Institute of Agricultural Remote Sensing and Information Technology Application, Zhejiang University, Hangzhou, 310029, China.
Ningbo agricultural food safety Management Station, Ningbo, 315000, China.
Environ Sci Pollut Res Int. 2017 Aug;24(24):19816-19826. doi: 10.1007/s11356-017-9516-1. Epub 2017 Jul 7.
Soil heavy metal contamination is a serious environmental problem. Human beings may be directly exposed to heavy metals in soils through the inhalation of soil particles, dermal contact, and oral ingestion, which can seriously threaten health. This study assesses the health risks associated with heavy metals in soils by determining the concentrations of eight heavy metals (Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni) based on 2051 surface-soil samples collected from the southern Yangtze River Delta of China. The mean concentrations were higher than the corresponding background values in Zhejiang Province and China as a whole, indicating an accumulation of heavy metals. The health risk assessment suggests that the non-carcinogenic and carcinogenic risks in the study area were not significant. The non-carcinogenic risk for children was the highest, followed by those for adults and seniors; the non-carcinogenic risk for the entire population was less than 1.0, the predetermined threshold. Carcinogenic risk for adults was the highest, followed by those for seniors and children; a few sample points had a value larger than the threshold of 1.0E-04. Arsenic represented the greatest contribution to non-carcinogenic and carcinogenic risk. Meanwhile, ingestion of heavy metals in soil was the main exposure pathway for carcinogenic risk, followed by inhalation and dermal exposure. The spatial method of Getis-Ord was used to identify hot spots of health risk. Hot spots with high hazard index (HI) and total carcinogenic risk (TCR) for children, adults, and seniors were mainly distributed in core urban areas, such as Jiangbei, Haishu, Yinzhou, Jiangdong, and the urban areas of some other counties, which coincided with industrial, mining, and urban areas of the study area and were strongly influenced by anthropogenic activities. These results provide a basis for heavy metal control in soil, source identification, and environment management in the Yangtze River Delta and other rapidly developing industrial regions in China.
土壤重金属污染是一个严重的环境问题。人类可能通过吸入土壤颗粒、皮肤接触和口服摄入等途径直接接触土壤中的重金属，这会严重威胁健康。本研究通过对中国长江三角洲地区采集的 2051 个表层土壤样本中 8 种重金属（Cr、Pb、Cd、Hg、As、Cu、Zn 和 Ni）的浓度进行测定，评估了土壤重金属的健康风险。平均值高于浙江省和全国相应的背景值，表明重金属积累。健康风险评估表明，研究区域的非致癌和致癌风险并不显著。儿童的非致癌风险最高，其次是成人和老年人；总人口的非致癌风险小于 1.0，是预定的阈值。成人的致癌风险最高，其次是老年人和儿童；少数采样点的值大于 1.0E-04 的阈值。砷对非致癌和致癌风险的贡献最大。同时，土壤重金属的摄入是致癌风险的主要暴露途径，其次是吸入和皮肤接触。Getis-Ord 空间方法用于识别健康风险的热点。儿童、成人和老年人高危害指数（HI）和总致癌风险（TCR）的热点主要分布在核心城区，如江北、海曙、鄞州、江东以及其他一些县的城区，这与研究区的工业、矿业和城区相吻合，并受到人为活动的强烈影响。这些结果为长江三角洲和中国其他快速发展的工业地区的土壤重金属控制、源识别和环境管理提供了依据。
