Naturally, Americans do things the hard way and measure radon in pCi/L. According to Google, > 1 pCi/L is equal to 37 Bq/m3 Our EPA recommends remediation if

Naturally, Americans do things the hard way and measure radon in pCi/L. According to Google, > 1 pCi/L is equal to 37 Bq/m3 Our EPA recommends remediation if your home measures more than two, strongly so if it measures more than 4 pCi/L. That 4 number is supposedly equivalent to smoking 8 cigarettes a day, in terms of cancer risk. Here in the upper Midwest US, geology creating more radon buildup combined with cold winters mean that our basements are in a constant state of slightly negative air pressure, drawing it inside. Not only can it enter through cracks in the concrete basement walls and floors, but many or most homes will have an opening in the floor somewhere for a sump pump to help move spring snow melt moisture away from the house. Supposedly, between 1/3 and 2/5 homes in the US have or need radon remediation, and it supposedly is the second-leading cause of lung cancer here, after smoking tobacco.