Cloth–Air Partitioning of Neutral Per- and Polyfluoroalkyl Substances (PFAS) in North Carolina Homes during the Indoor PFAS Assessment (IPA) Campaign

Abstract

Partitioning of per- and polyfluoroalkyl substances (PFAS) to indoor materials, including clothing, may prolong the residence time of PFAS indoors and contribute to exposure. During the Indoor PFAS Assessment (IPA) Campaign, we measured concentrations of nine neutral PFAS in air and cotton cloth in 11 homes in North Carolina, for up to 9 months. Fluorotelomer alcohols (i.e., 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH) are the dominant target species in indoor air, with concentrations ranging from 1.8 to 49 ng m– 3, 1.2 to 53 ng m– 3, and 0.21 to 5.7 ng m– 3, respectively. In cloth, perfluorooctane sulfonamidoethanols (i.e., MeFOSE and EtFOSE) accumulated most significantly over time, reaching concentrations of up to 0.26 ng cm– 2 and 0.24 ng cm– 2, respectively. From paired measurements of neutral PFAS in air and suspended cloth, we derived cloth–air partition coefficients (K ca) for 6:2, 8:2, and 10:2 FTOH; ethylperfluorooctane sulfonamide (EtFOSA); MeFOSE; and EtFOSE. Mean log­(K ca) values range from 4.7 to 6.6 and are positively correlated with the octanol–air partition coefficient. We investigated the effect of the cloth storage method on PFAS accumulation and the influence of home characteristics on air concentrations. Temperature had the overall greatest effect. This study provides valuable insights into PFAS distribution, fate, and exposure indoors.

Determination of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFAS) in Indoor and Outdoor Air

“…Another study reported much higher concentrations of 6:2 FTOH (10000−600000 pg/m 3 ) and 8:2 FTOH (2000−160000 pg/m 3 ) in kindergartens in California . 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH were the predominant PFAS species in indoor air environments, presenting concentration ranges of 1800−49000, 1200−5300, and 210−5700 pg/m 3 , respectively, in North Carolina . FTOH concentrations in offices in Boston ranged from not detected to 13000 pg/m 3 .…”

“…Whereas diet is thought to be an important source of PFAS exposure, contribution from other sources such as inhalation of indoor air is not known . Humans spend most of their time indoors, and volatile PFAS precursors such as FTOHs are often found at elevated concentrations in indoor air. , Inhalation of PFAS through indoor air is an important exposure pathway for children . Some studies have reported the occurrence of FTOHs in indoor and outdoor air, − but there is limited research on concurrent analysis of emerging neutral (nPFAS) and ionic PFAS (iPFAS) present in indoor air.…”

“…Humans spend most of their time indoors, and volatile PFAS precursors such as FTOHs are often found at elevated concentrations in indoor air. , Inhalation of PFAS through indoor air is an important exposure pathway for children . Some studies have reported the occurrence of FTOHs in indoor and outdoor air, − but there is limited research on concurrent analysis of emerging neutral (nPFAS) and ionic PFAS (iPFAS) present in indoor air. Collection and analysis of PFAS in air presents unique challenges due to the surfactant properties of these chemicals that contribute to adherence on surfaces of sampling devices .…”

External liquid calibration method for iodide chemical ionization mass spectrometry enables quantification of gas-phase per- and polyfluoroalkyl substances (PFAS) dynamics in indoor air

“…21 Recently, Eichler et al measured total gas-phase FTOH in eleven homes from North Carolina, USA, with concentrations ranging from 2.0 to 94 ng m −3 . 22 Despite the ubiquity and implications of PFAS to human and ecological health, progress in understanding the sources, transformations, lifetimes, and fates of PFAS in indoor and outdoor air is hampered by the long averaging times (hours to months) currently required for sampling neutral and ionic PFAS in air. 22–30…”

“…To address the need for real-time quantitative measurements of gas-phase PFAS, we describe and demonstrate the viability of a simple and cost-effective Calibration Apparatus for Manual Injection of Liquid Standards (CAMILS), utilizing the same seven compounds as Riedel et al 36 as well as three additional compounds not previously measured by I-HR-ToF-CIMS but which are relevant to indoor or outdoor air ( i.e. , one perfluorooctane sulfonamide (EtFOSA), 15,22,38 one fluorotelomer diol (FTdiOH), 39 and one fluorinated ether (E2)). 40 External calibration of I-HR-ToF-CIMS with the CAMILS allows for reproducible, real-time quantification of gas-phase PFAS, offering greatly enhanced temporal resolution as compared to offline methods.…”