Nitrogen Dioxide (NO₂)
A reddish-brown gas produced primarily by burning fossil fuels. Nitrogen dioxide is a major indicator of traffic-related air pollution and a precursor to ground-level ozone and PM2.5.
Regulatory Limits (µg/m³)
WHO Guideline
10
Most protective standard
EU 2030 Target
20
Directive 2024/2881
EU Current Limit
40
Being replaced in 2030
198 out of 688 tracked European cities currently exceed the EU 2030 NO₂ target.
Where Does NO₂ Come From?
- •Vehicle exhaust (the primary source in cities)
- •Power plants burning fossil fuels
- •Industrial boilers
- •Gas stoves and heaters (indoor source)
- •Shipping emissions in port cities
Health Effects of NO₂
Short-Term Exposure
- •Airway inflammation
- •Increased susceptibility to respiratory infections
- •Worsened asthma symptoms (especially in children)
- •Reduced lung function
Long-Term Exposure
- •Development of asthma in children
- •Chronic respiratory disease
- •Reduced lung development in children
- •Increased cardiovascular mortality
How to Protect Yourself
- 1.Choose walking and cycling routes away from busy roads
- 2.Keep car windows closed in heavy traffic
- 3.Ensure good ventilation when using gas stoves
- 4.Support low-emission zones in your city
- 5.Consider electric vehicles to reduce personal contribution
Highest NO₂ Levels in Europe
| # | City | Country | PM2.5 | AQI |
|---|---|---|---|---|
| 1 | Glasgow | United Kingdom | 19.0 | 19 |
| 2 | Inverclyde (Greenock) | United Kingdom | 14.8 | 15 |
| 3 | Kingston-upon-Hull | United Kingdom | - | |
| 4 | Belfast | United Kingdom | - | |
| 5 | City of Edinburgh | United Kingdom | - | |
| 6 | Tyneside conurbation | United Kingdom | 18.0 | 18 |
| 7 | Blackburn with Darwen | United Kingdom | - | |
| 8 | Leeds | United Kingdom | 30.1 | 30 |
| 9 | Doncaster | United Kingdom | - | |
| 10 | Lincoln | United Kingdom | - | |
| 11 | Warszawa | Poland | 14.7 | 15 |
| 12 | Dublin | Ireland | 7.8 | 8 |
| 13 | Brescia | Italy | 19.0 | 19 |
| 14 | Cardiff | United Kingdom | - | |
| 15 | London (greater city) | United Kingdom | - |