天鹅洲长江故道沉积物柱状样中有机氯农药高分辨率沉积记录

High Resolution Sedimentary Record of Organochlorine Pesticides in Sediment Cores from Tian'ezhou Oxbow

采用GC-ECD测定了天鹅洲长江故道沉积物柱状样中有机氯农药的含量，探讨了有机氯农药的垂直分布特征，结合^210Pb同位素定年分析研究该地区有机氯农药的污染历史。研究表明：20种有机氯农药均有检出，总有机氯农药含量范围为1．19-333．67ng／g（干重），平均值为62．54ng／g；20世纪60年代末期为该区有机氯农药使用的高峰期，1972年长江截弯取直使来自长江所携颗粒物的污染沉积有所减少，自我国禁用有机氯农药后维持多年较低含量水平，其农药主要为历史残留，至2004年湖区可能仍有部分新的有机氯农药污染物如林丹的输入。

Organochlorine pesticides （OCPs） in the sediment cores of Tian＇ezhou Oxbow were detected by GC-ECD,of which vertical distribution was discussed with 210Pb dating data. 20 compounds were detected. The concentration of total OCPs varies from 1.19ng/g to 333.67ng/g （dw） and the mean value is 62. 54ng/g （dw）. The study shows that the frequent use of OCPs in this area began in late 1960s. Yangtze River flow changed its way in 1972 and since then the OCPs contamination from Yangtze River has declined and maintained low level after the banning on OCPs use by Chinese Government. The OCPs contamination in the sediment was mainly historical residues though new input, such as Lindane, might have occurred until around the year of 2004..