Radon Retest Wander

If you have owned a home in St. Louis for more than a few years, you have likely heard about radon. It is a natural radioactive gas that comes from the breakdown of uranium in soil and rock. It can seep into homes through cracks in foundations, gaps around pipes, and other openings. The EPA radon guideline recommends action when levels reach 4.0 picocuries per liter or higher. But what happens after you test and maybe even install a radon mitigation system? Do you ever need