【摘要】 对北京昌平区油松和白皮松松针中的HCHs和DDTs的污染状况进行了初步研究.结果表明,昌平松针中HCHs总量与欧洲20世纪90年代基本持平,DDTs则高于欧洲,HCHs和DDTs均低于美国20世纪80年代水平,高于喜玛拉雅北坡、意大利山区和加拿大西部山区.昌平松针中HCHs和DDTs总量均比20世纪80年代北京地区下降了90%以上,表明自1983年以来,我国禁止生产和使用OCPs,已经取得了明显的效果.常绿树树叶OCPs污染具有逐年累积、多年富集的特征,其特点为不完全的线性关系,富集速率呈逐年下降的趋势.树叶OCPs异构体相对组成年际变化明显,α-HCH显著增加,P,P′-DDT下降,P,P′-DDE上升.研究显示,昌平地区近期没有HCHs工业品的使用,P,P′-DDT使用大幅度减少,而O,P′-DDT则有新的输入,三氯杀螨醇的使用很可能是O,P′-DDT的主要来源.更多还原

【Abstract】 In this work,pine needle samples of two kinds of pine trees,Chinese pine(Pinus tabulaeformis Carr.) and lacebark pine(Pinus bungeana) ,from Changping District,Beijing were analyzed to observe the pollution characteristic of HCHs and DDTs. Pine needle samples were collected in January,2006. The concentrations of HCHs(∑HCHs) in pine needles were comparable to that in Europe pine needles in 1990’s. ∑DDTs were higher than that in Europe. ∑HCHs and ∑DDTs were less than that of American pine needles in 1980’s,but higher than that of pine needles in Himalayas,China in 2005,also higher than that of pine needles from mountainous area in Italy and Canada. The significant decrease of ∑HCHs and ∑DDTs in pine needles in Changping from mid-1980s to the present indicated an obvious effect of implementation of the policy forbidding the production and use of OCPs in China since 1983. Year-to-year accumulation of OCPs in the foliage of evergreen trees was observed,characterized by occurrence of non-linearity,while accumulation rates decreased with each year. The annual variation of the isomers of OCPs in pine needles showed that α-HCH and P,P′-DDE increased,whereas P,P′-DDT decreased. The results indicated that the technical HCH and P,P′-DDT has been stopped or significantly reduced in use,but there was a new input of O,P′-DDT in recent years in this area,dicofol usage may be the main source.更多还原