The integration of an individual-based model into toxicokinetics to enhance ecological realism in evaluating population-level impacts of exposure to PCB

Polychlorinated biphenyls (PCBs) are classified as one the most extremely regulated anthropogenic contaminants and they have been deeply probed in aquatic ecosystems. However, there is very limited understanding of the population level effects of exposure to PCBs on terrestrial animal species and this has been unanimously indicated as a critical gap in ecological risk assessment. To bridge this information gap, we integrated an individual-based model (IBM) framework into toxicokinetics resulting in a deeper ecological insight to simulate the accumulation of a hypothetical PCB in a terrestrial three-level food chain at the population level. We then validated our simulated system utilizing the observed field bioaccumulation factors in a well-studied terrestrial preypredator, caribou-wolf. Key findings of the present study indicate that in a PCB-contaminated environment, where all food sources contain some amount of contaminants, producing more offspring results in lower toxic concentration in herbivores (prey) and higher concentration in carnivores (predator). Our novel contribution in this work is that we have achieved a validated system that enables us to investigate toxicokinetics in any animal species involved in a prey-predation interaction by providing lipid, non-lipid, and water fractions in their bodies. Additionally, we demonstrated how using IBM modelling approach could facilitate ecological risk assessment by offering detailed information of generations spanning as many years as required.