LAUSR

Metal contamination in soil, dust, and food matrices impacts the health of millions of people worldwide. During the past decades, various animal bioassays have been developed to determine relative bioavailability (RBA) of As, Pb, and Cd in contaminated soils, dust, and foods, which vary in operational approaches. This review discusses the strengths and weaknesses of different animal models (swine and mice), dosing schemes (single gavage dose, repeated gavage dose, daily repeated feeding, and free access to diet), and endpoints (blood, urine, and tissue) in metal-RBA measurement; compares metal-RBA obtained using mouse and swine bioassays, different dosing schemes, and different endpoints; and summarizes key findings on As-, Pb-, and Cd-RBA values in contaminated soils, dust, and foods. Future directions related to metal-RBA research are highlighted, including 1) comparison of metal-RBA determinations between different bioassays and different laboratories to ensure robust bioavailability data, 2) enhancing the metal-RBA database for contaminated dust and foods, 3) identification of physiological and physicochemical mechanisms responsible for variability in metal-RBA values, 4) formulation of strategies to decrease metal-RBA values in contaminated soils, dust, and foods, and 5) assessing the impacts of co-contaminants on metal-RBA measurement.