Scientists puzzle over soaring asthggma rates, especially in inner cities.(Chicago Tribune)

NEW YORK _ In America's asthma epidemic, Yolanda Garcia's impoverished South Bronx neighborhood very likely is at the epicenter. Rates of the potentially fatal respiratory disease are at least eight times the national average here, and often the victim is a child.

Despite advances in medication and therapy, scientists are struggling to explain why asthma rates are skyrocketing, not just in New York City but nationally, and why the increase has been so severe in inner cities. Even more alarming is the doubling of asthma deaths over the past two decades, according to the U.S. Centers for Disease Control and Prevention. Children, whose bodies are still developing, are the most susceptible.

"Children are dying and no one is paying attention," said Garcia, executive director of the Bronx community improvement group We Stay/Nos Quedamos, as a mother with three asthmatic children left her office. "Teachers come into our area, get asthma and leave. Over 100,000 trucks drive in and out of the Bronx each day. We're the main artery into Manhattan. And we're ground zero for the asthma epidemic."

But while…