ABSTRACT
Any adverse effect resulting from a chemical toxicant is primarily due to its interaction with a particular target within the organism or the cell. The availability and duration of the interaction of a xenobiotic with a given cellular target are dependent upon its toxicokinetic properties, i.e., its absorption, distribution, metabolism, and excretion (ADME). Any environmental contaminant that is not absorbed will not represent a particular toxicological risk for the organism (with the exception of contact toxicity). Distribution may lead to accumulation in nontarget organs, thus preventing its toxicological activity, or into organs specialised in metabolism and excretion. Metabolism can inactivate and eliminate the toxic compound and may lead to its excretion even if intermediate metabolites may have deleterious effects (see Chapter 8).
