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

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 (Kca) for 6:2, 8:2, and 10:2 FTOH; ethylperfluorooctane sulfonamide (EtFOSA); MeFOSE; and EtFOSE. Mean log(Kca) 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.

Harmful cyanobacterial aerosolization dynamics in the airshed of a eutrophic estuary.

In addition to obvious negative effects on water quality in eutrophic aquatic ecosystems, recent work suggests that cyanobacterial harmful algal blooms (CHABs) also impact air quality via emissions carrying cyanobacterial cells and cyanotoxins. However, the environmental controls on CHAB-derived aerosol and its potential public health impacts remain largely unknown. Accordingly, the aims of this study were to 1) investigate the occurrence of microcystins (MC) and putatively toxic cyanobacterial communities in particulate matter ≤ 2.5 µm in diameter (PM2.5), 2) elucidate environmental conditions promoting their aerosolization, and 3) identify associations between CHABs and PM2.5 concentrations in the airshed of the Chowan River-Albemarle Sound, an oligohaline, eutrophic estuary in eastern North Carolina, USA. In summer 2020, during peak CHAB season, continuous PM2.5 samples and interval water samples were collected at two distinctive sites for targeted analyses of cyanobacterial community composition and MC concentration. Supporting air and water quality measurements were made in parallel to contextualize findings and permit statistical analyses of environmental factors driving changes in CHAB-derived aerosol. MC concentrations were low throughout the study, but a CHAB dominated by Dolichospermum occurred from late June to early August. Several aquatic CHAB genera recovered from Chowan River surface water were identified in PM2.5 during multiple time points, including Anabaena, Aphanizomenon, Dolichospermum, Microcystis, and Pseudanabaena. Cyanobacterial enrichment in PM2.5 was indistinctive between subspecies, but at one site during the early bloom, we observed the simultaneous enrichment of several cyanobacterial genera in PM2.5. In association with the CHAB, the median PM2.5 mass concentration increased to 8.97 µg m-3 (IQR = 5.15), significantly above the non-bloom background of 5.35 µg m-3 (IQR = 3.70) (W = 1835, p < 0.001). Results underscore the need for highly resolved temporal measurements to conclusively investigate the role that CHABs play in regional air quality and respiratory health risk.

Per- and Polyfluoroalkyl Substances (PFASs) in Airborne Particulate Matter (PM2.0) Emitted During Floor Waxing: A Pilot Study.

Per- and polyfluoroalkyl substances (PFASs), with their water- and heat-resistant properties, have been widely used in industrial and consumer products, including floor waxes. Adverse health effects are associated with PFAS exposures (e.g., increased risk of cancer and immunotoxicity); however, exposures resulting from the use of PFAS-containing products are poorly understood. This study examines PFAS emissions during professional floor stripping/waxing and their potential for occupational exposures. We measured PFASs in dust and airborne particulate matter (PM2.0, aerodynamic diameter ≤ 2.0 µm) before, during, and after floor stripping/waxing activities in three rooms in a university building. PM2.0 samples were analyzed for 34 targeted PFASs by ultra-high performance liquid chromatography coupled to electrospray ionization triple quadrupole mass spectrometer (UHPLC/ESI-MS/MS). In total, ten PFASs were detected in PM2.0 collected during floor waxing. Five were consistently higher during floor stripping/waxing compared to before (two with 95% confidence interval): perfluoro-2-methoxyacetic acid, perfluorobutanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, and perfluorooctane sulfonic acid. For these five, estimated exposures during floor stripping were 80.6, 320.5, 83.8, 29.6, and 157.7 pg m-3 per hour of floor stripping, respectively, one order of magnitude greater than typical residential indoor and two orders of magnitude greater than ambient outdoor concentrations. Estimated emission rates were 3.0, 9.6, 3.4, 1.5, and 6.5 ng h-1m-2, respectively (34.6% uncertainty). Inhalation occupational exposures were in the range of 9.42-23.2 pg per kg body weight per hour of floor stripping across the five PFASs.