Metal interaction on arsenic toxicity in both in vivo and in vitro biological systems including human cells

Cadmium and lead are often co-exist with arsenic at elevated levels in the environment. They are of significant environmental and health concern. However, there is a scarcity of data for the interaction effect of cadmium and lead on arsenic. Previously, we have demonstrated cadmium or lead can reduce the bioavailability of arsenic when co-administered in solutions orally to rats. This binary mixture interaction effect could only explain 50% of the variation when soil was dosed to rats implicating other metals or factors may influence the bioavailability and kinetics of arsenic. In order to explore further and extend to ternary mixtures, in vitro systems including the United Barge Method (UBM) for bioaccessibility and human liver cells (HepG2 cell line) for toxicity evaluation were employed in this study. Results indicated that concentration addition may be appropriate for the risk assessment of these elements. However, interaction effects varied with dosages and soil properties.