Aquatic pollution caused by anthropogenic activities has been one of the major environmental problems worldwide for decades. Rapid industrialization and urbanization is releasing “traditional” and emerging pollutants into waters in unprecedented quantities and diversity, ultimately endangering biodiversity and human health. Meanwhile, the management and control of risks from chemical pollutants, with varying scientific composition, stringency, and efficacy, are being practiced in different countries and regions. A limiting factor for effective ecological risk assessment and management is the lack of knowledge of exposure, bioaccumulation, toxic effects, and mode of action of various types of pollutants in waters with contrasting physicochemical properties. For example, metals’ environmental behavior and bioavailability are highly dependent on their speciation and water chemistry (e.g., organic matter, pH, and hardness), thus requiring site-specific risk assessments. In comparison, organic pollutants are also highly complex in terms of toxicity prediction and risk assessment due to their infinite structural diversity and mode of action. Due to different physicochemical properties and interactive effects of pollutants, the biological impacts and toxicity mechanisms of pollutants in the natural environment are more complex, posing challenges to risk assessment. Therefore, studies on the toxicity mechanisms and ecological risk assessment of typical pollutants in aquatic environments are required.
