Long-term exposure to air pollution adversely affects lung function in teenagers, results of The Children’s Health Study indicate.

Previous studies of the effects of air pollution followed young children for only 2 to 4 years, Dr. W. James Gauderman and colleagues note in their paper, published in The New England Journal of Medicine. It was not known whether effects of exposure would persist through adolescence into adulthood.

They therefore followed children from age 10 to age 18, performing breathing tests each year. The study started with 1759 children enrolled in 1993, but with an attrition rate of approximately 10 percent annually, the final group included 747 subjects in 2001.

Data for various measures of air pollution were gathered from air monitoring stations set up in each of the 12 southern California communities where the children lived, and which had various levels of ambient air pollution.

Gauderman, at the University of Southern California, Los Angeles, and his colleagues found that children exposed to high pollutant levels were more likely to have poor lung function than their peers exposed to low levels.

The effects of air pollutants on lung function “were similar in boys and girls and remained significant among children with no history of asthma and among those with no history of smoking,” the authors write, “suggesting that most children are susceptible to the chronic respiratory effects of breathing polluted air.”

As younger adults, those who grew up in polluted areas will probably not suffer too much, Gauderman told Reuters Health. “There is some evidence that reduced lung function may translate into more severe symptoms if they come down with a cold or the flu.”

However, “The bigger consequences are likely to occur later in life, because data show reduced lung function in elderly patients is a strong risk factor for respiratory disease and heart disease, as well as death due to those conditions,” he continued.

“The concern is that if deficits develop early on and are carried with them throughout life, they’ll be at increased risk for these conditions at a younger age or perhaps at risk for more severe forms of those illnesses.”

The solution “rests on reduced emissions and regulatory decisions that keep pressure on reducing air pollution levels,” Gauderman concluded.

From one standpoint, these findings represent “good news,” Dr. C. Arden Pope, III, at Brigham Young University in Provo, Utah, comments in an accompanying editorial. Air pollution is just one of many risk factors for pulmonary and cardiovascular disease, but it is modifiable. Therefore, he suggests, “The control of air pollution represents an important opportunity to prevent disease.”

SOURCE: The New England Journal of Medicine, September 9, 2004.