Radon is a naturally occurring gas which is a part of everyones indoor air. It seeps into the building from the ground and accumulate in your home. To high levels is bad for your health! Radon is second leading cause of lung cancer, behind smoking.
Good news is that you can do something about it.
Where there is air there is radon! Humans cannot see, smell or taste it. Corentium simply makes it visible for you.