Mo. Rev. Stat. § 643.030

The discharge into the ambient air of air contaminants so as to cause or contribute to air pollution is contrary to the public policy of Missouri and in violation of this chapter. It is the intent and purpose of this chapter to maintain purity of the air resources of the state to protect the health, general welfare and physical property of the people, maximum employment and the full industrial development of the state. The commission shall seek the accomplishment of this objective through the prevention, abatement and control of air pollution by all practical and economically feasible methods.