Asthma and the Environment

Asthma is a chronic disease that affects the airways that carry oxygen in and out of the lungs. If a person has asthma, the inside of these airways is irritated and swollen. Asthma can cause shortness of breath, wheezing, coughing, and tightness in the chest. For some people, asthma symptoms only appear when they are exposed to something that irritates their breathing. Others have a kind of asthma that makes breathing difficult all of the time.

Asthma attacks have been linked to exercise, respiratory infections and exposure to environmental factors such as allergens, tobacco smoke, and indoor and outdoor air pollution. Asthma attacks can be reduced by taking medication and avoiding exposure to known triggers.

A number of studies have reported associations between air pollution exposures and asthma. For example, researchers have found an association between increased hospital admissions for asthma and particulate matter, an outdoor air pollutant.