摘要
为保障独山县农业规划和食品安全,系统采集120件农作物、120件根系土、10条土壤剖面和10件成矿母岩样品,测试As、Cd、Cr、Cu、Hg、Ni、Pb、Zn重金属元素和有机质含量、酸碱值等,采用单项指数法、地累积指数法、农作物富集系数和健康风险评估法对重金属污染状况开展评价。研究结果表明:(1)独山县根系土_(番茄)中As、Cu、Hg、Zn含量最高,平均值分别为21.38、22.180.42、110.39mg/kg;根系土玉米中Cd、Cr、Ni、Pb含量最高,平均值分别为1.05、111.12、29.02、34.50mg/kg;根系土酸碱度介于3.58~8.24,酸碱度小于6.5的样品占87.5%,总体偏酸性;单项指数研究表明,根系土中镉污染处于“轻度-中度污染”水平,土壤、农作物存在“轻度-中度污染”镉污染水平;地累积指数显示独山县农作物根系土中As、Cd、Hg、Zn受到人类活动影响;(2)独山县120件农作物中,水稻、玉米主要为Cd超标(水稻33.33%、玉米13.33%),其次为Pb(水稻3.33%)、Cr(30.00%);葡萄、茶叶、番茄无超标样品;由农作物富集系数可知,Cd的富集系数是As、Cr、Pb富集系数的数倍至上百倍,表明农作物吸收Cd、Pb能力强,尤其吸收Cd能力最强;农作物中As、Cd、Cr、Hg、Pb对成人和儿童的健康风险评价值均<1,这表明经农作物吸收重金属而无危害健康风险。
To benefit agricultural planning and guarantee food safety in Dushan County,totally 120 crop 120 rhizosphere soil samples,10 soil profile and 10 ore parent rock samples were collected to examine for heavy metal(loid)s(As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn),as well as organic matter concentrations and pH value.We evaluated the heavy metal(loid)pollution using the single-factor index method,geo-accumulation index method,crop enrichment factor,and health risk assessment method.Our findings indicate that:(1)In Dushan County,the highest concentrations of As,Cu,Hg,and Zn were found in tomato rhizosphere soils,averaging 21.38,22.18,0.42,and 110.39 mg/kg respectively.The highest Cd,Cr,Ni,and Pb concentrations were found in corn rhizosphere soil with mean values of 1.05,111.12,29.02,and 34.50 mg/kg respectively.The pH of rhizosphere soils ranged from 3.58 to 8.24,with 87.5%of samples showing a pH value below 6.5,indicating overall a slight acidity.Single-factor index analysis revealed"slight to moderate pollution"levels of Cd in rhizosphere soils,as well as"slight to moderate pollution"of Cd in soils and crops.Geo-accumulation index results showed that human activities influenced As,Cd,Hg,and Zn levels in crop rhizosphere soils.(2)Among the 120 crops,rice and corn exhibited the highest exceedances of Cd standards(33.33%for rice,13.33%for corn),followed by Pb(3.33%for rice),and Cr(30.00%).No exceedances were found in grapes,tea,and tomatoes.Crop enrichment factors indicated that Cd enrichment was several times to hundreds of times higher than that of As,Cr,and Pb,highlighting strong Cd and Pb uptake capacities in crops,especially for Cd.Health risk assessment values for As,Cd,Cr,Hg,and Pb in crops for both adults and children were all below 1,indicating no health risks associated with heavy metal(loid)uptake by crops.
作者
刘开坤
王福瑞
范云飞
LIU Kaikun;WANG Furui;FAN Yunfei(Nuclear Resources Geological Survey,Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang 550005,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2024年第5期607-620,共14页
Earth and Environment
基金
贵州省耕地质量地球化学调查评价(黔耕调2017-03)。
关键词
重金属
土壤
农作物
独山
heavy metal
soil
crop
Dushan County
