radon poisoning
https://home.sparklight.com/finance/category/press?source=syndication-cloud&title=what-are-the-symptoms-of-radon-poisoning/
Radon exposure is the second-leading ecological root cause of lung cancer cells fatality, after cigarette smoke (Copes 2007; EPA 2009a), and also the leading cause of lung cancer fatality for nonsmokers (EPA 2009b).