CONTRAST prioritisation tool: filtering and ranking contaminants of emerging concern in the marine environment using hazard-based approaches

Background: Increasing numbers of chemicals with little-known adverse effects are released into the marine environment. The present study addresses the lack of marine-specific prioritisation schemes by developing a prioritisation tool for organic contaminants. This tool supports decision-making processes regarding which chemicals to study further in terms of their occurrences and biological effects in the marine environment. It was supported by a database containing approximately 1.13 million chemicals, developed within the PikMe project. Criteria for chemical prioritisation were identified by a comprehensive literature review, then selected using the outcomes of a survey among experts. The prioritisation tool consists of filtering chemicals in the PikMe database using three parallel schemes—persistence and bioaccumulation, toxicity, and persistence and mobility characteristics (step 1)—followed by scoring based on modes of action, occurrence, and emission (step 2) and ranking by the final score (step 3). Results: Around 8000 chemicals were selected by filtering (step 1). The top 100 resulted from step 3 comprises 6PPD as the highest-ranked compound and other chemicals with high diversity of uses, e.g. pharmaceuticals as the predominant category of use, industrial chemicals, personal care products, flame retardants, and plastic additives. These chemicals were ranked in the top 100 due to dominant influence of diverse prioritisation criteria. Conclusions: Using the hazard-based approach that encompasses different adverse effects that contaminants of emerging concern can exert, the marine-specific prioritisation tool can guide decision-making in monitoring, ecotoxicological studies, and regulations regarding contaminants of emerging concern in the marine environment.