Source and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Ambient Air and Its Human Health Implications

In recent years, polychlorinated biphenyls (PCBs) in the environment gained scientific interest because of their persistent nature, widespread occurrence, and the potential threats they pose to humans and the environment. PCBs are recognized by the International Agency for Research on Cancer (IARC) as Group 1 carcinogens or cancer-causing substances. Although the occurrence and distribution of PCBs in various environmental matrices are reported in recent studies, the distribution and source of PCB pollution in ambient air across the globe still remain unclear. Inhalation exposure to these contaminants is often overlooked because ambient air is contaminated with different forms of PCBs. Exposure to PCBs in ambient air has recently been given unambiguous consideration in the human health risk assessment that form the basis of risk management decisions. The occurrence of high PCB levels, notably in urban and industrial areas, might result from extensive PCB use and intensive human activity. Furthermore, PCB exposure in the outdoor environment may pose a risk for humans through inhalation of contaminated air or ingestion of dust. In such settings, inhalation route may contribute significantly to PCB exposure. The data on human health effects due to PCB inhalation are scarce. Inorder to address this gap, this review discusses the occurrence, distribution, health impact, and various risk assessment techniques of PCBs for environmental and human health.