The analysis was prepared by researchers who compared air quality data during the lockdown period in Delhi, Lucknow, Mumbai and Kolkata, as stated by the Central Pollution Control Board (CPCB).
Analysis of PM 2.5 levels in Lucknow & Mumbai
As per the reports- "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. The safe limit for PM 2.5 (particulate matter measuring less than 2.5 microns) as prescribed by the CPCB is 40 ug/m3."
Regarding Lucknow, it is reported that- "Lucknow saw its PM 2.5 concentration in the three months, decrease consistently from 2019 but it still remained above permissible limits. Its average PM 2.5 concentration in 2019 for March, April and May was 103 ug/m3 which dipped to 92 ug/m3 in 2020 during the lockdown and further to 79.6 ug/m3 in 2021."
For Delhi, the average PM 2.5 concentration for the three months of lockdown dipped from 95.6 ug/m3 in 2019 to 69 ug/m3 in 2020 but was quickly back to 95 ug/m3 in 2021. The PM 2.5 concentration in the air above Kolkata, swayed from 41.8 ug/m3 in 2019 to 27.9 ug/m3 in 2020 and to 37.3 ug/m3 in 2021.
PM 10 concentration in Lucknow's atmosphere
A decreasing trend in PM 10 levels (any particulate matter in the air with a diameter of 10 micrometres or less, including smoke, dust, soot, etc.) has been noticed since 2017, however, in 2021, this number was higher. A report by CSIR on the assessment of ambient air quality of Lucknow revealed that the average level of PM 10 and PM 2.5 at all monitored locations- residential, commercial and industrial, was higher than the permissible limit during the 2021 lockdown period.
What do the experts say?
Experts state that lockdown lowered vehicular movement and led to reduced consumption of fossil fuels, however, air quality did not necessarily improve. They further state that any air quality improvement seen as a consequence of lockdown is neither consistent nor uniform.
-With inputs from IANS