水生生物を用いた各種のバイオアッセイの下水試料に対する感受性の比較

抄録

The sensitivities of the bioassays using various aquatic organisms to sewage samples were compared. The sewage samples used here were the influent and the secondary effluent obtained from the sewage treatment plant that receives industrial effluent. The aquatic organisms used in this study were Vihrio fischeri (MICROTOX®), Selenastrum capricornutum, Daphnia magna, Daphnia pulex, Daphnia carinata, Ceriodaphnia dubia, Moina macrocopa, Thamnocephalus platyurus (TOXKIT®), Paratya compressa improvisa, Tanichthys albonubes, Xenopus laevis, and Brachydanio rerio. The 50% effective concentration (EC50) values of influent were ranged from 5.6%(48h-EC50 of C. dubia) to 38.0%(48h-LC50 of T. albonubes), and the EC50 values of secondary effluent were ranged from 8.0%(48h-EC50 of C. dubia) to 92.3%(5min-EC50 of MICROTOX®). Among the acute toxicity tests, the tests using C dubia, T platyurus, and frog embryo were relatively sensitive to the sewage samples. The toxicity values for the sewage samples obtained from reproduction tests using D. magna, M. macrocopa, and C. dubia were in the same level. Moreover, we examined the data variation of D. magna acute toxicity test. The coefficient of variation (C. V. value) of the data obtained from 4 different organizations (companies) were about 30%.