Radon and Cancer Risk

Radon is a colorless, odorless gas that comes from the natural breakdown of uranium in soil, rock, and water. This radioactive gas can seep into homes and buildings through cracks in foundations, walls, and floors. When people breathe in radon over long periods, it can damage lung cells and increase cancer risk.

Understanding radon exposure helps people make informed decisions about testing their homes and reducing risk. Research shows that radon is the second leading cause of lung cancer in the United States, responsible for thousands of deaths each year. The good news is that radon problems can be found and fixed.

How Radon Forms and Enters Homes

Radon forms naturally when uranium in soil and rocks breaks down over time. This process happens everywhere, but some areas have higher levels than others. The gas moves up through the ground and can enter buildings through small openings in foundations.

Common entry points include cracks in concrete slabs, gaps around service pipes, floor drains, and sumps. Radon can also dissolve in well water and be released when the water is used for showering or cooking. However, breathing radon gas poses a much greater risk than drinking water with radon.

Weather conditions can affect radon levels in homes. Wind, rain, and changes in air pressure can influence how much radon enters a building. Indoor radon levels often change from day to day and season to season.

The Link Between Radon and Lung Cancer

When people breathe radon gas, tiny radioactive particles get trapped in their lungs. Over time, these particles give off radiation that damages lung tissue. Studies suggest this damage can lead to lung cancer years or decades later.

Research shows that radon exposure causes about 21,000 lung cancer deaths in the United States each year according to the Centers for Disease Control and Prevention. The risk is highest for people who smoke cigarettes and are also exposed to radon. However, radon can cause lung cancer in people who have never smoked.

The amount of risk depends on several factors. Higher radon levels and longer exposure times increase the chance of developing lung cancer. Cancer development from radon typically takes many years, making it important to address high radon levels as soon as possible.

Radon Levels and Geographic Distribution

Radon levels are measured in units called picocuries per liter of air (pCi/L). The Environmental Protection Agency recommends taking action to reduce radon levels at or above 4 pCi/L. Some areas of the country naturally have higher radon levels due to their geology.

The EPA’s radon zone maps show that parts of the Midwest, Appalachian region, and Rocky Mountain states often have elevated levels. However, high radon can be found in any state and any type of home. New and old homes, well-sealed and drafty homes, and homes with and without basements can all have radon problems.

Climate and building practices can influence indoor radon levels. Homes in colder climates may have higher levels because they are often built more tightly sealed and have heating systems that can draw radon up from the ground.

Testing for Radon in Homes

Testing is the only way to know if a home has high radon levels. Short-term tests measure radon for 2-90 days, while long-term tests measure for more than 90 days. Long-term tests give a better picture of average radon levels throughout the year.

Radon test kits are available at hardware stores, online, and through state radon programs. Some tests use charcoal canisters or alpha track detectors that are mailed to labs for analysis. Digital radon detectors can provide continuous readings over time.

Testing should be done in the lowest level of the home where people spend time regularly. Windows and doors should remain closed during short-term testing except for normal entry and exit. The EPA provides detailed testing guidelines to ensure accurate results.

Reducing Radon Levels

Several methods can reduce radon levels in homes. The most common and effective approach is a soil suction system, also called sub-slab depressurization. This system uses pipes and fans to draw radon from beneath the foundation and vent it safely outside.

Other reduction methods include sealing cracks and openings in foundations, improving ventilation, and installing radon-resistant features during construction. The best approach depends on the home’s design and the source of radon entry.

Professional radon contractors can design and install reduction systems. Many states certify or license radon contractors to ensure quality work. After installation, follow-up testing confirms that radon levels have been successfully reduced.

Radon in Other Settings

While homes are the primary concern for radon exposure, the gas can also be found in schools, workplaces, and other buildings. The EPA recommends that schools test for radon, especially in areas known to have higher levels.

Some workplaces may have elevated radon levels, particularly those in basements or lower levels of buildings. Underground mines historically had very high radon exposures, leading to increased lung cancer rates among miners before protective measures were implemented.

Water systems can also contain radon, especially those that use groundwater from wells. While drinking radon in water poses some risk, the greater concern is when radon is released from water into indoor air during everyday activities.

Common Myths and Misunderstandings

Myth: Only Old Homes Have Radon Problems

This is not true. Both new and old homes can have high radon levels. The age of a home does not determine its radon level. Factors like local geology, construction methods, and how the home contacts the ground are more important than age.

Myth: Homes Without Basements Don’t Have Radon Issues

Radon can enter any type of home, including those built on slabs or with crawl spaces. While basement homes may be more likely to have radon problems, homes without basements can still have dangerous levels of the gas.

Myth: Radon Only Affects Smokers

While the combination of smoking and radon exposure greatly increases lung cancer risk, radon can cause cancer in people who have never smoked. Research shows that radon is responsible for thousands of lung cancer deaths among non-smokers each year.

Key Takeaways

• Radon is a naturally occurring radioactive gas that can accumulate in homes and increase lung cancer risk
• Testing is the only way to know if radon levels are dangerous in a specific home or building
• Radon problems can be found in any type of home, regardless of age, construction, or geographic location
• Effective radon reduction systems can lower indoor radon levels and reduce health risks
• The combination of smoking and radon exposure significantly increases lung cancer risk
• Long-term exposure to elevated radon levels poses the greatest health risk, making early detection and mitigation important

Learn More

• EPA Radon Information – Comprehensive resource for testing and reducing radon
• CDC Radon and Health – Health effects and prevention information
• National Cancer Institute Radon Facts – Scientific information about radon and cancer risk
• World Health Organization Radon Fact Sheet – Global perspective on radon health risks
• US Preventive Services Task Force Lung Cancer Screening – Guidelines for lung cancer screening
• National Radon Safety Board – Educational resources and contractor information
• American Association of Radon Scientists and Technologists – Professional standards and certification information

Disclaimer: This information is for educational purposes only and is not medical advice. Talk to a healthcare provider about questions related to your health.