Fact Check: ULEZ expansion has a negligible effect on air quality
- London Fact Check
- Dec 19, 2022
- 1 min read
Updated: Feb 2, 2023
The claim:
Sadiq Khan: "By expanding the ULEZ, 5 million more people in Greater London will be able to breathe cleaner air."
Analysis:
This is misleading. The ULEZ expansion will have a negligible effect on air quality, according to the Mayor's own independent impact assessment.
The annual mean concentration of nitrogen oxides (NO₂) in outer London will drop only by 0.3µg/m3, from 20.2 to 19.9, a negligible change.
There will be no measurable effect on particulates (PM2.5), one of the most harmful forms of air pollution, which remains at 10.1µg/m3 regardless of whether the ULEZ expansion is implemented or not.
Academic research has also found the existing ULEZ delivered only small improvements in air quality, in the context of a longer-term downward trend in London's air pollution levels (Ma et al, 2021).
342,000 fewer people will be above the WHO limits for NO2 in Outer London with the expanded ULEZ. This is from the same report you are quoting.