摘要
为探讨沉积物中AVS(acid volatile sulfide,酸挥发性硫化物)和SEM(simultaneously extracted metals,同时提取金属)对重金属生物有效性和基准验证的影响,以泥鳅为受试生物,以死亡率、鳃部渗血率和体质量变化为测试终点,研究了沉积物和上覆水中重金属Pb、Cd对底栖生物的毒性效应,并对文献中Pb、Cd沉积物基准阈值进行了验证.结果表明:沉积物中Pb、Cd对泥鳅21d的LC50(半数致死浓度)分别为391、37.0 mg/kg;上覆水中ρ(Pb2+)和ρ(Cd2+)较低,对生物毒性效应贡献可以忽略.经验证,Pb和Cd的TEL(threshold effect level,临界效应浓度)和PEL(probable effect level,必然效应浓度)基本符合其所代表的意义,Pb、Cd加标浓度(以w计)低于其对应的TEL时不具有毒性,高于其对应的PEL时具有明显毒性,介于二者之间时毒性不确定.SEM/AVS(物质的量比)和生物死亡率有明显的相关性,当该比值大于1.00时,重金属对泥鳅有明显的毒性效应.
The toxicities of Pb and Cd in freshwater sediment and overlying water were evaluated using Misgurnus anguillicaudatus as the test species. The toxicity endpoints included mortality,gill bleeding and growth rate. The objectives were to investigate the toxic effects of the two heavy metals on benthic species,to evaluate the sediment quality guidelines（ SQGs） derived by biological effect database approach,and to investigate the effects of acid volatile sulfide（ AVS） and simultaneously extracted metals（ SEM） on SQGs. The results indicated that the LC50 s of Pb and Cd in the sediments were 391 and 37. 0 mg/kg,respectively. The contribution of the overlying water to the total toxicities was negligible due to the low metal concentrations in the overlying water. The evaluation of the SQGs indicated that the Pb/Cd SQGs were appropriate for the risk assessment. There were few toxic effects when the concentrations were lower than TEL,while there were distinct toxicities when the concentrations were higher than the PEL. However,the toxic effects were uncertain when the concentrations were between the TEL and PEL. Good consistency between the toxic effects of Pb and Cd on benthic organisms and SEM/AVS was observed. When SEM/AVS 1. 00,the two metals displayed obvious toxicities to M. anguillicaudatus.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2015年第7期1078-1084,共7页
Research of Environmental Sciences
基金
国家水体污染控制与治理科技重大专项(2012ZX07501-003-04)
