New Delhi: Reducing traffic pollution may do more than improve the quality of urban air. A five-year study published in The Lancet has found that children’s lung growth improved after London introduced its Ultra Low Emission Zone (ULEZ), offering new evidence that cleaner air can benefit children’s health.
The study examined more than 3,400 children who were between six and nine years old when they joined the research. They were followed for five years, beginning before London’s ULEZ came into force in April 2019. Researchers assessed their lung function every year and tracked air pollution levels around their homes.
Children in Luton, where no clean-air zone was introduced, served as a comparison group. The two cities provided a useful basis for comparison because both are urban settings, while only London introduced the ULEZ.
Before the ULEZ was introduced, children in London had slightly smaller lung capacity than children in Luton. They were also exposed to considerably higher levels of nitrogen dioxide, a pollutant closely associated with vehicle exhaust.
The pattern changed in the years that followed. Lung growth among the London children was faster than among those in Luton. On average, their lung capacity increased by about 10 millilitres more each year.
Although the annual difference was small, it accumulated as the children grew. After four years, the gap between the two groups had essentially disappeared, with average lung capacity becoming almost identical in London and Luton. Children who had started with a disadvantage in London appeared to have caught up with their peers.
The improvement coincided with a faster decline in air pollution in London, particularly nitrogen dioxide. The researchers also found that the proportion of London children with clinically impaired lung function fell from 14% at the beginning of the study to 9% after four years. In Luton, the proportion declined from 9% to 7%.
The study does not establish that the ULEZ alone caused every improvement observed, nor does it suggest that a clean-air zone can address every health problem associated with pollution. However, the timing and pattern of the findings are significant: London introduced the policy, pollution levels fell, and children’s lung growth improved relative to children in the comparison city.
Childhood is an important period for lung development. The lungs continue to grow through childhood and adolescence, and failing to reach their full potential may increase the risk of breathing problems and other serious health conditions later in life. Earlier research has linked traffic pollution with poorer lung development, while the question of whether cleaner urban air could improve lung growth remained less clear.
The findings provide some of the strongest evidence so far that reducing traffic pollution may help children’s lungs grow better.
The research also places a health dimension on policies aimed at reducing vehicle pollution. For millions of children growing up in cities where traffic remains a major source of air pollution, measures such as clean-air zones may have implications beyond emissions, congestion and the environment.
The study’s authors argue that cities should consider introducing clean-air zones more quickly and more widely. Their findings suggest that such measures may help children achieve healthier lung development during the years when their lungs are still growing.
The message from London is therefore broader than cleaner streets. Reducing air pollution may give young lungs a better chance to grow more normally, potentially influencing how well children breathe not only today, but for years to come.
BI Bureau
