Spatial-temporal patterns of anthropogenic and biomass burning contributions on air pollution and mortality burden changes in India from 1995 to 2014

Abstract. Anthropogenic and biomass burning emissions are the major sources of ambient air pollution. India has experienced a dramatic deterioration in air quality over the past few decades, but no systematic assessment has been made to investigate the individual contributions of anthropogenic and biomass burning emissions. In this study, we conducted a pioneering comprehensive analysis of the long-term trends of particulate matter with aerodynamic diameters < 2.5 μm (PM_2.5) and ozone (O₃) in India and their mortality burden changes from 1995 to 2014, using a state-of-the-art high-resolution global chemical transport model (CAM-chem). Our simulations revealed a substantial nationwide increase in annual mean PM_2.5 (6.71 μg m^-3 decade^-1) and O₃ (7.08 ppbv decade^-1), with the Indo-Gangetic Plain (IGP) and eastern central India as hotspots for PM_2.5 and O₃ trend changes individually. Noteworthy substantial O₃ decreases were observed in the northern IGP which were potentially linked to NO titration due to a surge in NOx emissions. Sensitivity analyses highlighted anthropogenic emissions as primary contributors to rising PM_2.5 and O₃, while biomass burning played a prominent role in winter and spring. In years with high biomass burning activity, the contributions from BB on both PM_2.5 and O₃ changes were comparable with or even exceeding anthropogenic emissions in specific areas. The elevated air pollutants were associated with increased premature mortality attributable to PM_2.5 and O₃, leading to 97.83 K and 73.91 K per decade. Despite a per capita decrease in the IGP region, the increased population offset its effectiveness.