The Department of Environmental Quality advised five counties, including Logan County, an Air Quality Health Advisory on Wednesday.
DEQ says the air quality in the county is unhealthy for sensitive groups.
Active children and adults and people with respiratory diseases such as asthma should limit prolonged exertion.
For particulate matter advisories, sensitive groups include those with heart disease, according to DEQ.
The department adds everyone should limit exposure to smoky areas.
Other counties in the “Unhealthy for Sensitive Groups” include Oklahoma, Osage, Washington and Tulsa.
There are six levels of air quality, including healthy, moderate, unhealthy for sensitive groups, unhealthy, very unhealthy and hazardous.