The toxicity of urban sewage on embryos of zebrafish

[Objective]To determine influence of urban sewage to zebrafish embryos and their larvas hatched into. [Method]By using of static method, toxic effects of urban sewage treated or untreated on zebrafish embryos and larvas were observed under control conditions in laboratory. Furthermore, their possible toxic mechanisms were also discussed. [Result]The sewage of M sewage treatment plant in AnNing District, Lanzhou, the effluent of contact tank of M sewage treatment plant, the effluent directly poured into the Yellow River from contact pool of M sewage treatment plant, all of them had toxicity to the embryos, and EC₅₀ of 72h was between 21.384% and 108.492%. Similarly, toxicity of water samples to larvas hatched from embryos treated was very obvious, too. [Conclusion]Those sewage mentioned above could reduce hatchability of zebrafish embryos, and increase toxicity to embryos and deformity to their larvas.