India imposed a nationwide lockdown on 25th of March, 2020 to contain the spread of coronavirus and flatten the curve. With people staying inside their homes, this lockdown seems to have been a boon to the infamously polluted air of Delhi. A standstill of commercial flights, passenger trains, vehicles and most of the industries have given way to a fall in the concentration of pollutants, cleaner air and clearer skies. A side by side look at air quality levels of past year and the current one leads one to the conclusion that it is, be it for a little while, getting better.
In the graph below, the Air Quality Index (AQI) substitutes of PM 2.5 (particulate matter 2.5 micrometre or less in diameter in the atmosphere) and NO2 (Nitrogen Dioxide) are shown. The particulate matters are created either when chemicals react in the atmosphere or are directly emitted from a source, such as construction sites, unpaved roads, smokestacks, fires etc. NO2 is emitted from all combustion engines from mobile sources, like road vehicles, boats, aeroplanes, etc. From when lockdown started until 30th of April, average daily PM 2.5 levels have gone down by about 40% and NO2 by a huge margin of 143%, the drop can be evidently seen in the below diagram.
AQI is usually above 150 in Delhi on a considerably good day, when anything above 50 is not satisfactory according to US-EPA standards. During the winter of 2019, AQI levels were higher than 999, and most stations were not able to measure it because it was off the measuring scale. Now, AQI has fallen as low as 30 in Delhi, and the summer is unbelievably comfortable with occasional rains even to the end of April. In the words of Mr Shashi Tharoor, ‘In Delhi, Pure joy!’; at least on air quality front, to be added. This isn’t exclusive to Delhi and other metropolitan cities, but also for other places, like Saharanpur in Uttar Pradesh and Jalandhar in Punjab, as people were awed at the rare sight of the Himalayan ranges from these places which are far south in the plains.
According to an analysis by CREA, the nationwide ‘Janata Curfew’ on March 22 had resulted in the lowest single-day traffic pollution levels on record. The absence of 11 million cars on the roads of Delhi and a consequent decrease in pollution contradicts the claim of the car lobby of Delhi that cars aren’t a major contributing factor in Delhi’s pollution, which is supported by the comment of Sunita Narain, Director of Centre for Science and Environment, that the drop in pollution levels has shown how polluting the role was of the vehicles in the city. She also added that the current safe air is not to be celebrated, because this is not a solution, but merely a consequence of the lockdown, and serious efforts are to be taken to deal with Delhi’s pollution.
The record-high air pollution levels of last winter had forced schools to be shut and flights to be either cancelled or diverted due to decreased visibility. Living in severely polluted conditions like that of Delhi has made the residents of Delhi potentially vulnerable to the coronavirus pandemic because it affects the respiratory system. Even though the skies are clearing, it is not enough to stop them from being vulnerable. India has very high levels of respiratory diseases, even among young children. According to the World Health Organization, people with pre-existing medical conditions and older people are at higher risk of becoming fatally ill of Coronavirus.
Once the lockdown is shifted and things begin to go back to normal, when cars, flights and industries go back into action, it is feared that instead of trying to maintain the current levels of air quality, things might either go back to how it used to be or even worsen, as industries would be trying to make up for the losses occurred during the past months. This can be seen in the case of China, which is coming out of the virus-induced lockdown. Since early March, the levels of NO2 have started to go back up with businesses and power-plants re-opening and cars returning to the roads. The government also has to keep in mind the levels of pollutants in the atmosphere when deciding on measures to revive the economy and attempt to not repeat what happened after the recession of 2008.
Noufa C.K is a graduate of Dual Master’s Degree in Applied Geoinformatics from the University of Salzburg, Austria and Central University of Karnataka, India
