PFOA, PFOS and PFHxS toxicokinetic considerations for the development of an in vivo approach for assessing PFAS relative bioavailability in soil.

A Sprague-Dawley rat model was utilized to elucidate perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) toxicokinetics with a goal of developing an in vivo approach for quantifying PFAS relative bioavailability in impacted soil. Following single dose administration (gavage) of ∼ 0.2-2000 µg kg BW of PFOA, PFOS or PFHxS, differences in PFAS blood, organ and excreta concentrations were observed over 120 h although linear dose responses were determined for area under the blood plasma time curves (AUC; PFOA, PFHxS), liver accumulation (LA: PFOS) and urinary excretion (UE; PFOA, PFHxS).

Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste.

Bioaccessibility and relative bioavailability of As, Cd, Pb and Sb was investigated in 30 legacy gold mining wastes (calcine sands, grey battery sands, tailings) from Victorian goldfields (Australia). Pseudo-total As concentration in 29 samples was 1.45-148-fold higher than the residential soil guidance value (100 mg/kg) while Cd and Pb concentrations in calcine sands were up to 2.

Remediation options to reduce bioaccessible and bioavailable lead and arsenic at a smelter impacted site - consideration of treatment efficacy.

In this study, smelter contaminated soil was treated with various soil amendments (ferric sulfate [Fe(SO4)], triple superphosphate [TSP] and biochar) to determine their efficacy in immobilizing soil lead (Pb) and arsenic (As). In soils incubated with ferric sulfate (0.6M), gastric phase Pb bioaccessibility was reduced from 1939 ± 17 mg kg to 245 ± 4.

Application of soil amendments for reducing PFAS leachability and bioavailability.

In this study, changes in PFAS leachability and bioavailability were determined following the application of RemBind®100 (R100) and RemBind®300 (R300; 1-10% w/w) to PFAS-contaminated soil (Ʃ PFAS 3.093-32.78 mg kg).

Plumbojarosite formation in contaminated soil to mitigate childhood exposure to lead, arsenic and antimony.

In this study, a novel method for lead (Pb) immobilization was developed in contaminated soils using iron (III) (Fe) in conjunction with 0.05 M HSO. During method optimization, a range of microwave treatment times, solid to solution ratios, and Fe(SO)/HSO concentrations were assessed using a mining/smelting impacted soil (BHK2, Pb: 3031 mg/kg), followed by treatment of additional Pb contaminated soils (PP, Pb: 1506 mg/kg, G10, Pb: 2454 mg/kg and SoFC-1, Pb: 6340 mg/kg) using the optimized method.

Intra- and Interlaboratory Evaluation of an Assay of Soil Arsenic Relative Bioavailability in Mice.

Hand-to-mouth activity in children can be an important route for ingestion of soil and dust contaminated with inorganic arsenic. Estimating the relative bioavailability of arsenic present in these media is a critical element in assessing the risks associated with aggregate exposure to this toxic metalloid during their early life. Here, we evaluated the performance of a mouse assay for arsenic bioavailability in two laboratories using a suite of 10 soils.

, and Spectroscopic Assessment of Lead Exposure Reduction via Ingestion and Inhalation Pathways Using Phosphate and Iron Amendments.

This study compared lead (Pb) immobilization efficacies in mining/smelting impacted soil using phosphate and iron amendments via ingestion and inhalation pathways using and assays, in conjunction with investigating the dynamics of dust particles in the lungs and gastro-intestinal tract via X-ray fluorescence (XRF) microscopy. Phosphate amendments [phosphoric acid (PA), hydroxyapatite, monoammonium phosphate (MAP), triple super phosphate (TSP), and bone meal biochar] and hematite were applied at a molar ratio of Pb:Fe/P = 1:5. Pb phosphate formation was investigated in the soil/post- bioaccessibility (IVBA) residuals and in mouse lung via extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structures (XANES) spectroscopy, respectively.

Predicting Arsenic Relative Bioavailability Using Multiple in Vitro Assays: Validation of in Vivo-in Vitro Correlations.

In this study, previously established arsenic (As) in vivo-in vitro correlations (IVIVC) were assessed for their validity using an independent data set comprising As relative bioavailability (RBA) and bioaccessibility values for 13 herbicide- and mine-impacted soils. The validation process established the correlation between As RBA (swine model) and bioaccessibility (five in vitro assays), determined whether correlations differed significantly from previous relationships and assessed model bias and error. The capacity of in vitro assays to predict As RBA was demonstrated by the strength of IVIVC; goodness of fit ranged from 0.

Validation of the predictive capabilities of the Sbrc-G in vitro assay for estimating arsenic relative bioavailability in contaminated soils.

A number of bioaccessibility methodologies have the potential to act as surrogate measures of arsenic (As) relative bioavailability (RBA), however, validation of the in vivo-in vitro relationship is yet to be established. Validation is important for human health risk assessment in order to ensure robust models for predicting As RBA for refining exposure via incidental soil ingestion. In this study, 13 As-contaminated soils were assessed for As RBA (in vivo swine model) and As bioaccessibility (Solubility Bioaccessibility Research Consortium gastric phase extraction; SBRC-G).

In situ formation of pyromorphite is not required for the reduction of in vivo pb relative bioavailability in contaminated soils.

The effect of phosphate treatment on lead relative bioavailability (Pb RBA) was assessed in three distinct Pb-contaminated soils. Phosphoric acid (PA) or rock phosphate were added to smelter (PP2), nonferrous slag (SH15), and shooting range (SR01) impacted soils at a P:Pb molar ratio of 5:1. In all of the phosphate amended soils, Pb RBA decreased compared to that in untreated soils when assessed using an in vivo mouse model.