Dust chokes Gurgaon, greens blame it on construction [http://cmsenvis.cmsindia.org/resources/newspaper/details.asp?id=89996]GURUGRAM: The Millennium City remained the country's second most polluted city for 24 hours with Air Quality Index (AQI) reported at 337 between Wednesday and Thursday.The most polluted city was Gaya with AQI recorded at 352, while the third most polluted city was Lucknow with AQI level at 321. The AQI in Delhi, on the other hand, was recorded at 264.