Deaths linked to toxic air in London fall by 40 per cent

Source: Greater London Authority (GLA), 24 June 2026

New analysis by Imperial College London’s Environmental Research Group, commissioned via Imperial Projects has revealed the success of London’s bold policies to reduce air pollution and improve health across the capital, with an approximate 40 per cent reduction in the number of estimated deaths linked to air pollution between 2019 and 2024.

The research also found that toxic air pollution in London has reduced markedly since 2019, translating into a substantial fall in the overall health burden:

1. Nitrogen Dioxide (NO2) levels, a traffic-related gaseous pollutant that exacerbates asthma, impedes lung development, and raises the risk of lung cancer, are down 41 per cent (2)
2. Fine particulate pollution (PM2.5) level, extremely small particles that can result in serious health impacts especially in vulnerable groups of people such as the young, elderly, and those with respiratory problems, are down 28 per cent (2)

In April 2019, the Mayor of London launched the world’s first 24-hour Ultra Low Emission Zone (ULEZ) in central London. The zone was expanded across inner London in 2021, and finally to cover the whole capital in August 2023, bringing the air quality and associated health benefits to more then 9 million people living in London. The ULEZ is now the largest clean air zone in the world of its kind.

Earlier estimates for 2019 suggested around 4,000 premature deaths were attributable to air pollution, based on evidence available at the time. This new Imperial College study uses an updated and more advanced methodology, drawing on a much larger body of scientific evidence, which shows that the impact of long-term exposure to air pollution on health is even greater than previously understood.

To provide a fair comparison, the updated methodology has been applied to both 2019 and 2024. This estimation shows a reduction from around 6,400-8,000 premature deaths in 2019 to approximately 3,800-5,100 in 2024 – a fall of around 40 per cent.

According to the research by Imperial’s independent experts, the boroughs with the highest number of deaths attributable to air pollution per 100k residents in 2024 were in outer London boroughs like Bexley, Havering and Sutton. The expansion to outer London was met with significant opposition. This underlines the significance of the Mayor taking on his opponents, while also reflecting the age profile of these boroughs, and the vulnerability of older people to diseases linked to air pollution.

Earlier this month a study by Imperial College London also found the Toxicity Charge and central London ULEZ are associated with a fall in hospital admissions in London – revealing that since their introduction, the schemes were linked to 9.3 per cent reductions in annual trends for heart-related emergency admissions, and a 5.1 per cent drop in annual trends in hospital admissions for all illnesses and health conditions in the scheme area. (3)
New evidence shows stronger associations between air pollution exposure and premature deaths, and recent evidence continues to show associations with dementia, type 2 diabetes, and childhood asthma. This underlines that the health impacts of air pollution in 2019 were even more severe than previously understood. reinforcing why taking action was so important.

Despite this progress, long term exposure to air pollution is still estimated to contribute to 3,800-5,100 premature deaths across London in 2024. The economic cost of this mortality burden in 2024 is estimated at £3.8 billion to £5.1 billion.

The improvement in London’s air quality reflects the cumulative impact of the Mayor’s bold action to cut emissions, alongside long-term pollution trends. In 2024, London met legal limits for NO2 pollution for the first time in 2024 – almost 200 years earlier than experts predicted if no action was taken.

To read the London Health Burden of Air Pollution study, visit: https://www.london.gov.uk/aqmortality