Presence of Contaminants of Emerging Concerns in the Environment

Contaminants of emerging concern (CECs) are a broad category of pollutants that can include everything from pesticides to pharmaceuticals, industrial chemicals, endocrine-disrupting compounds, and even microplastics and microfibers. While a handful of CECs are regulated either federally or at the state level, these regulations do not necessarily prevent harmful concentrations from accumulating in sensitive ecosystems. As a result, a complex cocktail of chemicals capable of interfering with endocrine function and a myriad of other physiological processes in aquatic organisms have long been part of aquatic habitats in the vicinity of outfalls and areas subject to run off from agriculture or industry. And with climate change now compounding some of the effects wrought by CEC exposure, regulatory levels likely need to be re-accessed. The combined impact of exposure is not well understood, especially considering that mixtures could exert additive or synergistic toxicity. Because these compounds are released into waterways and adsorbed to sediments on a daily basis, continued monitoring and the employment of strategies to reduce their presence are warranted. Thus, the purpose of this chapter is twofold: first, to describe the major classes of CECs and, second, to place their continued emission and presence in the environment in the context of the larger global challenge of human-induced damage to the planet from chemical and material contamination.