Existence of the environmental Kuznets curve has been argued. Some studies report there is an inverted U-shaped relationship between pollution and incomes. However it seems to vary among pollutants, functional forms, and estimation methods. In this paper, we examine pollution-income path for common air pollutants using conditional gamma density function. We find as GDP rises, not only the average pollution levels decline, but more importantly the variance of air pollutants suggesting convergence in pollution levels. Nevertheless, we cannot confirm there exists an inverted U-shaped path for common air pollutants.