The world's major cities battle with the most severe air pollution ever recorded

According to the latest data from IQAir, a global leader in air quality monitoring, some of the world's major cities are experiencing the most severe levels of air pollution ever recorded.

With unprecedented concentrations of fine particulate matter (PM2.5), several urban centres are now facing alarming public health risks, environmental degradation, and economic strain.

The 2025 IQAir World Air Quality Report shows that air pollution has surged to critical levels in key metropolitan areas, driven by a combination of industrial emissions, vehicular traffic, fossil fuel combustion, construction activities, and climate-related factors such as stagnant weather conditions and dust storms.

N’Djamena, the capital city of Chad, has emerged as the most polluted city in the world, drawing global attention to the often-overlooked air quality crisis in parts of Sub-Saharan Africa.

Located in the heart of the Sahel region, N’Djamena’s worsening air pollution stems from a combination of natural and human-made factors including open burning of waste, unregulated vehicle emissions and widespread use of biomass and charcoal for cooking.

Long known as a pollution hotspot, India's Delhi continues to experience hazardous air quality, especially during winter. The combined effects of stubble burning, vehicular pollution, and construction dust have led to toxic smog enveloping the city, forcing residents to stay indoors and schools to close.

With high population density and unregulated urban expansion, Dhaka, Bangladesh is again among the worst-hit cities. Brick kilns, traffic congestion, and industrial waste contribute heavily to its worsening air quality.

Air pollution is a major cause of disease and death worldwide, with the WHO estimating that it will take seven million lives globally in the next year.² The economic costs are also staggering, with an estimated loss of $225 billion in lost labour and trillions in medical costs.