Benzo(A)Pyrene is a cancer-causing compound found in coal tar and smoke. It can enter water from industrial pollution or leaching from coal tar-lined water pipes.

Benzo(A)Pyrene is a polycyclic aromatic hydrocarbon (PAH) formed during incomplete combustion of organic matter. It enters water systems through industrial emissions, vehicle exhaust, and wildfires. In older water distribution systems, it can leach from coal tar pipe linings. Benzo(A)Pyrene is persistent in the environment and bioaccumulates in aquatic organisms. Water utilities measure it in parts per billion (ppb) or nanograms per liter (ng/L). Reducing industrial pollution and updating water infrastructure can help minimize exposure.