DIGR Study

The investigators are studying the effects of exposure to diesel exhaust on lung inflammation in the presence and absence of an inhaled corticosteroid. Although data is mixed, studies show that asthmatics have increased lung inflammation and worse symptoms during periods of higher air pollution despite taking their anti-inflammatory corticosteroid medication. One possible reason is that air pollution exposure may decrease the ability of corticosteroids to combat inflammation.

Breathing in air pollution can cause inflammation in the airways and make it harder to breathe. This study wants to understand why asthma inhalers might not work as well when air pollution levels are high. We hope this will help us make better guidelines for using asthma medications and develop new treatments. Ultimately, we want to reduce asthma flare-ups in people who are sensitive to air pollution. We think that breathing in diesel exhaust might make asthma inhalers less effective by changing how certain genes are expressed.

To test this volunteers will inhale either a placebo or a corticosteroid, before sitting in an exposure booth for 2 hours breathing either filtered air or diluted diesel exhaust. Samples will be collected before and after exposure to analyze the effects of budesonide and diesel exhaust exposure.