It's another day of hazy conditions in parts of Nebraska.
The smoke is prompting officials in Lincoln and Omaha to issue health advisories.
The cities are warning sensitive groups to try and limit their outdoor activity.
The smoke from wildfires burning in Canada is expected to impact the area through the middle of the week. The smoke is made up of a mixture of gases and fine particles produced when wood and other organic materials burn. The microscopic particles can penetrate deep into a person's lungs.
The Nebraska Department of Health and Human Services said, starting Tuesday, poor air quality could impact the entire state due to wildfires.