According to general consensus, which chemical contaminant is considered the most widespread?

The most widespread chemical contaminant is recognized as polychlorinated biphenyls (PCBs). PCBs were widely used in electrical equipment, industrial processes, and various commercial products before they were banned in many countries due to their toxicity and persistence in the environment. Their ability to bioaccumulate and biomagnify in the food chain makes them particularly concerning.

PCBs are found in various environmental media, including soil, water, and sediment, and they can be transported over long distances, leading to contamination far from the original source. This widespread distribution and their persistence in the environment contribute to their classification as a major contaminant of concern. Unlike other contaminants listed, such as dioxins or mercury, PCBs have had a more extensive historical use and resulting environmental footprint, leading to their recognition as one of the most prevalent chemical hazards affecting public health and ecosystems.