Deepavali is associated in the past years with lots of air pollution and huge noise levels have happened most times in Chennai city. This time around the ambient air quality and noise levels were well within the permissible limits on Saturday. This was mentioned by the Pollution Control Board.
The air quality index was found to be moderate in Triplicane, satisfactory in Sowcarpet and good in places like Besant Nagar, Nungambakkam and T. Nagar etc. This was according to a release from TNPCB. Truth is that the real-time air quality index belonging to the Central Pollution Control Board presented a different picture.
According to TNPCB, the PM 10 results (or the particulate matter in the ambient air below the size of 10 microns) ranged from 52 to 111 micrograms per cubic metres on the Deepavali day against the prescribed limit of 100 micrograms per cubic metres. It must be recalled that on the Deepavali day in 2019 the PM 10 level ranged from 84 to 128 micrograms per cubic metres.
Against a standard of 60 micrograms per cubic metres, PM 2.5 (particulate matter of fewer than 2.5 microns) ranged from 32 to 59 micrograms per cubic metres on the Deepavali day. Except in Triplicane and in Sowcarpet, the PM 10 values were inside the limits in all stations on the Deepavali day. Information collected is in Triplicane and in Sowcarpet the PM 10 values were marginally higher at 111 and at 100 micrograms per cubic metres respectively. Within the limits were also the PM 2.5 values.
It was brought out that the gaseous pollutants like sulphur dioxide and nitrogen dioxide were well within the standard limits of 80 micrograms per cubic metres. The Central Pollution Control Board real-time air quality index data ranged from moderate to severe and this was in total contrast with the data from TNPCB. The data from central pollution control board revealed that the stations at Arumbakkam, Kodungaiyur, Manali Village and Royapuram recorded air quality index or ADI ranging from 302 to 500 and those at Alandur, Manali and Velachery recorded ADI ranging from 149 to 310.
— Chennaites (@ChennaitesDotIn) November 14, 2020
It is worthy to mention here that AQI in the range 401 to 400 is considered as severe and it could affect even the healthy people seriously plus affect those with diseases etc. Point is that ambient noise levels were in the range from 54 to 69 decibel during the pre-Deepavali on 9th November and on the Deepavali day it was in the range from 71 to 78 decibel. The values were found to be lesser on the day of Deepavali but the values were in the range from 4 to 6 Leq- equivalent continuous sound levels in decibels than those in the last year.