Emission reduction of black carbon and polycyclic aromatic hydrocarbons during COVID-19 pandemic lockdown

In this study, we evaluated the changes in concentrations of BC, PAHs, and PM2.5 before and during the lockdown period. Our results show that lockdown resulted in a significant reduction in concentrations of these pollutants. The average mass concentration of BC, PAHs, and PM2.5 before the lockdown was 11.71  ± 3.33 μgm−3, 108.71  ± 27.77 ngm−3, and 147.65  ± 41.77 μgm−3, respectively. During the lockdown period, the concentration of BC, PAHs, and PM2.5 was 2.46  ± 0.95 μgm−3, 23.19  ± 11.21 ngm−3, and 50.31  ± 11.95 μgm−3, respectively. The diagnostic ratio analysis for source apportionment showed changes in the emission sources before and during the lockdown. The primary sources of PAHs emissions before the lockdown were biomass, coal combustion, and vehicular traffic, while during the lockdown, PAHs emissions were primarily from the combustion of biomass and coal. Similarly, before the lockdown, the BC mass concentrations came from fossil-fuel and wood-burning, while during the lockdown period, most of the BC mass concentration came from wood-burning. Human health risk assessment demonstrated a significant reduction in risk due to inhalation of PAHs and BC-contaminated air.
Source: Air Quality, Atmosphere and Health - Category: Environmental Health Source Type: research