Children’s lung health improves following introduction of London’s ULEZ

Children’s lung health in London has improved following the introduction of the Ultra Low Emission Zone, with researchers finding that reductions in air pollution were strongly associated with faster lung growth.

The five-year study followed more than 3,400 primary school children in London and Luton and examined whether improvements in air quality following the introduction of ULEZ could help reverse lung growth previously affected by pollution.

Researchers established children’s lung function before ULEZ was introduced in central London in 2019 and continued to test them annually.

At the beginning of the study, children living in London had significantly smaller lung capacity than children living in Luton, which did not have a comparable low-emission zone. Over the following years, however, lung growth among the London children accelerated as their exposure to nitrogen dioxide fell. By the end of the study, the gap in lung function between children in London and Luton had closed.

Researchers found that children’s exposure to nitrogen dioxide fell around twice as quickly in London as it did in Luton during the study period. For every annual reduction in nitrogen dioxide exposure, children in London experienced approximately 10ml of additional lung capacity growth per year compared with children in Luton.

The proportion of London children considered to have clinically impaired lung function also fell from 14% at the beginning of the research to 9% by the end. In Luton, the proportion fell from 9% to 7%.

The Children’s Health in London and Luton study was led by Queen Mary University of London in collaboration with Imperial College London and researchers from the Universities of Bedfordshire, Oxford, Cambridge, Edinburgh and Southern California. It was funded by the National Institute for Health and Care Research and published in The Lancet Public Health.

Professor Chris Griffiths, joint senior author of the research, said the findings provided some of the strongest evidence yet that the harm caused to children’s development by traffic pollution can be prevented.

Air pollution is particularly concerning for children because their lungs are still developing. Exposure to pollutants including nitrogen dioxide has been associated with impaired lung development and an increased risk of respiratory disease later in life. ULEZ was initially introduced in central London in April 2019 before being expanded to inner London in 2021 and across all London boroughs in 2023. The scheme requires vehicles to meet minimum emissions standards or pay a daily charge to travel within the zone. Despite the improvements identified by researchers, air pollution remains a significant public health concern.

Pollution levels in London and other UK cities continue to exceed World Health Organization guidelines, with researchers stressing that further action is still required to protect children’s health.

The findings suggest that reducing children’s exposure to traffic-related pollution may not only prevent further damage but could allow lungs whose growth has already been affected to recover.

Stay informed with the stories shaping health and social care.