Delhi most polluted; Mumbai and Kolkata too on Swiss list

Mumbai and Kolkata too feature among top 10 polluted cities, as per Swiss firm’s ranking

November 13, 2023 10:49 pm | Updated November 14, 2023 06:53 am IST - NEW DELHI

Vehicles move on a road amid low visibility due to smog on Diwali, in New Delhi, on November 12, 2023.

Vehicles move on a road amid low visibility due to smog on Diwali, in New Delhi, on November 12, 2023. | Photo Credit: PTI

A day after Deepavali was celebrated in most parts of the country, three Indian metropolises featured on the list of the most polluted cities in the world, according to a ranking by Swiss air purifier company, IQAir.

On November 13, Delhi was the most polluted city in the world with an air quality index (AQI) of 287 followed by Lahore, Pakistan, at 195. Mumbai, at 153, and Kolkata, 166, were also present among the top 10 of the most polluted cities. The IQAir’s AQI measures data from 109 countries, and readings change hourly. It follows U.S. methodology and varies slightly from the Indian one.

Explained | Why is South Asia the global hotspot of pollution?

The values are a measure of the quantities of PM [particulate matter] 2.5, considered most harmful for respiratory health. Though pollution from firecrackers are short-lived compared to those from persistent sources such as vehicles, waste and biomass burning, the spike in pollutants has a pronounced effect on health.

Air pollution in parts of Delhi was 30 times the safe limits prescribed by the World Health Organisation (WHO), contributed in part by the firecrackers lit on Sunday night, according to figures from the Delhi Pollution Control Committee. This is despite a ban on firecrackers in the city.

Continuing worry

The most updated readings from these cities, as of Monday, suggested that air quality is deteriorating, with several monitoring stations reporting a value of 400, classified as in the ‘severe’ category.

The air quality of Delhi is likely to be in the “severe” category on Tuesday and Wednesday, according to the Centre’s Air Quality Early Warning System for Delhi. Air pollution in the “severe” category “affects healthy people” and “seriously impacts those with existing diseases”, according to the Central Pollution Control Board (CPCB).

Also read | Curbs on fireworks binding on all States: Supreme Court

Another joint analysis by Climate Trends and Respirer Living Sciences, which analysed all-India pollution levels on Deepavali day in several cities, reported that the highest average PM 2.5 pollution was reported out of Patna, Bihar, at 206 microgram/cubic metre. Like the IQAir ranking, it too report Delhi as being the most polluted city on the day after Deepavali.

Bengaluru reported the lowest levels of PM 2.5 among 11 cities analysed and their figures were lower than last year’s Deepavali (October 24), the report added.

‘Phase out firecrackers’

“Already poor average PM 2.5 levels crossed limits due to firecrackers in several cities. Our analysis shows that widespread burning, in defiance of the Supreme Court orders, took away the gains (in reducing pollutants) that were made due to rain. The cracker industry must be phased out,” said Aarti Khosla, Director, Climate Trends, “Delhi and other major cities must not continue to bear the burden of public health in the name of hollow support for traditions. We can look at community fireworks or lighting of lamps, as done in Ayodhya.”

Also read: Delhi air pollution: What you need to know right now?

Last week, the hazardous air quality in Delhi, which the Centre attributed to stubble burning in Punjab, prompted emergency measures to be imposed, including plans to impose odd-even rules on the use of cars as well as experiment with artificial rain. An unexpected rain improved air quality by over 100 percentage points.

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