New Delhi: Delhi witnessed a sharp spike in air pollution during Diwali celebrations, with some monitoring stations recording severe pollution levels. The Commission for Air Quality Management (CAQM) had invoked Stage III of the Graded Response Action Plan (GRAP) across Delhi-NCR on November 6, ahead of the festival, as a precautionary measure amid forecasts of worsening air quality.
Delhi's overall AQI stood at 372 in the 'very poor' category at 1 am on Monday, November 9, according to the CAQM dashboard. However, some monitoring stations recorded readings in the severe category.
At the Dwarka Sector 8 monitoring station, PM2.5 concentration reached 1,727 micrograms per cubic metre and PM10 was at 2,005 micrograms per cubic metre shortly after 11 pm on Sunday. PM2.5 remained elevated at 1,725 micrograms per cubic metre around 11.30 pm. The station at ITO recorded a PM2.5 concentration of 994 micrograms per cubic metre around 1 am.
These figures represent particulate matter concentrations, not AQI readings. They cannot be directly converted into AQI values because the index is calculated using specified averaging periods.
An India Today ground investigation also raised questions about the availability and timeliness of pollution data. At the NSIT Dwarka monitoring station, a guard told the reporters that the public display board had been switched off at 9 pm. At Lodhi Road, another guard said an AQI monitor was installed but its readings were no longer being displayed publicly.
The investigation also found that online AQI readings did not appear to reflect changing pollution levels in real time. The online figures checked by the team were 403 for Dwarka and 407 for ITO. The report noted that the unavailable public displays did not establish that the monitoring stations had stopped collecting or transmitting data.
Under the revised GRAP schedule, Stage I applies when the AQI is between 201 and 300, Stage II between 301 and 400, Stage III between 401 and 450, and Stage IV when it exceeds 450.
Stage III imposes restrictions on several construction and demolition activities across the NCR, including excavation, piling, demolition, open-trench work for laying services, brick and masonry work, operation of ready-mix concrete plants, major welding and gas-cutting, painting, polishing and stone cutting.
Operations of stone crushers and mining activities are also prohibited. Industrial units using unapproved fuels face closure or operational restrictions. Vehicles carrying construction materials and demolition waste are restricted from using unpaved roads.
The restrictions also cover BS-III petrol and BS-IV diesel light motor vehicles in Delhi and the NCR districts of Gurugram, Faridabad, Sonipat, Ghaziabad and Gautam Buddha Nagar. Delhi-registered diesel medium goods vehicles meeting BS-IV standards or below are restricted, while similar diesel light and medium goods vehicles registered outside Delhi are barred from entering the capital.
However, certain activities are exempt. Construction linked to essential infrastructure projects, including railways, metro services, airports, hospitals, highways, power transmission, pipelines, telecommunications, sewage treatment plants and water supply, can continue subject to dust-control measures. Less-polluting construction activities may also continue under prescribed norms.
Schools for children up to Class V in Delhi and specified NCR districts have been directed to conduct classes in hybrid mode, wherever online facilities are feasible. State governments may also decide whether public, municipal and private offices should operate with 50 per cent of staff physically present and the remainder working from home.
The CAQM has also advised residents to use public transport, walk or cycle for short journeys, combine errands to reduce travel and avoid unnecessary outdoor activities during periods of high pollution.
Meanwhile, Chennai also witnessed a rise in air pollution during Deepavali celebrations on Sunday, November 8. Despite intermittent rainfall and restrictions on firecracker timings, residents burst crackers across several neighbourhoods, with private monitoring platforms reporting a sharp spike in pollution levels during the night. (with inputs from media organisations)