The Mississippi plan was evaluated on the basis of the following classifications:
| Air quality control region
| Pollutant
|
|---|
| Particulate matter
| Sulfur oxides
| Nitrogen dioxide
| Carbon monoxide
| Photochemical oxidants (hydrocarbons)
|
|---|
| Mobile (Alabama)-Pensacola-Panama City (Florida)-Gulfport (Mississippi) Interstate | I | I | III | III | I
|
| Metropolitan Memphis Interstate | I | III | III | III | I
|
| Mississippi Delta Intrastate | III | III | III | III | III
|
| Northeast Mississippi Intrastate | II | III | III | III | III |