过背景值，而砷、镉、铬、铜、汞、镍、铅和锌的含量分别是其背景值的1.13、1.68、1.95、1.43、1.63、0.79、0.92和1.36倍。相关性、因子和空间结构分析结果表明，镉、铜、铅和锌具有很强的同源性，而铬和汞则表现出一定程度的异质性。分析进一步表明，除自然因素外，土壤中的镉、铜、铅和锌主要与道路交通和土地利用状况的分布有关。不同地区的农业生产措施也是影响土壤铬含量空间分布的重要因素。汞污染的主要来源是工业废物和城市生活垃圾填埋场，而砷的空间分布更可能是复合污染的结果。重金属的区域分布表明，除铬和汞外，重金属含量较高的地区主要集中在有机质含量较高的区县，如北京的西北郊和东南郊。北京郊区的农业土壤中没有明显的镍污染。
