Delhi's air 'very poor' for 4th day on trot, likely to remain so till Oct 31

A layer of toxic haze lingered over national capital on Monday as city recorded its air quality in 'very poor' category for fourth consecutive day.

A central government air quality monitoring ncy said air quality was likely to remain 'very poor' till October 31.

city recorded a 24-hour aver air quality index (AQI) of 353 on Monday. It was 349 on Sunday, 345 on Saturday and 366 on Friday.  Most of air quality monitoring stations in city recorded air quality in 'very poor' category, while pollution levels rose to 'severe' levels at Vivek Vihar (AQI 414), Wazirpur (404) and Anand Vihar (418).

An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.  According to Ministry of Earth Sciences' air quality monitor, SAFAR, wind direction and wind speed were favourable for transport of pollutants from farm fires in Punjab, Haryana and neighbouring regions.

share of stubble burning in Delhi's PM2.5 concentration was 16 per cent on Monday. It was 19 per cent on Sunday and nine per cent on Saturday.

NASA's satellite imry also showed a very dense cluster of fires in Punjab, Haryana and nearby regions.   SAFAR said farm fire count was 1,275 on Sunday.

According to Punjab Pollution Control Board, state has recorded 14,461 incidents of stubble burning between September 21 and October 25 as compared to 9,796 during corresponding period last year.

Haryana has recorded around 4,284 incidents of stubble burning this season so far.

central government's Air Quality Early Warning System for Delhi said predominant surface wind direction is rthwesterly with wind speed up to 12 kmph, favourable for transport of pollutants from farm fires.

A large number of farm fires were observed over Punjab, Haryana and Uttar Presh, which is likely to impact Delhi-NCR's air quality, it said.

" very poor air quality is likely to persist till October 31," it said.

air quality warning system said ventilation index – a product of mixing depth and aver wind speed – was around 12,500 meter square per second on Monday – favourable for dispersion of pollutants.

Mixing depth is vertical height in which pollutants are suspended in air. It reduces on cold days with calm wind speed.

A ventilation index lower than 6,000 sqm/second, with aver wind speed less than 10 kmph, is unfavourable for dispersal of pollutants.

Earlier in day, Delhi Environment Minister Gopal Rai said air pollution was t a problem of Aam Ami Party alone and everyone, irrespective of ir party affiliations, should join efforts to tackle it.

"It is responsibility of all governments and citizens of Delhi to contribute in reducing pollution. problem is t of AAP alone. I want to appeal to everybody to participate in this campaign, keeping party affiliations aside," Rai said.

Rai said switching vehicles off at red lights can reduce vehicular pollution by 15-20 per cent.

Severe air pollution in Delhi is a year-round problem, which can be attributed to unfavourable meteorological conditions, farm fires in neighbouring regions and local sources of pollution.

According to an analysis by  Council on Energy, Environment and Water, a Delhi-based think tank, transportation contributes most -- 18 to 39 per cent -- to Delhi's air pollution.

Ro dust is second largest source of air pollution in city (18 to 38 per cent), followed by industries (2 to 29 per cent), rmal power plants (3 to 11 per cent) and construction (8 per cent).

Representational Im: PTI