As India’s north continues to struggle with extreme pollution levels, the story has put a fresh spotlight on air quality in cities across Asia.
Beijing has long been notorious for its smog – but statistics show that India, Pakistan and Bangladesh have worse air by far.
So why is South Asia is so much more polluted?
Asia’s most polluted cities
Of the world’s most polluted 30 cities, 22 are in India, according to research by IQ AirVisual, a Swiss-based group that gathers air-quality data globally, and Greenpeace.
The remaining eight cities are all in Pakistan, Bangladesh and China – but the list doesn’t include Beijing, which comes in at number 122.
Just looking at global capitals, it’s also Asian cities that top the ranking.
Looking at overall countries, it’s Bangladesh that has the worst air, followed by Pakistan and then India.
All these rankings are based on average air quality per year.
As these countries have very different densities of measuring stations and transparency of data, the statistics have to be read with a degree of caution. But they certainly indicate an overall trend.