The United States Environmental Protection Agency recommends action for any house with a concentration higher than 148 Bq/m (given as 4 pCi /L). Nearly one in 15 homes in the U.S. has a high level of indoor radon according to their statistics. The U.S. Surgeon General and EPA recommend all homes be tested for radon. Since 1985, millions of homes have been tested for radon in the U.S.