As air turns poor, CPCB puts agencies on notice

NEW DELHI: After nearly three months of relatively clean air, Delhi's air quality dipped to the 'poor' zone on Thursday, with a citywide average AQI reading of 211.The city's air quality has fallen sharply by nearly 100 points in the last 48 hours. While the AQI was 112 (moderate) on Dussehra day, it rose to 173 (moderate) on Wednesday. The deterioration continued on Thursday, as a change in wind direction to northwesterly, stubble burning , local emissions from effigy-burning and other sources as well as falling mercury started making an impact.Track the pollution level in your cityForecasting agency SAFAR said low wind speeds were trapping pollutants and warned of a further dip in air quality in the next three days.CPCB wrote to state pollution control boards and other government agencies on Thursday, asking them to take appropriate measures to control dust and pollution.In letters sent to the municipal bodies in Delhi and NCR states as well as other agencies, CPCB asked for weekly action taken reports to be submitted and called for precautions to be taken during construction activities, particularly with dust, C&D waste and open burning.Among the agencies contacted by CPCB were NHAI, DMRC, CPWD, NBCCIL, PWD, DDA, DSIIDCL New Delhi, Ghaziabad Development Authority, Noida and Greater Noida authorities.A SAFAR bulletin said, “The southwest monsoon has started to retreat now. Wind speeds continue to be slow and variable with predominant direction from the west. Under these conditions, air quality is predicted to deteriorate further. Indications of increased fire activity during the last 48 hours are visible from satellite imagery and a further deterioration of AQI is expected for the next two days.”AQI is classified as “poor” at reading between 201 and300. It is below the “very poor” (301-400) and “severe” (401-500) zones while being worse than “moderate” (101-200), “satisfactory” (51-100) and “good” (below 50) levels.The last time Delhi had air quality in the “poor” zone was on July 14, when it touched an AQI of 235. Following that, a prolonged monsoon largely helped Delhi keep the AQI below 200. In fact, Delhi recorded two “good” air days in August while experiencing the cleanest September in the last nine years, according to CPCB data. SAFAR, however, said a late withdrawal of the monsoon was bad for Delhi’s air quality.“The late monsoon withdrawal is not good for air quality in north India. During the third to fourth week of October, the temperature will also start to cool. The anticyclone, which persists as part of the withdrawal, associated with clear skies and sinking motion will mean significantly calm surface winds. Both these conditions will lead to stagnant weather conditions (low wind speeds and descending air), which favours rapid fine particulate matter formation and accumulation of pollutants,” said SAFAR.On Wednesday, EPCA chairman Bhure Lal also wrote to NCR states, asking them to prepare for “very poor” and “severe” air under the GRAP from October 15. Air quality was likely to deteriorate from October 12 onwards, he said.“EPCA has been advised by the task force on GRAP, which is chaired by the member secretary of the CPCB that the coming period, beginning October 12, 2019, is projected to have adverse weather conditions, which exacerbate the potential for pollution,” said Lal.