The mean mass concentrations of black carbon (BC), biomass burning (BC)bb, and fossil fuel combustion (BC)ff have been estimated during March–May 2020 (during the COVID-19 outbreak) and March–May 2019 at a semiarid region of Agra over the Indo-Gangetic basin region. The daily mean mass concentration of BC in 2020 and 2019 was 3.9 and 6.9 µg m−3, respectively. The highest mean AAE was 1.6 in the year 2020 (Mar–May 2020) indicating the dominance of biomass burning. The mean mass concentration of fossil fuel (BC)ff and biomass burning (BC)bb is 3.4 and 0.51 µg m−3, respectively, in 2020 whereas 6.4 and 0.73 µg m−3, respectively, in 2019. The health risk assessment of BC has been analyzed in the form of attributable relative risk factors and attributed relative risk during the COVID-19 outbreak using AirQ + v.2.0 model. The attributable relative risk factors of BC were 20.6% in 2020 and 29.4% in 2019. The mean attributed relative risk per 10,000,000 populations at 95% confidence interval (CI) due to BC was 184.06 (142.6–225.2) in 2020 and 609.06 (418.3–714.6) in 2019. The low attributed factor and attributed relative risk in 2020 may be attributed to improvements in air quality and a fall in the emission of BC. In 2020, due to the COVID-19 pandemic, the whole country faced the biggest lockdown, ban of the transportation of private vehicles, trains, aircraft, and construction activities, and shut down of the industry leading to a fall in the impact of BC on human health.

Pratima Gupta has completed her PhD at the age of 29 years from DEI University, Agra and post-doctoral studies from Indian Institute of Technology, Delhi, India. Her research focuses on measurements and characterization of short lived climate forcer; exposure modeling of black carbon; climate change and public health. She has published many research papers in national and international journals of repute. Her work has been well recognized with various awards and fellowships such as Best Thesis presentation Award, 2021; CSIR-SRF, New Delhi, India 2019; ISCA (Indian Science Congress Association) Young Scientist Award 2018; IGAC Travel Award 2017.