Faculty of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, China.
Int J Environ Res Public Health. 2020 Dec 12;17(24):9296. doi: 10.3390/ijerph17249296.
Arable land soil is one of the most precious natural resources of Earth, it provides the fundamental material and numerous resources essential for the development of human society. To determine the pollution of potential toxic factors in the surface soil of cultivated land and its risks to human health, concentrations of five different potentially toxic elements (PTEs) were detected in 1109 soil samples collected in Xiangzhou, China, in 2019. In this study, health risk assessment was used to judge the degree of pollution in the study area, the result of Geographic Information System (GIS) was as used to research the spatial distribution characteristics of PTEs, and random forest (RF) was used to assess the natural and man-made influencing factors. We investigated the sources of PTEs through quantifying the indicators, which gave further insights. The main results are: (1) In arable land soil, the average content of PTEs is 0.14 mg/kg cadmium (Cd), 0.05 mg/kg mercury (Hg), 12.89 mg/kg arsenic (As), 29.23 mg/kg lead (Pb), and 78.58 mg/kg chromium (Cr), respectively. The content of As and Pb outpaced the background value of Hubei soil. (2) The human health risk assessment in Xiangzhou indicates that the most important exposure pathway is soil ingestion, occupied about 99% to health risks of PTEs; non-carcinogenic risk from exposure to As, Pb and Cr in soil was higher than the limit (overall potential risk index, HI > 1) for both children and adults. Moreover, carcinogenic risk postured by Cd, Cr, and As was higher than the limit (10) through soil exposure for both children and adults, indicating that Cd, As, Pb and Cr in soil have significant effect on people's health through exposure. (3) We found that the increased PTEs in the arable land soil mainly originated from potential water sources, air and soil pollution sources, breeding farms, and mining areas.
耕地土壤是地球最宝贵的自然资源之一，它为人类社会的发展提供了基本的物质和大量的资源。为了确定耕地表层土壤中潜在有毒因素的污染及其对人类健康的风险，我们于 2019 年在中国香洲采集了 1109 个土壤样本，检测了 5 种不同的潜在有毒元素（PTEs）的浓度。在本研究中，我们使用健康风险评估来判断研究区域的污染程度，使用地理信息系统（GIS）的结果来研究 PTEs 的空间分布特征，使用随机森林（RF）来评估自然和人为影响因素。我们通过量化指标来研究 PTEs 的来源，这为我们提供了更深入的见解。主要结果如下：（1）在耕地土壤中，PTEs 的平均含量分别为 0.14mg/kg 镉（Cd）、0.05mg/kg 汞（Hg）、12.89mg/kg 砷（As）、29.23mg/kg 铅（Pb）和 78.58mg/kg 铬（Cr）。As 和 Pb 的含量超过了湖北土壤的背景值。（2）香洲的人体健康风险评估表明，最重要的暴露途径是土壤摄入，约占 PTEs 健康风险的 99%；儿童和成人暴露于土壤中 As、Pb 和 Cr 的非致癌风险均高于限值（总体潜在风险指数 HI>1）。此外，儿童和成人通过土壤暴露，Cd、Cr 和 As 的致癌风险均高于限值（10），表明土壤中的 Cd、As、Pb 和 Cr 通过暴露对人体健康有显著影响。（3）我们发现耕地土壤中 PTEs 的增加主要来源于潜在的水源、空气和土壤污染源、养殖场和矿区。
