Question raised in Lok Sabha on air pollution, 21/07/2015. The ambient air quality is monitored by various State Pollution Control Boards, Pollution Control Committees for UTs, Central Pollution Control Board and NEERI at 593 locations in 249 cities, towns and industrial areas in 28 states and 5 UTs. The parameters being regularly monitored are SO2, NO2 and PM10 under National Air Monitoring Programme (NAMP). As per analysis of data for the year 2011, 2012 and 2013, levels of PM10 (annual averages) have been exceeded in 148, 137 and 152 cities, whereas for NO2 (annual averages) have been exceeded in 24, 12 and 11 cities, respectively. However, levels of SO2 (annual averages) have exceeded only in one city during 2012.