What is the average level of radon found in homes in the U.S.?

Based on a national residential radon survey completed in 1991, the average indoor radon level is about 1.3 picocuries per liter (pCi/L) (50 becquerels per cubic meter (Bq/m3)) in air in the United States. The average outdoor level is about 0.4 pCi/L (15 Bq/m3).

Learn more about radon by visiting Health Risks of Radon and the Radon webpage.