Risk Assessment of Chemical Mixtures

2. Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA

Abstract: Humans are exposed daily to numerous mixtures of chemicals present in their environment instead of just a single chemical. The classical health risk assessment for regulatory decisions uses the chemical toxicity of a single test agent one at a time. Comparison of the toxicity of even a simple chemical mixture with that of its parts often shows significant differences. Therefore, the classical chemical risk assessment paradigm does not necessarily represent real-world human exposure, making a risk assessment of chemical mixtures an even more complex process. In vitro, in silico, organs-on-a-chip, and 3D cell culture models are examples of alternative approaches that have been used for toxicity screening. Recent advances in new “omics” technologies continue to provide useful data for hazard and risk assessment of chemical mixtures. The new developing genomic and epigenomic technologies also show promise for human health risk assessment. However, all these exciting experimental models and tools must be validated and accepted before they can be used to support risk assessments of chemical mixtures for regulatory approval.