沉积物中六氯苯对颤蚓(淡水单孔蚓)的毒性效应研究

以淡水底栖动物颤蚓(淡水单孔蚓)为受试生物,研究了沉积物中六氯苯(HCB)对淡水单孔蚓14 d和28 d的毒性效应.结果表明,沉积物中HCB对颤蚓致死效应较低,当HCB浓度为190 mg· kg-,连续暴露28 d时,致死率低于8％.但HCB对颤蚓具有较强的慢性毒性效应,当HCB浓度为190 mg·kg-1,连续暴露28 d时,身体自断率高达90％,并且随着浓度升高和暴露时间延长,颤蚓自断率明显增高.HCB对颤蚓自断14 d和28 d的EC50分别为＞190 mg·kg-1和97.1 mg· kg-1.HCB对颤蚓行为(运动和挖掘)产生明显抑制作用.随着HCB浓度增加和暴露时间延长,颤蚓运动强度减弱,并伴随摄食量减少与体重减轻现象.

The toxic effects of hexachlorobenzene (HCB) in sediments to Monoplephorus limosus (Tubificid)

The toxicity of HCB in sediment to freshwater benthic animals Monopylephorus limosus (M.limosus) were investigated by exposing the worms in HCB spiked sediment for 14 and 28 days. The results indicated that the lethal effect of HCB to M.limosus was weak, and the mortality was less than 8% even exposed to 190 mg·kg^-1 for 28 d. However, obvious chronic toxicity effect was observed. The autotomy rate was up to 90% in 28-d test at the concentration of 190 mg·kg^-1 and it increased as the concentration of HCB and the exposure time increased. The EC₅₀s of autotomy in 14-d and 28-d tests were estimated to be >190 mg·kg^-1 and 97.1 mg·kg^-1, respectively. The presence of HCB in sediment had an inhibition effect on the behaviors, such as movement and burrowing activity of M.limosus. The movement reduced as the concentration of HCB and the exposure time increased. Moreover, the mean body weight of M.limosus decreased due to the reduced ingestion of food. Further research is needed to investigate the toxicity effects of HCB to benthic organisms in sediment.