In the past few decades, the world has witnessed an increase in energy consumption which has led to rise in CO2 emissions and air pollutants such as SO2, NOx, PM, VOCs. With this have also risen the levels of secondary air pollutants like Ozone which are formed by reactions between primary pollutants in favourable meteorological conditions. Pollutants like NOx and NMVOCs (non-methane volatile organic carbon) react in the presence of sunlight to produce Ozone at ground levels which is not only injurious to human health but also could do serious damage to the agricultural yields.
As part of the study, The Energy and Resources Institute (TERI) has assessed the energy and emissions scenarios for the year 2005 to 2030 for various States and UTs of India based on the GAINS Asia model for different pollutants like particulate matter, oxides of sulphur and nitrogen oxides. An inventory of NMVOCs emissions has also been prepared for the country. Then, overall inventories for India show that the industrial sector dominates the PM emissions, whereas the transport sector has the major share in NOx and power plants contribute more to the SO2 emissions. Biomass burning has the maximum share in NMVOCs emissions.
The ambient concentration of different air pollutants obtained from NAMP (National Air Monitoring Programme) for various cities shows that most of the major cities of the country violate annual ambient air quality standards for particulate matter concentrations. Delhi, Ghaziabad and Jharia have shown very high levels of PM10 concentrations.
In recent years, few cities have also violated the annual average standard for NOx and there is a trend towards its increase. Delhi, Bangalore, Pune and Kolkata have shown higher levels of NOx concentrations mainly because of rapid rise in vehicular fleet.
