Scientists have observed a striking and rapid recovery in the lung growth of children exposed to air pollution after the introduction of an Ultra Low Emission Zone (ULEZ) in London. A study tracking over 3,400 primary school children indicated that their lung capacity, which had been stunted by pollution, significantly improved and caught up with that of children in a less polluted control group in Luton.
The research, led by scientists at Queen Mary University of London, followed children aged six to nine for five years, measuring their lung function annually before and after the ULEZ was implemented in 2019. Initial findings showed that children within the London ULEZ had smaller lung capacities compared to their peers in Luton. However, after four years of the ULEZ being in effect, the lung capacity of the London children reached nearly identical levels to those in Luton.
Professor Chris Griffiths, a senior author of the study, described the speed of recovery as "stunning" and "impressive," stating that it demonstrates how an ambitious clean air zone can reduce pollution levels and rapidly restore stunted lung growth in children. The primary test, measuring the volume of air a child could forcibly exhale in one second, showed accelerated growth in the London group.
The study also observed a decline in the proportion of children with "clinically impaired" lung capacity – indicating lung damage leading to symptoms like coughs or breathlessness. In London, this figure fell from 14% to 9%. In Luton, where smaller-scale pollution control measures were also in place, the rate decreased from 9% to 7%.
Measurements of nitrogen dioxide exposure, a pollutant primarily from motor vehicles, showed a faster decrease in London than in Luton during the study period. Researchers believe this correlation is key, suggesting the observed improvements in lung growth were directly linked to the improved air quality resulting from the ULEZ policy.
Air pollution is known to stunt lung development in children, increasing their risk of conditions such as asthma, heart disease, diabetes, and premature death. Children are particularly vulnerable due to their developing lungs and immune systems, and their proximity to ground-level exhaust fumes. The case of nine-year-old Ella Adoo-Kissi-Debrah, who died in 2013 and posthumously became the first person in the UK to have air pollution listed as a cause of death, highlights the severe consequences of air pollution on young lives.
London's ULEZ was introduced by Mayor Sadiq Khan to combat high levels of nitrogen dioxide. The policy requires older, more polluting vehicles to pay a daily charge to enter central London, a measure later expanded city-wide. While aimed at improving air quality, the ULEZ has faced political opposition and public protests.