Radon is a colorless, odorless radioactive gas that poses significant health risks, primarily through inhalation of radon and its radioactive decay products. The main health concern is lung cancer, which develops when radon particles decay in the lungs and expose lung tissue to radiation over time. Radon is the second leading cause of lung cancer after smoking, and the risk increases with both the concentration of radon and the duration of exposure. Even non-smokers face elevated lung cancer risk from radon exposure, though smokers face compounded risk when exposed to both radon and cigarette smoke.
Radon accumulates in basements and lower levels of buildings where it seeps through cracks in foundations, gaps around pipes, and other openings in the structure. It can also be present in groundwater. Indoor radon levels vary significantly by geographic location, soil composition, and building construction.
Other potential health effects from radon exposure are less well-established but studied, including possible links to other cancers, though lung cancer remains the primary documented risk. Children may have higher lifetime risk of radon-related lung cancer due to longer potential exposure periods.
Radon risk can be mitigated through testing (radon test kits are available and relatively inexpensive), improved ventilation, sealing foundation cracks, installing radon mitigation systems, and using alternative water sources if radon is found in groundwater. Health agencies provide guidance on acceptable radon levels and remediation strategies. Regular testing is recommended, especially in homes located in areas with known radon presence.