Cutting down on air pollution can help improve the lung capacity of children and adolescents, finds a study.

The adverse impact of airborne pollutants on children's lung health is well-documented. According to the researchers, however, how changes in air quality can affect lung development in children and adolescents is less studied.

The study, published in the European Respiratory Journal, noted that lower exposure to airborne pollutants, even at relatively low levels, is associated with improvements in the development of lung function from childhood to early adulthood. For the study, the team tested the lung function of 4,000 individuals at the ages of 8, 16, and 24.

The researchers estimated, above all, concentrations of airborne pollutants, mostly from traffic, at sites where the participants lived from birth until early adulthood.

"When we compare the individuals living in the areas in which air quality has improved and those in which it hasn't, we find that lung function improved by a few per cent in the participants in the young adult age bracket," said first author Zhebin Yu, postdoc researcher at the Institute of Environmental Medicine, Karolinska Institutet in Sweden.

"But above all, we could see a 20 per cent lower risk of having significantly impaired lung function," Yu added.

The results are important since optimal lung development during childhood is a powerful determinant of good health in adulthood, said Professor Erik Melen, paediatrician and professor at the Department of Clinical Research and Education at the Institutet.

"It is ultimately of great importance since the lung function that children and adolescents develop as they grow up persists into adulthood," he said.

"If you have reduced lung function as an adult, you run a greater risk of chronic lung diseases like COPD, cardiovascular disease and premature death. So by improving air quality, we reduce the likelihood of children developing chronic diseases later in life."

Previous studies have shown that lung function growth can both improve and deteriorate over time, and these new results show that air pollution can play an important part in this.