As air quality in the capital deteriorated to the ‘severe’ level for the first time this season on Monday, Environment Pollution (Prevention and Control) Authority chairperson Bhure Lal said measures such as vehicular regulation and strict anti-dust measures will have to be taken if the situation persists. Meanwhile, the Ghaziabad administration ordered a temporary halt to construction activities in the region. The air quality index value in Delhi was recorded at 401, while it was 451 in Ghaziabad Vehicular regulation and road-rationing schemes such as odd-even and stopping the entry of trucks in Delhi are part of the Graded Response Action Plan (GRAP), notified two years ago. Both restrictions are imposed if the ‘emergency’ pollution levels extend over 48 hours at a stretch. READ | SDMC halts construction work, issues fines over dust pollution Bad air quality at this time of the year is concentrated in Delhi-NCR and parts of Uttar Pradesh. Of the 70 cities where air quality is monitored by the Central Pollution Control Board, eight recorded ‘severe’ air quality (AQI value of more than 400) Tuesday. According to scientists at the IMD, winds were mostly calm on Delhi over the past two days, but picked up in the Northwest direction on Tuesday. While increased wind speed usually aids the dispersal of pollutants, it brings in particulate matter and polluting gases from Punjab and Haryana during the crop-burning season. Actions taken under grap Emergency category Imposed when PM 2.5 above 300 µg/m3 or PM 10 above 500 µg/m3 for more than 48 hours Actions -Stop entry of truck traffic into Delhi -Stop construction activities -Introduce odd-even scheme Severe category Imposed when PM 2.5 above 250 µg/m3 or PM 10 above 430 µg/m3 Actions -Close brick kilns, hot-mix plants, stone crushers -Maximise generation of power from existing natural gas based plants -Intensify public transport services and introduce differential rates to encourage off-peak travel
