London Ultra Low Emission Zone Linked to Faster Lung Growth in Children

Researchers tracking more than 3,400 students aged 6 to 9 at schools in central London and in Luton, about 30 miles away, found that the Ultra Low Emission Zone (ULEZ) was associated with accelerated lung growth in London children. The zone, launched in 2019, charges drivers of older, more polluting vehicles a daily fee of roughly $17 to enter an area that initially covered about 8 square miles.

Between 2018 and 2022, scientists regularly measured each child's lung volume. Before the scheme began, children in London showed stunted lung growth compared with those in Luton. Over the study period, nitrogen dioxide exposure fell in both locations, but the decline in central London was more than twice as large.

As pollution dropped, the lung growth rate of London children increased until it matched that of their peers in Luton. The proportion of children with impaired lung function in London fell from 14 percent to 9 percent during the same interval.

The findings, published in The Lancet Public Health, indicate that reduced exposure to nitrogen dioxide — a pollutant known to impede lung development — can restore normal growth trajectories. Children without fully developed lungs face higher risks of asthma and other respiratory disorders later in life.

U.K. Health Minister Karin Smyth said the study underscores the impact of air quality on children's lung health and will help improve understanding of how pollution reductions can lower the risk of respiratory illness in adulthood.

Despite the measured health benefits, the ULEZ has sparked widespread protests and vandalism; hundreds of the more than 3,700 enforcement cameras installed citywide have been damaged or stolen.

The zone was expanded in 2021 and again in 2023 to cover all of Greater London. Officials estimate that roadside nitrogen dioxide levels have fallen by 27 percent across London since the scheme began, while deaths linked to toxic air have dropped by 40 percent.

Researchers caution that the study observes an association between the policy and health outcomes; other factors influencing lung growth were not fully isolated.