ABSTRACT
Paracel sus’s famous insight that the dos e makes the poiso n implies that toxic ologists must
determ ine the relationshi p betw een the dose level and the toxic respon se. Mo re generally, to
asses s the risk posed by any agent, it is ne cessary to determ ine the relationshi p betw een
exposure and respon se. Expos ure-res ponse relationshi ps are, in general , quantitati ve models
of the form r ¼ f( e ), wher e r and e are response and exposure metrics, respect ively. However, they may be qua litative relat ionshi ps such as: where introdu ced specie s e is pr esent, nativ e
specie s r is extirpate d. Hence, we may more gen erally state that we wish to estimat e the
expecte d response r given a specif ied exposure e , E( r je ). Expos ure-res ponse relationshi ps serve a t least three pur poses.
