Wind picks up but air crisis is far from over in Delhi-NCR

According to the Central Pollution Control Board (CPCB)’s 4pm bulletin, the average air quality for the preceding 24 hours had come down from 484 to 399. By evening, however, the AQI had started inching up and was at 411 by 11pm.

Winds picked up and sporadic rain in some parts of Delhi and the national capital region (NCR) helped bring air pollution out of the “emergency” status on Saturday, but weather officials and meteorologists warned the crisis may have only relented slightly and is not over yet.

The period till November 15 is vulnerable to pollution spikes.(Burhaan Kinu/HT PHOTO)

According to the Central Pollution Control Board (CPCB)’s 4pm bulletin, the average air quality for the preceding 24 hours had come down from 484 to 399. By evening, however, the AQI had started inching up and was at 411 by 11pm.

“Even though we have come out of the emergency levels air quality is still very poor and just two notches below the severe zone. It is like coming out of an ICU but still being in the hospital. There is no room for any complacency and we should take utmost care to keep pollution levels under check,” said D Saha, former head of the CPCB’s air quality laboratory.

Air quality is considered good when the AQI is below 50 and satisfactory as long as it is under 100. The concentration of PM2.5 pollutants – the most harmful of all aerosols – was at 293 µg/m3, nearly five times the level considered safe, around 11pm.

Scientists at the India Meteorological Department said chances of another spike in pollution levels is low till at least November 10 since another western disturbance – a weather phenomenon that brings in rain -- is likely to arrive around November 6–7.

The period till November 15 is vulnerable to pollution spikes since this is the time when farm fires in the neighbouring state of Punjab and Haryana peak and the resulting smoke settles over NCR and adjoining regions.

“Even though this spike is dissipating and air quality is improving, we are still in the critical pollution period and there could be a rise anytime if the weather parameters like wind speed and wind direction become unfavourable for Delhi and there is any additional input such as from burning,” said Gurfan Beig, the head of Union environment ministry’s System of Air Quality and Weather Forecasting And Research (Safar).

According to farmers in Punjab, where the bulk of farm fires has taken place this year, only half of paddy harvesting has been completed till now. “50% of paddy harvest is still left,” said Harinder Singh Lakhowal, the president of Bharatiya Kisan Union, Punjab.

It is stubble left behind after the harvest that is often burnt by farmers as a quick and cheap way of clearing the field for the next round of sowing, which usually needs to be completed by November 15.

The chief ministers of Delhi and Punjab wrote to the Union government over the air quality crisis on Saturday, separately urging the centre to step in.

“German chancellor Angela Merkel is in Delhi for an official visit. I wonder what impression would she carry of India with such high levels of pollution. The images of international cricketers playing cricket wearing masks does not create a good image of India,” Delhi CM Arvind Kejriwal wrote in a letter to Union environment minister Prakash Javadekar.

Punjab CM Amarinder Singh, in a letter to Prime Minister Narendra Modi, wrote, “we have persistently and foolishly refused to rise above political considerations to launch a collective search for a permanent solution”.

On Saturday, the contribution to Delhi’s pollution load (PM2.5 levels) from farm fires in Punjab and Haryana dropped from around 38% on Friday to around 17%. It is likely to come down further to around 12% on Sunday.