— Central Pollution Control Board (@CPCB_OFFICIAL) March 28, 2020
As many as 39 cities have recorded "good" air quality and 51 cities have recorded "satisfactory" air quality in the last few days, the CPCB data showed.
An AQI between 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 severe.
Environmentalists believe that the reduced pollution levels should act as a wake-up call for the government.
Jyoti Pande Lavakare, co-founder, Care for Air NGO, said the low AQI and the blue skies proved beyond doubt that a lot of the polluted air was "anthropomorphic, that is, man-made".
"Obviously, slowing down the economy to such a degree is not the ideal way to bring down air pollution, but at least it proves that it can be done. We can achieve the same outcome by doing this mindfully, using technology and low-emission alternatives," she said.
Lavakare emphasised on the need to realise that air pollution weakens the lungs, so countries like India with higher pollution and lower nutrition levels will be more affected by COVID-19, and morbidity and deaths are likely to be higher.
Ravina Kohli, environmentalist and part of the #MyRightToBreathe campaign, said it was a "huge wake-up call" for governments obsessed with development at the cost of the environment.
"We the people are the problem. Our communication on solutions now also includes how to reduce pollution at a personal level by being able to understand our behaviour and its consequences on our environment.
"For the first time, I believe our present generation will discover the critical importance and need for a focus on public health and the quality of air we breathe," she said.
Jai Dhar Gupta, environmentalist and founder of Nirvana Being that sells masks and purifiers to combat pollution, said humans need to figure out if they wish to go back to the normal that was there before or find a more sustainable normal.
"This has been a fantastic wake-up call and I think we had a reality check and we need to figure out a new normal. This is an opportunity, a chance to find a new sustainable life," he said.