World's Most Polluted Capital - Delhi: Decoding Contributing Factors

According to the World Air Quality Report 2023 published by the Swiss organization IQAir, Delhi has regained its status as the world's most polluted capital city for the fourth consecutive year since 2018.

Additionally, it is highlighted in the report that India has been identified as the third worst country in terms of air quality, with Begusarai in Bihar ranking as the world's most polluted metropolitan area, as reported by First Post.

How Severe Is the Pollution Situation in Delhi?

• The title of the world's most polluted capital city has been consistently held by Delhi for several years, with the trend continuing in 2023.
• In 2023, there was a worsening of air quality in Delhi, as indicated by an increase in PM2.5 levels from 89.1 micrograms per cubic meter in 2022 to 92.7 micrograms per cubic meter.
• Delhi first claimed the title of the most polluted capital city in 2018, a trend that continued through subsequent years.
• In 2021, among 107 global capital cities, Delhi maintained its position at the top of the list for poor air quality.
• Similarly, in 2020, Delhi retained its status as the most polluted capital city among 92 such cities.
• In 2019, among 85 capital cities, Delhi again held the title for its poor air quality.
• Begusarai emerged as the most polluted metropolitan area globally, with an average PM2.5 concentration of 118.9 micrograms per cubic meter, although it was not included in the 2022 rankings.

India's Air Quality Woes: A Lingering Predicament Revealed by Global Report

In 2023, India ranked third in terms of air quality out of 134 countries, with an average annual PM2.5 concentration of 54.4 micrograms per cubic meter, following Bangladesh (79.9 micrograms per cubic meter) and Pakistan (73.7 micrograms per cubic meter), as reported.

It was reported that an estimated 1.36 billion people in India were exposed to PM2.5 concentrations exceeding the World Health Organization's recommended annual guideline level of five micrograms per cubic meter. Similarly, in 2022, India was ranked as the eighth most polluted country, with an average PM2.5 concentration of 53.3 micrograms per cubic meter, as reported by First Post.

Furthermore, it was highlighted that approximately 1.33 billion people, constituting 96 per cent of the Indian population, experienced PM2.5 levels surpassing the WHO annual PM2.5 guideline by more than seven times. This pattern was evident in city-level data, with over 66 per cent of the country's cities reporting annual averages exceeding 35 micrograms per cubic meter.

According to the report, only seven countries-Australia, Estonia, Finland, Grenada, Iceland, Mauritius, and New Zealand-managed to meet the WHO annual PM2.5 guideline.

The data utilized to compile the report was aggregated from a global network of more than 30,000 regulatory air quality monitoring stations and low-cost air quality sensors operated by various entities, including research institutions, governmental bodies, universities, NGOs, private companies, and citizen scientists, as reported by First Post.

The 2022 World Air Quality Report encompassed data from 7,323 locations across 131 countries, regions, and territories, with the figures growing to include 7,812 locations in 134 countries, regions, and territories in 2023.

The Impact of Air Pollution on Health: A Global Concern

Causing an estimated one in every nine deaths worldwide, air pollution emerges as the greatest environmental threat to human health, according to the WHO.

An estimated seven million premature deaths worldwide are attributed to air pollution annually. Exposure to PM2.5 air pollution is linked to and worsens numerous health conditions, including asthma, cancer, stroke, and lung disease, as reported by First Post. Cognitive development in children can be impaired, mental health issues may arise, and existing illnesses, such as diabetes, can be complicated by exposure to elevated levels of fine particles.