This paper tests the Environmental Kuznets Curve (EKC) hypothesis for four local (SOx, NOx , CO, VOC) and two global (CO2, GHG) air pollutants. Using a panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful EKC exists only for CO, VOC and NOx , where for CO2 the curve is monotonically increasing. For GHG there is indication of EKC, but most countries are still on the increasing path of the curve. SOx emissions follow a U-shaped curve.