The indoor level of radon isn't going to be lower than outdoors. Indoors is either the same or higher than outdoors. Your level of exposure to radon will not go up by going outside. That's your background exposure level, and is already baked into the calculation of how much an effect an elevated exposure to radon in your home will have on you. Radon is a serious thing to consider, especially if your home has a basement. Radon mitigation is not a scam conspiracy.