Assessment of environmental safety of around landfill sites by ecotoxicological test using Medaka

Abstract

Even if the drainage from the leachate treatment facility satisfied the standard value of water quality control items etc., it is often opposed to discharge from local residents. In this study, we conducted a bio-toxicity test using Medaka on the leachate samples and treated leachate, where the landfill was completed and awaited for termination, and the pond water on the located upstream. As a result, in the leachate samples, Lethal Concentration, 50% (LC50) is 10.4 to 17.5 mg / L and No Observed Effect Concentration (NOEC) is 5.6 to 8.5 mg / L in terms of CODMn concentration. No toxicity was observed in the pond water and treated leachate. The results of gene expression analysis also showed high toxicity of the leachate samples. We also grasped the tendency of expression fluctuation. In addition, the characteristics of each gene expression level were understood. The genetic analysis is expected as a simple method of eco-toxicity in the future.