Geospatial Analysis and Mapping for Radon Awareness

Radon is the second leading cause of lung cancer in the U.S. Concentrations of indoor radon exceeding the Environmental Protection Agency’s (EPA) action level of the gas have been found in schools across the U.S., but there is no national radon surveillance program. To better understand multiple environmental factors contributing to indoor radon levels in homes and schools, the Geospatial Research, Analysis, and Services Program (GRASP) collaborated with various internal and external partners to identify spatial relationships between indoor radon levels and environmental factors.

GRASP radon work overview
Interested? Learn more about radon in your home.

Public Health Impact: This collaborative effort demonstrates how place and policy impact health. Our geographic locations can affect our exposure to environmental toxins and policies differ by state for radon testing policies and radon-resistant new construction practices in schools.


Partners: Environmental Medicine Branch, Division of Cancer Prevention and Control, and Division of Adolescent and School Health

Geospatial Expertise Provided: Geographic information systems (GIS) and data analysis


Radon Health Effects and Mitigation in the U.S.

Radon exposure is associated with 21,000 lung cancer deaths in the U.S. each year . Testing the indoor air of homes, schools, and other buildings is the only way to detect radon. If indoor radon levels exceed the EPA’s action level of 4 picocuries per liter (pCi/L) a mitigation system can be installed to reduce the amount of radon detectable in a home’s air. The 1988 Indoor Radon Abatement Act directs the EPA to maintain a county-level radon zone map to assist national, state, and local organizations to target resources for testing, mitigating, and implementing radon-resistant building construction.

Collaborative Radon Research

GRASP was instrumental in establishing a radon working group to discuss the radon efforts across CDC/ATSDR and to promote the benefits of applying geographic information system (GIS) science and technology to better understand indoor radon risks. These efforts continue to raise awareness about the importance of testing for indoor radon in homes and schools, installing mitigation systems to reduce indoor radon concentrations, and using radon-resistant construction techniques to prevent exposure.

GRASP also formed key partnerships across CDC to collaborate on various efforts to protect against radon. In collaboration with colleagues from ATSDR’s Environmental Medicine Branch and the Florida Department of Health, GRASP assisted in the development and distribution of educational materials about radon testing and reduction for elementary school students and teachers. This work prompted a pilot project providing radon education and test kits to an elementary school in metropolitan Atlanta in support of the science, technology, engineering, and mathematics (STEM) education programming for the school, reinforcing the idea that particles may exist in the air, even though they cannot be seen with the naked eye.

Additionally, GRASP formed a partnership with the Division of Adolescent and School Health (DASH) in the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention to analyze data from nationally representative samples of school districts and schools from the School Health Policies and Practices Study (SHPPS). Using SHPPS data, GRASP and DASH colleagues determined the percentage of school districts that had a policy requiring schools be tested for radon, and the percentage of school districts that had a policy addressing radon-resistant new construction practices. A second analysis of SHPPS data collected at the school level was examined to also determine the percentage of schools that had ever been tested for radon. These analyses examined differences in the policies and practices across EPA Radon Zones. Both evaluations indicated a need for improved awareness for radon testing and radon-resistant school construction.

Finally, GRASP provided expertise in geospatial science and GIS to CDC’s Division of Cancer Prevention and Control (DCPC) to support radon awareness efforts in state cancer control plans. GRASP created a map that shows if states mention radon in their cancer plans. As of 2018, they determined that about half of state cancer plans recognized a connection between radon and cancer risk.

Raising Awareness for Radon

The connection of place, policy, and health is key to raising awareness and expanding prevention measures against environmental hazards such as radon. GRASP’s collaborative work with partners and communities continues to improve public health knowledge about indoor radon levels in the U.S. and lung cancer risks. Their efforts help lay the foundation to support future radon work and encourage communities to take action to protect their health.

Learn more about place and health here.

Helpful Terms & Facts

Radon is an odorless, colorless, tasteless, radioactive gas that can cause lung cancer. Radon forms naturally when uranium and thorium break down in rocks, soil, and groundwater. People can be exposed to radon primarily from breathing radon gas that infiltrates from soil through cracks and gaps in buildings and homes.

Data Sources: School Health Policies and Practices Study (SHPPS)


Number of annual U.S. lung cancer deaths associated with radon


Percentage of cancer plans that recognize an association between radon and cancer risk since 2018

4 pCi/L

EPA’s recommended mitigation level for radon (measured in picocuries per liter of air)

Teacher in front of classroom with children raising their hands.

Page last reviewed: September 15, 2020