摘要
【目的】对海南岛西部矿区周边农用地土壤开展镉(Cd)、铅(Pb)、砷(As)浓度分析,探讨污染特征,评估健康风险,建立系统性研究。【方法】采集807个表层(0~20 cm)土壤并测定土壤Cd、Pb、As、p H和有机质含量;依据河流水系分布情况,基于30 m分辨率的DEM,通过对地形模拟水文过程,确定闭合的集水区域,把研究区划分为A、B、C、D 4个小流域,将自然地理单元与人类活动影响相结合,为污染治理提供精准的空间决策依据。采用综合运用单项污染指数法、内梅罗综合污染指数法、地累积指数法、潜在生态风险指数法和健康风险评价法开展Cd、Pb、As分布特征分析及风险评估。【结果】研究区内土壤呈酸性,有机质含量偏低;Cd、Pb、As超过背景值的点位比例分别达83.52%、62.83%、1.61%。单项污染指数结果表明,Cd、Pb、As无污染点位比例达97.52%、97.03%、100.00%。内梅罗综合指数结果显示,流域A、C属于中污染,流域B属于轻污染,流域D属于重污染。地累积指数结果表明,Cd、Pb轻度污染及以上的点位比例分别为27.63%、5.33%。潜在生态风险指数结果表明,研究区生态风险处于相对可控范围,流域A较强风险占比33.58%,存在局部生态高风险点,主要潜在生态危害元素为Cd。健康风险评价结果表明,Cd、Pb不足以对人体产生健康风险,As的致癌风险在可接受范围内。【结论】研究区内仅有个别点位Cd、Pb超标并有一定生态风险,As含量低且安全;不同流域中,3种重金属污染风险水平存在明显差异,应分流域分元素进行管控与治理,重点管控流域A、D的Cd高风险点区域及局部Pb重度污染点分布区域。
[Objective]There is an urgent need to conduct concentration analyses of cadmium(Cd),lead(Pb),nd arsenic(As)in the soil of agricultural land surrounding the western mining area of Hainan Island,to explore pollution characteristics,assess health risks,and establish a systematic research framework.[Method]A total of 807 topsoil(0-20 cm)samples were collected from the study area,and the concentrations of Cd,Pb and As,along with soil pH and organic matter content,were determined.Based on the distribution of rivers within the study area,the study area divided into four small watersheds.A comprehensive evaluation was conducted using the single factor pollution index method,nemerow pollution index,geo-chemical accumulation index,potential ecological risk factor and human health risk assessment to analyze pollution characteristics and risks of soil Cd,Pb and As.[Result]The soil in the study area was acidic with a relatively low organic matter content.The proportion of sampling points exceeding background values for Cd,Pb and As was 83.52%,62.83%and 1.61%,respectively.A highly significant correlation was observed between Cd and Pb concentrations.The single factor pollution index indicated that 97.52%,97.03%and 100.00%of the sampling points were classified as unpolluted for Cd,Pb and As,respectively.The results of nemerow pollution index showed that basins A and C were moderately polluted,basin B was lightly polluted,and basin D was heavily polluted due to individual points exceeding the standard.The geo-chemical accumulation index showed that 27.63%and 5.33%of the sampling points exhibited at least mild contamination for Cd and Pb,respectively.The potential ecological risk factor results indicated that the ecological risk in the study area was relatively controllable,with strong risk in watershed A accounting for 33.58%.There were local ecological high-risk pointsand the main potential ecological hazard element was Cd.Human healthrisk assessment results indicatedthat Cdand Pbposed nosig nificant health risks,while the carcinogenic risk of As remained within the acceptable threshold.[Conclusion]Certain sampling points in the study area exhibit elevated Cd and Pb concentrations with associated ecological risks,whereas As levels are low and considered safe.Among different river basins,there are significant differences in the pollution risk levels of the three heavy metals,necessitating element-specific and watershed-based management and remediation strategies.It is necessary to focus on controlling the distribution areas of Cd high-risk points and local Pb heavy pollution points in watershed A and D.
作者
蓝才鑫
陈华毅
赵晓阳
胡小飞
LAN Cai-xin;CHEN Hua-yi;ZHAO Xiao-yang;HU Xiao-fei(Hainan Academy of Environmental Sciences,Haikou 571226,China;School of Tropical Agriculture and Forestry,Hainan University,Haikou 570228,China)
出处
《西南农业学报》
北大核心
2025年第7期1391-1403,共13页
Southwest China Journal of Agricultural Sciences
基金
海南省自然科学基金项目(725RC842)。
关键词
热带
土壤污染
重金属
环境健康
安全利用
Tropics
Soil pollution
Heavy metals
Environmental health
Safe utilization
