The levels of air pollution during Diwali this year were found much higher as compared to the last year while a significant dip was found in noise pollution level, the Central Pollution Control Board (CPCB) revealed on Sunday.

In a special report, the CPCB said almost all pollutants reported higher values on Diwali day and pre-Diwali day this year as compared to 2019. "It is observed that if compared with 2019 pre-deepawali day (21.10.2019) concentrations of NO2, PM10 and PM2.5 were found to be much higher on pre-deepawali day (on 09.11.2020) at all the monitored locations, while SO2 concentrations were at similar level. On Deepawali day (14.11.2020), almost all the pollutants reported higher values as compared to 2019 Diwali day," the report stated.

However, the report attributed its outcome to high share of stubble burning and meteorological conditions and perennial issue of deteriorated air quality during November in Delhi-NCR, not on account of fire-cracker bursting. Though Pitampura recorded an increase in PM and SO2 indicating impact of firecracker bursting on Deepawali day, it added.

"The contribution of stubble burning in Delhi's PM2.5 concentration was 32 per cent on Diwali day this year as compared to 19 per cent last year. Therefore, it may be inferred that elevated PM2.5 concentrations in 2020 in comparison to previous year had enhanced contribution of stubble burning and the same is also reflected in elevated levels of CO and NO2," the report revealed.

The CPCB observed that the hourly average concentration of PM2.5 started increasing from 11 p.m. on November 14, it reached peak in most of the stations at around 1 a.m. and continued at higher levels till 5 a.m. The city level average calculated for PM10 and PM2.5 concentrations on Deepawali day (14.11.2020) were 645 µg/m3 and 483 µg/m3 respectively.

"Most of the parameters including PM2.5 monitored by stations set-up at IHBAS (Dilshad Garden), DMS (Shadipur) and NSIT (Dwarka) were found more on both pre-deepawali and deepawali days compared to 2019," the report added.

Meanwhile, the central agency noticed a significant drop in the noise pollution level this year in comparison to 2019.

The manual monitoring of six locations before Diwali revealed that the noise level was found declined at Lajpat Nagar, Mayur Vihar Phase-II, and Janakpuri, in comparison to previous year. However, the highest level was recorded at Kamla Nagar this year on pre-deepawali day, the report stated

Meanwhile, real-time monitoring of ten stations showed that day time noise levels have decreased in 2020 as compared to pre-deepawali day of 2019 at seven locations. Only NSIT Dwarka, R.K. Puram and ITO stations have recorded a slight increase in day time noise. The night time noise found increased at Anand Vihar and ITO, the report said.

CPCB carried out ambient air quality and noise level monitoring on select pre-Deepawali day (09.11.2020) and on Deepawali day (14.11.2020) in Delhi like previous years. Ambient Air Quality was monitored at 40 locations (3 manual stations and 37 real-time stations). Ambient Noise level was monitored at 16 locations (06 manual and 10 real-time noise monitoring stations). Three continuous air quality stations (operated by CPCB, NABL accredited) have been used for comparison with last five years' data.

CPCB carried out ambient air quality and noise level monitoring on pre-deepawali and deepawali day in Delhi. The air quality was monitored at 40 locations with 3 manual stations and 37 real-time stations. Meanwhile, the ambient noise level was monitored at 16 locations including 6 manual and 10 real-time noise monitoring stations.

The air quality dipped to severe at several places across the national capital on Saturday night owing to a combination of stubble burning and firecrackers burst during the Diwali celebrations in violation of a ban on the same.