A day after hundreds of effigies were burnt in the city to mark Dussehra, air quality turned ‘very poor’ again on Saturday. As per the Central Pollution Control Board (CPCB), Delhi’s 24-hour average air quality index value was 326, with primary pollutants being particulate matter 2.5 and 10.
While the air quality till Friday evening was in the ‘poor’ category, it deteriorated quickly at night. At RK Puram, the PM 2.5 concentration was recorded at 262 micrograms per cubic metre twice — once at 1 am and then at 7 pm. At India Gate, the highest value was 239 micrograms per cubic metre at 3 am.
Nitrogen dioxide values across the city also spiked. On Saturday night at India Gate, the value of NO2 was 107 micrograms per cubic metre, and at Jawaharlal Nehru Stadium it was 118 micrograms per cubic metre. It touched 140 micrograms per cubic metre at Anand Vihar and was 183 micrograms per cubic metre at RK Puram.
As per the forecast, air quality will remain in the ‘very poor’ category for the coming two days, and the concentration of pollutants, primarily PM 2.5, will increase.
The acceptable values for PM 2.5 is 60 micrograms per cubic metre. NO2 is primarily a by-product of fuel combustion and is a component in car, truck and bus emissions. Thermal Power Plants also produce NO2. But it was not just PM 2.5 that proved to be a problem.