35 Ill. Adm. Code 211.390
Air Pollution
Section 211
Section 211.390 Air
Pollution
"Air pollution" means
the presence in the atmosphere of one or more air contaminants in sufficient
quantities and of such characteristics and duration as to be injurious to
human, plant or animal life, to health, or to property, or to unreasonably
interfere with the enjoyment of life or property.