
A recent study has revealed a significant improvement in London’s air quality following the Ulez expansion. The levels of harmful pollutants linked to serious health issues, including respiratory diseases, heart conditions, and even premature births, have decreased considerably. Notably, some of the most deprived areas in the capital have seen the greatest improvements.
Despite facing strong opposition, Mayor Sadiq Khan defended the Ulez expansion, emphasizing that it has successfully reduced pollution, removed high-emission vehicles from the roads, and brought cleaner air to millions. He stated that earlier projections suggested it would take nearly 193 years to bring air pollution within legal limits. However, with the latest policies, this goal could be achieved much sooner.
The Ulez expansion to outer London boroughs in 2023 sparked legal challenges from several councils, and Labour leader Keir Starmer even blamed the policy for the party’s defeat in the Ruislip and Uxbridge by-election. However, a new report published by the Greater London Authority, with insights from an independent advisory group of experts, confirms that the scheme has had a positive impact, driving faster air quality improvements in London compared to the rest of the UK.
According to the report, air quality across London has improved significantly, particularly in outer boroughs, where pollution levels have reduced at a faster rate than in the rest of England. Additionally, greenhouse gas emissions have dropped substantially, with carbon dioxide reductions equivalent to nearly three million one-way passenger flights between Heathrow and New York.
Maria Neira, director of environment, climate change, and health at the World Health Organization (WHO), commended London’s efforts, stating that improving air quality through measures like the Ulez expansion is vital for public health. She highlighted that cleaner air directly contributes to reduced respiratory and cardiovascular illnesses, ultimately improving the quality of life for residents.
Key findings from the report include:
- A 27% decrease in roadside nitrogen dioxide (NO2) levels, a harmful gas known to aggravate asthma and increase lung cancer risks, since the introduction of Ulez in 2019.
- A 31% drop in small-particle emissions (PM2.5) from vehicle exhausts in outer London in 2024 compared to a scenario without the Ulez expansion.
- Improved air quality at 99% of monitoring sites across London since 2019.
The Ulez expansion was implemented in multiple phases, initially covering central London in 2019, expanding to inner boroughs in 2021, and finally covering the entire capital in August 2023. Under the scheme, non-compliant vehicles are subject to a daily £12.50 charge. However, with 97% of vehicles now meeting the required standards, the vast majority of drivers pay nothing.
Previous studies attributed around 4,000 premature deaths annually in London to air pollution. The new report highlights that the most deprived communities, particularly those near major roads, have seen an 80% reduction in exposure to illegal pollution levels. In outer London, this figure rises to 82% compared to a scenario without Ulez.
Experts, including Dr. Gary Fuller from Imperial College London, have praised the improvements, stating that each phase of the scheme has led to measurable reductions in air pollution. Similarly, Simon Birkett, director of Clean Air in London, emphasized that the policy has significantly cut nitrogen dioxide levels near busy roads, bringing London closer to meeting both legal air quality limits and WHO guidelines.
The findings reinforce the effectiveness of the Ulez expansion in reducing harmful pollutants and protecting public health, proving that ambitious clean air initiatives can yield substantial benefits for urban populations.