By Tammy Webber, Associated Press
CHICAGO - 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
rates of lung diseases such as asthma. But a new 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
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, 8 with air trapped in their lungs, and
4 with unusually prominent central airways. One child had a lung nodule.
In the coastal town, one child had mild over-inflation of the
rest had no damage.
Lung damage could be a precursor to problems such as pulmonary
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," said Fordham. "You can
find (problems) and do something for those kids."
Fordham said some of the children might be helped by vitamins,
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
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
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," said Fordham, adding
that another study of children in a moderately polluted city is planned.
Fordham said it would be difficult to duplicate the study in
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.
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