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What is EPA's Action Level for Radon and What Does it Mean?

Radon in air is ubiquitous (existing or being everywhere at the same time). Radon is found in outdoor air and in the indoor air of buildings of all kinds. The EPA recommends homes be fixed if the radon level is 4 pCi/L (picocuries per liter) or more. Because there is no known safe level of exposure to radon, the EPA also recommends that Americans consider fixing their home for radon levels between 2 pCi/L and 4 pCi/L.

The average indoor radon concentration for America’s homes is about 1.3 pCi/L. It is upon this national average indoor level that the EPA based its estimate of 21,000 radon-related lung cancers a year. The average concentration of radon in outdoor air is .4 pCi/L or 1/10th of EPA's 4 pCi/L action level.

Read A Citizen's Guide to Radon
Read about Radon's Health Risks
Find out how to test your home
Find out how to fix your home by reading a "Consumer's Guide to Radon Reduction: How to Fix Your Home"