Radon and Cancer (Fact Sheet)

How can people know if they have an elevated level of radon in their homes?

Testing is the only way to know if a person’s home has elevated radon levels. Indoor radon levels are affected by the soil composition under and around the house, and the ease with which radon enters the house. Homes that are next door to each other can have different indoor radon levels, making a neighbor’s test result a poor predictor of radon risk. In addition, rain or snow, barometric pressure, and other influences can cause radon levels to vary from month to month or day to day, which is why both short- and long-term tests are available.

Short-term detectors measure radon levels for 2 days to 90 days, depending on the device. Long-term tests determine the average concentration for more than 90 days. Because radon levels can vary from day to day and month to month, a long-term test is a better indicator of the average radon level. Both tests are relatively easy to use and inexpensive. A state or local radon official can explain the differences between testing devices and recommend the most appropriate test for a person’s needs and conditions.

The U.S. Environmental Protection Agency (EPA) recommends taking action to reduce radon in homes that have a radon level at or above 4 picocuries per liter (pCi/L) of air. About 1 in 15 U.S. homes is estimated to have radon levels at or above this EPA action level. Scientists estimate that lung cancer deaths could be reduced by 2 to 4 percent, or about 5,000 deaths, by lowering radon levels in homes exceeding the EPA’s action level.

The EPA has more information about residential radon exposure and what people can do about it in the Consumer’s Guide to Radon Reduction.

Where can people find more information about radon?

The National Radon Program ServicesExit Disclaimer at Kansas State University is funded by the EPA and aimed at promoting public awareness of radon, increased testing, and the reduction of radon in homes, schools, and buildings. It provides a variety of resources, including the National Radon Hotlines, referrals to state radon programs, radon test kit orders, radon mitigation promotion, and other technical assistance and outreach activities.

Consumers can contact the National Radon Hotline at:

• 1–800–SOS–RADON (1–800–767–7236) to reach an automated system for ordering materials and listen to informational recordings
• 1–800–55–RADON (1–800–557–2366) to contact an information specialist, or by sending an e-mail

More information is also available online from the EPA.

Selected References

1. Alavanja MC, Lubin JH, Mahaffey JA, Brownson RC. Residential radon exposure and risk of lung cancer in Missouri. American Journal of Public Health 1999; 89(7):1042–1048. [PubMed Abstract]

2. Darby S, Hill D, Doll R. Radon: a likely carcinogen at all exposures. Annals of Oncology 2001; 12(10):1341–1351. [PubMed Abstract]

3. Darby S, Hill D, Deo H, et al. Residential radon and lung cancer: detailed results of a collaborative analysis of individual data on 7148 persons with lung cancer and 14,208 persons without lung cancer from 13 epidemiologic studies in Europe. Scandinavian Journal of Work, Environment and Health 2006; 32(Suppl 1):1–83. Erratum in Scandinavian Journal of Work, Environment and Health 2007; 33(1):80. [PubMed Abstract]

4. Field RW. A review of residential radon case-control epidemiologic studies performed in the United States.Reviews on Environmental Health 2001; 16(3):151–167. [PubMed Abstract]

5. Field RW, Steck DJ, Smith BJ, et al. Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study. American Journal of Epidemiology 2000; 151(11):1091–1102. [PubMed Abstract]

6. Frumkin H, Samet JM. Radon. CA: A Cancer Journal for Clinicians 2001; 51(6):337–344. [PubMed Abstract]

7. Harley NH, Robbins ES. Radon and leukemia in the Danish study: another source of dose. Health Physics2009; 97(4):343–347. [PubMed Abstract]

8. Krewski D, Lubin JH, Zielinski JM, et al. A combined analysis of North American case-control studies of residential radon and lung cancer. Journal of Toxicology and Environmental Health, Part A 2006; 69(7):533–597. [PubMed Abstract]

9. Lagarde F, Falk R, Almrén K, et al. Glass-based radon-exposure assessment and lung cancer risk. Journal of Exposure Analysis and Environmental Epidemiology 2002; 12(5):344–354. [PubMed Abstract]

10. Möhner M, Gellissen J, Marsh JW, Gregoratto D. Occupational and diagnostic exposure to ionizing radiation and leukemia risk among German uranium miners. Health Physics 2010; 99(3):314–321. [PubMed Abstract]

11. National Research Council. Committee on Health Risks of Exposure to Radon: BEIR VI. Health Effects of Exposure to Radon. Washington, DC: National Academy Press, 1999.

12. U.S. Environmental Protection Agency (January 2009). A Citizen’s Guide to Radon: The Guide to Protecting Yourself and Your Family From Radon. Retrieved October 18, 2011.

Source: National Cancer Institute.