Estimated Daily Intake of Pfas Related to Different Particle Size Fractions of House Dust

Indoor environmental pollutants pose a risk to human health as many people spend a large part of their life indoors. In the current study, we analysed 25 per- and polyfluoroalkyl substances (PFASs) in seven different size fraction of house dust including two of which were representative for exposure via ingestion and inhalation. The estimated daily intake (EDI) for the individual PFAS and exposure pathways were calculated for children and adults. In addition, the total EDI for PFOA and its precursors was estimated. The highest concentrations of PFAS analysed in dust were the fluortelomer phosphate esters. For a worst-case scenario, the cumulative EDI of PFAS for children was 3.0 ng/kg bw per day. This was 17 times higher than the calculated EDI for adults. Ingestion of dust was found to result in 800 times higher PFAS exposure than inhalation. The contribution from PFOA precursors corresponded to only 1% of the EDI from dust indicating PFOA as the main source of exposure. The EDI’s of PFOA and PFOS from dust were lower than EDI’s from food ingestion reported by the Swedish Food Agency. Overall, our data indicated that the EDI for the sum of four PFASs: PFOA, PFNA, PFHxS and PFOS from dust intake alone is very close to the established tolerable weakly intake of 4.4 ng/kg bw in children, set by European Food Safety Authority (EFSA) in 2020. The combined EDI levels PFOA and PFOS from both dust and food exceeded the EFSA TWI for both children and adults. This study demonstrates that dust is a relevant exposure pathway for PFAS intake and that analysis of relevant particle size fractions is important for evaluation of dust as an exposure pathway