National capital Delhi is witnessing a repeat of 2016 and 2017 smog episode; yet appropriate action under Graded Response Action Plan (GRAP) has not been taken so far.
The Central Control Room, which monitors particulate matter (PM) 2.5 and PM 10 levels for 24 hours on behalf of the Central Pollution Control Board (CPCB), stopped providing updates after 9:30 pm on November 5, 2021.
PM 2.5 concentration remained in the emergency level (300 micrograms per cubic meter) in the air from the night of Diwali (November 4) till 9:30 pm November 5.
The air in Delhi-NCR still reeks of pollutants from firecrackers as well as stubble burning.
Yet, only 16 per cent of problems related to air pollution were solved through government agencies between October 15 and November 4. A total of 627 complaints related to air pollution were registered in Delhi-NCR from October 15 to November 4, of which 101 were resolved by various agencies, according to the Central Pollution Control Board (CPCB).
Rules under GRAP call for an air emergency if PM 2.5 levels in the air remain 300 µg/m3 or PM 10 levels at 500 µg/m3 or more for 48 hours.
The emergency includes ban on entry of heavy vehicles in Delhi-NCR as well as on construction activities, implementation of schemes like odd-even, etc.
It also includes closure of hot-mix plants and stone crushers. It stresses electricity generation from natural gas-based power plants in place of coal based-power power plants.
The last meeting of the sub-committee on the implementation of GRAP rules was held on November 3, 2021, a day before Diwali. It was decided to implement GRAP only for very poor category and not to take any additional steps. No meeting was held after that.
Avikal Somvanshi, program manager at Delhi-based Center for Science and Environment (CSE), said stringent measures are taken as soon as pollution hits emergency levels: “It is unfortunate that concrete steps have not been taken so far for people facing health emergency.”
Haze and smog remained over Delhi-NCR on the morning of November 6, 2021: At 10.05 am, AQI at 33 out of 39 monitoring stations was recorded in severe category. On the night of Diwali, at 8 pm, the AQI was recorded in the severe category at 17 stations in Delhi; on November 5, 29 stations recorded AQI as severe.
The CPCB has four important categories of air quality index. According to this, AQI of 1-50 is good; 51 to 100 is satisfactory; 101 to 200 is moderate; 201-300 is poor; 301 to 400 is very poor and 401-500 is severe.
At least 25 per cent of pollution in Delhi’s air is secondary PM 2.5, according to 2016 report by Indian Institute of Technology, Delhi. Various toxic gases such as sulphur dioxide and and nitrogen dioxide released after the burning of firecrackers get mixed in the atmosphere, causing secondary PM 2.5 pollution.
At present, the share of stubble pollution is around 35 per cent; it was 10 per cent before Diwali. PM 2.5 pollutants from firecrackers have aggravated the situation.
The trapped pollutants may get a chance to disperse on November 7, 2021, according to central agency System of Air Quality and Weather Forecasting and Research (SAFAR).