Delhi’s air quality continues at ‘severe plus’ category, AQI at 476

A day after implementation of restrictions under Stage IV of the Graded Response Action Plan (GRAP) in the national capital region of Delhi, the Air Quality Index (AQI) in Delhi marginally dipped to 476 at 12 noon Tuesday from 495, recorded at 9 pm Monday.

But it is not only Delhi, the AQI in Patna also is high at 308, in Lucknow it is 257, in Jaipur 211 and in Chandigarh 237, pointing to poor air quality in most of the places in north India.

Punjab, which has shown on record a huge decline in stubble burning incidents this year compared to year-ago, has too witnessing ‘poor’ or ‘very poor’ AQI at many places Tuesday, as per Central Pollution Control Board (CPCB) data.

The stubble burning cases in the state has dipped to 9,655 during September 15-November 18 from 33,719 in the year-ago period, a fall of over 71 per cent, according to satellite data collated by Indian Agricultural Research Institute (IARI).

Air quality has been classified in the Delhi-NCR under four different stages: Stage 1 - ‘poor’ (AQI 201-300), Stage 2 - ‘very poor’ (AQI 301-400), Stage 3 - ‘severe’ (AQI 401-450) and Stage 4 - ‘severe plus’ (AQI above 450).

As per the order of the Commission for Air Quality Management (CAQM), restrictions under Stage-IV of the Graded Response Action Plan (GRAP) under ‘Severe+’ air quality have been invoked in Delhi and adjoining areas with effect from 8 am November 18 to prevent further deterioration of air quality.

But, on the same day (November 18) Delhi recorded its second-worst air quality in six years with the AQI touching 494.

For the third straight day on Tuesday, Delhi’s air has been choked with thick grey with little sunshine as the pollution level remains in the ‘severe plus’ category. In some of the spots, the AQI has exceeded 500, but the CPCB does not have data to show if AQI breached its highest level, an anti-pollution activist said demanding strict implementation of the curbs.

Delhi recorded its coldest night of the season so far on Monday as the mercury dropped to 12.3 degrees Celsius from 16.2 degrees Celsius in the previous night, India Meteorological Department (IMD) said. Out of the 32 monitoring stations in the capital, 31 recorded AQI levels exceeding 480. Two stations, Alipur and Sonia Vihar, had 500 AQI.

Fog reduced visibility to 400 metres on Tuesday morning and it is likely to persist during the day, IMD has said in its forecast. The humidity levels were recorded at 89 per cent at 8.30 am. The maximum temperature is expected to settle at 24 degrees Celsius, it said.

Experts said that the Commission’s response should have been “preventive in nature” and not to wait to allow the air pollution to deteriorate. The CAQM in September issued revised guidelines in which it removed “three days of advance action”, experts said.

The earlier guidelines had said: “Based on the dynamic model and weather/ meteorological forecast by IMD/IITM on a day-to-day basis, actions under Stages II, III and IV of the GRAP shall be invoked at least three days in advance of the AQI reaching to the projected levels of that stage.”

But the revised guidelines say: “Based on the dynamic model and weather/ meteorological forecast by IMD/ITM on a day-to-day basis, actions under Stages II, III and IV of the GRAP shall be invoked in advance of the AQI reaching to the projected levels of that stage, also provided that the higher projected AQI levels are likely to sustain for longer periods (say 3 days or more).”