Radon is a radioactive gas that occurs naturally in soil and rock. It can enter drinking water through groundwater and poses a lung cancer risk when released into the air.

Radon, a colorless and odorless radioactive gas, forms naturally as uranium in soil and rocks decays. It can seep into groundwater through rock fissures, particularly affecting well water users. When contaminated water is used, radon can be released into the air, where it poses the greatest health risk. Radon levels in water are measured in picocuries per liter (pCi/L). While concerning, mitigation methods exist for homes with elevated radon levels in their water supply.