Most of the country?s major cities violate annual ambient air quality standards for particulate matter (PM) concentrations, according to a study conducted by The Energy and Resources Institute (Teri) in association with Toyota Motor Corporation of Japan.
The study assesses the energy and emission scenarios for 2005-2030 for various states and Union territories based on the GAINS Asia model for different pollutants like particulate matter, oxides of sulphur and nitrogen oxides. An inventory of non-methane volatile organic compounds (NMVOCs) emissions has also been prepared for the country.
The overall inventories for India show that the industrial sector dominates the PM emissions, whereas the transport sector has the major share in nitrogen oxides and power plants contribute more to sulphur dioxide emissions. Biomass-burning has the maximum share in emissions of NMVOCs.
Data from the National Air Monitoring Programme (NAMP) show Delhi, Ghaziabad and Jharia have very high levels of PM10 concentrations. In recent years, few cities have also violated the annual average standard for nitrogen oxides and there is a trend towards their increase. Delhi, Bangalore, Pune and Kolkata have shown higher levels of nitrogen oxides mainly due to a rapid rise in vehicular fleet.
Ozone monitoring is presently being carried out in few cities only and the results in Delhi show that concentrations have violated the set standards, specifically during higher photo-chemical activity.
Because of its chemistry with other pollutants, ozone is expected to be higher in the regions outside the urban centres and may cause significant damage to the agricultural yield in addition to its ability to impact human health.
This clearly indicates that among these pollutants, particulate matter pollution is most widespread in Indian cities. However, pollutants like nitrogen oxides and ozone are emerging threats for the future and proactive policies would be required for their control.
Sumit Sharma, Fellow & Area Convenor, Teri, said: ?This study is first of its kind, which simulates ozone concentrations across the whole Indian sub-domain. The result gives a fair idea about the intensity of ozone pollution in different regions and also helps in understanding the pre-cursors responsible for its formation. However, the modelled results have to be strongly complemented by actual primary monitoring of ozone, hence the need to strengthen our network for ozone monitoring is evident.?