Assertion: formaldehyde | /r/HasProperty | formed in large quantities
Facets:
value: in the troposphere
type: LOCATION
value: by the oxidation of hydrocarbons
type: CAUSE
Source sentences:
text: Formaldehyde is formed in large quantities in the troposphere by the oxidation of hydrocarbons (Calvert et al. 1972; WHO 1989) leading to elevated formaldehyde levels shortly after periods of high vehicular traffic (Grosjean et al. 1996).