Pollutants Period [4] [5] [6] [7] 2008 2014 Sulphur Dioxide (SO2) (µg/m3) Hourly 350 350 350 - - Daily 125 125 125 125 365 Annual 20 - - - - Winter (October-March) 20 - 20 - 80 -Nitrogen Dioxide (NO2) (µg/m3) Hourly 200 100 200 200 - Daily - - - - - Annual 40 20 40 40 100

Table 1: National and International Ambient Air Quality Standards for SO2 and NO2 (in μg/m3).