GIS-based emission inventory of heavy metals from road transport and NMVOCs associated with biomass burning for megacity Delhi

Clean air is an essential requirement for human health and well-being. The rapid evolution in urbanization poses a risk to human health. The significance of robust emission inventory has intensified with scientific advancement in air quality improvement. A comprehensive GIS-based emission inventory of heavy metals and NMVOCs from road transportation, road dust, and biomass burning covering the megacity of Delhi has been prepared in this study for the base year 2018. The emission of heavy metals from biomass burning and road dust was estimated by computing the chemical constituents of PM2.5. The emission of heavy metals from all sources is estimated as 695.202 Mg/year, with Zinc (Zn ∼ 48%) having the highest emissions, followed by Copper (Cu ∼ 21%). The share of road transportation emissions was 78%, followed by resuspended road dust emissions at 4%. The emissions of 23 NMVOCs (1.158 Gg/year) were calculated from biomass burning (fuelwood, agricultural residue, dung cake, and coal) with Dung cake (∼58%) and fuelwood (∼41%) as the major contributors. The maximum emission was ethene (∼29%), and the minimum was isopropyl benzene (∼0.06%). The finding of this study will assist environmental policymakers and stakeholders in developing mitigation methods to reduce emissions and enhance air quality.