Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Symposium Abstracts
*Slovak Medical University, Bratislava, Slovakia; †Slovak University of Technology, Bratislava, Slovakia; ‡University of California, Davis, CA, United States; and §Comenius University, Bratislava, Slovakia.
Background and Objective:
Polychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. The aim is a quantification of the effect of breastfeeding and consecutive normal food intake in infants using single-compartmental mathematical model.
A subgroup of 58 infants from a cohort of 1030 was used in a toxicokinetic study with sampling time schedule: 0 (blood cord) and 6, 16 and 45 months after birth. PCB was examined in blood serum. Open one-compartmental model of PCB kinetics was used for quantification of the effect of breastfeeding and consecutive normal food intake on PCB concentrations over time. The following three model parameters were evaluated from measured concentration-time profiles of PCB and length of breastfeeding using Monte Carlo Method: MRT (Mean Residence Time, in months), IBF and IF (Intensity of breastfeeding and of normal food intake, in PCB concentration per unit of time).
To date, we have processed 58 concentration-time profiles of serum PCB with various lengths of breastfeeding. Results show various types of model curves depending on the length of breastfeeding and food composition. Evaluated intensities of PCB exposure during breastfeeding (IBF) and consequent normal food intake (IF) and evaluated MRT enable prediction of the future time course of serum PCB and a check of the fit of the measured values.
The model was optimized for the sample on which it was developed. Length of breastfeeding predicts PCB concentration-time profile at given food schedule. The model takes into account a presently unknown PCB intensity (INEXT) using measured data from the next time period after the end of this initial phase. It should be tested in a further sample to determine generalizability.