Pollution distribution characteristics and ecological risks of typical emerging chemical contaminants in aquatic environments

Emerging contaminants (ECs), such as pharmaceuticals and personal care products and novel brominated flame retardants, present perceived or real risks to environmental health, even at trace levels. Advancements in analytical technologies including nontarget screening methods are uncovering a wider spectrum of ECs and the transformation products in aquatic environments, enhancing our understanding of their occurrence, transport and transformation, and interactions with biota. More importantly, the focus of identifying and assessing the risks of ECs is shifting from singular categories and toxicity to complex mixtures and multidimensional effects. This chapter highlights key EC categories that have received significant research attention, based on a scientific literature review. We critically examine the occurrence and distribution patterns of characteristic ECs across various aquatic environments in different geographical regions. A significant portion of the discussion is devoted to the transport and transformation of ECs, which are essential in determining their ecological effects. The chapter also highlights current research gaps and suggests expanding investigations into transformation pathways, enhancing monitoring, and developing models for EC transport and transformation. By establishing a foundation for a comprehensive method of assessing ECs’ ecological risks, this work contributes to better management of water systems increasingly affected by ECs.