After brief respite, pollution shoots up to 'severe' again

NEW DELHI: Air quality in Delhi, once again, returned to 'severe' on Sunday, despite lower quantity of smog in the morning.

Central Pollution Control Board (CPCB) predicted that smog is likely to increase during the nights. In most of areas of Delhi, air quality was 'hazardous', which agencies consider unfit for inhalation even for healthier people.

The hourly graph of the Central Control Room for Air Quality Management, which had briefly fallen below emergency levels on Saturday, recorded PM2.5 and PM10 concentration at 478 and 713 micrograms per cubic metre (µg/m³) by Sunday afternoon.

The corresponding 24-hour safe standards are 60 and 100. Visibility came down below 100 metres at many places.

The air quality index of the CPCB had a score of 460, as against Saturday's 403.

The most dominant pollutants were PM 2.5 and CO, according to the CPCB air bulletin.

Earlier, the Meteorological department had forecast rains on November 15 and 15, with environmentalists maintaining that only rain and high wind speed can bring down pollution levels.

Meanwhile, reports of construction works have been registered across the city to the Delhi Pollution Control Board.

There were also reports of heavy vehicles entering the city from other states, despite Lieutenant Governor Anil Baijal banning the entry of such vehicles into the capital.

Barely any punitive action was taken those who were seen flouting anti-pollution guidelines on Sunday.

If the prevailing levels of PM2.5 and PM10 persist for another 24 hours, the odd-even scheme is supposed to be implemented, according to the Graded Response Action Plan being enforced by the Environment Pollution (Prevention and Control) Authority.

The NGT on Saturday said that the odd-even scheme should be implemented "without any default" as and when PM10 level goes above 500 µg/m³ and PM 2.5 level crosses the limit of 300 µg/m³ during a span of 48 hours.

CPCB and SAFAR scientists maintained that the fresh spike in pollution was triggered mainly due to drop in inversion layer (the layer beyond which pollutants cannot disperse into the upper layer of the atmosphere), which in turn happened due to the sharp drop in minimum and maximum temperatures.

CPCB's air lab chief Dipankar Saha said the haze was basically a mixture of dust and moisture.

Formation of a thick cloud cover also resulted in the spike in moisture and drop in both minimum and maximum temperatures, he said.