Phoenix, Arizona – A dangerous gas could already be building inside homes across the Southwest as warm spring days and cooler desert nights keep windows closed, allowing radon—known as the “invisible killer”—to accumulate indoors within hours. The risk can increase quickly overnight as temperature swings limit natural ventilation.
According to the U.S. Environmental Protection Agency, radon is a radioactive gas that forms naturally in soil and enters homes through foundation cracks, slab floors, and crawl spaces. The Southwest—including Arizona, New Mexico, Nevada, and parts of Texas—generally falls within low to moderate radon zones, but elevated levels have been detected in localized areas, particularly where soil composition and home construction allow buildup.
Across cities like Phoenix, Albuquerque, Las Vegas, and El Paso, homes built on slab foundations are especially vulnerable during seasonal transitions. Many residents keep homes sealed overnight to maintain indoor temperatures, which can trap radon indoors and allow concentrations to rise without detection.
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 Southwest are urged to test homes now as conditions through April continue to support indoor buildup. Free and low-cost test kits are widely available, and mitigation systems can significantly reduce indoor levels before risks increase into early summer.
