福建戴云山脉土壤有机氯农药残留及空间分布特征

Distribution Characteristics of Organochlorine Pesticides in Soil from Daiyun Mountain Range in Fujian,China

为研究有机氯农药（OCPs）在福建戴云山脉表层土壤中的残留水平、来源和空间分布特征，采集福建戴云山脉101个表层代表性土壤样品，并用气相色谱（GC—ECD）法分析其20种OCPs的含量．结果表明，研究区域土壤中20种OCPs均被检出，除Endrin和口．HCH外，OCPs检出率均在90％以上．HCHs、DDTs、硫丹及硫丹硫酸脂的含量之和占OCPs总含量的79．51％，是主要的污染物．土壤中OCPs的含量范围为2．56～465．99ng.g-1，平均值为38．00ng·g-1．与国内外相比，HCH和DDT的残留水平相对较低，属于低污染区域；研究区内硫丹硫酸脂及硫丹存在一定的污染．来源分析显示研究区近期可能存在林丹和三氯杀螨醇的输入，硫丹的污染来源于历史使用．不同种植类型土壤对比结果表明，土壤中OCPs（HCHs＋DDTs＋硫丹硫酸脂＋硫丹）的平均含量依次为水田〉菜地〉果园，果园土壤污染主要源于林丹的输入，DDTs主要为三氯杀螨醇型污染．水田耕作中输入的硫丹类农药是土壤污染的主要原因．

Totally 101 typical surface soil samples were collected from Daiyun Mountain Range, and 20 compounds of OCPs were analyzed by a Ni electron capture detector （GC-ECD） to investigate the horizontal distribution and composition of organochlorine pesticides（OCPs）in the surface soil of Daiyun Mountain Range. The results showed that all OCPs were detected in the soil samples. The detection ratios of OCPs were all over 90% , except for Endrin and β-HCH. The sum concentration of HCHs, DDTs, Endosulfan and Endosulfan sulfate, accounted for 79.51% of the total OCPs, which were considered to be the dominant OCPs in the Daiyun Mountain Range. The OCPs concentrations in the surface soils ranged from 2. 56 to 465.99 ng.g-1 with a mean value of 38.00 ng.g-l. Compared with other regions, the concentrations of HCHs and DDTs in this study stayed in a low pollution level. Endosulfan and Endosulfan sulfate showed a certain degree of risk in the surface soil of the study area. Source analysis showed that new input of lindane and dicofol might occur in the survey region. The historical application was the prime source of Endosulfan. The residue level of OCPs in different lands was in the following order： paddy land 〉 vegetable land 〉 orchard. The OCPs pollution of orchard soil was primarily due to the new input of lindane and dicofol, while the pollution of paddy land was mainly from the usage of Endosulfan.