A generalized model for the prediction of lead body burdens

A compartmental model of a typical 70-kg male for lead intake, distribution, and transport has been developed based on previous pharmacokinetic models and experimental results for lead in the human body. A set of first-order, linear ordinary differential equations with constant coefficients is solved to predict lead levels in blood, bone, and other compartments as a function of time resulting from inputs from air and/or ingestion. The model has been shown to be in excellent agreement with the measurements of blood lead for a controlled study by M. B. Rabinowitz et al. (1976, J. Clin. Invest., 58, 260-270). Favorable agreement was also found with blood and urine results reported by T. B. Griffin et al. (1975, "Lead," pp. 221-240) providing that an allowance was made for an unmeasured input of lead, originating from smoking, snacks, etc. The predictions of the newly formulated model are compared with those of the established Bernard model (S. F. Bernard, 1977, Health Phys., 32, 44-46). Predictions of blood lead concentration for short periods (on the order of months) are fitted better by the new model, while both models predict similar behavior over the longer term (on the order of 5 years and greater).