Using a physiologically based pharmacokinetic model to evaluate aggregated exposure to PCDD/Fs and PCBs via ingestion in children

Abstract

Exposure to persistent organic pollutants such as polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) could promote several adverse health effects. This study aimed to quantify the relative contributions of various exposure pathways to the body burden of PCDD/Fs and PCBs. We used a physiologically based pharmacokinetic model to simulate the internal exposure dynamics across different ages and for different exposure scenarios. We incorporated various parameters into the model to account for exposure through ingestion. These included dietary factors (vegetarian or mixed diet and consumption of home-produced eggs from contaminated areas), breastfeeding duration, maternal age, and soil concentrations. The modelled results from the simulated serum concentration showed that dietary intake, particularly from animal-fat-rich foods produced on contaminated areas, constitutes the predominant source of exposure. Breastfeeding significantly impacts early-life body burden temporarily, while soil and dust ingestion contribute minimally, even in the presence of high PCDD/F concentrations in soil. When an average diet is consumed in conjunction with six months of breastfeeding, the No-Observed-Adverse-Effect Level is not reached at 9 years old for PCDD/Fs WHO-TEQ-05 concentration. These findings highlight the need for targeted public health recommendations, such as reducing animal fat consumption, to mitigate the population's overall body burden.

Keywords: Breastmilk concentration; Dioxin-like compounds; PBPK model; Polychlorinated dibenzo-p-dioxins and dibenzofurans.