Delhi AQI Turns ‘Poor’ For First Time This Season At 245, GRAP Stage I Measures Invoked

Delhi’s air quality deteriorated to the ‘poor’ category for the first time this season on Wednesday, with the Air Quality Index (AQI) climbing to 245 from 179 a day earlier. The city also recorded its most polluted day after Dussehra in five years, as unfavourable weather conditions and emissions from firecrackers and Ravana effigy burning contributed to worsening air quality.

The Commission for Air Quality Management (CAQM) invoked Stage I of the Graded Response Action Plan (GRAP) in response to the deterioration. The contribution of stubble burning to Delhi’s PM2.5 pollution was estimated at 3.9% on Wednesday, with forecasts indicating a possible rise over the following two days.

GRAP Stage I Measures Kick In As AQI Rises

Under Stage I of GRAP, the entry of intercity and interstate buses from Haryana, Uttar Pradesh, Rajasthan, Punjab, Himachal Pradesh, Madhya Pradesh, Uttarakhand and Jammu and Kashmir that do not meet BS-VI emission standards and run on neither electricity nor compressed natural gas (CNG) is prohibited. Regulations governing the use of diesel generator sets have also come into effect.

The measures call for expanding public transport through additional CNG and electric buses, Metro and Regional Rapid Transit System (RRTS) services. The Delhi Metro will operate 20 additional trips on weekdays from Thursday.

“The forecast by India Meteorological Department and Indian Institute of Tropical Meteorology has also predicted that AQI will remain in the poor category in the coming days,” the CAQM said, adding that agencies across the National Capital Region (NCR) would implement, monitor and review Stage I measures to prevent further deterioration.

Data from the Central Pollution Control Board (CPCB) showed that Delhi’s AQI began rising early Wednesday, reaching 227 at 7 am and 245 at 4 pm, when the CPCB releases its 24-hour average AQI bulletin. The index climbed further to 248 by 8 pm.

The last time Delhi recorded an AQI higher than Wednesday’s post-Dussehra level was in 2021, when it reached 284 the day after the festival. This year, an AQI higher than 245 was last recorded on July 24, when it stood at 246 in the ‘poor’ category amid dust carried towards north-west India from Iran, Afghanistan and Pakistan.

Seven monitoring stations recorded ‘very poor’ air quality on Wednesday: Pusa at 329, Chandni Chowk at 326, Jahangirpuri at 313, Punjabi Bagh at 312, Patparganj at 304, Mandir Marg at 303 and Vivek Vihar at 302.

Dussehra Emissions And Weather Conditions Add To Pollution

Mahesh Palawat, vice-president of Skymet Meteorology, attributed the deterioration partly to Dussehra celebrations, including the burning of Ravana effigies.

“Falling night temperatures and light winds may have further contributed to the deterioration.... Traffic emissions, industrial smoke and dust tend to accumulate under such conditions, while fireworks during the celebrations may also have contributed to the overnight rise in pollution. The haze observed Wednesday followed Tuesday’s celebrations,” he said.

Sunil Dahiya, founder of the think tank Envirocatalyst, said slow-moving north-westerly winds were bringing additional emissions from farm fires and festive activities, adding to pollution from regional sources and within Delhi.

The Decision Support System (DSS), which operates under the Union Ministry of Earth Sciences, estimated that stubble burning’s contribution to Delhi’s pollution could rise to 7.4% on Thursday, increase further to 15.9% on Friday and fall to 4.1% on Saturday.

Delhi’s air quality had deteriorated to the ‘poor’ category on October 14 last year, with an AQI of 211, before slipping into the ‘very poor’ category on October 20, when the index reached 345.

Meanwhile, Delhi Traffic Police has urged commuters to reduce vehicle emissions by using the Metro and other public transport, carpooling and avoiding unnecessary trips. It has also advised motorists to maintain their vehicles and ensure they have valid Pollution Under Control Certificates.