According to EPA estimates, what is the incidence of homes in the U.S. that have radon levels above 4 pCi/L?

The correct answer indicates that the EPA estimates approximately 1 in 15 homes in the U.S. have radon levels exceeding 4 pCi/L. This statistic is significant because it highlights the prevalence of radon as a health hazard in residential environments. The value of 4 pCi/L is established as the action level at which mitigation measures are recommended to reduce radon concentrations, which is important for public health due to the association between long-term radon exposure and lung cancer risk.

Understanding this statistic helps homeowners recognize the importance of radon testing, particularly in areas known for higher soil gas levels. The EPA's estimate serves as a crucial reminder for homeowners to be vigilant and proactive about monitoring radon levels within their households. Active mitigation strategies can prevent potential health risks associated with elevated radon concentrations, reinforcing the necessity of awareness and action in maintaining safe living environments.