Transfer of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) from Oral Exposure into Cow's Milk - Part II: Toxicokinetic Predictive Models for Risk Assessment.

Understanding the transfer of polychlorinated dibenzo- p -dioxins (PCDDs) and dibenzofurans (PCDFs) as well as polychlorinated biphenyls (PCBs) from oral exposure into cow's milk is not purely an experimental endeavour, as it has produced a large corpus of theoretical work. This work consists of a variety of predictive toxicokinetic models in the realms of health and environmental risk assessment and risk management. Their purpose is to provide mathematical predictive tools to organize and integrate knowledge on the absorption, distribution, metabolism and excretion processes. Toxicokinetic models are based on more than 50 years of transfer studies summarized in part I of this review series. Here in part II, several of these models are described and systematically classified with a focus on their applicability to risk analysis as well as their limitations. This part of the review highlights the opportunities and challenges along the way towards accurate, congener-specific predictive models applicable to changing animal breeds and husbandry conditions.