State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Sci Total Environ. 2024 Jan 1;906:167773. doi: 10.1016/j.scitotenv.2023.167773. Epub 2023 Oct 14.
Soil environmental risk threshold of cadmium (Cd) is an important index in formulating soil protection policy. Environmental risk threshold refers to the maximal allowable critical concentration of hazardous substances in the environment. Although there is less study on how to determine soil Cd environmental risk threshold, it is a crucial indicator in formulating soil conservation policies and a key factor in assessing soil environmental quality. The main research content of the study is deducing the environmental risk threshold, aiming to provide scientific basis for the study of environmental quality standards of agricultural land and provide technical support for the protection of Cd pollution of agricultural land. The hazard concentration of 5 % species (HC, which protects 95 % of species) was determined here using different toxicological data of Cd from 23 test endpoints, interspecific extrapolation using the species sensitivity distribution (SSD) method, and a prediction model was created on the basis of several soil parameters. According to the findings, Cd effective concentration (EC) (Cd concentration which blocks 10 % of an endpoint's bioactivity) varied from 0.109 to 221 mg·kg, and the hormetic response induced by Cd reached 118 % displaying in the dose-response curve of Lolium perenne L.. Toxicology data was rectified by the aging factor considering biogeochemical processes of the newly added pollutants prior to SSD curves fitting. After that, the prediction model was created with the equation of LogHC = 0.147 pH + 0.067 OC -1.616. The field test properly validated the prediction model, demonstrating its ability to forecast Cd toxicity levels for various soil conditions. This study offers a scientifically sound methodology for determining the environmental risk limitation for Cd and identifies critical paths for the preservation of environmental species.
土壤环境镉（Cd）风险阈值是制定土壤保护政策的重要指标。环境风险阈值是指环境中有害物质的最大允许临界浓度。尽管如何确定土壤 Cd 环境风险阈值的研究较少，但它是制定土壤保护政策的关键指标，也是评估土壤环境质量的关键因素。本研究的主要研究内容是推导出环境风险阈值，旨在为农用地环境质量标准的研究提供科学依据，为农用地 Cd 污染的保护提供技术支撑。本研究使用来自 23 个测试终点的不同 Cd 毒理学数据，采用物种敏感性分布（SSD）方法进行种间外推，基于几个土壤参数创建了一个预测模型，确定了 5%物种危害浓度（HC，保护 95%的物种）。结果表明，Cd 有效浓度（EC）（阻断 10%生物活性终点的 Cd 浓度）在 0.109 至 221mg·kg 之间变化，Cd 在蕈草叶片伸长率生物测试剂量-反应曲线上诱导了 118%的兴奋效应。在拟合 SSD 曲线之前，通过考虑新添加污染物的生物地球化学过程的老化因子对毒理学数据进行了修正。之后，创建了预测模型，其方程为 LogHC = 0.147 pH + 0.067 OC -1.616。田间试验结果验证了预测模型的有效性，表明其能够预测不同土壤条件下 Cd 的毒性水平。本研究为确定 Cd 的环境风险限值提供了科学合理的方法，并确定了保护环境物种的关键途径。
