The Dangers of Radon
See how Radon is dangerous and ways to detect it.
Radon has an action level of 4 pCi/L (pico-curies per liter) which is a unit for radioactive concentrations. But under 4 pCi/L is still not acceptable you are just not in grave danger. In normal day outside there is about .4 pCi depending on your surroundings. A geiger counter can be used to monitor the level. PA has one of the largest radon levels in the country!
Like most radiation it does not only have one use but all of its commercial uses have to do with the radiation it emits. It can be used to cure cancer in small amounts but it also can cause cancer with too much exposure.