Being in the Washington Metro, there are many homes that have radon. Unfortunately,most people don't know they have it because it is an odorless gas and you can't see it but it can cause lung cancer. Before you run out of your house know that testing is very economical, usually around $125-163 in Montgomery. County. Best to have a professional inspector do it (in MD they have to be licensed). They can use canisters or an air sample test. Talk to the inspector and go onto the EPA site for more Info. Whomever does the test should not be the company who also does the Remediation. Just make sure theyare MDE approved. Basically they would need to dig a hole past your foundation and seal all cracks in the lowest part of your home. This is about $1000-$1500 depending on the size of home and whether it has a passive system or not. By the way it is a falicy that if you are on a slab or don't have a basement, or that it is a walkout than you are okay. I know all of this from first hand since my first house came back with high levels. Good luck and hope this helps you.