Context:
• The World Air Quality Report 2025, released by IQAir (Switzerland), highlights worsening global air pollution levels, with alarming data on PM2.5 concentrations across countries and cities.
Key Highlights:
- Data / Findings on Air Quality
• Only 14% of cities met the WHO PM2.5 guideline (5 µg/m³) in 2025 (down from 17% in 2024)
• Pakistan emerged as the most polluted country, with levels 13× above WHO limit
• Loni (Uttar Pradesh) ranked as the most polluted city globally, with 22× higher PM2.5 levels - Regional Trends
• Central and South Asia remain the most polluted regions globally
• 25 of the most polluted cities are located in India, Pakistan, and China - India’s Performance
• India ranked 6th most polluted country (improved from 5th in 2024)
• New Delhi remains the most polluted capital globally for the 8th consecutive year - Stakeholders Involved
• IQAir (global air quality monitoring agency)
• National governments and environmental regulators
• WHO and global environmental organizations - Significance / Concerns
• Severe public health risks (respiratory diseases, cardiovascular issues)
• Impacts productivity and economic growth
• Highlights urgency for air pollution control policies
Relevant Prelims Points:
- PM2.5:
– Particulate matter with diameter ≤ 2.5 micrometres
– Can penetrate lungs and bloodstream, causing severe health issues - WHO Air Quality Guidelines:
– Annual PM2.5 limit: 5 µg/m³ - IQAir:
– Swiss organization monitoring global air quality data - Major Sources of Air Pollution:
– Vehicular emissions
– Industrial pollution
– Crop burning
– Construction dust
Relevant Mains Points:
- Air pollution as a public health crisis:
– Linked to millions of premature deaths globally
– Disproportionate impact on urban poor and vulnerable groups - Regional concentration in South Asia:
– Driven by rapid urbanization, industrialization, weak enforcement
– Transboundary pollution adds to the crisis - India-specific challenges:
– Persistent issues in Delhi NCR (stubble burning, traffic, weather patterns)
– Weak monitoring and enforcement mechanisms - Policy responses and gaps:
– Existing measures: NCAP (National Clean Air Programme)
– Gaps in implementation, coordination, and accountability - Way Forward:
– Strengthen air quality monitoring and data transparency
– Promote clean energy and sustainable transport
– Enforce stricter industrial and vehicular emission norms
– Encourage regional cooperation for transboundary pollution
UPSC Relevance:
• GS 3: Environment, Pollution, Public Health
• Prelims: PM2.5, WHO Guidelines, IQAir