Air

Delhi’s poor air days start, will only deteriorate

Dip in temperature, calm surface winds and steady increase in farm fires in Punjab and Haryana reason for poor air quality 

 
By Shagun Kapil
Published: Thursday 08 October 2020
Air quality in the national capital turned ‘poor’ for the first time this season October 7, 2020. Photo: Vikas Choudhary

Air quality in the national capital turned ‘poor’ for the first time this season October 7, 2020, according to Central Pollution Control Board (CPCB) bulletin. It is expected to deteriorate further in the next three days.

The pollution board attributed a dip in temperature, calm surface winds and a steady increase in farm fires in Punjab and Haryana in the last few days to the deteriorating air quality.

The Air Quality Index (AQI) in Delhi was 215 October 7, according to CPCB.

An AQI between 0-50 is considered ‘good’; 51-100 ‘satisfactory’; 101-200 ‘moderate’; 201-300 ‘poor’; 301-400 ‘very poor’and 401-500 ‘severe’. An AQI above 500 falls in ‘severe-plus or emergency’ category.

The AQI was recorded at 200 at 8 am on October 8.

It is likely to remain in the ‘poor’ category in the next three days, but will increase in magnitude, said System of Air Quality and Weather Forecasting and Research (SAFAR) website under the Ministry of Earth Sciences.

Out of 36 areas in Delhi monitored by the CPCB, Delhi Pollution Control Committee (DPCC) and India Meteorological Department (IMD), at least 14 recorded ‘poor’ quality air October 8 morning. Particulate Matter 2.5 was the lead pollutant in many areas.

 “PM2.5 is now becoming the lead pollutant instead of PM10 as a characteristic of winters,” SAFAR said.

Crop fires in Punjab have started early and are high in number compared to the last few years, said Pawan Gupta, senior scientist at Universities Space Research Association, National Aeronautics and Space Administration. But they have been limited to a few districts, he added.   

The boundary-layer wind direction and speed are favourable for slow transport of external emission sources, and local conditions are conducive for accumulation of pollutants in Delhi, said SAFAR.

It added that the synergised fire counts over Punjab, Haryana and neighbouring border regions were 336 on October 6. 

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