Philadelphia, Pennsylvania – A dangerous gas could already be building inside homes across the Mid-Atlantic as cool spring nights keep windows closed, allowing radon—known as the “invisible killer”—to accumulate indoors within hours. The risk can increase rapidly overnight as fluctuating temperatures lead residents to seal homes against lingering cold.
According to the U.S. Environmental Protection Agency, radon is a radioactive gas that forms naturally in soil and seeps into homes through foundation cracks, basements, and crawl spaces. The Mid-Atlantic region—including New York, New Jersey, Pennsylvania, Delaware, Maryland, and Virginia—contains pockets of both moderate and high radon potential, with elevated levels frequently detected in interior and suburban counties.
Across major population centers like Philadelphia, Newark, Baltimore, and Northern Virginia suburbs, older homes and widespread basement construction increase the risk of indoor buildup. In Pennsylvania and parts of New York, geology further raises exposure potential, especially in areas with shale and granite beneath homes.
Health officials warn radon is the second leading cause of lung cancer in the United States, linked to about 21,000 deaths annually. The gas produces no smell or immediate symptoms, making testing the only reliable way to detect it.
Residents across the Mid-Atlantic are urged to test homes now as conditions through April continue to trap indoor air. Free and low-cost test kits are widely available, and mitigation systems can significantly reduce levels before risks increase into early summer.
