Per- and polyfluoroalkyl substances (PFAS) in marine sediments from a Norwegian fjord near an airport: Historical records, distribution, and controlling factors

Airports have been identified as one of numerous sources of extremely persistent, toxic and bioaccumulative per- and polyfluoroalkyl substances (PFAS), as part of aqueous film-forming foams (AFFF) during fire drills. The historically strongly contaminated terrestrial environment around Flesland airport in Bergen, Norway, raised concern for potential contamination in the surrounding fjords. To investigate this, surface sediments and sediment cores were collected from several locations adjacent to the airport area. One of the cores was dated by ²¹⁰Pb. Two analytical methods, a target method for 24 specific PFAS compounds in marine sediments, and a total oxidizable precursor (TOP) assay method, were established, validated and applied to the samples. The results were combined with previously collected data on surface sediments from fjords and open sea areas in Western Norway. While TOP assay results for sediments and pore water indicated a significant PFAS precursor load at locations close to the airport, and sediment cores showed a continuous increase in PFAS levels (since at least 1980s in the dated core), relatively low levels of PFAS were found in marine sediments off the airport area (1.1 μg/kg dry weight or less for the sum of nine most abundant PFAS in surface sediments). The results agree with earlier data on PFAS background levels in marine sediments from unaffected areas and imply a dispersion of the contamination from the airport elsewhere. Sea current modeling and grain size determination suggest local hydrodynamical and sedimentological conditions as the main factors of influence for the contamination status in the area.