Contaminants of Emerging Concern - Final Report
An Urban Water Research Team has been studying the gap between scientific knowledge and governance of contaminants of emerging concern. The Urban Water team is multidisciplinary and comprises Dr. Kim Gilbride (from the Department of Chemistry and Biology), Dr. Rania Hamza (from the Department of Civil Engineering), Dr. Patricia Hania (from the Department of Law and Business).
Contaminants of emerging concern (CECs) are broadly defined as compounds that are not currently monitored or regulated. Research has shown that CECs discharged from wastewater treatment plants (WWTPs) are present in downstream freshwater sources, which are relied upon for drinking water and fish habitat. However, the lack of a CEC regulatory framework for WWTPs combined with the narrow characterization of CECs as discrete chemicals (without consideration for synergistic impacts) has resulted in a knowledge and governance gap that leaves freshwater, ecosystem and human health unprotected.
One key objective of this study was to classify the types, numbers, and effects of CECs currently documented in wastewater through a comprehensible and multi-sectoral search of scientific, legal, and grey literature. The goal was to improve the characterization of CECs to better understand the impacts they have on freshwater ecosystems and human health. The team discovered that the definition of CECs has become ambiguously defined overtime as it is used to describe any compound in water sources that isn’t monitored or regulated but poses a risk to ecological health. There are over 600 CECs identified through literature review. The scope of the study focused on pharmaceuticals (PhACs), microplastics (MPs), and per- and poly-fluoroalkyl substances (PFAS).
PhACs include prescription, veterinary, and over-the-counter therapeutic drugs used to treat human and animal diseases. Unmetabolized PhACs are carried to WWTPs through sewage. Antibiotic resistance and disruption of endocrine system pathways in vertebrates are major risks associated with PhACs in source waters. MPs are commonly defined as plastics less than 5 mm in size. Due to their physical properties, MPs can absorb, transport, and leach out contaminated and endocrine-disrupting toxins and act as vectors of bacterial pathogens. Lastly, PFASs are human-made organic compounds used in commercial and industrial goods. The PFAS compound is considered toxic, bioaccumulative, and persistent in the environment. All three types of substances have been found to harm freshwater ecosystems or human health due to the lack of their characterization and regulation. The PDF filereport provides more information on the full study.