Impact and Correlation of Air Quality and Climate Variables with COVID-19 Morbidity and Mortality in Dhaka, Bangladesh

The COVID-19 pandemic unexpectedly stopped the steady life and enhanced environmental quality. To apprehend the transmission of COVID-19 and the improvement of air quality, we have studied air quality indicators (PM_2.5, PM₁₀, AQI, and NO₂), CO₂ emission, and climate variables (temperature, relative humidity, rainfall, and wind velocity) in the extremely polluted and densely populated Southeast Asian megacity Dhaka, Bangladesh from March to June 2020. The Kendall and Spearman correlations were chosen to test the connotation of air quality and climate variables with COVID-19 morbidity and mortality. The average concentrations of PM_2.5, PM₁₀, and CO₂ were 65.0 ± 37.9 and 87.1 ± 52.8 µm m_-3, and 427 ± 11.8 ppm, respectively. The average PM_2.5 and PM₁₀ drastically reduced up to 62% during COVID-19 lockdown in Dhaka comparing with March 2020 (before lockdown). Comparing with the same period in 2019, PM_2.5 reduced up to 33.5%. The average NO₂ concentration was 35.0 µmol m_-2 during the lockdown period in April, whereas 175.0 µmol m_-2 during March (before lockdown). A significant correlation was observed between COVID-19 cases and air quality indicators. A strong correlation was obtained between climate variables and the total number of COVID-19 morbidity and mortality representing a favorable condition for spreading the virus. Our study will be very expedient for policymakers to establish a mechanism for air pollution mitigation based on scientific substantiation, and also will be an essential reference for the advance research to improve urban air quality and the transmission of the SARS-CoV-2 virus in the tropical nations.