Delhi, as we all know is the capital of India and therefore the political centre of the country. When we look at the timeline of Delhi, we will find that it has been a strategic location since the medieval era when it was ruled by the Tomara and Chauhan dynasties and it has remained the dominant power of the Indian subcontinent ever since. Delhi has always been in the spotlight for one or other reason.
However, in recent years it has gathered attention of the country for reasons that are not so impressive. Delhi has been struggling with a lot of social, cultural, and environmental issues. The purpose of this article is to list the reason for its worst environmental issue. i.e., Air pollution. And to fully understand the situation we need to first get familiar with the terminologies.
What is Air Quality Index (AQI)?
Air is a homogenous mixture of different gases. All the gases present in this mixture are in different proportions. Within this mixture, if the concentration of some of the gases like Carbon monoxide, sulphur dioxide, nitrogen dioxide, etc. increases, then it has health effects on the human body. These health effects ranges from minor breathing discomfort to serious lung and heart diseases.
The Indian Ministry of Environment, Forest and Climate Change launched AQI initiative under ‘Swachh Bharat’ in a bid to increase awareness among people in regards to air quality of their surrounding in a format of One-Number-One-Colour Description. So that, its easier for common people to understand the cleanliness of their vicinity.
The Indian Government has categorized AQI in six categories after considering the volume of eight pollutant (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb). The National Air Quality Standards are prescribed as:
What is the AQI of Delhi?
The AQI for Delhi is worsening every year since last decade and it ranges from 350 to 480 which is categorized as very poor and severe as per the Indian Government. The live AQI can be found on The Central Pollution Control Board’s website.  If we look at the seasonal variations, The AQI start deteriorating in October and is worst during winters. The two major culprits for higher AQI in Delhi out of the eight pollutants, are PM10 and PM2.5.
What are PM10 & PM2.5?
PM stands for Particulate Matter. And the numbers indicate the diameter of the particulate matters in µm (micro-meter). One µm is equal to one-millionth of a meter (1/1000000). Here is an image to put this in perspective.
These particulate matter are suspended in the air and causes health hazards when inhaled during day-to-day activities.
So, why is Delhi polluted?
Till now we have figured out that the reason for higher pollution in Delhi can be pinned down to two types of pollutants PM10 and PM2.5 and the presence of a higher concentration of these two pollutants around Delhi.
Therefore, we mainly need to find the reason behind the increased concentration of this particulate matter to get the answer to our question. A study in this regard was conducted by Dr. Mukesh Sharma of IIT-Kanpur in year 2015 which categorized the major sources of PM10 and PM2.5 in simple categories for better understanding. The studies concluded following:
If we broadly categorize them further than following categories emerges:
Combustion-Based Pollution
These are ground-level sources of particulate matters. Activities like diesel, petrol & Natural gas combustion i.e., vehicular exhaust, cooking & heating, burning of biomass (which can be linked to crop residue burning, majorly from the state of Punjab), open waste burning, etc. Delhi has around 1.18 lakh crore registered motorized vehicles on its roads which means around 643 vehicles per 1000 people in Delhi. All this contributes to 56% of particulate matters suspended in Delhi’s vicinity.
Mechanical Process-Based Pollution
The rest of the Particulate matters suspended in the air are due to construction activities, dust storms and constant vehicular movement. Vehicular moment results in the resuspension of settled particulate matters and therefore contributes to the overall pollution. The industrial sources can be distant from the city itself but the PM particles are transported through air towards the city and therefore results in an increase in PM concentration.
What can be done?
A systematic approach to either control or prevent the emission of particulate matter can improve the situation in Delhi. A switch in choice of fuel, a law regulating vehicular emission, and alternate use of biomass (instead of wasting or burning it) can prove to be effective in leaps and bound. The Delhi government has taken several steps towards spreading awareness against biomass burning and implemented laws to regulate vehicular emissions in recent years. And by the collective efforts of residents of Delhi, the problem can and should be solved.Â
Also read:
