Cleaner air may help children’s lungs grow better: Lessons from London study

The impact of cleaner air on children's lung development has been highlighted by a recent study conducted in London. The research, published in The Lancet, indicates that when traffic pollution decreases, children's lungs can grow more effectively. The study compared children in London, where the Ultra Low Emission Zone (ULEZ) was introduced, to children in nearby Luton, where no such clean-air zone was in place.

This matters because childhood is a critical period for lung growth, and failing to reach full lung potential may raise the risk of respiratory issues and other health problems later in life. Previous studies have linked traffic pollution with poorer lung development in children, but this study provides strong evidence that improving air quality can enhance children's lung growth.

Researchers tracked over 3,400 children aged six to nine for five years, monitoring their lung function annually while also measuring local air pollution levels. Before the ULEZ, London children had slightly smaller lung capacity and higher exposure to nitrogen dioxide, a pollutant from vehicle exhaust. However, after the ULEZ took effect, London children's lung growth accelerated, increasing by about 10 millilitres per year on average.

This difference persisted after four years, with London children's lung capacity nearly matching that of Luton's. The reduction in nitrogen dioxide pollution in London also corresponded with a decline in the proportion of children with clinically impaired lung function. While the study doesn't claim that the ULEZ is a cure-all for pollution-related health issues, it suggests that cleaner air may help children achieve healthier lung development during critical growth years.

The findings emphasize that cleaner air benefits not just today's children but also their long-term respiratory health.