Boom! Poison is off charts in Delhi after frenzied Diwali night of fireworks
A frenzied Diwali night of fireworks turned Delhi's pollution more toxic on Thursday despite a preemptive Supreme Court ban late last month to save the air quality from more deterioration.
The air quality worsened through the day and went off the charts by the evening as the city recorded its worst pollution of the year the morning after the festival.
The court had restricted fireworks to two hours - 8-10 pm - and ordered use of cleaner green firecrackers. But Delhi failed spectacularly in preventing the air quality from spiralling into the most dangerous category.
There were no "green" fireworks available for sale and revellers let off fireworks long into the night. The air quality index (AQI) showed severe-plus emergency pollution levels as loud bangs rent the air in Delhi.
Partly as a result of smoke from firecrackers, the AQI in Delhi jumped to 642, according to data by the Centre-run SAFAR (System of Air Quality and Weather Forecasting And Research).
Early morning at 1 am, smoke layers became thick and started to trap pollutants near the surface rapidly. However, air quality recovered by afternoon and became 'very poor' with no additional local emissions added. It settled at an AQI of 390, as per the CPCB (Central Pollution Control Board).
The contribution of PM2.5 and PM10 had increased from 50 per cent to 70 per cent on Wednesday night, indicating an increased share of locally generated firecracker emissions, SAFAR said.
On Thursday, the PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) level was recorded at 492 gm-3, more than eight times the permissible limit.
The PM10 (particles in the air with a diameter of less than 10 micrometres) level was recorded at six times the permissable limit at 618 ug/m3, according to the SAFAR. India's official permissible PM2.5 limit is 60 ug/m3, while that of PM10 is 100 ug/m3.
Ultra fine particulate pollutants PM2.5 and PM10 in the air pose health hazards as they can enter the respiratory system and reach the bloodstream. Violations were also recorded in Mumbai, Kolkata, Jaipur and other major cities.
With inputs from Abhishek Anand