Formatted Title
PFAS in Biological Samples at AFFF Site, Alaska
Background/Objectives
This study compares PFAS uptake in terrestrial invertebrates, terrestrial vertebrates, and aquatic invertebrates from soil, sediment, and surface water. The data used to support this study are part of an ongoing PFAS remedial investigation at a site in the interior of Alaska adjacent to the Yukon River. Three different areas of interest are included in this study. Area 1 was historically used from the late 1950s through 1991 for fire protection training activities, which included the use of aqueous film-forming foam (AFFF). Area 2 is a former fire station constructed in 1972 where AFFF was historically stored in drums and was subsequently released during a flood in 2013. Area 3 encompasses the outfall of a sanitary sewer system that historically and currently serves the facility, including two former fire stations. Wastewater potentially contained AFFF, as well as non-AFFF sources of PFAS from residential and industrial sources. The purpose of this study is to improve understanding of the nature of uptake of PFAS in biota and to support ecological risk assessments.
Approach/Activities
Surface soil, sediment, surface water and biota samples were collected in 2022. Three (3) surface soil (0 to 2 feet below ground surface) samples were collected from Area 1 and 21 surface soil samples were collected from Area 2. Fourteen (14) sediment samples and 11 surface water samples were collected from Area 3. Biota samples were collected from the vicinity of the media samples by a qualified biologist using lethal pitfall trapping and netting for terrestrial specimens and a 600-micron D frame net for aquatic invertebrate specimens. Invertebrates were collected from three different locations each at Areas 1 and 2. Invertebrates included grasshoppers (Melanoplus spp.), bees (Apidae), spiders (Araneae), and flies (Diptera). Catches from individual traps within each area were composited. Vertebrate specimens (voles) were collected from all three trap locations in Area 1 and from two trap locations in Area 2. Vertebrate analyses included the whole animal, not specific organs. In Area 3, aquatic invertebrate specimens were collected and composited from three locations. The dominant species was water beetles (Dyticus spp.). All media were analyzed for 25 PFAS following QSM 5.3 Table B-15. The maximum of each PFAS compound detected in samples from the vicinity of each biota collection area was considered representative of exposures by the local biota, because PFAS concentrations vary significantly in surface soils and sediments.
Results/Lessons Learned
- Not all PFAS compounds detected in soil or sediment were detected in biota samples.
- PFAS compounds detected in terrestrial invertebrates and vertebrates vary in type and magnitude.
- All perfluorocarboxylic acids (PFCAs) were detected in soil samples. PFCAs up to PFHxA (C6) were detected in terrestrial invertebrates, whereas heavier molecular weight PFAS up to PFDoDA (C12) were also detected in vertebrates. PFCAs were detected in terrestrial but not in aquatic invertebrates.
- All perfluorosulfonic acids (PFSAs) were detected in soil samples. Only PFSAs between PFPeS (C5) and PFOS (C8) were detected in terrestrial invertebrates, but all PFSAs were detected in vertebrates. Similar PFSAs were detected in terrestrial and aquatic invertebrates.
- NMeFOSAA was detected at higher concentrations in sediment than in soil, and NMeFOSAA was detected in aquatic invertebrates but not in terrestrial biota.
- PFAS compounds that exceeded Argonne National Laboratory ecological screening values were detected in biota samples.