Smart Air examined air pollution data from twenty UK cities to create a ranking of the most polluted cities in the UK. Are you in the UK and looking to avoid the harmful effects of air pollution? Then this article is for you!

Scroll down to find a full list of the UK’s most polluted cities and their annual PM2.5 levels in micrograms (µg/m3). It is important to note that the WHO recommended annual limit is 5 micrograms.

The rankings for the most polluted cities in the UK are based on PM2.5 air pollution data in 2024.

Rankings: 10 Worst AQI Cities in the UK in 2024

1. Worthing (9.4 µg/m³)

2. Manchester (8.7 µg/m3)

3. Bournemouth (8.4 µg/m³)

4. Derry (8.4 µg/m³)

5. Thurrock (8.3 µg/m³)

6. Leeds (8.2 µg/m3)

7. Medway (8.2 µg/m3)

8. Hartlepool (8.1 µg/m³)

9. Plymouth (8 µg/m³)

10. Sheffield (7.9 µg/m3)

Analysis: Most Polluted Cities in the UK

Below is a heat map created by the UK government’s National Atmospheric Emissions Inventory (NAEI) on PM2.5 across the UK. The map reflects our rankings, with densely populated areas of England particularly affected by high PM2.5:

The Risks of UK Air Pollution

As you can see, many of the UK’s largest and most populous cities average over double the WHO’s recommended limit of PM2.5 levels (µg/m3).

PM2.5 means ‘particulate matter’ (particles of pollutant) which are less than 2.5 micrometers in width. They are considered to be dangerous pollutants due to their ability to enter deep into the lungs and bloodstream. Studies have shown that PM2.5 raises blood pressure, inflammation, and rates of heart attacks and strokes.