According to CNN, wildfires in parts of Washington, Oregon and California are afflicting parts of those states with hazardous air quality that could trigger health emergencies in some cases.

The smoke that is blanketing Washington, Oregon and California is smoke coming from the wildfires burning in British Columbia, according to the National Weather Service Seattle. Air quality advisories are in effect for portions of Washington and Oregon, according to the NWS. The air quality was considered unhealthy in western parts of Washington.

The unhealthy level on the Air Quality Index means that everyone could experience health effects, with possibly more serious health issues for children, seniors and people with medical conditions. Wildfire smoke can include particles from burning vegetation and building materials mixed with gases.