Millions of Cases of Asthma may be Caused by Chemicals in Air Pollution: New study

A new study has found that nearly 2 million new cases of pediatric asthma every year may be caused by a traffic-related air pollutant, a problem particularly important in big cities.  Equally disturbing, a second study by the same research team finds that 1.8 million excess deaths around the world are linked to urban air pollution.