Air Quality Guide

Air Quality	Health Effects Statement	Cautionary Statement
Good (0-50)	Air quality is satisfactory, and air pollution poses little or no risk.	None.
Moderate (51-100)	Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. (See below for sensitive groups.)	Unusually sensitive people should consider limiting prolonged outdoor exertion.
Unhealthy for Sensitive Groups (101-150)	Members of sensitive groups may experience health effects. The general public is less likely to be affected.	Sensitive groups should reduce prolonged or heavy outdoor exertion.
Unhealthy (151-200)	Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.	Sensitive groups should avoid prolonged or heavy outdoor exertion. Everyone else should reduce prolonged or heavy outdoor exertion.
Very Unhealthy (201-300)	Health alert: The risk of health effects is increased for everyone.	Sensitive groups should avoid all physical activity outdoors. Everyone else should avoid prolonged or heavy outdoor exertion.
Hazardous (301-500)	Health warning of emergency conditions: Everyone is more likely to be affected.	Everyone should avoid all outdoor exertion.
Beyond Index (>500)	Extremely High Levels: Steps to reduce your Exposure – Click Here.

Sensitive Groups

PM2.5: People with heart or lung disease, older adults, and children. For more information, click here.

Ozone: People with lung disease, children, older adults, and people who are active outdoors, including outdoor workers. For more information, click here.

County	Site	Units	8-Hour	Hour Of Day	1 Hour	Hour Of Day
East Asia	Beijing	ppb	45	07 PM	51	02 PM
East Asia	Guangzhou	ppb	35	11 PM	38	11 PM