Contribution of Indoor Air and Dust to Children's Per- and Polyfluoroalkyl Substance Exposure in the Faroe Islands

The people of the Faroe Islands are uniquely exposed to per- and polyfluoroalkyl substances (PFASs); despite no local production of these compounds or manufacturing of consumer products, residents exhibit elevated serum concentrations of PFASs. Consumption of pilot whales, a traditional part of the Faroese diet, contributes to exposure but does not fully account for observed trends in serum, suggesting the importance of additional exposure pathways. This research assessed the significance of indoor exposure pathways through measuring air and dust concentrations of a broad scope of PFAS nonvolatile precursors, volatile neutral precursors, and legacy ionic PFASs, and determining the estimated daily intake (EDI) for 15-year-old children. Across the 40 homes, the EDI for children from indoor exposure was 0.001, 0.012, and 0.129 ng/kg bw for low, intermediate, and high exposure scenarios, respectively. Indirect exposure to perfluoroalkyl carboxylic acids from air contributed the most to the EDI, followed by indirect exposure to perfluorooctanesulfonic acid in dust in the high exposure scenario. Indoor exposure equated to approximately 0.2% (low), 2% (intermediate), and 20% (high) of the European Food Safety Authority (EFSA) tolerable weekly intake, while the average consumption of pilot whale contributed about 60%. This study highlights the importance of understanding indoor exposure as a potentially significant contributor to total exposure to PFAS, especially with the declining consumption of pilot whales in the Faroese population.