The pollutants, said Davis, can cause people to die prematurely from asthma, breathing disorders and heart disease. There are more than a thousand studies from 20 countries all showing that you can predict a certain death rate based on the amount of pollution. Some experts, however, say that the direct connection between air pollution and death is not that clear, even in cities. Dr. Russell V. Luepker, a cardiologist and professor at the University of Minnesota, said that air pollution is not recognized as a significant cause of heart disease in the United States. Dr. Marian Frieri, a professor of medicine and an asthma expert at State University of New York at Stony Brook, said that air pollution can contribute to asthma inflammation but is only one factor on top of another condition.
Ozone can increase the reaction to allergies, for instance.
It is like a second whammy effect. She said although the study concentrated on just four cities that have a combined population of 45 million, the conclusions probably could be applied to cities worldwide. The data are consistent with a World Health Organization study that estimated that air pollution would cause about 8 million deaths worldwide by 2020, she said. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.