EFFECT OF BODY SIZE ON THE UPTAKE AND BIOCONCENTRATION OF DI-2-ETHYLHEXYL PHTHALATE IN RAINBOW-TROUT

Three groups of rainbow trout (Salmo gairdneri) having average body weights of 2.9, 61 and 440 g were exposed at 12°C by the water to di‐2‐ethylhexyl phthalate (DEHP). The kinetics of uptake and bioconcentration were characterized in each group using a compartmental model. Most of the model parameters, when expressed per unit body weight, were similar in the three sizes of fish. The two major exceptions were the uptake rate parameter, a measure of the capacity of the gill to extract DEHP from water and the apparent size (volume of distribution) of the large DEHP storage compartment, which is a measure of the capacity of the fish to accumulate DEHP. The values of these parameters declined as body weight increased; they followed the allometric equation with body weight exponents of 0.44 and 0.77, respectively. The body weight‐associated changes in the pharmacokinetic parameters caused the bioconcentration factor to decline as body weight increased, from 51.5 to 1.6. Copyright © 1990 SETAC