海河干流表层沉积物中的有机氯农药残留

Organochlorine Pesticides in Surficial Sediments of Haihe River

采用现场采样及室内分析方法,调查了海河干流表层沉积物中持久性有机氯农药(OCPs)的残留状况。结果表明,所测样品中有机氯农药总浓度为8.95￣239.92ng·g-(1均值67.3ng·g-1)(干重),HCHs、DDTs在所有采样点均有检出,含量分别为3.30￣75.96ng·g-(1均值18.25ng·g-1)、1.57￣221.57ng·g-(1均值48.78ng·g-1)。沉积物中有机氯农药的成分分析结果表明,OCPs残留物可能主要来自农田土壤的残留,近期基本无新的污染源输入。与国内外部分河流表层沉积物中HCHs、DDTs的含量相比,海河表层沉积物中的有机氯农药含量较高。

In the paper, the concentration of organochlorine pesticides （OGPs） in sediment samples collected from 9 sites of Haihe River, Tianjin, were analyzed quantitatively by using gas chromatography and a Ni63 electron capture detector （GC-μECD）. HCHs （ -HCH, - HCH, -HCH, -HCH） and DDTs （p,p＇ -DDT, p,p＇ - DDE, p,p＇ -DDD） were detected in all sampling sites; with the mean concentrations of total OCPs being 67.3ng·g^-1 d.w. （range, 8.95-239.92 ng·g^-1） and mean concentrations of HCHs and DDTs being 18.25 ng·g^-1 d.w. （range, 3.30-75.96ng·g^-1） and 48.78ng·g^-1 d.w. （range, 1.57-221.57 ng·g^-1）, respectively. Compared with the world＇ s other fiver/estuary systems, concentrations of HCHs and DDTs in surfical sediments from Haihe River were higher, which illustrates that the contamination of OCPs was serious in Haihe River. In addition, the possible pollution sources of organochlorine pesticides were investigated according to the isomers characteristics for HCHs and metabolites of DDTs. The ratios of -HCH to -HCH were ranged from 0.35-15.8, and the ratios of （DDE＋DDD） /T-DDD were higher than 0.5, both of which indicated the main pollution source was the use of pesticide in agriculture in history. Our results show that organochlorine pesticide contamination in Haihe River sediments are mainly due to the runoff of OCPs applied in agricultural in history, and there is no new discharge of organochlorine pesticides into the river recently.