Classic Contaminants in Aquatic Ecosystems: POPs, PFAS, Heavy Metals, and Microplastics

Legacy contaminants and persistent organic pollutants (POPs) entered the aquatic system from industrial, urban, and agricultural sources in high concentrations often before their high persistence and toxicity were fully understood. Legacy contaminants are highly resistant to degradation and remain in aquatic systems for decades which contributes to their toxicity and chronic exposure. These contaminants are typically hydrophobic and accumulate within the tissues of aquatic biota. Past and current regulation of POPs has significantly decreased their production and use, although improper waste disposal, runoff, and wastewater effluent provide continued input into aquatic systems. These pollutants can be transported globally via atmospheric and ocean circulation and are thus detected in regions where there is nearly nonexistent industrial activity. This chapter covers the uses, sources, fate, and transport of major classes of legacy and emerging contaminants: (1) DDT, (2) PCBs, (3) dioxin, (4) PFAS, (5) mercury and heavy metals, (6) microplastics, and (7) harmful algal bloom toxins. Other wide range of chemicals like PAHs, pharmaceutical personal care products, and pesticides are covered in Chaps. 2 , 3 , 7 and 10 of this book.