珠江口水体、沉积物及水生动物中HCHs和DDTs的含量与生态风险评价

Risk assessment and investigation of HCHs and DDTs in the water,sediment and aquatic animals from the Pearl River Estuary in China

利用气相色谱(GC-ECD)方法对珠江口水、沉积物及水生动物体内六六六(HCHs)和滴滴涕(DDTs)的污染现状进行了调查,并对该类污染物在水体多介质中的转移分配规律及对水生态环境安全的影响作了初步研究.结果表明,珠江口表层水中HCHs总量检出范围为1.12～8·91ng·L-1,平均值为4.25ng·L-1;;DDTs总量检出范围为2.61～16.86ng·L-1,平均值为7.66ng·L-1.表层沉积物(以干重计)中HCHs总量检出范围2.51～4.75ng·g-1,平均值为3.61ng·g-1;;DDTs总量检出范围为3.01～6.24ng·g-1平均值为4.33ng·g-1.水生动物中河蚬体内的HCHs和DDTs含量最高,分别为44.49和122.62ng·g-1;;虾类次之,为41.04和82.27ng·g-1;;鱼类最低,平均值分别为27.95和65.43ng·g-1.同国内外其他地区河流比较,珠江口水体和底泥中的HCHs和DDTs污染程度较低,但仍具有一定的潜在生态风险.林丹、三氯杀螨醇取代工业生产HCHs、DDTs,成为该水域有机氯污染的重要来源.

A preliminary investigation on the concentration and distribution of HCHs and DDTs in the water, sediment and aquatic animals from the Pearl River Estuary was carried out using GC-ECD. The total concentrations of HCHs were in the range of 1. 12 -8.91 ng·L^-1 with an average of 4.25 ng·L^-1, and DDTs were in the range of 2.61 -16.36 ng·L^-1 with an average of 7.66 ng·L^-1 in the surface water. In surface sediments （dry weight）, the total HCHs ranged from 2.51 -4.75 ng·g^-1 with an average value of 3.61 ng·g^-1 and the total DDTs ranged from 3.01 - 6.24 ng·g^-1 with an average value of 4.33ng·g^-1. In the aquatic animals, the average of HCHs and DDTs were 44.49 ng·g^-1and 122.62 ng·g^-1 in shellfish; 41.04 ng·g^-1 and 82.27 ng·g^-1 in shrimp ; and 27.95 ng·g^-1 and 65.43 ng·g^-1 in fish, respectively. The concentration of HCHs and DDTs in fish were lower than those of other aquatic animals. Although the levels did not exceed the Chinese national limits for organochlorine compounds in aquatic animals, potential ecological risks still exist