symptoms of radon gas poisoning

https://www.google.com/maps/d/u/0/edit?mid=1SH7JnkrnmcE_Aaxuw5RBaItN1NjVGreX&ll=36.14683223511943%2C-86.76655149999999&z=10

Radon can not be seen, scented, really felt, or otherwise discovered, other than with a test. That's why, according to the EPA, the only method to understand for certain if you have a radon problem is to examination.