Context: 

According to the 2024 World Air Quality Report released by IQAir, Delhi remains the most polluted national capital in the world for the sixth consecutive year. 

More on the news: 

• The report underscores the severe air quality challenges faced by India, with Delhi continuing to lead the world in harmful PM2.5 concentration levels.
• India saw a 7% decline in PM2.5 concentrations in 2024, from 54.4 µg/m³ in 2023 to 50.6 µg/m³ in 2024, and six of the ten most polluted cities are still located in the country.

Key Findings of the Report:

• Delhi, with an average PM2.5 concentration of 91.8 μg/m³, has remained the most polluted capital globally.
• India ranks fifth globally in terms of air pollution, with an average Air Quality Index (AQI) of 50.6 μg/m³, which is almost 10 times higher than the World Health Organization’s (WHO) annual guideline of 5 μg/m³, highlighting the urgent need for significant air quality improvements.
• The report reveals that 13 out of the 20 most polluted cities in the world are in India. 
• Notable cities like Byrnihat (Assam-Meghalaya border), Faridabad, Ghaziabad, Gurgaon, Noida, Muzaffarnagar, and Greater Noida are among the world's top air pollution hotspots.
• Byrnihat, India was the most polluted metropolitan area in 2024, with an annual average PM2.5 concentration of 128.2 μg/m3.
• Crop stubble-burning remained the major contributor to PM2.5 levels, accounting for 60% of pollution during peak periods.
• Other major sources of pollution in the country included vehicular emissions, industrial discharges, and construction dust.

Global Air Quality:

• The 20 most polluted cities – located in India, Kazakhstan, Chad, Pakistan, and China – exceeded WHO guidelines by more than 10 times.
• Only 12 countries, regions, and territories recorded PM2.5 concentrations below the World Health Organization’s (WHO) recommended average annual limit of 5 µg/m3.
• Globally, only 17% of cities met the WHO’s air pollution guidelines, indicating that air pollution remains a critical global issue.
• Out of the 138 countries and regions analysed, 126 (91.3%) exceeded the WHO's annual PM2.5 guideline value of 5 μg/m³.
• While air quality in Southeast Asia has improved, the report notes that transboundary haze and the lingering effects of El Niño conditions continue to influence air pollution levels in the region.
• Africa faces significant challenges in monitoring air quality, with just one air quality monitoring station for every 3.7 million people on the continent.

Health Implications of Air Pollution in India:

• The report highlights that air pollution in India is a major public health concern, reducing the life expectancy of Indians by an estimated 5.2 years.
• Overall, 35% of the Indian cities reported annual PM2.5 levels exceeding 10 times the World Health Organization (WHO) limit of 5 micrograms per cubic meter.
• PM2.5 particles, which are microscopic and can enter the bloodstream through the respiratory system, pose a severe threat to public health, contributing to a range of respiratory diseases and cardiovascular problems.