According to the American Lung Association, there are 23 million Americans currently suffering from asthma, 7.1 million of them children, whose developing lungs are particularly susceptible to asthma triggers.
Other studies presented at the same conference contradicted the findings of the Basel team - reporting rising levels of allergies and asthma, particularly in northern and eastern Europe.
The Chronic Disease Prevention and Control Research Center will focus on asthma, where rates are much higher among inner-city children, particularly blacks.