NEW DELHI: As Delhi’s air quality plunged into the severe category again, a report released by the Centre for Science and Environment (CSE) on Thursday revealed that vehicular emissions are the biggest contributor to pollution in the city, accounting for over 50% of the particulate matter during the early phase of winter (October 24-November 8). The other major sources included household sources, industry, construction, waste burning and road dust.
The report was based on an analysis of real-time source contribution data on the trend every alternate hour during the study period, generated by the Indian Institute of Tropical Meteorology-Pune. Other sources included DG sets, crematoria, restaurants, airport etc..
Anumita Roychowdhury, executive director, research and advocacy, CSE, said that after the closure of all coal-based power plants, expansion of natural gas usage in industry and controls on dirty fuels, vehicles had emerged as the biggest real-time contributor among the local sources of winter pollution this year. “Action on transportation has to gather strong momentum. At the same time, action on waste management, clean energy access in households and dust control must be speeded up,” she said.
The report highlighted that during November 2-6 (Diwali week), the contribution of NCR emissions dominated in the initial phase going up to 70-80%, but its share declined during the smog episode post-Diwali (November 5-8) and the local sources’ share increased. Delhi’s air turned ‘severe’ post-Diwali due to firecrackers and stubble burning along with calm winds. “The contribution of biomass burning from other states remained low in the initial pre-Diwali phase but peaked post-Diwali,” the report said.
Also, it was noticed that the contribution of Delhi’s own sources go up during evening hours and lasts until early morning (7:30 pm-9:30 am). An additional analysis of the trends in traffic speed during October 27-November 6 on 15 key stretches showed that vehicular congestion is back to pre-pandemic times and correlates with the pollution peaks.
Roychowdhury said that in the absence of measures like integrated public transport, walking/cycling infrastructure and parking area management, Delhi, where vehicle numbers are “explosive at 1.32 crore”, is unable to enforce emergency action to control traffic volumes during smog episodes.