Impacts of COVID-19 Pandemic on Air Quality Index (AQI) During Partial Lockdown in Karachi Pakistan

Abstract

A novel infectious disease (COVID-19) was identified in the late months of 2019, with human to human transmission, and rapidly spread in the world, which now has turned into a global pandemic. The coronavirus (COVID-19) is extremely threatening world public health problem. Up-till now, more than 200 countries and states had been affected by this pandemic. The number of contagions and deaths still increasing day by day. Different steps have been taken worldwide to control COVID-19. Countries all over the world have applied specific type of lockdown in order to control / slow down the intensity of infection and mitigate it. This lockdown due to COVID-19 not only smashed the economic growth but also exert a positive impact on the environment and improves the level of air quality in the city/country. This study was carried out for investigation of air quality before and during the periods of lockdown levied to reduce the spread of a novel coronavirus (COVID-19) in the environment of Karachi city. Concentrations of four pollutant parameters (PM 10 , SO 2 , NO 2 and CO) were used to calculate the results according to the criteria of Air Quality Index (AQI). We have analyzed data collected from fourteen different monitoring locations along the busy roads in commercial, residential and industrial areas of Karachi during the lockdown period. Data were compared to the five-year monthly mean and to the four-week before the partial lockdown. The results proved that during lockdown air quality is significantly improved. Among the selected pollutants, concentrations of PM 10 have observed maximum reduction (50%) in comparison to the before lockdown period. In compare to the last year (i.e. 2019) during the said time period the reduction of PM 10 is as high as about 60%. Among other pollutants, SO 2 , NO 2 and CO the level have also reduced about 60-70% during lockdown period. About 40% to 50% improvement in air quality is identified just after four days of commencing lockdown. Overall, the study is assumed to be a useful tool to the regulatory bodies to control the air quality and also explained its relation to health hazards to provide awareness in the society.