Asthma is a 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. The airways are sensitive and more likely to react strongly to allergens and irritants in the air. Asthma episodes and more serious asthma attacks are caused by triggers. Important asthma triggers are:
- environmental tobacco smoke (secondhand smoke)
- dust mites
- outdoor air pollution
- cockroach allergen
- strenuous physical exercise
- some medicines
- bad weather, such as thunderstorms, high humidity, or freezing temperatures
- some foods and food additives
- strong emotional states that can lead to hyperventilation and an asthma attack.
Asthma and the Environment
A number of studies have reported associations between air pollution exposures and asthma. Specifically, researchers have found an association between increased hospital admissions for asthma and particulate matter, an outdoor air pollutant. Air pollution can make asthma symptoms worse and trigger attacks. Two key air pollutants can affect asthma. One is ozone (found in smog). The other is fine particulate pollution (found in haze, smoke, and dust). When ozone and particle pollution are in the air, adults and children with asthma are more likely to have symptoms. Ozone is often worst on hot summer days, especially in the afternoons and early evenings. Particle pollution can be bad any time of year, even in winter. It can be especially bad when the weather is calm, allowing air pollution to build up. Particle levels can also be high near busy roads, during rush hour, and around factories and when smoke is in the air from wood stoves, fireplaces, or burning vegetation.
Exposure and Risk
A person can get asthma at any age. Asthma affects all races, ages, and genders. Although asthma affects people of all ages, it often starts in childhood and is more common in children than in adults.
Reduce Your Risks
To avoid having asthma symptoms caused by environmental triggers you should minimize dust, control pet dander, and eliminate mold, allergens, and irritants in your home, school or workplace. Since air pollution can trigger asthma symptoms, you should be aware of pollution levels in your area and check air quality alerts before going outdoors or participating in strenuous outdoor activities. You can also sign up with the U.S. Environmental Protection Agency's (EPA) EnviroFlash to receive free automatic air quality forecasts to your e-mail, cell phone or pager.
For more information about asthma:
- American Lung Association
- Centers for Disease Control and Prevention
- National Heart, Lung and Blood Institute
- Asthma and Cleaning Products, What Workers Need to Know (August 2013)
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