Persistent organic contaminants in food: Exposure, hazard potential, and health assessment

Environmental emissions of organic contaminants are caused by man-made and natural combustion processes, industrial production facilities, and the release from products. Food represents the main source of human exposure for some of these compounds. This is the case for three groups of persistent organic contaminants: (1) per- and polyfluoroalkyl substances (PFAS), (2) polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and for (3) polycyclic aromatic hydrocarbons (PAHs). The issues regarding PCDD/F emissions were already recognized as a problem in the 1970s and have since then been effectively regulated; the impact of PFAS as global anthropogenic environmental contaminants was identified much later. A system of toxicity equivalency factors (TEF system) was established for the assessment of the toxic potency of a mixed exposure to PCDD/F and certain PCBs. For the health assessment and regulation of PAHs and PFAS, no such system has been implemented so far. For PFAS, a re-evaluation of the present tolerable daily intake values (TDI values) is currently being discussed, as new insights into toxicology and epidemiology have been gained. The persistence in the environment of the compound groups discussed here leads to entry into the food chain over long periods of time, even if access into the environment is minimized. This requires a long-term continuation of the monitoring of food stuffs and forward-looking risk assessment approaches and regulatory measures.