Assertion: radon | /r/HasProperty | prevalent
Facets:
value: in many areas in the u.s.
type: LOCATION
value: extremely
type: DEGREE
Source sentences:
text: Radon is extremely prevalent in areas with large levels of granite concentrations.
text: Radon is the 2nd leading cause of lung cancer and is prevalent in many areas in the U.S. but is particularly high in the midwest (see linked map).