In a positive turn of events, Delhi witnessed a notable improvement in air quality, with the Air Quality Index (AQI) standing at 317 at 4 pm, a significant improvement from the previous day’s 405. This improvement prompted the government to downgrade the pollution alert level from ‘severe’ to ‘very poor,’ bringing relief to the national capital.
The key factor contributing to the enhanced air quality was the increase in wind speed. Neighboring areas, including Ghaziabad, Gurugram, Greater Noida, Noida, and Faridabad, also recorded air quality levels ranging from “very poor” to “severe” on the same day, underlining the regional impact of pollution.
Following this positive development, the Commission for Air Quality Management (CAQM) took the decision to lift the Stage-IV curbs under the Graded Response Action Plan (GRAP) in Delhi. However, it is important to note that anti-pollution measures under Stage I to Stage III of GRAP will continue to remain in effect, as announced by the CAQM.
The Stage-IV restrictions, which were enforced on November 5, included a ban on all diesel four-wheelers that did not comply with BS-VI emission norms. Additionally, all Delhi-registered diesel medium and heavy goods vehicles, except those essential for emergency services, were prohibited from plying in the national capital. The recent relaxation allows diesel trucks to re-enter Delhi, providing some respite to logistical operations.
A joint project conducted by the Delhi government and the Indian Institute of Technology (IIT), Kanpur, revealed that vehicular emissions accounted for approximately 45% of the capital’s air pollution on the previous day, a figure expected to decrease to 38% on the current day. The study emphasized the need for ongoing efforts to address vehicular pollution.
The second major contributor to Delhi’s air pollution identified by the research is secondary inorganic aerosols, including particles such as sulfate and nitrate. These particles form in the atmosphere due to the interaction of gases and particulate pollutants from various sources such as power plants, refineries, and vehicles. This category accounts for 19 to 36% of the air pollution in the city over the recent days, indicating the multi-faceted nature of the pollution challenge.
In conclusion, as Delhi experiences a positive shift in air quality, it becomes imperative for authorities and citizens alike to remain vigilant and committed to sustainable practices that contribute to long-term improvements in the region’s air quality.