Role of Modeling Techniques in the Risk Assessment of Mixture Effects

Abstract

Humans and organisms in the environment are simultaneously exposed to multiple chemical substances, while risk assessment is usually conducted separately for every single substance. In order to assess the risk due to exposure to multiple chemicals, it is essential to conduct a risk assessment of mixture effects. Since the risk assessment of single chemicals is the basis of that of mixture effect, various modeling techniques used for the assessment of single chemicals are generally applied to the assessment of mixture effect. The modeling techniques for exposure assessment include those for estimating concentration in the environmental media, estimating internal concentration in the human body, and estimating model parameters along with the flow of chemical substances in the environment. The modeling techniques for hazard assessment include modeling the toxicity mechanism, modeling the dose-response relationship, and estimating the no-observed adverse effect level. Modeling techniques also play an essential role in the risk assessment of mixture effects for determining how to combine the effects of multiple chemicals and in what range of chemicals.