Delhi's air quality has plunged to 'severe' category, which carries the risk of affecting people's respiratory system, as smoke caused by fireworks, as part of Diwali festivities, blanketed the national capital.
The Centre's System of Air Quality and Weather Forecasting and Research (SAFAR) recorded the level of respirable pollutants, PM 2.5 and PM 10, at 283 and 517 micrograms per cubic metre respectively around 8 PM, violating the safe limits by multiple times.
The prescribed standards of PM 2.5 and PM 10 are 60 and 100 respectively, and anything beyond that can harm the respiratory system as the ultra fine particulates can embed deep into the lungs and also enter the bloodstream.
SAFAR's monitoring stations at Pusa Road, Mathura Road, Dhirpur, Delhi University, Pitampura as well as neighbouring Noida had air quality in the 'severe' zone.
It had forecast that the city's air will be severely polluted on October 30 and 31.
The Central Pollution Control Board's (CPCB) monitoring stations, in areas like R K Puram, Anand Vihar, Mandir Marg and Shadipur, had similar 'severe' readings as well.
People have been advised not to go outdoors when air quality turns 'severe' as it has adverse effect especially on children, elders and those having heart or lung diseases.
Delhi Pollution Control Committee's (DPCC) real-time readings were also indicative of the increasing levels of pollution with the rise in the numbers of crackers going off.
By 8 PM, DPCC's Punjabi Bagh and Anand Vihar stations had PM 2.5 readings of 202 and 240 micrograms per cubic metre respectively, while PM 10 had risen to 429 and 766 micrograms per cubic metre.
Pollution peaks in the national capital during Diwali as a hazardous mix of noxious gases and respirable pollutants hang very close to the surface due to low temperature and near-stagnant wind movement.
Smoke emanating from farm fires raging across agricultural fields of neighbouring Punjab and Haryana worsens the situation.
"It is already evident from the analysis of pollution data that the number of days falling in severe and emergency categories has increased during the second half of December. It has hit the emergency levels yesterday. This situation demands immediate response," a CSE statement said.
Referring to the latest Delhi government data that showed a massive jump in the number of registered vehicles in the city, CSE said "uncontrolled motorisation" was threatening to undo the gains of the ongoing action against pollution.
The total number of registered vehicles plying in the city rose by nearly 10 lakh in 2015-16 financial year, an increase that went hand in hand with a fall in the number of DTC buses and ridership, establishing the public transport system's further erosion, the Delhi Statistical Handbook 2016 said.
"Despite improved wind speed on December 29 (from 1.4 metre per second to 1.7 metre per second), the PM 2.5 levels have increased and crossed the emergency levels of 300 microgramme per cum -- 5.3 times higher than the standard.
"Over the last three days, temperature is dropping continuously. As much as 14 per cent of the days in December have been in emergency category, 21 per cent days in severe category and 65 per cent of the days in very poor category," it said.
