A CITY THAT SMOKES: CURIOUS CASE OF SMOG IN DELHI

The capital city region of India, New Delhi has consistently topped the list of polluted cities. The polluted air is equivalent to puffing 10 cigarettes daily. But what is the reason behind this & why do winters make it worse? Let’s find out!

This problem in national capital region of India (NCR) began in 1990s largely owing to vehicular emissions. Following legislative & judicial intervention in late 90s, public transport vehicles running on petrol and diesel were converted to operate on compressed natural gas.

Despite reforms, pollution in NCR has not reduced. With rising population, sources of pollution have also increased. NCR has seen a surge in number of vehicles & industrial emissions. Construction activities in NCR also contribute a lot to the pollution levels.

While these factors manage to keep the air quality index (AQI) in NCR at worryingly high levels throughout the year with AQI usually around 200 or more, NCR’s geography and topography also contributes in making things worse for its residents.

In summer, air in lowest part of atmosphere is warmer & lighter thereby rising easily & carrying pollutants away from ground & mixing it with cleaner air in upper layer of atmosphere. In winters, the cool air near earth’s surface is dense which gets trapped under the warm air.

This effectively forms a ‘lid’ in the atmosphere due to which pollutants in air do not get enough space to disperse in the atmosphere during winters. NCR which experiences cold, dry winters thus ends up having a blanket of pollution.

NCR is a land-locked region. It falls in the Indo-Gangetic plain which is akin to a valley surrounded by Himalayas and other mountain ranges. Consequently, low wind speeds and lack of moisture during winters make it difficult to disperse pollution.

NCR also receives pollution caused by stubble burning (traditionally done to restore soil fertility) which is rampant in the autumn months when the wind direction prevailing in NCR is north-westerly bringing the pollutants caused by stubble burning in north western India to NCR.

While NCR has been the unfortunate victim of its poor placement, it has its share of political challenges too. NCR falls in different provinces governed by 3 different governments which makes law making to curb pollution tough. Most measures so far have not provided any relief.

While most residents hope that things will change for the better, it remains to be seen if NCR will change for better like London after the Great Smog of 1952 or if NCR residents will continue to die a death each day in the toxic town.