Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Technical Centre for Soil, Agricultural and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Sci Total Environ. 2021 Aug 1;780:146567. doi: 10.1016/j.scitotenv.2021.146567. Epub 2021 Mar 19.
Conventional assessment of soil environmental quality commonly focuses on soil heavy metals (HMs), neglecting the HMs in agricultural products. To response this shortcoming, a comprehensive assessment combining both soil environmental quality and agricultural product security for evaluating soil HM impact is urgently required. This comprehensive assessment incorporates not only the HM contents in soil and agricultural product but also soil environmental quality standards, soil elemental background values, and safety standards for HMs in agricultural products. In this study, it was applied to evaluate the potential risk of HMs in soil-crop systems (i.e., soil-vegetable, soil-maize, soil-rice, and soil-wheat systems) along the Yangtze River in Nanjing, Jiangsu Province, Southeast China. Furthermore, Cd/Cd isotope ratio analysis was used to identify the specific contamination sources. The mean concentrations of Cd, As, Hg, Pb, Cu, Zn, and Cr in the surface soils (0-20 cm) were 0.26, 11.07, 0.09, 32.63, 38.57, and 107.92 mg kg, respectively, exceeding the corresponding soil background values. Fertilizer and atmospheric deposition were the major anthropogenic sources of HM contamination in crop-growing soils. In addition to the crop type, soil pH and organic matter also influenced the transfer of HMs from soils to the edible parts of crops. Results of comprehensive assessment revealed that approximately 11.1% of paired soil-crop sites were multi-contaminated by HMs, among which paddy soils had the highest potential risk of HMs followed by maize soils, vegetable soils, and wheat soils. To evaluate the potential risk of HMs in arable land, this study provides a novel, scientific and reliable approach via integrating soil environmental quality and agricultural product security.
传统的土壤环境质量评估通常侧重于土壤重金属（HMs），而忽略了农产品中的 HMs。为了应对这一不足，迫切需要结合土壤环境质量和农产品安全来评估土壤 HM 影响的综合评估。这种综合评估不仅包括土壤和农产品中的 HM 含量，还包括土壤环境质量标准、土壤元素背景值以及农产品中 HM 的安全标准。本研究应用于评估中国东南部江苏省南京市长江沿线土壤-作物系统（即土壤-蔬菜、土壤-玉米、土壤-水稻和土壤-小麦系统）中 HM 的潜在风险。此外，还利用 Cd/Cd 同位素比值分析来识别特定的污染来源。表层土壤（0-20cm）中 Cd、As、Hg、Pb、Cu、Zn 和 Cr 的平均浓度分别为 0.26、11.07、0.09、32.63、38.57 和 107.92mgkg，超过相应的土壤背景值。化肥和大气沉降是作物种植土壤中 HM 污染的主要人为来源。除了作物类型外，土壤 pH 值和有机质也影响了 HM 从土壤向可食用作物部分的迁移。综合评估的结果表明，约有 11.1%的土壤-作物配对地点受到 HM 的多污染，其中水稻土受 HM 的潜在风险最高，其次是玉米土、蔬菜土和小麦土。为了评估耕地中 HM 的潜在风险，本研究通过整合土壤环境质量和农产品安全，提供了一种新颖、科学和可靠的方法。
