贵阳市典型污染区蔬菜和水稻重金属富集特征及质量评价

Enrichmentccharacteristics and Quality Assessment of Heavy Metals in Vegetable and Rice in Typically Polluted Areas of Guiyang

工矿业发展易引发城市周边土壤重金属污染。为掌握贵阳市典型污染区农产品重金属污染状况及富集特性,本文选择磷矿区、煤矿区、铝矿冶炼区及养殖废水灌溉区农田土壤蔬菜和水稻为研究对象,利用电感耦合等离子体质谱仪X2(ICP-MS)测定重金属。结果表明磷矿区、铝矿冶炼、煤矿区、污水灌溉区和对照区土壤综合污染指数分别为1.18、1.17、1.34、2.01和0.678,Cd点位超标率达80.85%,是特征污染元素;蔬菜样品中有2个Cd超过国家食品安全限值,超标率为3.2%;重金属富集系数较低,表现为Cd(0.1)﹥Cu(0.09)﹥Zn(0.05)﹥As(0.01)﹥Cr(0.005)﹥Pb(0.003);煤矿区稻米Cd、Cu、Zn分别超标6.7、1.1和1.5倍,THQ值均大于1。典型污染区土壤重金属污染严重,但蔬菜富集系数低,食物链风险相对较小,煤矿区稻米具有潜在健康风险。

The development of industry and mining can easily cause heavy metal pollution in the soil around the city.In order to well understand the heavy metal pollution status and enrichment characteristics of agricultural products in typically polluted areas in Guiyang.The phosphate soil area,coal mining area,aluminum smelting area,and aquaculture wastewater irrigation area were selected as the research fields for agricultural soil and products of vegetable and rice.Heavy metals were measured by an inductively coupled plasma mass spectrometer X2(ICP-MS).The results showed that the comprehensive pollution index of soil in phosphate mining area,aluminum smelting,coal mining area,sewage irrigation area and control area were 1.18,1.17,1.34,2.01,and 0.678,respectively.The Cd point exceeds the standard rate of 80.85%,which is a characteristic pollution element.2 Cd in the vegetable sample exceeded the national food safety limit with an over-standard rate of 3.2%.The enrichment factor of heavy metals was low,showing Cd(0.1)>Cu(0.09)>Zn(0.05)>As(0.01)>Cr(0.005)>Pb(0.003);Cd,Cu,and Zn in the coal mining area exceeded the standards by 6.7 times,1.1 times,and 1.5 times,respectively,and the THQ values were all greater than 1.In words,soils in typical contaminated areas are seriously polluted by heavy metals,but the enrichment coefficient of vegetables is low.The risk of the food chain is relatively small,but rice in coal mining areas has potential health risks.