Delhi AQI: Brace for toxic air as peak pollution period begins
NEW DELHI: If you thought the city's air quality that has been steadily deteriorating within the 'very poor' range for five straight days was bad enough, brace for what could follow in the next couple of weeks. AQI data of the past few years reveals that November 1 to 15 is the year's most polluted fortnight in the capital. Delhi pollution In the past five years, the first fortnight of November recorded an average AQI of 370, higher than the peak winter periods of December 16-31 (351) and January 1-15 (324), as per Delhi Pollution Control Committee data. Track the pollution level in your city With Diwali falling on November 12, farm fires starting to peak and meteorological conditions that are likely to keep pollutants trapped close to the ground, experts said Delhiites are likely to witness multiple days of very toxic air. Enforce GRAP strictly to beat November pain, say experts Delhi recorded its most polluted day of the season on Tuesday, with average AQI at 364, in the 'very poor' category for the past five days. The forecast of Union earth sciences ministry's Air Quality Early Warning System for Delhi says that the AQI is likely to remain in 'very poor' category for the next few days. In November last year, the AQI air quality had turned 'severe' in the first week. Delhi has not so far recorded any 'severe' day (AQI above 400) in this season. November 2022 recorded 11 'severe' air days, making it the most polluted November since the Central Pollution Control Board started measuring AQI in 2015. Experts said the risk of multiple days of 'severe' air quality occurring in mid-November was high this year. Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment (CSE), said, "In the past, we have noticed prolonged smog episodes (higher number of consecutive days of severe pollution levels) when Diwali and increased crop residue burning occur together deeper into the winter and atmospheric conditions turn adverse." "To manage air quality during this period, it will require advanced action and preparation for implementation of stringent Graded Response Action Plan (GRAP) measures across the region and containment of fire incidents. GRAP can only prevent additional loading of pollution when high pollution is already trapped due to cool and calm conditions. Prevention of pollution is the only way to avoid smog episodes and high exposure," she added. Gufran Beig, chair professor National Institute of Advanced Studies (NIAS) and founder, the System of Air Quality and Weather Forecasting and Research (SAFAR), said the period till November 15 is the most vulnerable. "In the first fortnight of November this year, the stretch from November 6 to 8 is likely to be the worst. NIAS is developing a model using fire counts, current and climatology of the past 10 years, and other factors using artificial intelligence. The initial report of the pilot model shows that AQI may rise from November 6 to 8. However, AQI is likely to remain in the 'very poor' category till November 15," said Beig. Beig agreed that to improve the air quality, drastic steps are needed in the entire airshed region. "The steps taken under GRAP in Delhi have to be enforced strictly in the entire airshed. However, there is a possibility that a western disturbance may impact the region during the period till November 15. If there is good rainfall activity under the influence of the western disturbance, air quality would improve due to the 'wash out' effect. But if the western disturbance brings only moisture to the region, the air quality can deteriorate," added Beig.