Levels of deadly pollutants cut after ULEZ expansion, study finds

Levels of deadly pollutants in the air people breathe have dramatically fallen since the expansion of the Ultra Low Emission Zone (Ulez), a study has found.

Data from the first year since the zone’s expansion shows “substantial improvements” in air quality, with some of the poorest communities seeing some of the biggest benefits.

The Mayor of London, Sadiq Khan, said: “When I was first elected, evidence showed it would take 193 years to bring London’s air pollution within legal limits if the current efforts continued. 

“Due to our transformative policies we are now close to achieving it this year.”

Bromley, Merton, Croydon, Sutton and Harrow have seen the largest reductions in Nitrogen Oxide (NOx) emissions, which were 15 per cent lower in 2024 than would be expected without the Ulez expansion.

Particle emissions (PM2.5) from vehicle exhausts are about 31 per cent lower, and nitrogen dioxide (NO2) levels – a toxic gas that exacerbates asthma and raises the risk of lung cancer – are estimated to be 14 per cent lower in outer London in 2024.

The report, published today by the Greater London Authority (GLA), is the largest analysis of the scheme’s impact so far.

Mr Khan extended ULEZ from the inner London boroughs across the whole of London in August 2023.

The controversial move was initially challenged by a coalition of conservative-led councils, including Bexley, and Bromley, which took legal action.

But, the planned expansion was ruled lawful by the High Court.

Sir Khan said: “The decision to expand the ULEZ was not something I took lightly, but this report shows it was the right one for the health of all Londoners.

“With boroughs in outer London seeing some of the biggest reductions in harmful emissions and London’s deprived communities also seeing greater benefits, this report shows why expanding ULEZ London-wide was so important.”

For the most deprived communities living near London’s busiest roads, the report found an estimated 80 per cent reduction in people exposed to illegal levels of pollution in 2023 – this increased to 82 per cent in outer London, compared with a scenario without the Ulez.

Air pollution increases the risk of developing asthma, lung cancer, heart disease and stroke. In London, about 4,000 premature deaths were previously attributed to toxic air every year.

Rosamund Kissi-Debrah, the mother of Ella Kissi-Debrah, who became the first person in the UK to have air pollution cited on their death certificate, said she was “delighted” by the findings.

She said: “My daughter Ella died from emissions from the South Circular Road close to where we live, and I will not stop until everyone in London can breathe safe, clean air, regardless of where they live in the city.”

But, she warned that there is “still so much more to do.”

She said: “I will ensure that politicians and decision-makers are held to account, and do all they can to protect people’s health and clean up the air we breathe.”

TfL data also shows that 96.7 per cent of vehicles seen driving in London are now ULEZ compliant, up from 91.6 per cent in June 2023 and 39 per cent in February 2017.

Van compliance in outer London is more than 90 per cent for the first time. In February 2017, just 12 per cent of vans met the ULEZ standards.

Today’s report also shows that carbon emissions have substantially reduced, with carbon dioxide equivalent to nearly 3million one-way passenger trips between Heathrow and New York saved.

Dr Maria Neira, Director, Department of Environment, Climate Change and Health at the World Health Organization (WHO): “The WHO commends the efforts of cities like London in implementing measures to reduce emissions from vehicles and improve air quality, which ultimately contribute to a healthier and more sustainable urban environment.”

Pictured top: The report, published today by the Greater London Authority (GLA), is the largest analysis of the scheme’s impact so far (Picture: TfL)