Can the mouse model successfully predict mixed metal(loid)s bioavailability in humans from contaminated soils?

Area of Science:

• Environmental Science
• Toxicology
• Ecotoxicology

Background:

• Mouse models are widely used to assess metal (loid) bioavailability for human risk assessment.
• The accuracy of mouse models for predicting mixed metal (loid) bioavailability remains a subject of extensive scientific debate.
• Understanding metal (loid) bioavailability is crucial for environmental risk assessment and remediation strategies.

Purpose of the Study:

• To evaluate the suitability of mouse models for predicting lead (Pb) and arsenic (As) bioavailability in mixed contamination scenarios.
• To compare in vivo bioavailability data from mouse models with in vitro bioaccessibility measurements using various established methods.
• To determine the correlation between in vivo and in vitro data for mixed metal (loid) exposures.

Main Methods:

• Soils contaminated with lead (Pb) and arsenic (As) were used in aging, bioavailability (mice), and bioaccessibility (in vitro) tests.
• In vitro methods included the relative bioaccessibility leaching procedure (RBALP) and Unified Bioaccessibility Research Group Europe (BARGE) method (UBM) and National Institute for Public Health and the Environment (RIVM) gastric and intestinal phases.
• Correlations between mouse model bioavailability and in vitro bioaccessibility for Pb and As mixtures were analyzed.

Main Results:

• Mouse kidney tissue lead (Pb) bioavailability significantly correlated with Pb bioaccessibility from RBALP, UBM gastric/intestinal, and RIVM gastric phases (p < 0.01).
• The RBALP and UBM gastric/intestinal methods demonstrated the highest predictive power for lead (Pb) bioavailability in mixtures.
• The mouse model showed limitations in explaining the in vivo-in vitro correlation (IVIVC) for arsenic (As) bioavailability in mixed metal (loid) exposures.

Conclusions:

• Mouse models can successfully predict lead (Pb) bioavailability in mixed metal (loid) contaminated soils, demonstrating strong in vivo-in vitro correlation (IVIVC).
• Specific in vitro methods like RBALP and UBM are effective predictors of lead (Pb) bioavailability in complex mixtures.
• The mouse model's utility for predicting arsenic (As) bioavailability in mixed contamination warrants further investigation and may be less reliable than for lead.