study period at any of the other types of stations. Of course, this table does not indicate whether the absolute values of the component indices are increasing or decreasing, but it does identify the problem pollutants towards which special attention should be paid in the formulation of control programs. Three other pollutants, SO2, CO, and O3, surpass their respective standards less frequently than TSP. Only NO2 is generally well under its standard.A result of the study is that there is consistent agreement between EVI and NAQI. A disparity may arise when pollutants frequently exceed their standards. In this case, one would expect EVI to be considerably greater in value than NAQI because it accumulates excess values rather than taking only the maximum value in excess of the standard. Additionally, NAQI could also be greater than EVI because it includes an additional annual term. It also has an additional subindex for NO2, but the effects of this pollutant are probably negligible in this case.