官厅水库和永定河沉积物中多氯朕苯和有机氯农药的污染

CONTAMINATION OF PCBs AND ORGANOCHLORINATEDPESTICEDES IN THE SEDIMENT SAMPLES OF GUANTINGRESERVOIR AND YONGDING RIVER

利用气相色谱－电子捕获检测(ＧＣ－ＥＣＤ)方法对官厅水库－永定河流域沉积物中２６种多氯联苯(ＰＣＢｓ)同系物和１３种有机氯农药进行了分析测定,在４个采样点均检出多氯联苯和部分有机氯农药．其中ＰＣＢｓ和有机氯农药总量的最高点均出现在永定河下游的三家店,分别为９．７ｎｇ·ｇ－１和２６．７ｎｇ·ｇ－１,按照国际关于沉积物质量的同类研究结果,判定为轻度污染水平．ＨＣＨ最高仅为４．５０ｎｇ·ｇ－１,属轻度污染,ＤＤＴ浓度以八号桥和三家店样点最高,分别为２３．２ｎｇ·ｇ－１和２６．７ｎｇ·ｇ－１,属中度污染．有机氯农药总量分布为三家店＞八号桥＞官厅大坝＞雁翅,表明永定河下游多氯联苯和有机氯农药不仅来自官厅上游,也来自下游地区．

To find the sources of persistent organic pollutants (POPs) in Yongding river, a river used to be the drinking water resource for Beijing city, 26 PCB congeners and 13 organochlorinated pesti-cides in the sediment samples were analyzed. PCBs and organochlorinate pesticides were detected in all samples. The highest concentrations of total PCBs (9.7ng·g-1) and organochlorinated pesti-cides (26.7ng·g-1) were observed at the site down-stream of Yongding river closing to Beijing city. These levels of PCBs and organochlorinated pesticides suggested the slight sediment pollution, in comparison with literature data in other parts of the world. The highest concentration of HCHs (4.5ng·g-1) in sediment was also found at the site down-stream of Yongding river, which was in lower level when compared with other river sediments in China. The highest concentrations and moderate pollutions of DDTs were observed in Bahaoqiao, from which the river flows into the reser-voir (23.2ng·g-1) and Sanjiadian which is the site closing to Beijing city (26.7ng·g-1). This result indicated that there are at least two pollution sources in the river basin area. Our results pro-vide the basic data and a clue for the further study on pollution of POPs in the area.