BHUBANESWAR: It seems the ban on crackers on Diwali this year did not bring much change to air quality of the Capital city as it continued to remain in the moderate category. A comparative analysis shows that air quality of the city around this time was also moderate last year.
Data obtained from the Odisha State Pollution Control Board (OSPCB) shows Bhubaneswar's 24-hour average AQI on Diwali day stood at 137 as compared to 164 last year.
There, however, was a marginal fall in air quality on the festival day November 14 compared to the pre-monitoring day on November 9. As per Central Pollution Control Board (CPCB) air quality index (AQI), a score between 0 and 50 is considered safe, while 51-100 is placed in the satisfactory bracket.
For the moderate category, the score is in the 101-200 range. Similarly, a score between 201 and 300 is considered poor, 301-400 very poor and above 400 plus falls under severe category. With a thick envelope of smog, Delhi generally scores beyond 400 around this time.
The six sampling stations, where the AQI was analysed pre-Diwali and during the festival, showed that the average particulate matter (PM) - 10 level in the City was around 95 milligram per cubic metre (mg/m3) on the pre-monitoring day and 117 mg/m3 on the day of the festival. The PM 10 level was 80 mg/m3 at Unit-8 on the pre-monitoring day and 136 mg/m3 on the day of Diwali and 100 mg/m3 and 99 mg/m3 respectively at IRC Village.
This level remained more or less same in the remaining stations at Capital Police Station, Patrapada, OSPCB Central Laboratory and Palasuni. The level of PM 2.5, considered to be more hazardous, also deteriorated marginally from the level of good to moderate. It remained at the 71 mg/m3 level during the festival on November 14 against 54 mg/m3 on November 9.
The AQI continued to remain in satisfactory category at Konark. The quality of air in Puri, however, was found to have found to be much better during the festival this year compared to the previous year. The AQI of the pilgrim town which was poor during Diwali last year improved to moderate level this year. It remained 137 in 2020 against 203 in 2019.