HELENA — Air quality across many parts of Montana this week took a dive, and was rated by the state Department of Environmental Quality as ranging from "unhealthy for sensitive groups" to "hazardous."
The cause of the poor air quality is smoke pouring in to Montana from wildfires in several western states, including Oregon and California.
Here is an explanation from MT DEQ about the different categories:
- HAZARDOUS: All children and adults should avoid or limit all outdoor exertion
- VERY UNHEALTHY: Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion
- UNHEALTHY: Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion
- UNHEALTHY FOR SENSITIVE GROUPS: Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion
- MODERATE: Unusually sensitive people should consider limiting prolonged outdoor exertion
