People with lung diseases, such as asthma, chronic bronchitis, emphysema, and chronic obstructive pulmonary disease
2. Infants and young children
3. People who work or exercise outdoors
4. Adults over 65
5. People with a cardiovascular disease
6. People in poverty; people who lack access to health care
7. People who smoke or are exposed to second-hand smoke
8. People working in occupations where there is high exposure to contaminated air
9. People who spend a lot of time near busy roadways