Acute Toxicity Of Typical Contaminants To Freshwater Organisms And The Biological Criteria For Freshwater Lindane In China

Water quality criteria which indicates the ecological effects of pollutants scientifically, is the theoretical basis for water quality standards development and environmental management. Because of the lack of basic toxicity data, the current water quality criteria in China is established on foreign water quality criteria, it is difficult to provide suitable protection to the aquatic system and human health in China. Four indigenous aquatic organisms (Chironomidae larvae, Limnodrilus hoffmeisteri, Daphnia magna and Rana chensinensis) were selected to study acute toxic effects of typical pollutants on those aquatic organisms. And the present study developed freshwater aquatic life lindane criteria in China mainly based on the SSD method of the USEPA and the SSD method of the EU, the study contributes to establish relative water quality criteria and standard in China. The detail results and main conclusions were summarized as follows:The toxicity of the typical contaminants (Hg2+, Cr6+, Pb2+,2,4-DCP,2,4,6-TCP, PCP,1,2,4-TCB, nitrobenzene, chlorpyrifos and lindane) to freshwater organisms were studied by acute toxicity tests of Chironomidae larvae, Limnodrilus hoffineisteri, Daphnia magna and Rana chensinensis. The detail results and main conclusions were summarized as follows:C. larvae was less sensitivity to Pb2+,2,4-DCP had higher toxicity to C. larvae. Hg2+showed the highest toxicity to L. hoffineisteri, Cr6+, 2,4,6-TCP, PCP and chlorpyrifos had higher toxicity to L. hoffmeisteri, while Pb2+,2,4-DCP and1,2,4-TCB were moderate toxicity to L. hoffmeisteri, nitrobenzene had only lower toxicity to the testing organism. The order of the toxicity to L.hoffmeisteri was Hg2+> PCP> Cr6+>chlorpyrifos>2,4,6-TCP>2,4-DCP>1,2,4-TCB> Pb2+> nitrobenzene.In order to accurately evaluate the toxicity of lindane on indigenous aquatic organisms (C.larvae, L.hoffmeisteri, D.magna and R.chensinensis), and provide data for scientifically deriving the water quality criteria protecting aquatic organisms in China. The result of acute toxicity test showed:48h-LC50of lindane on D.magna and C.larvae were3.18mg·L-1and28.44mg·L-1, respectively;96h-LC50of lindane on R.chensinensis and L.hoffineisteri were8.22mg·L-1and8.38mg·L-1, respectively.According to Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses (1985Guidelines) issued by USEPA, the freshwater aquatic species existing widely in China were selected and their toxicity data were collected, combined with the characteristics of Chinese aquatic biota. The biological criteria for lindane of freshwater in China were derived and discussed. The results showed that the acute and chronic criteria of China derived using USEPA-SSD method and EU-SSD method were8.99μg·L-1and0.87μg·L-1,3.34μg·L-1and1.15μg·L-1, respectively, the values deriving by the two methods were not much different. The results were stricter than the limits of lindane specified by the water quality standards in China. Compared with the CMC derived by USEPA, the CMC or AWQC values were great in this study.