London ULEZ children lung growth accelerated measurably in the years following the zone’s introduction, according to a study published in The Lancet Public Health and led by researchers from Queen Mary University of London in collaboration with Imperial College London and the Universities of Bedfordshire, Oxford, Cambridge, Edinburgh and Southern California, with funding from the National Institute for Health and Care Research.
The research tracked more than 3,400 children aged between 6 and 9, comparing those living in Central London’s ultra low-emissions zone (ULEZ) with peers in the nearby suburb of Luton. The study period extended back to before the ULEZ came into force in 2019, allowing the team to observe how lung development shifted as exhaust emissions fell.
The Numbers Behind London ULEZ Children Lung Growth
Children were assessed using a device that measures how much air a person can forcefully breathe out in one second, a standard indicator of lung power and development. London children recorded an additional 233 millilitres of air breathed out per year, compared with 223 millilitres for children in Luton, a gap that widened as London’s pollution levels dropped faster than Luton’s over the study period.
The starting conditions were not in London’s favour. At the outset of the study, the University of Oxford Research Archive records that NO2 exposure in London was more than double that in Luton. Researchers modelled that nitrogen dioxide levels in London were higher by 19 micrograms per cubic metre, according to Queen Mary University of London. With Luton starting from a cleaner baseline, it was Luton children whose lungs were developing faster at the beginning of the study period.
Four years after the ULEZ was implemented, the picture had shifted. London’s children had closed the gap with their suburban peers, with particulate measurements falling faster in the capital and lung development accelerating in step.
Impaired Lung Function Rates Fall in Both Cities
The study found that in Central London, the proportion of children with impaired lung function fell from 14% to 9% as pollution levels dropped. Such impairment can include conditions like asthma and carries consequences for health across a lifetime, since lung development in childhood is a key predictor of respiratory problems in later life.
The comparison with Luton is instructive here too. According to the BBC, the proportion of Luton children with clinically impaired lung function also fell over the study period, from 9% to 7%. Both cities improved, but London’s steeper decline in pollution produced a correspondingly steeper improvement in children’s respiratory health.
The research did not come from a single institution working in isolation. Beyond Queen Mary University of London, which led the work, the study drew on collaboration with Imperial College London and researchers from five other universities across the UK and the United States. That breadth of institutional involvement lends the findings a robustness that single-site studies can struggle to achieve, though the authors and their funders at the National Institute for Health and Care Research will be aware that translating results from one urban policy into lessons for other cities remains complex.
London Among Cities Cutting Pollution Worldwide
The findings arrive against a broader backdrop of improving urban air quality in many parts of the world, though the pace and scale vary considerably. London ULEZ children lung growth offers one measurable, child-level outcome from a policy that has faced political pressure since its introduction and subsequent expansion.
Cities elsewhere are also making headway. Earlier this year, 19 out of 100 cities worldwide surveyed for air quality were found to have substantially improved since 2010, including Hong Kong, Beijing, and several cities on mainland China, alongside San Francisco, Warsaw, Bangkok, Amsterdam, Rotterdam, Rome, Heidelberg, Berlin and Paris.
The evidence from the Queen Mary University of London research programme now gives policymakers something specific to point to: a measurable improvement in children’s lung development directly associated with lower vehicle emissions in a defined zone. Whether other cities adopt similar low-emission approaches, and what timescales they commit to, will determine how many more children’s lungs develop as they should.
