Pollutant-Specific Health Effects Statements
for the Air Quality Index (AQI)
| AQI Category |
Ozone (O3) |
Fine Particles (PM2.5) |
Carbon Monoxide |
Sulfur Dioxide |
|---|---|---|---|---|
| Good | None | None | None | None |
| Moderate | Unusually sensitive individuals may experience respiratory symptoms. | None | None | None |
| Unhealthy for Sensitive Groups |
Increasing likelihood of respiratory symptoms and breathing discomfort in active children and adults with respiratory disease, such as asthma. | Increasing likelihood of respiratory symptoms in sensitive individuals, aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly. | Increasing likelihood of reduced exercise tolerance due to increased cardiovascular symptoms, such as chest pain, in people with cardiovascular disease. | Increasing likelihood of respiratory symptoms, such as chest tightness and breathing discomfort, in people with asthma. |
| Unhealthy | Greater likelihood of respiratory symptoms and breathing difficulty in active children and adults and people with respiratory disease, such as asthma; possible respiratory effects in general population. | Increased aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; increased respiratory effects in general population. | Reduced exercise tolerance due to increased cardiovascular symptoms, such as chest pain, in people with cardiovascular disease. | Increased respiratory symptoms, such as chest tightness and wheezing in people with asthma; possible aggravation of heart or lung disease. |
| Very Unhealthy | Increasingly severe symptoms and impaired breathing likely in active children and adults and people with respiratory disease, such as asthma; increasing likelihood of respiratory effects in general population. | Significant aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; significant increase in respiratory effects in general population. | Significant aggravation of cardiovascular symptoms, such as chest pain, in people with cardiovascular disease. | Significant increase in respiratory symptoms, such as wheezing and shortness of breath, in people with asthma; aggravation of heart or lung disease. |
| Hazardous | Severe respiratory effects and impaired breathing likely in active children and adults and people with respiratory disease, such as asthma; increasingly severe respiratory effects likely in general population. | Serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; serious risk of respiratory effects in general population. | Serious aggravation of cardiovascular symptoms, such as chest pain, in people with cardiovascular disease; impairment of strenuous activities in general population. | Severe respiratory symptoms, such as wheezing and shortness of breath, in people with asthma; increased aggravation of heart or lung disease; possible respiratory effects in general population. |
PDF version of Health Effects Table
Content last updated on June 7, 2011