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Radon in Sioux City, IA
Sioux City is in Woodbury County, and every Iowa county is in the EPA's highest radon zone. Here are the verified facts that matter for homeowners.
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The Numbers for Iowa
- EPA Zone 1 statewide. The EPA has identified all counties in Iowa as Zone 1, meaning a predicted average indoor screening level above 4 pCi/L.
- Average indoor level. The Iowa Department of Public Health reports an average indoor radon level of 8.5 pCi/L in Iowa, compared with 1.3 pCi/L in the United States.
- Share of homes. The state estimates that as many as 5 in 7 Iowa homes have elevated radon levels.
- Health burden. The EPA estimates radon is responsible for about 21,000 lung cancer deaths a year in the United States, and approximately 400 a year in Iowa.
- Action level. The EPA recommends fixing a home at 4 pCi/L or higher and says to consider fixing between 2 and 4 pCi/L.
These come from the EPA Map of Radon Zones and the Iowa Department of Public Health's radon fact sheet for home buyers and sellers. The state agency has since been reorganized under Iowa Health and Human Services, so look for current radon pages there.
Why Iowa Has So Much Radon
Radon forms when uranium and radium in soil and rock break down. The Iowa Department of Public Health explains that glacial activity long ago left ground-up mineral deposits, including uranium, in the soil and upper crust across Iowa. Because radon is a gas, it travels through soil and can seep into buildings.
Radon enters a house because the lower levels are typically at lower pressure than the soil around the foundation. Warm air rising in a heated house creates a small vacuum below, and soil gas is drawn in through cracks in the foundation, floors and walls, hollow-block walls, openings around floor drains, pipes and sump pumps, and crawl spaces. Cold weather and tightly sealed homes can make the effect stronger, which is one reason winter levels can run higher.
Health Effects, Plainly
The EPA says radon is the number one cause of lung cancer among non-smokers and responsible for about 21,000 lung cancer deaths each year, with about 2,900 of those among people who never smoked. The Iowa Department of Public Health describes radon as the leading cause of lung cancer in non-smokers and the second leading cause overall.
Radon does not cause short-term symptoms you would notice. The risk comes from breathing elevated levels over many years, and the risk rises with the level and the length of exposure. That is why the guidance is to test and fix rather than wait for a sign. We are not a medical source, so talk with a doctor about personal health questions.
Local Resources
- Siouxland District Health Department. It has sold short-term radon test kits to the public and has used the data to guide radon efforts in the area. Contact the department for current availability.
- Iowa radon program. The state publishes information on radon and a list of credentialed radon measurement and mitigation specialists, organized by county, on its website. Search for the Iowa radon program on the state Health and Human Services site.
- EPA radon pages. The EPA publishes the Map of Radon Zones, a consumer guide to radon reduction and health risk information at epa.gov/radon.
- American Lung Association. Publishes Iowa-specific radon information for homeowners.
What to Do Next
- Test your home. See radon testing for how to do it correctly.
- Compare to 4 pCi/L. Use the EPA's guidance on when to fix.
- If you need a system, read about radon mitigation and cost factors, then request a quote.
- Buying, selling or building? See home sale testing and new construction systems.
Common Radon Myths
- My neighbor tested low, so I am fine. The Iowa Department of Public Health notes that radon levels can vary considerably from house to house, even on the same street, and a high and a low level can be found in homes directly next to each other.
- New homes do not have radon. The state says radon is found in new and old homes alike.
- Only houses with basements are affected. The state says radon is found in homes with and without basements.
- If it were a problem I would smell it. Radon is odorless and invisible. Testing is the only way to know.
- A map tells me if I need to test. The EPA says its zone map should not be used to decide whether individual homes need testing, and recommends testing all homes.
Common Questions
Is all of Iowa in the highest radon zone?
Yes. The EPA has identified all counties in Iowa as Zone 1, the highest category, meaning a predicted average indoor screening level above 4 pCi/L.
What is the average radon level in Iowa homes?
The Iowa Department of Public Health reports an average indoor level of 8.5 pCi/L in Iowa, compared with 1.3 pCi/L for the United States.
Where can I get a radon test kit in Sioux City?
The Siouxland District Health Department has sold short-term test kits to the public, and kits are also sold by retailers and laboratories. Contact the department for current availability.
Nearby Communities
We route requests from Sioux City and the surrounding area. Pick your town, or see the full service area list.
Know Your Radon Level, and Fix It If You Need To
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