Validation of the Predictive Capabilities of the Sbrc-G in Vitro Assay for Estimating Arsenic Relative Bioavailability in Contaminated Soils

Abstract

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 vivo and in vitro data were used to assess the validity of the As RBA-bioaccessibility correlation previously described by Juhasz et al. (2009). Arsenic RBA and bioaccessibility in the 13 soils ranged from 6.8±2.4% to 70.5±6.8% and 5.7±0.3% to 78.4±0.8% respectively with a strong linear relationship (R2=0.75) between in vivo and in vitro assays. When the As in vivo-in vitro correlation was compared that of Juhasz et al. (2009), there was no significant difference (P>0.05) indicating that the relationship between As RBA and As bioaccessibility was consistent thereby demonstrating its validation. For these data, a grouped linear regression model was developed (R2=0.82) with a slope and y-intercept of 0.84 and 3.56 respectively. A number of cross validation methodologies (2-fold, repeat random subsampling, leave one out) were utilized to determine the performance of the linear regression model. Residuals and prediction errors ranged from 5.4 to 9.4 and 6.9-12.2 respectively illustrating the capacity of the SBRC-G to accurately predict As RBA in contaminated soil.

A Pooled Data Analysis to Determine the Relationship between Selected Metals and Arsenic Bioavailability in Soil

“…The effect from phosphate was not determined in this study either, although some authors stated that the phosphate can decrease the intestinal absorption of As [ 31 ]. Potentially, the high P/As molar ratio may reduce As RBA due to P competition of the in vivo system.…”

“…Potentially, the high P/As molar ratio may reduce As RBA due to P competition of the in vivo system. The effects from some other metals (such as Mn and Mg) were not determined since most literature did not report the concentrations of these two elements, while Juhasz et al [ 31 ] demonstrated the efficacy of Mn and Mg surfaces to sorb As. In detail, due to the elevated concentrations of both Mn and Mg, dissolution and precipitation processes may decrease the as absorption and availability in gastrointestinal tract.…”

The association of tryptophan and phenylalanine are associated with arsenic-induced skin lesions in a Chinese population chronically exposed to arsenic via drinking water: a case–control study

“…Moreover, mathematical modelling to assess the linkage between small molecular metabolites and arsenic toxicity has advanced 28. Developing a simple and interpretable modelling approach for the early detection of arsenic-induced lesions is of great theoretical value and realistic meaning,29 although it might be difficult due to population-specific complexities and effect of some potential unmeasured covariates such as diet and genetic determinants.…”

Using Delaunay triangulation and Voronoi tessellation to predict the toxicities of binary mixtures containing hormetic compound

“…In this paper, mixture toxicity (n = 60) were randomly divided into two disjoint parts; 1/3 of the combined toxicity (n = 20) was allocated to the test set, 2/3 of the combined toxicity (n = 40) and single toxicity (n = 24) were combined resulting in a training set. The holdout method was repeated 20 times with randomly selected training and holdout sets53.…”