— Exposure to traffic pollution can significantly stunt a childs lung development, new research shows.
The study finds that youngsters who live within 500 metres of major highways develop weaker lungs with less air capacity than their counterparts who live at least 1500 metres away from arterial roads.
James Gauderman of the University of Southern California in Los Angeles, US, and colleagues followed nearly 3700 children in the area from age 10, measuring the participants lung function every year. As part of the test, the children took a deep breath and exhaled with force into a machine that gauged the volume and speed of air leaving their lungs.
By the time they reached age 18, those participants living within 500 metres of a motorway performed significantly worse on the lung function test than their more distant peers.
After controlling for other factors, such as socioeconomic status, Gaudermans team found that teens who grew up near big roads exhaled air 7% slower from their lungs than those who were raised least 1500 metres away from heavy traffic areas. And their overall air capacity was reduced by 3%, on average, in comparison to youngsters living further from traffic pollution.
This finding is important because teen years are a significant time for lung development, which is nearly complete by age 18. At the start of the study, the 10-year-old children living near roadways had performed only about 1% worse than their counterparts.
Traffic pollution might trigger an inflammatory response in the lung airways of children, making them less able to contract and push out air, the researchers speculate.
Cheapness at a price
Gauderman is concerned that exposure to traffic pollution is setting children up for a lifetime of health problems linked to poor lung function. Even a small decrease in lung capacity and strength might substantially raise the risk of serious health problems, he adds.
Reduced lung function in childhood is a known risk factor for the development and worsening of asthma in children and the development of chronic pulmonary disease later in life, explains Stephen Holgate at the University of Southampton in the UK. He adds that decreased lung strength has also been linked to heightened risk of serious lung infection in childhood.
Gauderman says his results should discourage the construction of housing developments and schools near major roadways. He adds that while these areas may be the cheapest to develop, doing so could contribute to long-term public health problems.
Journal reference: The Lancet (DOI: 10.1016/S0140-6736(07)60037-3)