Open AccessAssessing the Immediate Effect of Covid-19 Lockdown on Air Quality: A Case Study of Delhi, India
Author(s) -
Ankit Sikarwar,
Ritu Rani
Publication year - 2020
Publication title -
journal of environmental geography
Language(s) - English
Resource type - Journals
eISSN - 2060-467X
pISSN - 2060-3274
DOI - 10.2478/jengeo-2020-0009
Subject(s) - air quality index , air pollution , inverse distance weighting , particulates , covid-19 , new delhi , pollutant , megacity , air pollutants , geography , population , environmental science , pollution , environmental health , meteorology , mathematics , multivariate interpolation , statistics , medicine , economy , metropolitan area , bilinear interpolation , chemistry , archaeology , pathology , disease , infectious disease (medical specialty) , ecology , biology , organic chemistry , economics
In India, a nationwide lockdown due to COVID-19 has been implemented on 25 March 2020. The lockdown restrictions on more than 1.3 billion people have brought exceptional changes in the air quality all over the country. This study aims to analyze the levels of three major pollutants: particulate matter sized 2.5 μm (PM 2.5 ) and 10 μm (PM 10 ), and nitrogen dioxide (NO 2 ) before and during the lockdown in Delhi, one of the world’s most polluted cities. The data for PM 2.5 , PM 10 , and NO 2 concentrations are derived from 38 ground stations dispersed within the city. The spatial interpolation maps of pollutants for two times are generated using Inverse Distance Weighting (IDW) model. The results indicate decreasing levels of PM 2.5 , PM 10 , and NO 2 concentrations in the city by 93%, 83%, and 70% from 25 February 2020 to 21 April 2020 respectively. It is found that one month before the lockdown the levels of air pollution in Delhi were critical and much higher than the guideline values set by the World Health Organization. The levels of air pollution became historically low after the lockdown. Considering the critically degraded air quality for decades and higher morbidity and mortality rate due to unhealthy air in Delhi, the improvement in air quality due to lockdown may result as a boon for the better health of the city’s population.