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In vitro modeling of the post-ingestion bioaccessibility of per- and polyfluoroalkyl substances sorbed to soil and house dust
Citation:
Parker, B., E. Valentini, S. Graham, AND J. Starr. In vitro modeling of the post-ingestion bioaccessibility of per- and polyfluoroalkyl substances sorbed to soil and house dust. TOXICOLOGICAL SCIENCES. Society of Toxicology, RESTON, VA, 197(1):95-103, (2024). https://doi.org/10.1093/toxsci/kfad098
Impact/Purpose:
Soils and house dusts are sorbents that can function as sinks for many regulated organic compounds. Since children ingest relatively large amounts of soil and dust, it is important to understand the factors that determine uptake of sorbed organic toxicants when estimating the toxicity of these chemicals to children. Considering ingestion of soil or house dusts with sorbed organics, bioaccessibility is defined as the percent of contaminant desorption from the soil or dust. In this study we develop an in vitro post ingestion bioaccessibility model for Per- and polyfluoroalkyl substances (PFAS) sorbed to soils and house dusts. The results show that bioaccessibility depends on the PFAS chain length, number of branches, and the carbon content of the soil or house dust. The data will be useful for PFAS risk assessments and those studying children's health exposure factors such as Office of Children's Health Protection
Description:
Per- and polyfluoroalkyl substances (PFAS) are regularly found in soils and dusts, both of which can be consumed by children at relatively high amounts. However, there is little data available to model the bioaccessibility of PFAS in soils and dusts when consumed, or to describe how the physiochemical properties of PFAS and soils/dusts might affect bioaccessibility of these chemicals. Because bioaccessibility is an important consideration in estimating absorbed dose for exposure and risk assessments, in the current study, in vitro assays were used to determine bioaccessibility of fourteen PFAS in 33 sets of soils and dusts. Bioaccessibility assays were conducted with and without a sink, which was used to account for removal of PFAS due to their movement across the human intestine. Multiple linear regression with backward elimination showed that a segmented model using PFAS chain length, number of branches, and percent total organic carbon (%TOC) explained 78.0-88.9% of the variability in PFAS bioaccessibility. In general, PFAS had significantly greater bioaccessibility in soils relative to dusts and the addition of a sink increased bioaccessibility in the test system by as much as 10.8% for soils and 20.3% for dusts. The results from this study indicate that PFAS bioaccessibility in soils and dusts can be predicted using a limited set of physical chemical characteristics and could be used to inform risk assessment models.
URLs/Downloads:
DOI: In vitro modeling of the post-ingestion bioaccessibility of per- and polyfluoroalkyl substances sorbed to soil and house dust
https://pubmed.ncbi.nlm.nih.gov/37740396/