What is certain is that radon gas is colorless, odorless and tasteless. Unlike smoke alarms and carbon monoxide alarms, there are no radon alarms that can be purchased from retail suppliers. There is conclusive undisputed medical evidence that radon causes cancer, but at what levels and after how long an exposure seems unclear. Testing from a professional will cost between $100 and $200, and, full disclosure, you can also buy test kits in home improvement centers and hardware stores if you prefer. The cost for mitigation typically runs from $500 to $1,100, depending on whether the home has a sump pump, availability of an electrical circuit and other factors.