Linking Anthropogenic Chlorine Emissions to Regional Air Quality in India

India experiences severe air pollution driven by human activities. The role of anthropogenic chlorineis significant yet underexplored, with its mechanisms poorly understood and impacts largely unquantified, despite its importance in atmospheric oxidation and secondary pollutant formation. Using theGEOS-Chem chemical transport model, we quantify the impact of human-derived chlorine emissions onparticulate chloride (pCl– ), particulate matter (PM2.5), ClNO2, and O3 in the boundary layer over India.