Chemical mixtures: toxicologic interactions and risk assessment

Abstract There is increasing public concern regarding health risks from multiple chemical exposures and combined exposure to chemical and nonchemical stressors (cumulative risk). These exposures may involve more than one exposure pathway and typically vary over time with respect to the total exposure level and the relative proportions of component chemicals. Research on toxicology and risk assessment of multichemical exposures is complicated further because toxicologic interactions vary with exposure sequence, duration and route, as well as with total dose, relative chemical proportions, and endpoint.