Geographical characteristics that promote persistence and accumulation of PFAS in coastal waters and open seas: Current and emerging hot spots

Abstract

Poly- and perfluoalkyl substances (PFAS) have been found in ocean water, sediments, and marine organisms. The objective of this study was to identify coastal and open water conditions that affect accumulation and transport characteristics of PFAS in coastal areas and open waters. Coastal conditions were compared based on the classification for Shoreline Cleanup and Assessment Technique (SCAT). Open sea conditions were evaluated in relation to ocean currents. PFAS data available in the literature from different coastal areas and open seas were compiled. Tidal flats, sheltered shores, salt and brackish marshes, bays and estuaries, mangroves, and areas with coral reefs, sea grasses, kelp have conditions that are favorable for PFAS accumulation and ecosystems in these environments are vulnerable to long term PFAS exposure and bioaccumulation. The areas near the centers of gyres in oceans trap and accumulate floating debris as well as PFAS contaminated particles. PFAS accumulation in highly productive coastal areas with mangrove forests, seagrasses and salt marshes can affect the ecosystems in these locations. PFAS data from marine environments indicate that some areas in the Indian Ocean (41.1 ng/L), North Pacific Ocean (12.8 ng/L), and North Atlantic Ocean (4.0 ng/L) relatively high levels of PFAS. Marine organisms with long life spans are likely to accumulate high levels of PFAS over their lifespan. PFAS concentrations at vulnerable coastal waters and open seas should be monitored systematically and periodically to establish the baseline conditions and evaluate the changes in PFAS levels water column and sediments overtime.