Contribution of different source sectors and source regions of Indo-Gangetic Plain in India to PM2.5 pollution and its short-term health impacts during peak polluted winter

Abstract

PM2.5 pollution in India increases severely during the winter season due to adverse meteorological conditions and shows comparatively higher pollution loading in Indo-Gangetic Plain (IGP). However, investigation of the role of major sources and different states of IGP in local and regional higher PM2.5 pollution for effective formulation of mitigation policies has been limited. In this study, the Weather Research and Forecasting model coupled with chemistry (WRF-Chem v 3.9.1) was used to quantify the contribution of emissions from major source sectors and source regions of IGP to local and regional PM2.5 pollution during winter. The short-term premature mortality and its apportionment has also been estimated. Contributions from seven source states of the IGP to local and regional PM2.5 pollution at eight major cities of the IGP have been investigated. The residential and transport sector emerge as leading contributors with ~40–50% share in ambient PM2.5 pollution over IGP, whereas the contributions of the industrial (~5–20%) and energy sectors (~5–40%) varies significantly across the IGP. While the contributions of local sources were found to dominate in all IGP states, significant contributions were also seen from neighboring IGP states. At megacity Delhi, significant contribution in local PM2.5 pollution was observed by transportation (~49%) and energy (~24%) sectors, and at Kolkata, it was from residential (~48%) and industrial (~24%) sectors. January 2016 mean short-term premature mortality estimates for Delhi and Kolkata are found 61(33–91) and 44(23–64) persons/day, respectively, with local sources contributions of 40(21–58) and 29(15–42) persons/day, respectively.