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New Delhi most polluted city in the World

Most polluted city; Did you know that there are cities where breathing can harm you? Air pollution affects everyone, however,

By Ground report
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NGT orders action report on Delhi’s Air Pollution

Did you know that there are cities where breathing can harm you? Air pollution affects everyone, however, there are different levels of air pollution. Therefore, it would not be unusual to ask about the quality of the air, since being very dirty could cause negative effects on health.

The report, using data from 2010 to 2019, found that global patterns of exposure to the two key air pollutants were "strikingly different". While exposure to PM2.5 pollution tends to be higher in cities located in low- and middle-income countries, NO 2 exposure is higher in cities in high- and low- and middle-income countries.

Delhi and Kolkata ranked first and second in the list of the 10 most polluted cities when PM2.5 levels were compared, with Delhi and Kolkata reporting an average annual exposure (relative to population) of 110 µg/m3 and 84 µg/m3. respectively. µg/m3 refers to micrograms per cubic meter, according to the report titled Air Quality and Health in Cities.

However, no Indian city appeared in the list of the top 10, or even the top 20, polluted cities when N0 2 levels were compared. This list saw Shanghai at the top with an average annual exposure of 41 µg/m3. Average NO 2 levels for Delhi, Kolkata and Mumbai, according to the report, ranged from 20 to 30 µg/m3.

Although nitrogen pollution is not a big problem in India, PM2.5 is still the biggest concern in Indian cities. Out of 7,239 cities, India hosts 18 of the 20 cities with a severe increase in PM2.5 count from 2010 to 2019. The other two cities are in Indonesia. All of these cities saw an increase of more than 30g/m3 during that decade.

Due to this high exposure to PM2.5 pollution, Kolkata also ranks 8th among the world's most populous cities related to the highest PM2.5 related disease burden in 2019. Kolkata has 99 deaths for every lakh of citizens exposed to such high levels of PM2. .5 contamination. Delhi is ahead of Calcutta both in terms of exposure to PM2.5 (110 g/m3, which is 22 times the WHO safe limit) and in the highest burden of disease.

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Most polluted city, A State of Global Air Report 2022

The report, using data from 2010 to 2019, found that global patterns of exposure to the two key air pollutants are strikingly different. While PM2.5 exposure tends to be higher in cities located in low- and middle-income countries, nitrogen dioxide exposure is higher in cities in high- and low- and middle-income countries.

NO2 comes primarily from the burning of fuels, often in older vehicles, power plants, industrial facilities, and residential cooking and heating. Since city residents tend to live closer to busy roads with heavy traffic, they are often exposed to higher NO2 pollution than residents of rural areas. In 2019, 86% of the more than 7,000 cities included in this report exceeded the WHO NO2 guideline of 10 g/m3, affecting some 2.6 billion people. While PM2.5 pollution tends to draw more attention in known hotspots around the world, less data is available for NO2 on this global scale.

Cities in South Asia, West Sub-Saharan Africa, and East Asia reported PM2.5 exposures greater than 35 μg/m3 (the WHO's less stringent limit). India and Indonesia witnessed the most severe increase in PM2.5 pollution, while China saw the biggest improvements. India hosts 18 of the 20 cities with the most severe increase in PM2.5 pollution (more than 30 μg/m3) from 2010 to 2019; the other two cities are in Indonesia. Of the 50 cities with the most severe increase in PM2.5, 41 are in India and nine are in Indonesia.

Out of the 103 most populous cities in 21 different regions of the world, three Indian cities made it into the top 20 with the highest annual weighted average PM2.5 exposures in 2019: New Delhi, Kolkata and Mumbai.

PM2.5 levels in Delhi averaged 110 μg/m3, making it the world's most polluted city in this regard. Kolkata came second on the list, with average PM2.5 levels of 84 μg/m3. Mumbai also found a place here, ranking 14th with average PM2.5 levels of 45.1 μg/m3.

Such particulate levels also translate to health problems, and were calculated by the State of the Global Air based on several factors, including the relationship between different levels of PM2.5 and the increased risk of death due to illnesses caused by the pollution and population size.

In South Asia, the three cities mentioned above in India, along with Dhaka in Bangladesh and Karachi in Pakistan, showed mortality rates higher than the global urban median (58 deaths/100,000 people). Delhi and Kolkata are among the top 20 of the 103 most populous cities in each region that had the highest PM2.5-related disease burden in 2019 (measured at 106 and 99 deaths per 100,000 people, respectively).

In general, cities in East, South and Central Asia and those in Central and Eastern Europe experienced a disproportionately high disease burden from PM2.5 exposure.

Regarding NO2, the world average was 15.5 μg/m3, higher than the WHO limit of 10 μg/m3. Of the 103 most populous cities in the 21 regions, 81 reported NO2 exposures higher than the global average.

"As cities around the world grow rapidly, the health impacts of air pollution on residents are also expected to increase, underscoring the importance of early interventions to reduce exposures and protect public health." Pallavi Pant, a senior scientist at HEI, who oversaw the publication of the report, said in a press release.

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