Radon is a gas that is created in bedrock and is the second leading cause of lung cancer. Since we live in an area with a lot of bedrock, radon is an issue in Western North Carolina if it builds up in a house above acceptable EPA limits (4.0 pico curies per liter). I ALWAYS recommend radon testing during your due diligence period in purchasing a home, and it is a good idea for sellers to test if they have never done so. Even if radon has been tested in the past, it should be retested regularly because as a gas, its levels fluctuate, especially with barometric pressure, temperature and seasons. Radon is relatively easy to mitigate from a house.
Here is more information on radon: click here
Increasingly, more homes in our market have radon mitigation systems already installed, and some contractors are routinely installing them as they build - just in case. Even when a home has a system in place, I suggest testing the radon levels to make sure the system is working properly. Don't freak-out over radon. It can be addressed in a highly successful and fairly affordable manner.