EVERY winter, Delhi wakes up to the same grim reality. Schools close, construction stops, vehicles are banned, and emergency meetings are convened as the Air Quality Index slips from “very poor” to “severe” and beyond. Masks return, lungs suffer, and the city braces for another season of toxic air. Yet when the smog lifts, so does our collective urgency. This annual cycle reveals a deeper problem that Delhi continues to treat air pollution as a short-term emergency rather than a long-term governance and public health challenge.
Our recent work at TERI shows that annual average PM2.5 concentrations in Delhi routinely exceed national standards by nearly three times, with citywide annual averages violating the annual standard of 40 µg/m³ by about three times. Winter concentrations are far worse, with repeated “severe” and “severe plus” AQI days every year. TERI’s analysis for 2019 indicates that transport (23%), industries including power plants (23%) and biomass burning (14%) are the dominant contributors to winter-time PM 2.5 concentrations in Delhi, with road and construction dust remaining important contributors to overall PM 2.5 emissions. Even when emergency measures are enforced, the resulting reduction in pollution levels is marginal and temporary. The air improves briefly, only to deteriorate again because the underlying drivers remain unchanged.
The Graded Response Action Plan (GRAP) was conceived as an emergency response mechanism and it functions within those limits. It is activated after pollution levels have crossed the harmful thresholds.
Even after accounting for the control measures under a business-as-usual (BAU) scenario, winter PM2.5 concentrations in Delhi are projected to decline by only about 9-28% between 2019 and 2030, and yet remain extremely high, around 129-164 µg/m³, more than double the daily national standard.
Air quality considerations should be embedded into routine decision-making across transport, infrastructure, energy systems, waste management, land use planning and public health through the year.
Delhi lies within a larger airshed, encompassing multiple urban, industrial and agricultural regions across the NCR. Within Delhi, transport dominated by two- and three-wheelers accounts for over 40% of PM2.5 emissions, followed by road dust (21%) and construction (11%). In the wider NCR, industries (40%), agricultural residue burning (15%), residential biomass use (14%) and heavy-duty transport dominate the emissions. These emissions are transported into Delhi. The degradation of the Aravalli range further increases dust transport into the NCR.
Stubble burning contributes to episodic peaks, but is not the dominant driver of Delhi’s year-round exposure. Overemphasis on it risks obscuring the role of chronic urban and peri-urban sources. Effective mitigation, therefore, requires coordinated planning across Delhi and the NCR using the airshed-based approach.
Electrification of transport has rightly received policy attention. The benefits of cleaner vehicles are undermined by severe congestion and poor traffic management, which increase vehicle idling, fuel consumption and real-world emissions. Unregulated growth of last-mile transport, particularly e-rickshaws, has created congestion choke points across the city. Despite a shift towards e-buses, weak route optimisation, poor last-mile integration and unreliable service limit the shift away from private vehicles. Without demand management, congestion pricing and investment in high-capacity public transport, electrification alone will not deliver meaningful gains.
Road dust and construction dust are among the most underestimated contributors to PM2.5, particularly outside winter. Poor road quality, potholes, repeated utility digging and uncoordinated reconstruction generate loose material. Manual sweeping, still widely practised, often re-suspends fine dust into the breathing zone, increasing exposure for sanitation workers, pedestrians and commuters; this also reflects a governance gap where agencies like the PWD are assessed primarily on construction timelines rather than environmental performance indicators. Vacuum-assisted mechanised sweeping, wall-to-wall paving and strict construction dust controls are among the most cost-effective interventions. But they remain under-implemented.
Waste burning persists due to weak source segregation and enforcement. Residential biomass use continues in informal settlements. Numerous small and unregistered industries operate with limited oversight.
Perhaps the most striking gap is the limited integration of health considerations into policy design and response mechanisms. Air pollution is associated with respiratory illness, cardiovascular disease, stroke, chronic obstructive pulmonary disease, lung cancer, adverse pregnancy outcomes, impaired cognitive development in children, metabolic disorders and worsening of non-communicable diseases. Initiatives like dedicated chest clinics in government hospitals are important, but they address acute respiratory episodes rather than the broader spectrum of long-term pollution-related health impacts. Integrated surveillance, prevention and chronic disease management are needed. Surveillance systems that link air quality data with health outcomes, develop city-specific exposure-response functions and move towards health-based thresholds for action are needed.
These interventions are also economically justified, with long-term health and productivity benefits outweighing implementation costs. Delhi does not lack policy frameworks. What is insufficient is adequate financing, balanced sectoral allocation, inter-agency coordination and a long-term urban planning vision that places health at the centre of air quality governance. Improving air quality requires moving beyond seasonal responses towards everyday governance, where clean air is treated as a routine public good rather than an episodic crisis.