Assertion: radon | /r/HasProperty | accumulated in building
Facets:
value: in sufficient quantities
type: OTHER
Source sentences:
text: Radon is a naturally occurring radioactive gas that, when it has accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time.
text: Radon is a naturally occurring radioactive gas that, when it has accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time.