Exploring the linkage between PM2.5 levels and COVID-19 spread and its implications for socio-economic circles

Abstract

A pneumonia-like disease of unknown origin caused a catastrophe in Wuhan city, China. This disease spread to 215 countries affecting a wide range of people. World health organization (WHO) called it a pandemic and it was officially named as Severe Acute Respiratory Syndrome Corona virus 2 (SARS CoV-2), also known as Corona virus disease (COVID-19). This pandemic compelled countries to enforce a socio-economic lockdown to prevent its widespread. This paper focuses on how the particulate matter pollution was reduced during the lockdown period (23 March to April 15, 2020) as compared to before lockdown. Both ground-based and satellite observations were used to identify the improvement in air quality of Pakistan with primary focus on four major cities of Lahore, Islamabad, Karachi and Peshawar. Both datasets have shown a substantial reduction in PM_2.5 pollution levels (ranging from 13% to 33% in case of satellite observations, while 23%-58% in ground-based observations) across Pakistan. Result shows a higher rate of COVID-19 spread in major cities of Pakistan with poor air quality conditions. Yet more research is needed in order to establish linkage between COVID-19 spread and air pollution. However, it can be partially attributed to both higher rate of population density and frequent exposure of population to enhanced levels of PM_2.5 concentrations before lockdown period.

Fig. 1

Shows images taken by various individuals (residents) of these 4 cities in Pakistan before lockdown (upper panel) and during lockdown (lower panel) periods.

Fig. 2

(a) Average of AOD from 2016 to 2020 over Pakistan, (b) AOD level during lockdown period, (c) difference in AOD level betwwen (a) and (b). MODIS AOD data product downloaded from (https://ladsweb.modaps.eosdis.nasa.gov/).

Fig. 3

Percentage reduction in AOD levels over Pakistan and major cities during the socio-economic lockdown. MODIS data downloaded from (https://ladsweb.modaps.eosdis.nasa.gov/).

Fig. 4

Percentage reduction in ground level PM_2.5 concentrations (ug/m³) for before and during lockdown periods. PM2.5 data downloaded from (https://pk.usembassy.gov/embassy-consulates/air-quality-data/).

Fig. 5

The dashboard of Ministry of National Health Services developed for COVID-19 information. It is further amended by adding information about COVID-19 cases registered, recovered and deaths reported in 4 major cities till 3rd June 2020. Average AOD map is also presented. Data obtained from(http://covid.gov.pk/).