Assertion: carbon tetrachloride's concentration | /r/HasProperty | 1.0 μg/m3
Facets:
value: in several homes in u.s. cities
type: LOCATION
Source sentences:
text: Also, in several homes in U.S. cities, typical indoor concentrations were about 1.0 μg/m3 (0.16 ppb), with some values up to 9 μg/m3 (1.4 ppb).