Air quality takes a beating in Chennai

The city's ambient air quality went for a toss here on Diwali day with clouds of smoke hovering following bursting of firecrackers on Wednesday evening, as a two to four fold increase in PM10 pollutant level was noted when compared with data of last year.
The Particulate Matter (PM 10) ranged between as high as 777 to 387 (values in microgram per cubic metre) in city areas that were monitored on Deepavali day.
The recorded values were several times higher than the National Ambient Air Quality Standards which is 100 for PM 10.
Last year Diwali saw PM 10 hovering between only 102 and 178 here.

According to data made available by Tamil Nadu Pollution Control Board, parameters of SO2 (Sulphur dioxide), NO2 (Nitrogen dioxide) and PM10 were monitored in residential, commercial and mixed localities incuding Triplicane, T Nagar and Sowcarpet on Diwali and pre-festival days.
Notably, ahead of Deepavali, the PM10 was well within the NAAQ Standards with 47 being the lowest and 70 highest.

Due to the weather condition on Diwali day, Particulate Matter did not dissipiate and got concentrated and this was the reason for the higher PM10 values, the Board said.
Although PM10 witnessed a spike on the festival day, other two parameters of SO2 and NO2 were well within the range on that day.

While NO2 ranged between 19 (lowest) to 29 (highest), 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 to 19 on Diwali with pre-Diwali data showing a still lesser level of pollution in respect of SO2.
Both the NO2 and SO2 values for last Diwali was still lower than the current figures (current figures are well within the range) showing still lesser pollution in the previous year.