Mechanisms and health implications of toxicity increment from arsenate-containing iron minerals through in vitro gastrointestinal digestion

•Arsenic release was coupled with goethite and hematite dissolution.•As(V) reduction to As(III) mediated by proteinases with toxicity increment.•The higher exposure risk of As-containing hematite than goethite.•Adding CaCl2 can be effective dietary strategy to reduce As bioaccessibility.