pollution
type: Concept
narrower: nitrogen oxides

nitrous oxide
type: Concept
broader: nitrogen oxides

concepts
type: Collection
type: ConceptGroup
member: nitrogen oxides

nitrogen oxides
type: Concept
definition: Nitrogen oxides are a group of chemical compounds involving the elements of nitrogen and oxygen in different configurations. They include nitric oxide (NO), which usually takes a gaseous state and is the most stable of the oxides. [Source: Encyclopedia of Environment and Society; Nitrogen Oxides]
narrower: nitrous oxide
broader: pollution