ABSTRACT

The previous chapter dealt with how chemicals in a mixture may interact and affect each other’s availability for uptake by organisms. This chapter covers the approaches dealing with 1) how such bioavailable fractions are absorbed, distributed, metabolized, and excreted in the organism (toxicokinetics), and 2) how the mixture toxicity is caused once the biological target in the organism has been reached (toxicodynamics). Using plain English, toxicokinetics (TK) can be considered what the body does to the chemicals, and toxicodynamics (TD) can thus be considered what the chemicals do to the body. It is often difficult to distinguish where toxicokinetics ends and toxicodynamics starts.