According to the Decision Support System (DSS), emissions from NCR districts such as Noida, Gurgaon, Faridabad, and Bulandshahr are major contributors to pollution in Delhi. The DSS estimates the daily contribution of pollution sources in Delhi’s PM2.5 based on meteorological conditions. Noida was found to be the highest contributor to regional pollution in Delhi’s PM2.5, followed by Ghaziabad and Bulandshahr. Industries and bio-fuel burning are also significant contributors to pollution.