HYDERABAD: Air pollution is not just limited to the air around us but includes the atmosphere above us. As far as the Greater Hyderabad region is considered, the troposphere above it has been found to be an NO2 emission hotspot.
Troposphere is the lowest layer of atmosphere, which extends till about 10 km from the Earth’s surface. The gaseous emissions on Earth’s surface inevitably enter into the atmosphere. Greenpeace India observed the concentration of NO2 over India using the Tropospheric Emission Monitoring Internet Service (TEMIS), which provides the data on tropospheric NO2.
The report ‘India NO2 air pollution map: Highlighting India’s worst NO2 emission hotspots’ points out that the tropospheric emission hotspots are mainly located over major cities and areas where coal-based thermal power plants are located. The reasoning - NO2 is majorly emitted by vehicles due to burning of fuel and by thermal power plants due to burning of coal. The concentrations are worse over parts of Peddapalle and Kothagudem districts.
As a result, while the high tropospheric NO2 concentration over Greater Hyderabad can be attributed to the lakhs of vehicles plying the city roads, in Peddapalle and Kothagudem districts it is the presence of high capacity coal-fired power plants operated by NTPC and TSGENCO at Ramagundam and Kothagudem.
Troposhperic NO2 concentration close to that of Greater Hyderabad region was also observed over Bhupalpally, which is home to another coal-fired TSGENCO power plant.
The satellite data shows that though not as high as in the hotspots but areas miles away from the hotspots are also affected with low levels of troposhperic NO2 concentration. For example, low tropospheric NO2 concentrations were recorded as far as Kagaznagar in Adilabad or Warangal and Siddipet, which are 100-150 km away from power plant in Ramagundam.
Multi-fold harm
While NO2 is dangerous in itself, it also increases the concentration of Particulate Matter and Ozone, both of which are harmful for humans