Hazardous Serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; serious risk of respiratory effects in the general population. Visibility < .7 Miles Everyone should avoid any outdoor exertion; people with respiratory or heart disease, the elderly, and children should remain indoors. Very Unhealthy Significant aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; significant risk of respiratory effects in the general population. Visibility .7-1.1 Miles People with respiratory and heart disease and the elderly and children should avoid any outdoor activity; everyone else should avoid prolonged exertion. Unhealthy Increased aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly, increased respiratory effects in the general population. Visibility 1.2-2.74 Miles People with respiratory or heart disease, the elderly and children should avoid prolonged exertion; everyone else should avoid prolonged exertion. Unhealthy for Sensitive Groups 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. Visibility 2.75-4.44 Miles People with respiratory or heart disease, the elderly and children should limit prolonged exertion Moderate Possibility of aggravation of heart or lung disease among persons with cardiopulmonary disease and the elderly. Visibility 4.45 - 11.5 Miles Good Visibility >11.6 Miles

How We Calculate Air Quality