Assessment of Risks from Radon in Homes
For More Information on Radon Health Risks:
Radon Frequently Asked Questions
Radon Publications
- Citizen's Guide to Radon
- Home Buyer's and Seller's Guide to Radon
- Consumer's Guide to Radon Reduction
Technical Support Document to the 1992 Citizens Guide [EPA 400-R-92-011, May 1992] Copies can be ordered from EPA's National Center for Environmental Publications (NSCEP) www.epa.gov/nscep
The Agency has updated the estimates of lung cancer risks from indoor radon based on the National Academy of Sciences’ (NAS) latest report on radon, the Biological Effects of Ionizing Radiation (BEIR) VI Report (1999). EPA worked closely with the Science Advisory Board (SAB), an independent panel of scientific experts, to determine how best to apply the risk models developed by the BEIR VI committee. The SAB’s advice and recommendations were incorporated modifying and extending the methods and approaches used in BEIR VI to construct a single model yielding results midway between the results obtained using the two models preferred by the BEIR VI committee. The Agency's updated calculation of a best estimate of annual lung cancer deaths from radon is about 21,000 (with an uncertainty range of 8,000 to 45,000), which is consistent with the estimates of the BEIR VI Report. A single risk model also permitted the Agency to calculate a numerical estimate of the risk per unit exposure [lung cancer deaths per working level month (WLM)] which will be used to update estimated lung cancer risks from radon in various publications, including “ A Citizen’s Guide to Radon.”
- Read the full text of the updated risk assessment, “EPA Assessment of Risks from Radon in Homes PDF” (PDF, 99 pp, 1.1MB About PDF)
- [EPA 402-R-03-003]
Additional resources related to the updated risk assessment include:
- a Summary Fact Sheet on the updated risk assessment
- updated Radon Frequent Questions
- The National Academy of Sciences BEIR VI Report
The following is an updated chart of the lifetime risk of lung cancer death per person from radon exposure in homes (excerpted from the updated radon risk assessment).
Radon Level a | Lifetime Risk of Lung Cancer Death (per person) from Radon Exposure in Homes b | ||
pCi/L | Never Smokers | Current Smokers c | General Population |
20 | 36 out of 1,000 | 26 out of 100 | 11 out of 100 |
10 | 18 out of 1,000 | 15 out of 100 | 56 out of 1,000 |
8 | 15 out of 1,000 | 12 out of 100 | 45 out of 1,000 |
4 | 73 out of 10,000 | 62 out of 1,000 | 23 out of 1,000 |
2 | 37 out of 10,000 | 32 out of 1,000 | 12 out of 1,000 |
1.25 | 23 out of 10,000 | 20 out of 1,000 | 73 out of 10,000 |
0.4 | 73 out of 100,000 | 64 out of 10,000 | 23 out of 10,000 |
a Assumes
constant lifetime exposure in homes at these levels. b Estimates are subject to uncertainties as discussed in Chapter VIII of the risk assessment. c Note: BEIR VI did not specify excess relative risks for current smokers. |