Sources of Coastal PFAS Contamination
PFAS reach coastal and marine environments through multiple pathways: river discharge carrying industrial and municipal PFAS loads to estuaries and near-shore waters; direct stormwater discharge from coastal cities; submarine groundwater discharge from coastal aquifers; and AFFF use at coastal military installations and airports. Atmospheric PFAS transport and deposition is also a significant source for open ocean contamination.
Coastal contamination hot spots include estuaries receiving PFAS from upstream industrial sources (Delaware River, Chesapeake Bay tributaries), bays near military bases with AFFF use histories (San Diego Bay, Pearl Harbor, Hampton Roads), and recreational beaches near stormwater outfalls from urban areas.
PFAS in Seawater and Marine Life
Seawater from contaminated coastal areas contains PFAS at concentrations reflecting upstream sources and dilution. While seawater concentrations are generally lower than freshwater in contaminated areas, the ecological pathways are extensive: PFAS bioconcentrate in marine algae, invertebrates, and fish, creating elevated concentrations in seafood from affected areas.
Marine mammals — dolphins, seals, polar bears — show some of the highest PFAS concentrations measured in any organism, due to their position at the apex of marine food chains and their high-fat diets. Arctic marine mammals show elevated PFAS despite living far from industrial sources, demonstrating global transport through ocean currents and atmospheric pathways.
Beach Swimming and Seafood Safety
Swimming in PFAS-contaminated coastal water contributes to PFAS exposure through ingestion of small amounts of water and potentially through dermal absorption of short-chain PFAS. For most recreational beach swimmers, this exposure is modest compared to drinking water exposure. However, surfers, swimmers, and water sports enthusiasts with high water contact time in contaminated areas face elevated coastal PFAS exposure.
Seafood safety from PFAS-contaminated coastal waters depends on species (shellfish and fatty fish bioconcentrate more), fishing location, and consumption frequency. State fish advisories cover many coastal water bodies near known PFAS sources. Checking state advisory websites before consuming recreationally caught coastal seafood in potentially affected areas is prudent protective practice.