AIR POLLUTION – MONITORING MODELLING AND HEALTH

90
Air Pollution – Monitoring, Modelling and Health
Pollutant
/Season
Background Residential Industry kerbside
Wint Post-
Mon
Sum Wint
Post-
Mon
Sum Wint
Post-
Mon
Sum
Wint
Post-
Mon
PM 10 355 300 232 505 671 81 546 781 229 451 941 337
PM 2.5 - - 131 301 - 30 197 314 52 306 361 107
SO 2 8 15 8 14 18 78 85 77 11 20 20 12
NO 2 31 33 25 73 88 29 159 142 60 109 121 47
Table 3. Average air quality levels (μg/m3) in Delhi at background, residential, industry
and kerbside areas for winter, post monsoon and summer periods of 2007 (Nat.Rep., 2010).
Sum
It can also be seen that in terms of PM levels, Delhi shows highest air pollution levels during
post-monsoon. Observations at Delhi show much higher variability according to the
characteristics of the monitoring station area. NO 2 levels are exceeded at the residential area
sites in Delhi (35%), NO 2 levels generally exceed the ambient air quality standards at
kerbside locations, particularly during winter and post monsoon seasons at Delhi by 85 –
95%.This analysis shows that PM problem is severe and NO 2 is the emerging pollutant that
requires immediate planning to control its emissions. NO 2 is mainly contributed by manmade
sources such as vehicles, industry and other fuel combustion activities. Delhi exhibits
high percentage of NO 2 from energy production owing to presence of power plants. Fig. 3
presents the trend of annual variation of Respirable Suspended Particulate Matter (RSPM or
PM 10 ), SO 2 and NO 2 in Delhi in 2001-2008. The annual average RSPM and NO 2
concentrations are increasing in Delhi while SO 2 values are declining due to the low sulfur
fuel use in power plants. Other fuels consumed in domestic use and, in some cities, for
vehicles, are LPG and CNG respectively.
Fig. 3. Trends in annual average concentrations of RSPM, SO 2 , and NO 2 in residential areas
of Delhi (National air quality standard is 60 for RSPM ,NO 2 and SO 2 ).