Full Breakdown
London’s Ultra-Low Emission Zone Boosts Children’s Lung Growth, Study Finds
8/19/2026, 5:56:42 AM
Core Event: Lung Capacity Gains After ULEZ Implementation
A five-year longitudinal study compared lung development in primary-school children living inside London’s Ultra-Low Emission Zone (ULEZ) with peers in Luton, a nearby town without such a zone. Researchers measured forced expiratory volume each year from before ULEZ entered force in 2019 through 2022. By the end of the period, children in London had caught up to the Luton cohort, achieving near-identical lung-capacity levels.
Background & Context
London introduced the ULEZ in 2019 under Mayor Sadiq Khan to curb traffic-related nitrogen-dioxide (NO2) emissions. The scheme required older, higher-polluting vehicles to pay a daily charge to enter central London, later expanding to cover the entire capital. Prior research had linked chronic exposure to traffic pollutants with lower lung capacity in children and higher risks of asthma and other diseases. The new study offered a rare opportunity to assess whether a city-wide clean-air policy could reverse such harms.
Data & Statistics
- Participants: 1,664 London children and 1,750 Luton children (ages 6-9).
- Clinical impairment: In London, the share classified as “clinically impaired” fell from 14 % to 9 %; in Luton it moved from 9 % to 7 %.
- NO2 exposure: London children’s exposure declined twice as fast and twice as much as that of Luton children over the five-year span.
- Lung-capacity convergence: Initial tests showed London children’s lung volumes were smaller; after ULEZ implementation, annual growth accelerated, resulting in comparable capacities across the two groups.
Official Statements & Responses
- Mayor Sadiq Khan said introducing and expanding the ULEZ involved “incredibly difficult decisions” but that he could not stand by while Londoners, especially children, suffered from toxic air.
- Prof Chris Griffiths (senior author, Queen Mary University of London) called the speed of lung-capacity catch-up “surprising and impressive,” noting its relevance for urban children worldwide.
Criticism & Opposition
- Kevin McConway, emeritus professor at the Open University, argued that the full impact of the COVID-19 pandemic must be accounted for and suggested studying additional cities to separate ULEZ effects from pandemic-related emission drops.
- Prof Stephen Burgess (University of Cambridge) cautioned that the improvements might not be solely attributable to the ULEZ, pointing to possible confounding factors such as altered travel behavior after the scheme’s rollout.
Conflicting Reports & Gaps
While the study shows a strong correlation between reduced NO2 levels and improved lung function, the causal link remains unproven. Researchers acknowledge that contemporaneous changes—most notably the pandemic’s influence on traffic patterns—could have contributed to the trends. Further longitudinal work in multiple cities is needed to confirm that clean-air zones are the primary driver of the health gains.
Verbatim Quotes
- “Traffic pollution in cities damages children’s health and development,” — Chris Griffiths, Queen Mary University of London
