Deaths linked to air pollution in London fell an estimated 40 percent between 2019 and 2024, according to a new Imperial College London study. That’s the good news. The more complicated part: the same research revised the original death estimates sharply upward, because it turns out the science had been underestimating how badly pollution was hurting people.
Earlier models put roughly 4,000 premature deaths down to air pollution in London in 2019. Stronger evidence linking air quality to heart disease, dementia, and diabetes has pushed that figure to between 6,400 and 8,000. By 2024 it had come down to between 3,800 and 5,100. Progress against a worse starting point than anyone calculated.
Two findings, one clear message
Dr. David Dajnak of the Imperial Environmental Research Group was direct about what the numbers show: London’s air quality has improved substantially since 2019, and pollution “remains a serious public health risk” despite that. Nitrogen dioxide fell 41 percent across the city over five years. Fine particulate pollution dropped 28 percent. Those numbers don’t happen by accident; they follow a decade of deliberate changes to how vehicles are allowed to operate in the city.
How the ULEZ changed the equation
The Ultra-Low Emission Zone launched in central London in 2019 and expanded to inner boroughs in 2021. Vehicles that don’t meet emission standards, diesel cars from before 2015 or petrol from before 2004, pay £12.50 (about $16) a day to drive in. About 97 percent of vehicles in the zone are now compliant.
In 2023, Mayor Sadiq Khan pushed the ULEZ out to cover all of London, against significant local opposition. A study for the Greater London Authority found roadside nitrogen dioxide was 27 percent lower than it would have been without the scheme. Khan called the Imperial findings “overwhelming and unarguable” evidence that bold policy had “reduced pollution, improved public health and saved lives.”
Where the problem persists
The boroughs with the highest ratios of pollution-related deaths in 2024 were Bexley, Havering, and Sutton, all in outer London and all newly inside the expanded ULEZ. The city has also put £2.7 million (about $3.4 million) into indoor air filters for 200 primary schools and grown its zero-emission bus fleet from 30 to over 3,000 in the past decade.
Professor Stephen Holgate of the Royal College of Physicians said the scale of improvement was “so encouraging,” a reminder that sustained policy can produce “real, measurable benefits.” But Jemima Hartshorn of Mums for Lungs pointed out that more than 100,000 children were still hospitalized for breathing problems in London in 2024. “Other cities and regions are still more polluted,” she said. “Londoners need more action, and so does the rest of the country.”
