Baltimore, MD / Wilmington, DE – As winter cold settles across the Mid-Atlantic and homes remain tightly sealed, health officials in Maryland and Delaware are warning residents about a serious indoor health threat that often goes undetected. January marks National Radon Action Month, drawing attention to radon gas—commonly referred to as the “invisible killer” inside the home.
According to the U.S. Environmental Protection Agency (EPA), radon is a naturally occurring radioactive gas released from soil and rock. It can enter homes through foundation cracks, basements, crawl spaces, and utility openings. Parts of both Maryland and Delaware are classified as moderate to elevated radon risk, with higher levels detected in homes across central Maryland, northern Delaware, and surrounding counties.
Health experts say winter creates ideal conditions for radon buildup. In cities like Baltimore and Wilmington, homes and apartment buildings are sealed to conserve heat, allowing radon to accumulate indoors for extended periods. Long-term exposure to radon is the second leading cause of lung cancer in the United States, linked to an estimated 21,000 deaths each year. Smokers face the highest risk, but non-smokers are also vulnerable.
Unlike carbon monoxide, radon exposure does not cause immediate symptoms. Medical professionals warn the damage often occurs silently over many years, making home testing the only reliable way to detect elevated levels.
State health agencies in Maryland and Delaware recommend that residents test their homes—especially during winter when radon concentrations are typically highest. Test kits are relatively inexpensive, and mitigation systems can significantly reduce radon levels when elevated readings are found.
As National Radon Action Month continues, officials urge residents across both states to test now to reduce long-term health risks from this hidden indoor threat.
