Lockdown Didn't Help Us Breathe Clean Air, Pollution Levels Above Allowed Limits In Many Cities
One of the biggest, yet surprising positive changes the lockdown brought in 2020 was how the air quality across major cities in India improved, as industries were shut and vehicles were off the roads.
For the first time in a long while, Delhi had clean, blue skies and air had become breathable.?
One year later
But one year later things are not the same as data analysed by a climate communications initiative, Climate Trends showed that pollution levels remained above permissible limits.
Researchers compared the Central Pollution Control Board (CPCB) air quality data for Delhi, Lucknow, Mumbai and Kolkata over the three months from March 2019¡ªwhen there was no lockdown¡ªand 2020 and 2021¡ªwhen there was complete lockdown in these cities.
They found that pollution levels remained above permissible limits in Delhi and Lucknow, but Mumbai's PM 2.5 concentration only increased year on year from March to May from 2019 to 2021.
Kolkata showed improvement
Kolkata was the only city that showed an improvement in air quality.
The study revealed that except Mumbai, all cities showed a dip in the average PM 2.5 levels during the three months in 2020. Mumbai's average concentration of PM 2.5 between March and May in 2019 was 21.6 micrograms per cubic meter of air, or ug/m3, which increased to 31.3 ug/m3 in 2020 and then to 40.3 ug/m3.
On the other hand, Delhi's average PM 2.5 concentration for the three months dipped from 95.6 ug/m3 in 2019 to 69 ug/m3 in 2020 but was quickly back to 95 ug/m3 in 2021.
Similarly, Kolkata's PM 2.5 concentration swayed from 41.8 ug/m3 in 2019 to 27.9 ug/m3 in 2020 and 37.3 ug/m3 in 2021. While there was a complete lockdown in 2020, the 2021 lockdown saw a high movement of people seeking healthcare facilities due to increased COVID-19 cases and the state elections in West Bengal.
G.C. Kisku, Chief Scientist, Environmental Toxicology, CSIR-Indian Institute of Toxicology Research, said, "The partial or complete lockdowns during 2020 and 2021 lowered vehicular movement and subsequently led to reduced consumption of fossil fuels.
"Closure of industrial establishments during lockdown periods also added to it. But the levels are still relatively higher this year. The good thing is that there has been a decreasing trend in PM10 levels from 2017 onwards, however, this year, the observed levels of PM 2.5, PM 10, SO2, and NO2 at all locations were found to be relatively higher as compared with monitoring data of previous year."
