Researchers find lung damage in healthy children exposed to high levels of air pollution
Wednesday, November 28th 2001, 12:00 am
By: News On 6
CHICAGO (AP) _ Some children who appear in perfect health have measurable lung damage from exposure to air pollution, researchers found, suggesting such damage could lead to lung disease.
Past research has found that children living in polluted areas have higher rates of lung diseases such as asthma. But the new study found that in polluted areas, even children with no symptoms of lung problems had signs of damage.
The study is the first to use X-ray imaging to measure changes in children with no symptoms of lung problems, the researchers said.
Chest X-rays of 241 children in Mexico City were compared with those of 19 children living in a small coastal town. Throughout the 20-month study, smog levels in Mexico City exceeded U.S. air quality standards for more than four hours a day on average. Particulate matter _ tiny pieces of soot and other materials in the air _ also was above U.S. standards.
Researchers found 63 percent of the Mexico City children had excessive inflation of both lungs, said Dr. Lynn Ansley Fordham, an associate professor of radiology and chief of pediatric imaging at the University of North Carolina School of Medicine.
In addition, 52 percent of the urban children had abnormal numbers of interstitial markings _ fine lines that could indicate inflammation along the airways, Fordham said.
CT scans of 25 children with the most abnormal X-rays found 10 with mild thickening of the walls of the bronchial airways, eight with air trapped in their lungs and four with unusually prominent central airways. One child had a lung nodule.
In the coastal town, one child had mild over-inflation of the lungs. The rest had no damage.
Lung damage could be a precursor to problems such as pulmonary disease, but the findings also might point to a reliable way to test children early, before lung disease develops, Fordham said.
``X-rays are a relatively inexpensive, easy-to-obtain screening for children,'' Fordham said. ``You can find (problems) and do something for those kids.''
Fordham said some of the children might be helped by vitamins, better diet, and staying inside when air pollution is at its peak.
She and Dr. Lilian Calderon-Garcidueana of the University of North Carolina and the National Institute of Pediatrics in Mexico City presented the study Wednesday at the Radiological Society of North America's annual meeting.
Joel Schwartz, an environmental epidemiologist at Harvard's School of Public Health, said other research has indirectly linked air pollution with respiratory ailments. But to find radiographic evidence of lung abnormalities in seemingly healthy children ``is pretty unusual,'' he said.
The results ``are showing what we suspect _ that there are chronic effects that can be seen in the lung that would show up this early ... on X-ray,'' said Schwartz, who was not involved in the study.
Some of the changes, such as airway thickening, might disappear if the children moved to a less polluted area, ``but it would certainly take a long time to reverse,'' Schwartz said.
Although Mexico City is more polluted than U.S. cities, the results can be generalized to other polluted areas, Fordham said. She said a study on euthanized dogs in Mexico found that those from moderately polluted areas _ similar to some areas of the United States _ had thickening of the lungs' lining, inflammation and particulate matter lodged in the lungs.
The findings might be more severe in dogs because of their poor diets, but ``we presume the same things could be found in people,'' Fordham said, adding that another study of children in a moderately polluted city is planned.
Fordham said it would be difficult to duplicate the study in the United States because of the high rates of asthma and higher levels of indoor air pollution from such things as carpet and glues, which could skew the results. It also was easier to find Mexican children who had lived in the same neighborhood all their lives.