New Delhi, Nov 1: Diwali fireworks pushed pollution in Delhi to a dangerous level, the worst in three years, as it turned the air highly toxic due to a deadly cocktail of harmful respirable pollutants and gases, engulfing the city with a cover of thick smog triggering health alarms.
Various monitoring agencies including Delhi Pollution Control Committee (DPCC), Central Pollution Control Board, Pune-based SAFAR and Centre for Science and Environment were unanimous about the severity of the air quality in the city.
As per DPCC's real time monitoring mechanism, the ultra pollutant PM 2.5 breached the safe standard by over 14 times at Anand Vihar, Delhi's most polluted area, at 2.30am.
Many other areas including densely populated R K Puram had nearly similar readings when pollution peaked past mid night.
Read more: Pics: Smog covers Delhi a day after Diwali
Noise pollution, which was monitored at five locations in the city, was marginally higher than last year as it ranged between 66.1 decibel(A) and 75.8 dB(A), while last year, it had varied from 65.9 dB(A) to 74.8 dB(A), according to DPCC findings.
In the morning, the city woke up to the season's worst air quality as smoke from Diwali fireworks, coupled with moisture and nearly stagnant wind movement, shrouded the city in a thick cover of smog. Commuters in several areas found it difficult to find their way as the visibility level plunged to nearly zero in several areas.
SAFAR, an agency of Earth Sciences Ministry, said air quality was not only severe but plunged to its worst in three years during Diwali mainly due to low wind movement and falling boundary layer, that traps pollutants close to the surface. The most critically polluted period was between 11am on October 30 and 10am on Monday.
The volume of sulphur dioxide (SO2), which can aggravate asthma, also breached the safe standards, indicating that the crackers contained a high level of sulphur. It averaged between 20-131 ug/m3 while it was between 26-64 ug/m3 last year.
On Diwali night, PM 10 ranged from 448 (micrograms per cubic metre) g/m3 to 939 g/m3 in Delhi as against the national safe standard of 100 g/m3, DPCC said.
The 24-hour average of PM 2.5, particles that measure less than 2.5 microns in diameter, ranged between 180 g/m3 and 440 g/m3. The prescribed standard for it is 60.
Diwali in 2015 saw PM 10 averaging between 296 and 778 g/m3 while in 2014, the same was recorded between 421 and 790 g/m3.
In case of PM 2.5, the average concentration recorded in 2015 was between 184 and 369 g/m3. The data for 2014 was not immediately available.
Prolonged exposure to PM 2.5 and PM 10 beyond the safe limits can harm the respiratory system as the ultra fine particulates can find their way deep into the lungs and also enter the bloodstream.