基于多评估方法的县域镉污染风险管控研究

为支撑区域尺度重金属镉（Cd）污染农田的分区管理决策，以湖南省某典型粮食大县为案例，通过区域网格采集土壤和水稻样品，分析县域Cd污染空间分布特征，结合单因子评价、地累积指数法和人体健康风险法，评估该县Cd污染风险。结果表明：不同评价方法对Cd污染风险区划分差异较大。单因子指数法显示该县仅有5.9%的区域存在污染风险，地...

Risk management of cadmium pollution at the county level based on multiple evaluation methods

To support zoning decision-making for Cd-contaminated arable land at a regional scale, this study used a typical cereal production county in the Hunan Province to evaluate the contamination risk. Paired soil-rice samples were collected using the grid method to assess the risk and spatial distribution characteristics of Cd pollution using single factor evaluation, the geo-accumulation index, and human health risk assessment. The results showed obvious differences in Cd contamination zoning among the three evaluation methods. The single factor evaluation showed that only 5.9% of the county was at risk. In contrast, the geo-accumulation index showed that 29.2% of the county was at risk, primarily in the middle and eastern areas, while the health risk assessment showed that 90.0% and 82.7% of the county was at risk to children and adults, respectively, mainly in the mid-eastern and southern parts of the county. Scenario analysis showed that acidification management was an effective measurement to reduce the risk of land with slightly to moderately contaminated acidity, with the health risk area decreasing by 22.0%~37.8%. These findings suggest that human health-oriented risk assessment should be addressed in contamination zoning and risk management schemes in acidic areas of China, and that acidification amendment is an effective measure to reduce the risk of slight to moderate Cd-contaminated land for safe utilization.