A Generic Toxicokinetic Model for Persistent Lipophilic Compounds in Humans: An Application to TCDD

This paper discusses a toxicokinetic model describing the distributionof TCDD in the human body during a lifetime. The model dividesthe body into several physiological compartments, their weightsbeing functions of age. Ingested TCDD is instantaneously distributedover all compartments according to their lipid content. Theliver eliminates TCDD from the body by a first-order process.Intake depends on age, as estimated from food consumption surveydata combined with data on TCDD concentrations in various foods.It is shown that historical changes in intake, due to changesin environmental concentrations and in dietary habits, shouldbe taken into account as well. Elimination rate and bioavailability,the only unknown parameters in the model, were estimated bycalibrating the model to human data on internal concentrations.The generic formulation of the model makes it suitable for slowlyeliminated lipophilic compounds in general.