太湖北部湾沉积物有机氯农药残留特征及评价

采用GC-ECD联用检测技术分析了太湖北部贡湖大贡山（1号点）、小贡山（2号点）与梅梁湖马山（3号点）、拖山（4号点）不同季节有机氯农药中4种HCHs同系物及4种DDTs同系物含量。结果表明,含量最高的为γ-HCH与DDT,分别占总量的45%以上,其次是β-HCH与DDD,而o,p-DDE基本未检出。不同监测点表现出了季节变化,受＂引江济太＂调长江水入太湖的影响,贡湖中1号与2号监测点夏季OCP总量高于其他季节,而梅梁湖受周围生产及竺山湖大桥入污影响,3号监测点不同季节OCPs总量变化不显著,4号监测点冬季高于春季,夏季受高温影响,OCPs总量出现最小值。采用生态风险值对沉积物中OCPs进行风险评价,太湖北部湾沉积物中OCPs总量较低,尚未对生态构成严重威胁,但由于这类物质的生态累积效应,其潜在危害仍不容忽视。

The Distribution and Risk Assessment of Organochlorine Pesticides in Surface Sediment of Taihu

The contents of four HCHs congeners（α-HCH, β-HCH, γ-HCH and δ-HCH）and four DDTs congeners（P,P-DDE, P,P-DDD, P,P-DDT and O,P-DDE）in the sediments of Gong Bay（Large Gongshan, 1st and Small Gongshan, 2nd）and Meiliang Bay（Mashan, 3rd and Tuoshan, 4th）in the northern of Taihu were determined in different seasons by using GC-ECD detection technology. The contents of γ-HCH and DDT were the highest, accounting for 45% of total OCPs, followed by β-HCH and DDD, and O,P-DDE were not detected in the sediments. The OCPs contents in different sites showed a seasonal variation. The total OCPs of the 1st and 2nd sites in summer were higher than those in the other seasons due to the impact of diverting water from Yangtze River. However, the total OCPs did not change significantly in different seasons in the 3rd site influenced by surrounding production and pollution. The concentrations of OCPs were higher in winter than in spring and summer in the 4th site. The risk assessment was completed on OCPs in the sediments by using the ecological risk value methods. Although the low total contents of OCPs in the sediments of northern Taihu have not constituted a serious threat to the ecological system, the potential hazards should not be ignored for their accumulative effect in the environment.