The human health risks and corresponding body thresholds of OCPs and PCBs in the Tibetan Plateau

Although organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been banned or restricted for years, they remain significant contaminants posing health risks in some places where are favorable for their enrichment, such as areas with high latitude or altitudes. However, the elucidation of environmental risks and the establishment of a clear relationship between these risks and human health are areas that remain significantly underdeveloped. Literatures on the concentrations of OCPs and PCBs in soil of the Tibetan Plateau were reviewed to calculate local health risk indexes and create risk maps. A food chain model (ACC-Human) was applied to predict human body concentrations of these chemicals. Higher risk areas are located in the southeastern Tibetan Plateau, suggesting influences from potential emissions in adjacent regions and long-range transport. Based on the concentration-risk relationships, the most toxic chemicals identified were PCBs, with a body concentration threshold as low as 13 ng/g lipid. Given the ongoing emissions from industrial production or historical legacy, it is hightime to lay a particular focus on PCBs in mountainous areas like the Tibetan Plateau.