Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Ecotoxicol Environ Saf. 2021 Jun 1;215:112106. doi: 10.1016/j.ecoenv.2021.112106. Epub 2021 Mar 21.
Plastic shed production system (PSPS) provide abundant vegetable products for human consumption. Comprehensive and accurate heavy metal (HM) risk assessment of soil and vegetable under plastic sheds is crucial for human health. Pollution assessment, bioavailability and mobility evaluation and health risk assessment of Cd, Cr, Cu, Zn Ni, Pb, and As were performed in a presentative Plastic shed production system. The concentrations of the Cd, Cu and Zn exceeded their background value. Positive I values suggested that soil under plastic sheds was widely contaminated with Cd. The bioavailability of heavy metals in soils was evaluated using DTPA extraction and DGT methods. The results of both methods demonstrated that Cd, Cu, and Zn have high bioavailability, especially Cd. Analogically, the results of mobility assignment based on DIFS showed that Cd has a high migration risk due to the large available pool. Based on specific cultivation and management patterns of plastic shed production system, pH reduction and salt and nutrient accumulation may increase the heavy metals migration risk in soil under plastic sheds, while a high organic matter content may reduce the heavy metals migration risk. The average concentrations of Cd, Cr, Cu, Zn, Ni, Pb, and As in vegetables were 0.023, 0.226, 0.654, 2.984, 0.329, 0.041, and 0.010 mg/kg, respectively. All samples were well below the threshold. The order of target hazard quotient of different heavy metals caused by vegetable consumption was Cd > Cr > As > Cu, Ni, Pb, Zn, and the average total hazard index value was below 1, which demonstrated that risk of vegetable consumption in the study area. However, due to its high concentration and transfer coefficient in spinach, Cd might pose a health risk to humans, which requires special attention. In this study, Cd caused a significant issue than other HMs, whether pollution level, health risk and migration risk. DGT and DIFS can be used as an effective evaluation tool in the research of controlling heavy metals migration in soil-crop systems.
塑料大棚生产系统（PSPS）为人类提供了丰富的蔬菜产品。对土壤和大棚蔬菜进行全面、准确的重金属（HM）风险评估对人类健康至关重要。本研究采用污染评价、生物有效性和迁移性评价及健康风险评价方法，对典型 PSPS 土壤和蔬菜中 Cd、Cr、Cu、Zn、Ni、Pb 和 As 的含量进行了研究。结果表明，Cd、Cu 和 Zn 的浓度超过了背景值。I 值为正表明大棚土壤受到了广泛的 Cd 污染。采用 DTPA 提取和 DGT 方法评价了土壤重金属的生物有效性。两种方法的结果均表明，Cd、Cu 和 Zn 的生物有效性较高，尤其是 Cd。同样，基于 DIFS 的迁移性赋值结果表明，由于较大的有效库，Cd 具有较高的迁移风险。基于 PSPS 特有的栽培和管理模式，土壤 pH 值降低、盐分和养分积累可能会增加大棚土壤中重金属的迁移风险，而较高的有机质含量可能会降低重金属的迁移风险。蔬菜中 Cd、Cr、Cu、Zn、Ni、Pb 和 As 的平均浓度分别为 0.023、0.226、0.654、2.984、0.329、0.041 和 0.010mg/kg，均低于检出限。不同重金属通过蔬菜摄入对人体造成的目标危害商的顺序为 Cd>Cr>As>Cu>Ni>Pb>Zn，平均总危害指数值低于 1，表明研究区蔬菜食用风险较低。然而，由于 Cd 在菠菜中的浓度和转移系数较高，其可能对人体健康构成威胁，需要特别关注。本研究中，Cd 造成的问题比其他重金属更为突出，无论是污染水平、健康风险还是迁移风险。DGT 和 DIFS 可作为研究控制土壤-作物系统中重金属迁移的有效评价工具。
