London’s ULEZ Linked to Improved Lung Function Growth in Children
- Children living in areas with clean air zones show improved lung development, according to new research published in Nature Medicine on August 28, 2026.
- Introduced in 2019, London’s Ultra Low Emission Zone (ULEZ) is the world’s largest clean air zone.
- Following the implementation of ULEZ, pollution levels dropped more than twice as fast in London as they did in Luton.
Children living in areas with clean air zones show improved lung development, according to new research published in Nature Medicine on August 28, 2026. The findings provide the first direct evidence that traffic pollution reduction schemes can benefit pediatric respiratory health, addressing a significant evidence gap in urban public health policy.
Evaluating London’s Ultra Low Emission Zone
Introduced in 2019, London’s Ultra Low Emission Zone (ULEZ) is the world’s largest clean air zone. Researchers tracked lung function growth over time by working with children in central London, where ULEZ was implemented, and comparing them with children in Luton, a town northwest of London lacking a clean air zone. Lung function was measured annually through school-based spirometry tests, while home address air pollution exposure was estimated using computer modelling for nitrogen dioxide (NO₂) and particulate matter including PM₁₀ and PM₂.₅. Before the ULEZ policy took effect, baseline measurements revealed stark disparities between the two locations. Children in London faced nearly double the nitrogen dioxide exposure levels compared to their peers in Luton, resulting in significantly smaller lungs. Data show that approximately 1 in 7 children in London suffered from impaired lung function prior to the intervention, contrasted with roughly 1 in 11 children in Luton.
Measured Improvements in Pediatric Lung Growth
Following the implementation of ULEZ, pollution levels dropped more than twice as fast in London as they did in Luton. The data show that London children experienced faster annual lung growth than children in Luton, with improvements linked directly to reductions in nitrogen dioxide originating primarily from vehicle exhaust emissions. Higher individual exposure to pollution consistently associated with slower lung development. After four years of observation, the performance gap in lung function between London and Luton children closed completely. The proportion of London children experiencing poor lung function dropped from 1 in 7 down to 1 in 11, matching the baseline proportion recorded in the comparison town.
Implications for European Public Health
The study establishes that clean air zones work effectively, that children can recover from early pollution exposure, and that long-term health benefits are attainable. Urban centers across Europe continue to record air pollution levels exceeding World Health Organization guidelines, keeping the findings relevant for cities considering similar traffic restriction policies. Major European cities including Paris, Brussels, Berlin, Amsterdam, Barcelona, Milan, and Warsaw already operate low-emission zones, though until now empirical evidence regarding direct pediatric health benefits remained limited. Broader European initiatives continue to target respiratory health through complementary avenues. The LungHealth4Life project, funded by the EU4Health program and led by Lungs Europe, launched in September 2024 to curb lung disease burdens among children via enhanced school testing and public awareness. Meanwhile, the UK Medical Research Council supports the NEXUS research partnership to address unregulated non-exhaust vehicle emissions, such as particulate matter shed by tire and brake wear.