广州部分区域表层土壤中有机氯农药分布特征

通过在冬、夏两季对广州市部分市区和远郊区的表层土壤样品中OCPs(有机氯农药)的采样和气相色谱-电子捕获检测法分析,对OCPs残留现状进行了研究.结果表明,土壤中w(HCHs)为0.29～14.90 ng/g,未超过GB 15618—1995《土壤环境质量标准》的一级自然背景值.w(DDTs)为nd～697.70 ng/g.海珠区和黄埔区部分地点w(DDTs)超过一级自然背景值.DDTs为主要残留有机氯农药,平均占w(OCPs)的85.1%.所观察到的较低的w(α-HCH)/w(γ-HCH)(小于1)和w(γ-HCH)>w(β-HCH)的结果,有可能是林丹输入所致.一些地点可能有新的DDT输入.按土地利用类型划分,表层土壤中w(OCPs)为工业区>农田>果园>未利用地>居民区绿地>森林公园. 

Distribution and Characteristics of OCPs in Surface Soils in Certain Districts of Guangzhou

The residual status of organochlorinated pesticides(OCPs) in urban and outer suburban districts of the city of Guangzhou was studied by analyzing OCPs in surface soil samples collected in winter and summer.The total HCHs concentrations in the soils ranged from 0.29 ng/g to 14.90 ng/g,which did not exceed the Level Ⅰ(natural background level) of China’s National Soil Quality Criteria,GB 15618-1995.The total DDTs concentrations in the soils ranged from nd to 697.70 ng/g,and exceeded Level Ⅰ in several samples from Haizhu and Huangpu Districts.Different soil samples had different OCPs compositions.DDTs were the main pollutants in the research areas,occupying 85.1% of the total OCPs.The observed low w(α-HCH)/w(γ-HCH) ratios(less than 1),and the general phenomena of w(γ-HCH)>w(β-HCH) in these soils may be attributed to the recent use of lindane.There may be new sources of DDTs inputs at some sites.Based on the land use type,the sequence of total OCPs concentrations in the surface soils was as following: industrial zone>farmland>orchard>deserted land>residential green areas>forest park.