New Delhi, Oct 31: Air pollution during this Diwali was worse than the previous two years with even the 24-hour average of respirable pollutants breaching the safe standards by multiple times, as per data released by the Delhi government.
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).
The Delhi Pollution Control Committee (DPCC) data of PM 2.5 and PM 10 takes into account figures from 6 pm on October 30 till 6 am on October 31. Pollution reached an alarming high past midnight.
"The ambient air is influenced by plumes of smoke from farm fires in Punjab and Haryana. There is no significant wind movement and the fireworks add to that. So, this is an accumulative effect," a Delhi Environment Department official said.
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) µg/m3 to 939 µg/m3 in Delhi as against the national safe standard of 100 µg/m3, DPCC said.
The 24-hour average of PM 2.5, particles that measure less than 2.5 microns in diameter, ranged between 180 µg/m3 and 440 µg/m3. The prescribed standard for it is 60.
Diwali in 2015 saw PM 10 averaging between 296 and 778 µg/m3 while in 2014, the same was recorded between 421 and 790 µg/m3. In case of PM 2.5, the average concentration recorded in 2015 was between 184 and 369 µg/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.
"A detailed analysis shows that the air quality dipped after 7 pm due to bursting of fire crackers. Pollutants due to the crackers and a calm condition (no significant wind movement) attributed to the present situation," the government said.