The data measures PM2.5 (also known as fine particulate matter) that is acquired from ground-based air quality monitoring stations in cities across the globe.
In order for a city to be classified as having ‘good’ air quality, the PM2.5 must not exceed 12. The classification then goes from ‘moderate’, ‘unhealthy for sensitive groups’, ‘unhealthy’, ‘very unhealthy’ to hazardous.
No cities currently fall into the last two categories.
But Ghaziabad is at 110.2, making it into the ‘unhealthy’ air quality range.
The top 10 features six Indian cities, one from China and three from Pakistan.
The first UK city comes in at 1366 in the form of south-east English city Chatham (14), then Stockton (13.1) and Belfast (12.9) rounding out the most polluted cities for air in the UK. They’re all still in the ‘good’ air quality area of classification.
Meanwhile, the first US city that makes the list is Royal Palm Beach at number 752 in the global ranking. The top three are Portola and Maywood.
Interestingly, the world’s most polluted countries from 2019 has Bangladesh topping the list, with Pakistan, Mongolia, Afghanistan and India rounding out the top five.
The United Kingdom comes in at 78 on this list, while the USA comes in at 87.