云南省盈江县旧城—姐冒地区铅地球化学特征及风险评价

Geochemical Characteristics and Risk Assessment of Lead in the Soils of Jiucheng-Jiemao District in Yingjiang,Yunnan

基于云南省盈江县旧城—姐冒地区4706件土壤表层样品和9条土壤垂向剖面,开展土壤Pb地球化学特征研究,并结合“全国第二次土地调查”图斑进行土壤Pb引发人体健康风险评价。结果表明:研究区表层土壤Pb平均含量为43.40 mg/kg,其背景值是全国土壤A层平均值的1.55倍,样品超标率为3.10%;表层土壤Pb元素空间分异明显,分布特征受成土母质和人为活动等因素共同影响;残坡积土壤剖面中Pb含量较多继承了成土母质的物质组成,表现出由表层向深层轻微富集的特征,不同成土母质发育的土壤中Pb含量特征整体表现为:花岗岩>板岩>片麻岩、变粒岩>碎屑岩;第四系冲积土壤剖面中叠加有明显的人为活动影响,Pb含量表现出由深层向表层富集的特征;研究区土壤Pb引发人体健康风险的可能性整体较小,在目前的土地利用和耕作方式下,基本可以得到安全利用。

Based on 4,706 topsoil samples and 9 vertical soil profiles of Jiucheng-Jiemao district in Yingjiang County,Yunnan Province,the geochemical characteristics of lead in soils were studied and human health risk assessment was performed in combination with the Second National Land Survey Patch.The results showed that the average concentration of Pb in the topsoils was 43.40 mg/kg,while the background concentration of Pb was 1.55 times of that in A horizon of National Soil Survey.The ratio of the samples exceeding the national standard(GB 15618-2018)was 3.10%.A significant difference occurred in the spatial distribution of Pb in soils which was affected by both soil parent materials and anthropogenic activities.The Pb content characteristics in the residual soil profiles had more inherited the characteristics of their parent material,showing a lightly enrichment from the top layer to the deep layer.The characteristics of the Pb content in the soils developed by different parent materials were as follows:granite>slate>gneiss,metagranite>clastic rock.Obviously,the human activities were superimposed in the alluvial soil profile so that the Pb content showed an enrichment from deep to top.The possibility of human health risks caused by soil Pb in the study area was relatively small.And the soil could be utilized safely under current land pattern.