@kedim I too had never smoked and also read about radon gas. I ordered the kits and tested our basement and bedroom, both results were so low they were not factors. It’s difficult to say why I’m dealing with this but in the end it doesn’t matter now just getting through this disease keeping it at bay and even trying to cure it. U do understand your desire to find out as I had done. At least you can put a check on your list of causes. Best of luck going forward.