Prior national radon maps relied on county level averages that masked significant block to block variation. This 2025 analysis pulled more than 6 million individual indoor measurements collected over two decades and built monthly, community level estimates of indoor radon concentrations. The resulting maps give public health programs and homeowners a far more precise picture of where risk is highest and when seasonal spikes occur.
Study· Exposure mapping
High Resolution National Radon Maps Based on Massive Indoor Measurements in the United States, 2025
Researchers used more than 6 million US radon measurements collected between 2001 and 2021 to develop detailed estimates of monthly community level radon concentrations.