THOOTHUKUDI: The Air Quality Index (AQI) of Thoothukudi on Monday was 146, which falls under the moderate category under Central Pollution Control Board's air quality standards. The coastal city reported a higher concentration of PM10 (Particulate Matter), recording a maximum of 496, owing to bursting of crackers for Deepavali festival.
According to the data, as the residents were in a festive mood on Sunday evening, AQI gradually increased to 84 at 6 pm, 87 at 7 pm, and suddenly shooting up to 101 at 8 pm before touching 117 at 9 pm with the steep rise of PM10 levels in the atmosphere. An hourly calculation reveals that the PM10 level was 430 by 8 pm on Sunday, and it further peaked to 496 by 9 pm. The average of PM10 for 24 hours was 146. Simultaneously, the NO2, SO2, CO and Ozone were on the higher side on Sunday.
Meanwhile, AQI rose to higher levels during the daytime on Monday touching 146 by 4 pm with the prominent pollutant being PM10 as per the real-time air quality monitoring website. "AQI of 146 could cause breathing troubles for the public," said a professor on the request of anonymity. According to the Central Control Room for Air Quality Management, a website of CPCB, PM10 presence surpassed the permissible level during the 24 hours between 4 pm on Sunday and 4 pm on Monday. While its permissible level is 100 ug/m3 (microgram/meter cube), it clocked 515 ug/m3 by 8 pm and 706 ug/m3 by 9 pm on Sunday.
A scientist of TNPCB, wishing not to be named, attributed the increasing AQI level to the prevalence of cloudy climate and lesser sunlight owing to the northeast monsoon. "This prevented the dispersal of the smoke emanating due to the crackers and vehicle movements among other factors," he added.