Kolkata chokes on Diwali night as noisy crackers make way for smokier ones

KOLKATA: All three automated pollution-monitoring stations in the city recorded a PM2.5 count of above 500 for five straight hours on Diwali night, sparking a debate on whether the drive for less-noisy crackers pushed revellers to go for fireworks emitting more light — and smoke — and causing the stratospheric levels of

air pollution

.


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The highest PM2.5 count for the period between 12 midnight and 5 am on Thursday was recorded by the monitoring station at the US Consulate. It logged 624 at 1 am before going on the blink from 2 am to 4 am. The other two stations — on the

Rabindra Bharati University

campus and at Victoria Memorial — too recorded a constant PM2.5 count of 500 for these five hours.

PM2.5 refers to particulate matters of size 2.5 micrometres, which are considered to be the most hazardous for human health because their tiny size lets them enter lungs and the blood stream unhindered. A count between 91 and 120 is deemed to be poor; a count between 121 and 250 is considered to be very poor; and anything above 250 is classified as severe.

The 500-or-above counts logged by the city for five consecutive hours, environmentalists said, would put the 2018 Diwali as one of the most polluting in recent years. The high PM2.5 count also ensured that Kolkata’s air quality index, a 24-hour average of the most prominent pollutants, remained more than 370 throughout Thursday. The Kali Puja night, too, was almost as bad, as TOI reported in its Thursday morning edition.

The alarming levels of air pollution focused debate on the city’s push for less-noisy crackers this Kali Puja and Diwali. To generate the colourful lights emitted by these less-noisy fireworks, manufacturers pack them with hazardous metals like barium,

potassium

, copper,

manganese

, aluminium, zinc and antimony. The fireworks burst, releasing fine particulate matter into the air; these enter the lungs and blood stream along with the air we inhale.

West Bengal Pollution Control Board chairman Kalyan Rudra is among the experts who have been insisting that fireworks, which do not make much sound, may be more harmful as toxic chemicials and metals are used to produce colourful lights.

‘Children, elderly are most at risk’

WBPCB chairman Kalyan Rudra said, “We have to focus on air quality as it affects both the poor and the rich. Some may ask what permanent harm crackers being burst on one or two nights can do. But we find conditions remaining poor for days after a dramatic plunge in air quality.”

“Another worry is these festivals take place at the onset of winter, when dispersal of pollutants is a problem,” he added.

Preventive medicine expert Arup Dutta confirmed that the fine particulate matter, laden with heavy metals and toxic chemicals, entering the lungs could cause multiple problems — from severe COPD to fatal strokes. Studies have conclusively shown that children and the elderly are the most vulnerable. “The higher conentration of PM2.5 makes Kolkata’s air even more toxic,” environment scientist Sudipta Bhattacharya of Saviours and Friends of Environment (SaFE) agreed.

Atmospheric conditions have only aggravated matters. A low cloud cover during the day and absence of sunlight have made dispersal of pollutants excruciatingly slow. National Environment and Engineering Research Institute scientists said decrease in temperature and wind speed have led to rise in PM2.5 values.