地形和季节变化对有机氯农药分布特征的影响——以四川省成都经济区为例

INFLUENCE OF LANDFORM AND SEASON ON DISTRIBUTION CHARACTERISTICS OF ORGANOCHLORINE PESTICIDES(OCPS)——A CASE IN CHENGDU ECONOMIC REGION,SICHUAN PROVINCE,CHINA

在成都经济区典型地貌单元(平原区和丘陵区)采集春季和秋季样品,共计52件农作物样品和100件土壤样品,通过美国EPA8080A方法测试样品中有机氯农药含量,以研究不同地貌单元不同季节有机氯农药污染分布特征。结果表明:土壤中DDT含量高于HCH含量;平原区绵竹市土壤中有机氯农药含量高于丘陵区盐亭县土壤有机氯农药含量;在平原区的绵竹市,秋季采集的土壤中有机氯农药含量高于春季样品中有机氯农药含量;在丘陵区的盐亭县,春季采集的土壤有机氯农药含量高于秋季样品中含量。农作物中有机氯农药的检出率较高,各种作物浓度均未超标,但对人们健康具有潜在危害。油脂含量高的粮食作物中有机氯农药含量高于叶类蔬菜和果实类蔬菜中有机氯农药的含量。地貌类型、土壤有机质含量以及有机氯农药施用是造成两个地区春、秋季土壤含量特征不同的主要原因,而植物的吸收方式、OCP的物理化学性质是影响农作物中OCP含量不同的主要因素。

52 biological samples and 100 soil samples in mountain and plain landforms in Chengdu Economic Region,Sichuan Province were collected at spring and autumn respectively. The US EPA method 8080A was used to analysis concentrations of organochlorine pesticides （OCPs） in soil and organism to investigate pollution states at different landforms and seasons. The results showed that concentrations of DDT in soil were higher than HCH in soil,and the concentrations in Mianzhu （landform is plain） were higher than that in Yanting （mountain area）. The seasonal characteristic in Mianzhu was that OCP concentrations of soil collected at autumn were higher than that collected at spring. However,the result was conversely in Yanting,the spring one was higher than that in autumn. The detectable ratios of OCP in plants were very high, whereas the concentrations in plant were below national standards, which existed potential harm to human health. The concentrations of OCP in crops with rich oils were higher than in leaf-shaped vegetables, higher than in fruit-shaped vegetables. Landform,organic matters and pesticides usage were major factors on the difference of seasonal soil OCP concentrations, and absorption styles and physical and chemical properties of OCPs were responsible for different concentrations in organism.