猕猴桃产区土壤重金属分布特征及生态环境污染风险评价——以西安市周至县为例

Distribution characteristics of soil heavy metals and ecological environment pollution risk assessment in the kiwifruit production area of Zhouzhi in Xi′an

通过对西安市周至猕猴桃产区土壤重金属元素的空间分布特征及生态风险进行分析,结合该地区人们的活动、周围环境影响和土壤背景,深入了解土壤环境质量状况,为产区土壤重金属防控提供理论依据,为猕猴桃高质量发展提供基础保障。在周至县猕猴桃主产区16个乡镇街办,采用梅花五点法采集192个土壤样品,测定土壤严格控制的5种重金属含量(Pb、Cd、Hg、As、Cr),并测定土壤pH值。应用地积累指数、潜在生态风险指数、健康风险指数法结合地统计法和地理信息系统(GIS)对5种重金属指标和pH进行了评价分析。周至猕猴桃产区土壤重金属Pb、Cd、Hg、As和Cr平均含量未超过GB 15618-2018《土壤环境质量农用地土壤风险管控标准》和HJ 332-2006《食用农产品产地环境质量评价标准》规定的限值,总体处于清洁水平。周至猕猴桃产区土壤重金属潜在生态风险低,且没有显著的人体健康风险。

In order to provide the theoretical basis for the prevention and control of soil heavy metals,and the basic guarantee for local high-quality kiwifruit development in Zhouzhi kiwifruit production area of Xi′an,the spatial distribution characteristics and ecological risk of soil heavy metal elements was analyzed,and the in-depth understanding of the soil environmental quality status was investigated combined with the area human activities,surrounding environment and soil background.192 soil samples from 16 townships of Zhouzhi County were collected,and contents of heavy metals(Pb,Cd,Hg,As,Cr)as well as the pH values were analyzed and evaluated by using geo-accumulation index,potential ecological risk index,health risk index method combined with geostatistical method and geographic information system(GIS).The results showed that the average contents of heavy metals(Pb,Cd,Hg,As,Cr)in the soil did not exceed the limit specified in GB 15618-2018“Soil Environmental Quality and Soil Risk Control Standards for Agricultural Land”and HJ 332-2006“Environmental Quality Assessment Standards for Edible Agricultural Products Producing Areas”.The contents of heavy metals in the soil were generally at a clean level.The potential ecological risk of soil heavy metals in Zhouzhi is low and imposes no significant risk for human health.