Information Source - National Center for Disease Control and Public Health

Index Range	Good	Fair	Moderate	Bad	Very Bad
Levels of Health Concern	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Very Unhealthy
Index Level Impact on Your Health
	Index Level - Good Levels of Health Concern - GoodAir quality is considered satisfactory, and air pollution poses little or no risk for health.	Index Level - Fair Levels of Health Concern - ModerateAir quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.	Index Level - Moderate Levels of Health Concern - Unhealthy for Sensitive GroupsMembers of sensitive groups may experience health effects. The general public is not likely to be affected.	Index Level - bad Levels of Health Concern - UnhelthyEveryone may begin to experience health effects; members of sensitive groups may experience more serious health effects.	Index Level - Very bad Levels of Health Concern -Very UnhelthyHealth alert: everyone may experience more serious health effects.
Recomendations to Protect Your Health
PM Particles less than 2.5 and 10 µm	Index Level - Good Levels of Health Concern - GoodNone	Index Level - Fair Levels of Health Concern - ModerateUnusually sensitive people should consider reducing prolonged or heavy exertion.	Index Level - Moderate Levels of Health Concern - Unhealthy for Sensitive GroupsThe following groups should reduce prolonged or heavy exertion: People with heart or lung disease Children and older adults	Index Level - bad Levels of Health Concern - UnhelthyThe following groups should avoid prolonged or heavy exertion: People with heart or lung disease Children and older adults Everyone else should reduce prolonged or heavy exertion.	Index Level - Very bad Levels of Health Concern -Very UnhelthyThe following groups should avoid all physical activity outdoors: People with heart or lung disease. Children and older adults. Everyone else should avoid prolonged or heavy exertion.
NO2 Nitrogen Dioxide (NO2)	Index Level - Good Levels of Health Concern - GoodNone	Index Level - Fair Levels of Health Concern - ModerateIndividuals who are unusually sensitive to nitrogen dioxide should consider limiting prolonged outdoor exertion.	Index Level - Moderate Levels of Health Concern - Unhealthy for Sensitive GroupsThe following groups should limit prolonged outdoor exertion: People with heart or lung disease Children and older adults	Index Level - bad Levels of Health Concern - UnhelthyThe following groups should avoid prolonged outdoor exertion: People with heart or lung disease Children and older adults Everyone else should limit prolonged outdoor exertion.	Index Level - Very bad Levels of Health Concern -Very UnhelthyThe following groups should avoid all physical activity outdoors: People with heart or lung disease People with heart or lung disease Everyone else should limit outdoor exertion.
O3 Ozone	Index Level - Good Levels of Health Concern - GoodNone	Index Level - Fair Levels of Health Concern - ModerateUnusually sensitive people should consider reducing prolonged or heavy outdoor exertion.	Index Level - Moderate Levels of Health Concern - Unhealthy for Sensitive GroupsThe following groups should reduce prolonged or heavy outdoor exertion: People with lung disease, such as asthma Children and older adults People who are active outdoors	Index Level - bad Levels of Health Concern - UnhelthyThe following groups should avoid prolonged or heavy outdoor exertion: People with heart or lung disease, such as asthma Children and older adults People who are active outdoors Everyone else should limit prolonged outdoor exertion.	Index Level - Very bad Levels of Health Concern -Very UnhelthyThe following groups should avoid all physical activity outdoors: People with heart or lung disease, such as asthma Children and older adults People who are active outdoors Everyone else should limit outdoor exertion.
SO2 Sulphur Dioxide (SO2)	Index Level - Good Levels of Health Concern - GoodNone	Index Level - Fair Levels of Health Concern - ModerateNone	Index Level - Moderate Levels of Health Concern - Unhealthy for Sensitive GroupsPeople with asthma should consider reducing exertion outdoors.	Index Level - bad Levels of Health Concern - UnhelthyChildren, asthmatics, and people with heart or lung disease should reduce exertion outdoors.	Index Level - Very bad Levels of Health Concern -Very UnhelthyChildren, asthmatics, and people with heart or lung disease should avoid outdoor exertion. Everyone else should reduce exertion outdoors.
CO Carbon Monoxide (CO)	Index Level - Good Levels of Health Concern - GoodNone	Index Level - Fair Levels of Health Concern - ModerateNone	იIndex Level - Moderate, bad, very Bad Levels of Health Concern - Unhealthy for Sensitive Groups, Unhealthy, Very UnhealthyPeople with heart disease, such as angina, should avoid exertion and sources of carbon monoxide, such as heavy traffic.