"Air pollution" means the presence in the outdoor atmosphere of one or more air contaminants or any combination thereof in such quantity and duration as may tend to:
1. Injure human health or welfare, animal or plant life or property.
2. Limit visibility or interfere with scenic, esthetic and historic values of the State.
3. Interfere with the enjoyment of life or property.
(Added to NRS by 1971, 1192)