Freeways found hazardous to child’s respiratory health
LOS ANGELES – Children living near busy highways have significant impairments in the development of their lungs that can lead to respiratory problems for the rest of their lives, University of Southern California researchers have found in the largest and longest study of its kind.
The 13-year study of more than 3,600 children in 12 southern California communities found that the damage from living near a freeway is about the same as that from living in communities with the highest pollution levels, the team reported Thursday in the online version of the medical journal The Lancet.
“If you live in a high pollution area and live near a busy road, you get a doubling” of the damage, said lead author W. James Gauderman, an epidemiologist at USC’s Keck School of Medicine.
“Someone suffering a pollution-related deficit in lung function as a child will probably have less than healthy lungs all of his or her life,” he said.
The greatest damage appears to be in the small airways of the lung, damage that is normally associated with the fine particulate matter emitted by automobiles.
“This tells me that I wouldn’t want to be raising my children near a significant source of fine-particle air pollution,” said economist C. Arden Pope of Brigham Young University, an expert on air pollution and health who was not involved in the study.
The study was funded by the California Air Resources Board, the National Institute of Environmental Health Sciences, the Environmental Protection Agency, the National Heart, Lung and Blood Institute and the Hastings Foundation.
There has been a growing body of research about the effects of air pollution on the lungs and cardiovascular system, but most have focused on short-term effects, linking pollution episodes to heart attacks, asthma attacks, hospitalization, and so forth.
What is unique about this study is the large number of children involved and the length of time they were studied.
Gauderman and his colleagues recruited groups of fourth-grade students, average age 10, in 1993 and 1996. Their schools were scattered from San Luis Obispo to San Diego counties.
The team collected extensive information about each child’s home, socioeconomic status and other relevant facts.
Once each year, the team visited the schools and measured the children’s lungs, assessing both how much air could be expelled in one breath and how quickly it could be expelled.
Results from the study reported in 2004 indicated that children in the communities with the highest average levels of pollution suffered the greatest long-term impairment of lung function.
In the new study, Gauderman and his colleagues found that, by their 18th birthday, children who lived within 500 yards of a freeway had a 3 percent deficit in the amount of air they could exhale and a 7 percent deficit in the rate at which it could be exhaled compared to children who lived at least 1,500 yards from a freeway. The effect was independent of the overall pollution in their community.
The results were also independent of the children’s initial health and whether they were smokers. “This suggests that all children, not just susceptible subgroups, are potentially affected by traffic exposure,” Gauderman said.