A recent study by the Centre for Science and Environment (CSE) highlighted changing air quality patterns in Delhi and the National Capital Region (NCR). The analysis compared pollution levels during the farm fire-influenced months of October and November with the post-stubble burning period in December. Surprisingly, pollution levels have intensified after the stubble burning season, indicating a significant contribution from local and regional sources such as vehicles, industry, and waste burning.
The study emphasized that despite a decrease in farm fire impact on PM2.5 levels in December, overall pollution levels have risen. This shift underscores the need for continuous efforts to combat pollution from urban and regional sources throughout the year. The analysis also pointed out that the smog affecting the region is a result of a combination of local emissions, regional influences, and secondary aerosol formation, necessitating coordinated action at the airshed level.
The worsening pollution was observed across various urban areas in the NCR, with most cities experiencing a notable increase in PM2.5 levels. Notably, Noida saw a 38% rise, Ballabhgarh 32%, Baghpat 31%, and Delhi 29%. The surge in pollution is attributed to local emissions and unfavorable winter meteorological conditions that hinder the dispersion of pollutants, as explained by experts from CSE.
Data from the Decision Support System (DSS) for the first half of December revealed the complexity of the pollution issue, with only 35% of PM2.5 originating from local sources within Delhi. The majority of pollutants, 65%, came from neighboring NCR districts and beyond. Within Delhi, vehicles were identified as the primary local emission source, accounting for nearly half of all local emissions, according to the Clean Air program at CSE.
The analysis utilized real-time data from air quality monitoring stations in Delhi-NCR, with inputs on stubble fire smoke contribution sourced from the Ministry of Earth Science’s System of Air Quality and Weather Forecasting and Research (SAFAR). Additionally, real-time source contribution and chemical composition data were obtained from the Decision Support System (DSS) developed by IITM.
