Jan. 25, 2007 — Children living close to freeways may have slower lungdevelopment between ages 10 and 18 than those living farther away.
That’s according to a study of more than 3,000 southern California children,published in The Lancet‘s online edition.
“Since lung development is nearly complete by age 18 years, anindividual with a deficit at this time will probably continue to have less thanhealthy lung function for the remainder of his or her life,” writeresearcher W. James Gauderman, PhD, and colleagues.
The study may raise “important questions for society about the structureof the transportation system, engines, fuels, combustion, and road dust inurban areas,” editorialists write in The Lancet.
About the Study
Gauderman works in the University of Southern California’s preventivemedicine department.
He and his team studied 3,677 children in 12 communities in southernCalifornia.
The children were in the fourth grade (average age: 10 years) when the studystarted in the 1990s. They took yearly lung function tests for up to eightyears.
Children 10 to 18 go through a period of rapid lung development, theresearchers note.
The researchers also looked at how close the children lived to freeways andfound that 440 lived less than a third of a mile from one.
Their results showed that the children living that close to a freeway hadslower lung development during the study, compared with those living at leastthree times farther from a freeway.
The findings held after the researchers took other factors into account,including family income, race, asthma, smoking, regional air quality, and kidswho moved during the study.
Local roads that weren’t freeways were not associated with slower lungdevelopment.
The children weren’t followed beyond age 18, so it’s not clear how welltheir lungs functioned later in life.
Freeway Pollution the Problem?
The concentration of pollutants in the area near major freeways may be theproblem, but it’s hard to rule out other influences, note Gauderman andcolleagues.
It’s also not clear what factors, if any, influenced the kids’ lungdevelopment before age 10, say the editorialists. They included ThomasSandstrom, MD, PhD, of the respiratory medicine and allergy department ofUniversity Hospital in Umea, Sweden.
“However, these questions should not distract from the major achievementof follow-up of such a large group of children through secondary school withrepeated lung function tests,” write the editorialists.
The study was funded in part by the California Air Resources Board, theNational Institute of Environmental Health Sciences, and the EnvironmentalProtection Agency.