长江口南支表层沉积物中有机氯农药的研究

Studies on organochlorine pesticides in surface sediments of the south branch of Yangtze estuary

利用GC-ECD测定了长江口南支表层沉积物中20种有机氯农药的含量，并对其组分、分布和来源进行了分析．结果表明，样品中有机氯农药总量为0．46-12．09ng／g（平均值为4．54ng／g），其中主要为HCHs和DDTs，其组分特征表明它们来自环境中的早期残留．有机氯农药含量的空间分布差异较大，趋势呈南支南岸沿线〉南航道〉北航道．在不同功能区的分布差异性表明沿岸排污口和城市支流是长江口南支表层沉积物中有机氯农药的主要来源．与其他地区相比，该区的有机氯农药含量较低；以沉积物生态风险评估值为基准的分析表明，研究区内DDT含量有潜在的生态风险．

The contents of 20 kinds of organochlorine pesticides （OCPs） in the surface sediments of the south branch of Yangtze estuary were determined using GC-ECD, and their composition distribution and source were analyzed. The total OCPs amount in the samples was 0.46-12.09 ng/g（with mean value of 4.54ng/g）, in which were mainly HCHs and DDTs, and their composition characters indicated that they came from the early residues in the environment. The spatial distribution of OCPs contents varied greatly, with tendency assuming： the south coast along the line 〉 the south waterway 〉 the north waterway; the distribution of OCPs in different functional areas showed that the sewage drainage outlets along the coast and the tributaries flowing across cities were the main sources of OCPs in surface sediments of the south branch of Yangtze estuary. Compared to other regions, the OCPs content in this region was lower. The analysis using sediment ecological risk assessment value as standard showed that the DDT content in this region had a potential ecological risk.