• P-ISSN 0974-6846 E-ISSN 0974-5645

Indian Journal of Science and Technology


Indian Journal of Science and Technology

Year: 2020, Volume: 13, Issue: 32, Pages: 3339-3348

Original Article

Effect of lockdown on air pollutants during COVID – 19 over Hyderabad

Received Date:14 August 2020, Accepted Date:19 August 2020, Published Date:02 September 2020


Objective: To understand the temporal characteristics of air pollutants during lockdown and to assess the impact of them on air quality. Method: We have analyzed the ambient monitoring data, from Central Pollution Control Board (CPCB), of air pollutants from 27th January to 12th July 2020 to compare prelockdown (27th Jan to 22nd March), during lockdown (23rd March to 17th May) and post lockdown (18th May to 12th July) effects over six stations in Hyderabad. Further, to understand the significant differences in PM concentrations we have evaluated rate of change (ROC) over a defined period of time. Pearson correlation analysis was used as an indicator of the relation between PM2.5 and PM10 for the study period. Findings: Our results show a significant decline in PM2.5 (27%) and PM10 (34%) concentrations during lockdown. This indicates positive effect of lockdown on air quality over Hyderabad. The contribution of PM2.5 in PM10 (46%) during lockdown remains same when compared to previous years though the concentrations have decreased. The PM2.5 was highly correlated with PM10 over all the stations. A substantial decrease in PM2.5 (27%) and PM10(39%) compared to the same period of previous years were observed. Apart of particulate matter the concentration of NO2 decreased by 33% during lockdown. Another noticeable point observed is that the concentrations of CO and SO2 showed a marginal decrease and they remained below permissible limits (NAAQS) during study period. Novelty / Recommendations: Overall, this study may be helpful to understand how air pollution is affected during COVID – 19 pandemic and provide important signs regarding the control of emissions by subsequently implementing stringent rules, like complete lockdown at least one day per week, imposing traffic rules, encouraging online teaching, digital shopping etc., to heal and save the environment.

Keywords: Covid-19; lockdown; air pollutants; particulate matter; air quality


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© 2020 Polisetty et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Published By Indian Society for Education and Environment (iSee)


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