World Air Quality Report 2024

GS III-Environment

Why in the News?

The World Air Quality Report 2024, published by the Swiss organization IQAir, ranked India as the 5th most polluted country globally. This marks an improvement from its 3rd place ranking in 2023.

Key Findings of the Report

India’s Air Pollution Status

• Country Ranking: India ranked 5th most polluted in 2024, moving down from 3rd place in 2023.
• Most Polluted Capital: Delhi remains the most polluted capital city worldwide, with a PM2.5 concentration of 91.6 µg/m³ (micrograms per cubic meter).
• Polluted Cities:
  • 6 out of the world’s 10 most polluted cities and 13 of the top 20 are located in India.
  • Byrnihat (Assam-Meghalaya border) topped the list with the highest PM2.5 level at 128.2 µg/m³.
  • Other severely polluted cities include Mullanpur (Punjab), Gurugram, Faridabad, Bhiwadi, and Noida.
• PM2.5 Levels:
  • India witnessed a 7% reduction in PM2.5 levels, dropping from 54.4 µg/m³ in 2023 to 50.6 µg/m³ in 2024.
  • Despite this improvement, pollution levels still exceed the WHO’s recommended limit of 5 µg/m³ by tenfold.
  • 35% of Indian cities reported PM2.5 levels above this threshold.
• Major Pollution Sources:
  • Vehicle emissions, industrial activities, and biomass burning are primary contributors.
  • Crop stubble burning in Northern India was responsible for up to 60% of PM2.5 pollution during peak months.

Global Air Pollution Trends

• The world’s most polluted countries in terms of annual average PM2.5 levels are:
  1. Chad (91.8 µg/m³)
  2. Bangladesh (78 µg/m³)
  3. Pakistan (73.7 µg/m³)
  4. Congo (58.2 µg/m³)
• The report states that the majority of the global population breathes unsafe air, with only 12 countries, regions, or territories maintaining PM2.5 levels below the WHO’s recommended threshold.

Understanding Air Pollution

• Definition: Air pollution occurs when chemical, physical, or biological contaminants alter the natural composition of air.
• Major Pollutants: Key air pollutants include Particulate Matter (PM), Carbon Monoxide (CO), Ozone (O₃), Nitrogen Dioxide (NO₂), and Sulfur Dioxide (SO₂)—all of which contribute to respiratory illnesses and premature deaths.
• Health Impact:
  • According to the World Health Organization (WHO), 99% of people worldwide are exposed to polluted air, with low- and middle-income countries being most affected.
  • Long-term PM2.5 exposure in India reduces life expectancy by an estimated 5.2 years.
  • A Lancet Planetary Health Study (2009–2019) linked air pollution to 1.5 million deaths annually in India.
• WHO Air Quality Guidelines (AQG): The WHO provides standards and recommendations to help governments lower air pollution levels and improve public health.