NEW DELHI: It is not the Haryana and Punjab farmers, but the vehicular pollution that is the largest contributor to the national capital’s poor Air Quality Index (AQI), accounting for over 50% more harmful pollutants than other sources.
A new study by the Delhi-based environmental think tank ‘Centre for Science and Environment (CSE)’ reveals that vehicular emission is the top contributor to Delhi’s pollution during winter -- more than stubble burning, road dust or bursting of firecrackers.
CSE has analysed the current trends in particulate matter pollution, trends in motorisation, congestion impacts, and the state of public transport to understand this growing challenge.
An estimated 1.1 million vehicles enter and exit Delhi daily, worsening the air quality. The traffic caused by this vehicle influx intensifies pollution, particularly nitrogen oxides (NOx), which account for 81 per cent of NOx pollution in the city.
The analysis says Delhi needs to cut current 60% of its air pollution to meet the target of the National Ambient Air Quality Standards for PM2.5. Additionally, the annual PM 2.5 levels show an improvement of 7% in 2023 when compared to the 2019 levels. Further, the PM2.5 winter peak has reduced by almost 35% in 2023-24 compared to the 2019-20 level but the average PM2.5 concentration has almost stagnated and has been the highest in the last five years.
When stubble burning was at peak between October 10-20, the contribution of average farm fire to Delhi’s PM2.5 level was only 0.7%, says the report.
Further, when stubble burning induced pollutants increased sharply since October 22, the PM2.5 levels reached 213 µg/m³, which falls in the ‘very poor’ category. On October 31, the concentration was 206 µg/m³, only 3 per cent lower than the October 23 peak, even though the stubble burning contribution on October 31 doubled compared to October 23.
“The data clearly indicates that local sources are the primary contributors to the elevated PM2.5 levels in Delhi, as concentrations remained high even when the impact of stubble burning was minimal,” says Anumita Roy Choudhary, Executive Director of CSE and one of the authors of the study.
The study underlines that explosive motorisation, choking congestion and inadequate public transport services are weakening the emission gains from different technology measures in the transport sector.
Delhi Government has taken a number of measures such as implementing the largest ever CNG programme for the public transport and local commercial transport, phasing out of 10-year-old diesel and 15-year-old petrol vehicles, restrictions on entry of non-destined trucks, introduction of Bharat Stage 6 emissions standards, and onset of the fleet electrification.
Despite that, vehicles are still the key polluter due to the growing mobility crisis.