Delhi air remains ‘poor’ for second consecutive day

Delhi’s 24-hour average air quality index (AQI) was logged at 233 at 4pm on Wednesday, worse than Tuesday’s reading of 211 (poor), according to the Central Pollution Control Board’s (CPCB’s) daily bulletin

New Delhi

Smog during the morning hours at Dwarka. (Vipin Kumar/HT Photo)

Delhi’s air quality remained in the “poor” category for a second consecutive day on Wednesday, with agencies forecasting “very poor” air quality on the day of Diwali, as meteorological conditions gradually begin to turn adverse.

Delhi’s 24-hour average air quality index (AQI) was logged at 233 at 4pm on Wednesday, worse than Tuesday’s reading of 211 (poor), according to the Central Pollution Control Board’s (CPCB’s) daily bulletin.

Experts attributed the deteriorating air quality to a combination of a drop in wind speeds, mist in the early hours of the day, and heavy traffic on roads. Adding firecracker emissions and stubble burning to the mix will worsen air quality around Diwali, they said.

“Delhi’s air quality is very likely to be in the ‘poor’ category from October 16 to October 18. The outlook for the subsequent six days shows the air quality is likely to be in the ‘poor’ category, which will become ‘very poor’ category on October 20 and 21,” the Centre’s Air Quality Early Warning System (EWS) for Delhi said in its forecast.

At 4pm on Wednesday, of the city’s 39 ambient air quality stations, eight were in the “very poor” range, with the worst at Anand Vihar (349), Wazirpur (324) and Patparganj (317).

The Decision Support System (DSS), a model that calculates the estimated contribution of sources of pollution to Delhi’s PM2.5, said the contribution of stubble burning was only around 0.2% on Wednesday, marginally down from a contribution of 0.5% on Tuesday. However, this is forecast to rise to 4% by Friday and 4.8% by Saturday. The top contribution to Delhi’s PM2.5 on Wednesday was the transport sector, which accounted for 16.7%, followed by pollution from adjoining Ghaziabad (8%) and Gautam Budh Nagar (7.8%), data showed.

Mahesh Palawat, vice president at Skymet meteorology, said haziness is likely to increase near Diwali as winds drop and shallow fog is seen in the early hours. “Daytime temperature will increase, but there will be low wind speeds and a slight haze in the morning. Meteorological conditions will, overall, be unfavourable in the next few days,” he said.

Tuesday was the first ‘poor’ air day of the season and the first for the capital since the pre-monsoon period, when Delhi recorded a poor air day on June 11 (245). The spike in AQI -- over 200 -- also prompted the Commission for Air Quality Management (CAQM) in NCR and Adjoining Areas to hold an emergency meeting and invoke stage-1 measures of the Graded Response Action Plan (GRAP) – an emergency based plan, across the entire NCR with immediate effect.

The measures introduced included periodic mechanized sweeping and water sprinkling on roads, strict vigilance of PUC norms and action against visibility polluting vehicles, regular lifting of solid waste and stopping construction and demolition (C&D) sites in Delhi with an area of more than 500 sqm which are not registered with the state government through their online portal on dust.