Systematic review of current approaches to prioritise chemical contaminants of emerging concern for research and management in the water industry

ABSTRACT Graphical abstract outlines the aims of the study, the approach, findings and opportunities. Contaminants of emerging concern (CEC), such as pharmaceuticals, hormones and industrial chemicals, pose a significant challenge for the water industry due to their presence in matrices including wastewater and drinking water. This is compounded by a lack of knowledge about their occurrence, environmental fate and/or toxicity, making it difficult to assess and mitigate risks. In this systematic review we investigated approaches used to prioritise CEC in matrices relevant to the water industry for research and management. Most approaches were specific to a geographic location, with fewer studies considering CEC risk at the national or international level, despite CEC being a global issue. Further, most prioritised CEC in surface water, wastewater and drinking water, with few considering recycled water, groundwater or biosolids. The methods used to prioritise CEC varied from a simple screening based on (predicted) persistent, bioaccumulative and toxic (PBT) properties to automated workflows considering many different criteria. A risk quotient (RQ) or equivalent approach, where measured or predicted occurrence data were compared to toxicity data, was the most common method to identify and rank priority CEC. This systematic review identified several limitations when applying existing CEC prioritisation tools for the water industry, with opportunities for prospective prioritisation models outlined.