We know that children who live in areas with excess air pollution have higher rates of asthma and other lung diseases. A study presented at the November 2001 annual meeting of the Radiological Society of North America’s suggests that some children who appear in perfect health have measurable lung damage from exposure to air pollution.
The study compared the chest x-rays of children living in Mexico City (where pollution exceeds US air quality standards for an average of 4 hours a day) to children living in a seaside Mexican town. Over 63% of apparently healthy children breathing city air had signs of obstruction on x-ray, over 50% had signs of inflammation, and 18% had signs of more advanced damage. Of those living in by the sea, only 5% had mild obstruction, and none had inflammation or more advanced damage.
The researchers, from the University of North Carolina, said that the study would have been difficult to perform 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 confuse the results.