delhi

Updated: Jan 02, 2020 10:22 IST

The first day of 2020 started with the city’s air quality plunging to ‘severe’.

Though, the sun shone bright and wind speed was moderate, additional emissions from vehicular traffic, bonfires and the bursting of fire-crackers on New Year eve pushed up the pollution level in the Capital, said officials at government’s pollution forecasting agencies.

The overall 24-hour average air quality index (AQI), as calculated by the Central Pollution Control Board (CPCB)’s 4pm bulletin was 437, as against 387 in the ‘very poor’ zone the previous day.

The System of Air Quality and Weather Forecasting and Research (SAFAR), ministry of earth science’s weather and air quality monitoring centre, forecast said that though with bright sun and constant winds, the meteorological conditions have become favourable for higher dispersion of pollutants, additional sources of emission on New Year’s eve led to deterioration in air quality.

“Pollution levels showed an upward trend from 8pm onwards on Tuesday night and peaked between midnight and 1am. This is one of the underlying cases of domination of emissions over favourable surface wind conditions, which has been a driving factor this winter for sudden variability in air quality,” said a senior SAFAR scientist.

However, he added that the air quality is likely to improve with an approaching Western Disturbance, which will trigger stronger winds and hence better ventilation for dispersion of pollutants.

“Air quality is likely to improve to the higher-end of the ‘very poor’ zone by January 2. Further significant improvement is expected around January 3,” he said.

According to CPCB officials too, pollution levels started shooting up around 8pm onwards on New Year’s eve and peaked after midnight. ( soumava.haldar )

Scientists at the India Meteorological Department (IMD) said the wind speed will increase to 20-25 kmph on Thursday with chances of light rainfall in Delhi-NCR.

According to CPCB officials too, pollution levels started shooting up around 8pm onwards on New Year’s eve and peaked after midnight. The levels of PM 2.5 — the most harmful aerosols in Delhi’s air — were 250ug/m3 at 1am (on Wednesday) from 188ug/m3 at 7pm on Tuesday.

At 7am on January 1, the PM2.5 levels spiked further to touch 304ug/m3, breaching the ‘emergency’ mark. It continued to spike thereafter and was recorded as 328ug/m3 at 7 pm. The safe limit of PM 2.5 is 60ug/m3.

PM 10 (coarse particles) levels were 426ug/m3 at 7pm, close to the emergency mark of 500ug/m3. The safe limit of PM 10 is 100ug/m3.

Delhi’s air quality remained in the ‘severe’ zone since December 28 — except for December 31, when the AQI improved to 387. Previously, Delhi had witnessed two other short spells of ‘severe’ air on December 11-12 and December 20-21.

However, according to experts, despite frequent peak pollution episodes, the unusual cold spell in the Capital this time, which lasted for 18 days, took the focus away from city’s foul air quality.

Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment (CSE), said, “Extreme climatic conditions was being experienced by not just Delhi but the whole of northwest India. The air quality has seen frequent ups and downs. Climate change has been affecting the overall environment and has emerged as a challenge, to deal with which action plans need to be made accordingly.”

Roychowdhury added that though air quality is expected to improve from Thursday, it is a reminder that Delhi needs dedicated round the year action to prevent the frequent smog episodes.