Answer:

Explanation:

March is the start of spring season in India – when most cities, especially in the north, experience good air quality. A scene near Nizamuddin, New Delhi. Photo: VED/Unsplash.

The year 2020 started off on the wrong foot, thanks to the new coronavirus virtually shutting down the world. India also took some necessary precautions, one of them in the form of a nationwide lockdown that Prime Minister Narendra Modi kicked off on March 24 for 21 days, and which was recently extended to May 3. For a country whose cities are so dense and always teeming with activity, the lockdown has presented sights both eerie and beautiful. In Jalandhar, for example, people could see the Dhauladhar mountain range of Himachal Pradesh, 250 km away, for the first time in 30 years.

Answer:

Urban air quality in most megacities has been found to be critical and Kolkata Metropolitan City is no exception to this. An analysis of ambient air quality in Kolkata was done by applying the Exceedance Factor (EF) method, where the presence of listed pollutants’ (RPM, SPM, NO2, and SO2) annual average concentration are classified into four different categories; namely critical, high, moderate, and low pollution.