Black Hawk County Board of Health
Position Statement on Radon
Original adoption: November 29, 2017; Revised: January 28, 2026
(References used in the development of the position statement are shown at the end of the statement.)
Radon is a naturally occurring, odorless, colorless, and tasteless radioactive gas that seeps into homes and buildings from the soil. Exposure to radon is the leading cause of lung cancer among non-smokers and the second leading cause overall. The U.S. Environmental Protection Agency (EPA) and the Surgeon General estimate radon-related lung cancers result in approximately 21,000 deaths annually in the United States. Lung cancer is the third most common cancer in Black Hawk County and the county ranks 11thhighest among Iowa’s 99 counties in lung cancer incidence. Each year in Black Hawk County, there are about 125 new cases and 66 deaths from lung cancer.
Radon exposure is the leading cause of lung cancer among people who have never smoked and causes approximately 12% of lung cancers annually in the United States. And for people who have smoked, the EPA estimates that radon exposure can increase their risk of lung cancer by 10x.
There are three zones that measure the potential for elevated indoor radon levels with Zone 1 having the highest potential for a predicted average indoor screening level greater than 4 pCi/L, Zone 2 having a moderate potential and Zone 3 having a low potential. The entire state of Iowa is designated by the EPA as Zone 1.
Iowa has the largest percentage of homes (71.6%) at or above the EPA’s action level of 4 picocuries per liter (pCi/L). In fact, the average radon level in Iowa homes is 8.5 pCi/L, compared to an overall U.S. average of 1.3 pCi/L. In Black Hawk County, almost 40% of test results performed from 2000 – 2024 are at or above 4 pCi/L.
Radon exposure is not only an environmental risk, but the lack of protective policies makes it a health equity challenge. While radon testing is relatively inexpensive, mitigation can be financially burdensome for many Iowans. The financial and legal burdens of testing and mitigation disproportionately affect low-income, rental, and underserved communities who lack the authority or resources to mandate risk reduction.
Black Hawk County Board of Health Recommendations
The Board of Health advocates for the following state or local policies and public health measures to reduce the impact of radon exposure. The recommendations are based on standards set by the EPA, Surgeon General, the American Lung Association, and/or the Iowa Department of Health and Human Services.
- Mitigation Levels: The Board of Health strongly recommends that radon mitigation actions be taken in homes with radon levels at or above 4 pCi/L. As no exposure to radon is completely safe, the Board also recommends that mitigation actions be considered for levels between 2pCi/L and 4pCi/L. Most homes can achieve a radon level less than 2pCi/L with a quality radon reduction system.
- Mandatory Radon-Resistant New Construction (RRNC): The Board advocates for the mandatory adoption of Radon-Resistant New Construction (RRNC) techniques (as outlined in the current International Residential Code) in all new residential and commercial construction within Black Hawk County jurisdictions. This map shows the known cities and counties that have adopted RRNC requirements for new construction.
- Mandatory Testing and Mitigation in Rental Properties: The Board advocates for state or local ordinances mandating testing in all residential rental properties, disclose all known results to existing and potential tenants, and follow the EPA guidelines for mitigation.
- Re-Testing and Maintenance: The Board recommends that homes be re-tested every two years and following any major structural renovations. In addition, active mitigation systems should be maintained regularly.
- Schools and Childcare Centers: The Board supports the Iowa Code requirements for public schools and childcare centers and advocates for strict compliance monitoring, full funding for mitigation, and extending mandatory testing and mitigation requirements to all private schools.
- Healthcare Provider Involvement: The Board encourages all local healthcare providers to incorporate radon education into routine physicals and well-child visits, and to facilitate access to low-cost or free test kits to increase home testing rates.
- Real Estate Transactions: The Board supports the national recommendations that all homes be tested for radon as part of the real estate transaction process.
References
- Eidy, M., Regina, A. C., & Tishkowski, K. (2024, January 26). Radon toxicity. In StatPearls [Internet]. StatPearls Publishing.
- Iowa Cancer Registry.(2025, May 13). Cancer in Black Hawk County.
- Iowa Cancer Consortium. (n.d.). Radon.
- U.S. Environmental Protection Agency. (2016, December). A citizen’s guide to radon.
- U.S. Environmental Protection Agency. (2025, November 19). Health risk of radon.
- American Lung Association. (n.d.). Radon in Iowa.
- Iowa Department of Health and Human Services.(n.d.). Radon resources.
- Iowa Department of Health and Human Services.(n.d.). Radon county metrics dashboard.