In vitro bioaccessibility and in vivo relative bioavailability in 12 contaminated soils: Method comparison and method...

Area of Science:

• Environmental Science
• Toxicology
• Geochemistry

Background:

• In vitro-in vivo correlations (IVIVC) are used to link arsenic (As) bioaccessibility in soils to its relative bioavailability (RBA).
• The predictive power of existing IVIVC models for As-RBA in soils beyond their development dataset is uncertain.
• Arsenic contamination in soils poses risks, necessitating accurate bioavailability assessments for health risk evaluation.

Purpose of the Study:

• To evaluate the ability of established IVIVC models to predict As-RBA in a set of 12 diverse As-contaminated soils.
• To develop and validate a new IVIVC model for predicting As-RBA using bioaccessibility data from various in vitro assays.
• To identify the most suitable in vitro assay for predicting As-RBA in contaminated soils.

Main Methods:

• Measured As bioaccessibility using five in vitro assays: SBRC, IVG, DIN, PBET, and UBM.
• Determined As-RBA using a mouse blood model across 12 As-contaminated soil samples.
• Applied established IVIVC models and developed a new IVIVC model correlating bioaccessibility and measured As-RBA.

Main Results:

• Established IVIVC models significantly underestimated or overestimated As-RBA, demonstrating their poor predictive performance on new soils.
• A new IVIVC model developed using the 12 soils showed varying predictive strengths (r² from 0.50 to 0.83) across assays.
• The In Vitro জৈব (IVG) assay provided the best prediction of As-RBA (r² = 0.83), with UBM and SBRC also showing suitability.

Conclusions:

• Established IVIVC models are unreliable for predicting As-RBA in diverse contaminated soil environments.
• The IVG assay demonstrates significant potential for accurately assessing As bioavailability in Chinese contaminated soils.
• Further research is needed to validate these findings and refine models for improved health risk assessments.