Radon In Basement Echo

If you live in York County, Pennsylvania, you probably know someone who has tested their basement for radon. Maybe you have done it yourself. The test kit arrives in the mail, you hang it in the lowest lived-in level of the house, and a few days later you get a number. That number tells you the average radon level in your basement. If it is above 4 picocuries per liter, the United States Environmental Protection Agency recommends you take action. But what does that action l