Pollution rank: Kol 49th among 259 Indian cities in AQI global report

Kolkata: Kolkata has been placed 49th in pollution ranks among 259 cities in India in IQAir's 2025 World Air Quality Report, underscoring persistent air quality challenges across eastern India and the wider South Asian region. The report, released by Swiss air quality technology organisation IQAir, evaluates pollution levels, based on annual average PM2.5 concentrations—fine particulate matters, small enough to penetrate deep into the lungs and bloodstream. Loni in Uttar Pradesh is ranked the most polluted city in India in 2025, recording a PM2.5 concentration of 112.5 µg/m³. It is followed by Byrnihat in Assam (101.1 µg/m³) and Delhi (99.6 µg/m³), reinforcing the trend of extreme pollution across northern and north-eastern India. With an annual average PM2.5 concentration of around 51 µg/m³, Kolkata falls in the category of cities that exceed the WHO guideline by more than 10 times. In the survey, Kolkata ranks 49th among 50 most-polluted cities in India, scoring better than only Delhi among mega cities."The World Air Quality Report reveals two competing realities: an air pollution crisis and the rise of communities, scientists and data working to meet the challenge," said Aidan Farrow, senior scientist, Greenpeace International. "In 2025, familiar culprits, like industrial agriculture, wildfires and fossil fuels, left their mark in the data collated by IQAir worldwide. This open, transparent data is an essential tool for holding polluters accountable and securing a healthy environment for everyone."The report, which has analysed air quality data from 9,446 cities across 143 countries, shows a broader picture of deteriorating air quality in South Asia. India ranked the sixth most polluted country globally in 2025, with an average PM2.5 concentration of 48.9 µg/m³, trailing behind Pakistan, Bangladesh, Tajikistan, Chad and the Democratic Republic of the Congo. Globally, the report highlights a worrying stagnation in progress on air quality improvement. Only 14% cities worldwide met the WHO's annual PM2.5 guideline in 2025, down from 17% the previous year. Also, 91% countries exceeded safe limits.Experts have attributed the worsening air quality to a combination of factors, such as industrial emissions, vehicular pollution, construction dust and seasonal influences, like crop-burning and temperature inversions. Additionally, climate change-driven events, like wildfires, played a significant role in elevating global pollution levels. The report says wildfire emissions contributed substantially to atmospheric particulate matter.The WHO recommends an annual average PM2.5 level of no more than 5 µg/m³, highlighting the severity of pollution exposure in urban India. In Bengal and Kolkata metropolitan region, several places also feature prominently in the pollution ranking, Madhyamgram marked seventh nationally with a PM2.5 level of 83.3 µg/m³, Barrackpore 21st with 62.6 µg/m³ PM2.5 level and Howrah 30th with 55.1 µg/m³. The figures indicate that air pollution is not confined to Kolkata but is a regional issue, affecting suburban and industrial zones alike.IQAir emphasised that a lack of comprehensive monitoring remains a critical barrier to tackling air pollution globally. Millions of people still lack access to real-time, localised air quality data, limiting both public awareness and policy response.Despite some regional improvements, the survey highlights an urgent need for coordinated action, say experts. Expanding air quality monitoring networks, transitioning to cleaner energy sources, and implementing stricter emission controls are seen as key steps towards mitigating the crisis.