Variation Of Black Carbon And Particulate Matter In Bhubaneswar During The Pre-monsoon: Possible Impact Of Meteorology And COVID-19 Lockdown

To combat the present COVID-19 pandemic, a coun-trywide lockdown (LD) was imposed in India from 25 March until 31 May 2020. This unique scenario brought a decline in various anthropogenic activities leading to a considerable decrease in the concentra-tion of several atmospheric pollutants. In this scenar-io, CSIR-IMMT Bhubaneswar carried out black carbon (BC), PM₁₀ and PM_2.5 analysis through optical and gravimetric measurements, respectively, during March-May 2020 followed by a comparison with pre-vious years (2017–2018) of observation. There was a reduction of ~33% in average overall BC concentra-tion along with a significant drop in PM₁₀ (33%) (P < 0.05) and PM_2.5 (~38%) (P < 0.05) during the entire LD period as compared to 2017–2018. During LD, contribution from biomass burning was enhanced by almost 3 times as compared to 2017–2018. Howev-er, the simultaneous meteorological variation during the LD period prevents clear distinction of the impact of lockdown on BC and PM.