Chennai’s ambient air quality went for a toss on Diwali with clouds of smoke hovering, following bursting of firecrackers on Wednesday evening (18 October), as a two-to- four-fold increase in the PM10 pollutant level was noted, compared to last year.
The particulate matter (PM 10) ranged between as high as 777 and 387 (values in micrograms per cubic metre) in the city areas which were monitored on Diwali.
The recorded figures were several times higher than the National Ambient Air Quality (NAAQ) Standards which is 100 for PM10.
Last year, Diwali saw PM 10 hovering between only 102 and 178.
According to data made available by the Tamil Nadu Pollution Control Board, the parameters of SO2 (sulphur dioxide), NO2 (nitrogen dioxide) and PM10 were monitored in residential, commercial and mixed localities, including Triplicane, T Nagar and Sowcarpet on Diwali and the pre- festival days.
Notably, before Diwali, the PM10 level was well within the NAAQ Standards with 47 being the lowest and 70 highest.
Due to the weather condition on Diwali day, the particulate matter did not dissipate and instead, got concentrated. This was the reason for the higher PM10 values, the board said.
Though PM10 witnessed a spike on Diwali, the other two parameters of SO2 and NO2 were well within the range on that day.
While NO2 ranged between 19 and 29, the NAAQ reference value was 80 (micrograms per cubic metre). On pre-Diwali days, the average value was still lower.
Similarly, while the NAAQ value was 80 for SO2, the city neighbourhoods recorded values ranging between 11 and 19 on Diwali with the pre-Diwali data showing a still lesser level of pollution with respect to SO2.
Both the NO2 and SO2 values for last Diwali were still lower than the current figures (which are well within the range), showing still lesser pollution in the previous year.
Noise Levels of Chennai City
(With inputs from PTI)
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