Air quality worsens ahead of Diwali

Keep windows shut, wear masks, prefer short walks, minimise use of private vehicles, Delhites advised

New Delhi: Keep windows shut, wear masks, prefer short walks, minimise use of private vehicles are among the recommendations of government bodies for Delhites who are battling dangerous pollution levels in the city.

Delhi's air quality continues to remain 'very poor' for the fourth consecutive day on Saturday, prompting the Central Pollution Control Board and the Centre-run System of Air Quality Forecasting and Research to issue separate advisories for people.

In the NCR region, Ghaziabad recorded severe pollution level, while Gurgaon, Faridabad, Noida and Greater Noida all recorded 'very poor' air quality, according to a data by the Central Pollution Control Board data Saturday.

The eight areas in Delhi that recorded severe air quality Saturday are Anand Vihar, Dwarka Sector 8, Narela, Punjabi Bagh, Bawana, Mundaka, Vivek Vihar and Rohini.

The CPCB-led task force recommended public to avoid strenuous outdoor activities and minimise the use of private vehicles to reduce exposure to toxic air.

The task force also gave recommendations to the Supreme Court-appointed Environment Pollution Control Authority to deal with the deteriorating air quality.

The task force also recommended closure of all construction activities involving excavation, civil construction, stone crushers, hot mix plants that generate dust pollution during November 1 to 10.

Other measures included shutdown of coal and biomass based industries (excluding thermal and waste-to-energy plants) from November 4 to 10, intensification of efforts by transport department to check polluting vehicles and controlling traffic congestion in Delhi-NCR between November 1 and 10, according to the minutes of the meeting.

The task force also recommended efforts to provide uninterrupted power supply in NCR areas to avoid requirement of operating diesel generator (DG) sets.

The task force said that at the beginning of November, the situation may deteriorate further on account of localised emissions during festival and regional contribution due to stubble burning.

Stubble burning from Punjab and Haryana Saturday caused 32 per cent of pollution in Delhi, according to a report by the SAFAR.

The report, which analysed the impact of pollutant PM2.5 (presence of particles in the air with a diameter of less than 2.5 micrometres), showed that highest contribution since October 11 by stubble burning was seen Friday at 36 per cent.

PM2.5 is the presence of particles in the air with a diameter of less than 2.5 micrometres, while PM10 is the presence of particles in the air with, and both are considered the major atmospheric pollutants.

PM2.5, in particular, poses greater harm as its fine particles can easily be inhaled into the respiratory tract. "On Thursday and Friday more stubble was burnt in Punjab and Haryana due to which its contribution to PM2.5 pollution increased," an official said, adding that the impact of pollution by stubble burning on the national capital could be seen only a day after the stubble is burnt.

"Pollution would reduce in the next couple of days if the weather condition remains same. The weather conditions include wind direction, temperature etc," he said.

The report also analysed the trends of different factors causing pollution since 2010 and it said transport emission in the national capital has increased significantly at 41 per cent in the last eight years.

The residential bio-fuel emission declined significantly in Delhi at 64 per cent since 2010, the report said. D Saha, former air quality chief at the CPCB, said meteorological factors like wind speed, solar direction and temperature are mostly responsible for increasing pollution levels in the city.

"If these factors come under control, the air quality automatically improves," he said. The measures recommended by the task force are only preventive steps and not to create panic as the air pollution in Delhi is governed by meteorological conditions, he said.

"One strong wind is enough for dispersion of entire pollutants load. Clear sky in south, southeast and western part will improve ventilation coefficient and will improve situation in Delhi and NCR," Saha said.

The India Institute of Tropical Meteorology, Pune, said large number of biomass fire spots were seen in satellite imageries in the neighbouring states of Delhi.

"The prevailing meteorological conditions are not very favourable for dispersal of pollutants for the next two days due to very low ventilation index and low wind speed," the IITM warned.

"As per the Air Quality Forecast, the air quality is likely to be in very poor to severe category at various places in Delhi for next two days.

The dominant pollutant of AQ Index is PM2.5 and PM10," the IITM said. Meanwhile, SAFAR also gave a health advisory to public due to increasing pollution levels.

The recommendations of the health advisory included people with heart or lung disease, older adults and children to avoid prolonged or heavy exertion.