The aims of this symposium are to serve as an interdisciplinary scientific forum to present and discuss the cutting-edge researches in environmental chemistry and toxicology in the aquatic environment, and to promote international communications and collaborations on environmental science researches. It is our hope that the integration of a variety of environmental topics related to chemical contaminants including toxicokinetics, toxicodynamics, molecular toxicology, systems toxicology, computational modeling, and hazard and risk assessment in aquatic organisms will provide novel insights into the complex environmental challenges and effective and systematic solutions for the improvement of environmental health.