WEDNESDAY, Aug. 15, 2007 (HealthDay News) -- Long-term exposure to high levels of air pollution causes reduced lung growth and function in children, according to a study of almost 3,200 Mexico City eight-year-olds.
Previous studies have suggested that short-term exposure to air pollution is associated with reversible problems in lung function. The authors of this new study said the effects of long-term exposure to air pollution -- such as that experienced by people who live in cities with major air pollution -- have not been conclusively documented.
"Our study revealed significant deficits in lung function growth in children with long-term exposure to air pollutants. In addition to the important impact of lung health, early lung deficits may increase the risk of developing chronic obstructive lung disease later in life, as well as cardiovascular morbidity and general mortality," wrote lead author Dr. Isabelle Romieu.
It's not clear whether the lung damage in these children is reversible. The findings were published Aug. 15 in the American Journal of Respiratory and Critical Care Medicine.
The researchers measured the children's lung function and looked at their exposure to common urban pollutants: ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM10).
"At the beginning of the study and at each phase of follow-up, children exposed to lower O3 and PM10 concentrations had better lung function values than children exposed to higher concentrations," the authors wrote.
They noted that the effect of air pollution on forced expiratory volume in one second (FEV1) -- a measure of lung function -- among children in the study was greater than the effect of exposure to mothers' smoking among children in the United States.
The U.S. Centers for Disease Control and Prevention has more about air pollution and respiratory health.