Per- and Polyfluoroalkyl Ether Acid (PFEA) Concentrations in Indoor Dust are Higher in Homes Closer to a Fluorochemical Manufacturing Facility

Concentrations of 48 per- and polyfluoroalkyl substances (PFAS) were measured in settled dust samples from 65 homes of GenX Exposure Study participants residing near a fluorochemical manufacturing facility in North Carolina. Eight PFAS [perfluoro(3,5-dioxahexanoic) acid (aka PFO2HxA), perfluoro-2-(perfluoromethoxy)propanoic acid (PMPA), perfluoro-2-ethoxypropanoic acid (PEPA), 6:2 fluorotelomer phosphate diester (6:2 diPAP), 6:2/8:2 fluorotelomer phosphate diester (6:2/8:2 diPAP), perfluoropropanoic acid (PFPrA), perfluorodecanesulfonic acid (PFDS), and 2-(<i>N</i>-ethyl-perfluorooctanesulfonamido)acetic acid (N-EtFOSAA)] were detected in >90% of the dust samples. Dust concentrations of six per- and polyfluoroalkyl ether acids (PFEAs) produced at the facility (PEPA, PMPA, perfluoro-2-methoxyacetic acid (PFMOAA), PFO2HxA, hexafluoropropylene oxide dimer acid (HFPO-DA aka GenX), and ethanesulfonic acid, 2-[1-[difluoro(1,2,2,2-tetrafluoroethoxy)methyl]-1,2,2,2- tetrafluoroethoxy]-1,1,2,2-tetrafluoro- (Nafion byproduct 2) were significantly negatively associated with home distance from the facility. Homes closer to the facility had higher summed mass concentrations of 12 targeted PFEAs (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:munder><mml:mo>∑</mml:mo><mml:mn>12</mml:mn></mml:munder><mml:mi>PFEAs</mml:mi><mml:mo>)</mml:mo></mml:math> but not higher <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:munder><mml:mo>∑</mml:mo><mml:mn>48</mml:mn></mml:munder><mml:mi>PFAS</mml:mi></mml:math>. Trifluoroacetic acid (TFA), an ultrashort chain PFAS, and three diPAPs (8:2/6:2 diPAP, 6:2 diPAP, and 8:2 diPAP) were the major contributors to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:munder><mml:mo>∑</mml:mo><mml:mn>48</mml:mn></mml:munder><mml:mi>PFAS</mml:mi></mml:math>, and these compounds did not show relationships with distance. Based on our previous findings associating PFEAs in well water and human serum, our current findings indicate dust could be an important PFAS exposure source.