The city's traffic police periodically builds up a hype over anti-pollution steps being under-taken by the department and at the end of every exercise takes credit for challaning thousands of vehicle owners who were supposedly polluting the Capital's air with their two, three or four-wheeler monsters. The anti-pollution drives of the Delhi Traffic Police are much publicised through media. A local Non-Governmental Organisation - Vatavaran - struck upon the idea of finding out by how much has the city's pollution level decreased. And much to its shock, the study revealed that despite all the hue and cry, pollution by various types of vehicles in Delhi during the past 18 months has actually reduced by only 3.4 per cent.