天津市郊农田土壤中有机氯农药残留的局地分异

Local Spatial Variation of Organochlorine Pesticides in Agricultural Soils from Tianjin

在天津 3处典型污灌与非污灌农田各采集了 10个表土样品 ,测定了其中α -HCH、β -HCH、γ -HCH、δ -HCH、p ,p’ -DDE、p ,p’ -DDD、p ,p’ -DDT和o ,p’ -DDT等 8种有机氯农药含量 ,籍以研究该地区有机氯农药在地块中的局部分异。结果表明 ,所研究地块中两类化合物含量均表现出显著的非均一特征。其中污灌土地中的(DDT)以及污灌农田中的HCH含量都具有与灌溉方向密切相关的空间分布特征。这样的规律性空间变异导致他们的空间波动幅度高于其他地块。鉴于上述趋势性和非趋势性空间分异 ,在开展相关研究时有必要在目标地块中采集重复样或混合样。

Ten surface soil samples were collected from each of the three blocks of agricultural soil with or without wastewater irrigation. α-HCH,β-HCH, γ-HCH, δ-HCH, p,p'-DDE, p,p'-DDD, p,p'-DDT, and o,p'-DDT were analyzed to study the local spatial variation of the organochlorine pesticides. Significant variations in the contents of the chemicals were demonstrated. The variations were partially introduced by the wastewater irrigation which was characterized by linear reduction of the organochlorine compounds following the pattern of the wastewater irrigation. Duplicate or composite sampling is, therefore, necessary for sample collection.