Why the air is getting worse across the West
WASHINGTON, DC — Air quality warnings are in effect across five states as a mix of wildfire smoke and ground-level ozone drives unhealthy conditions in large parts of the western United States. The National Weather Service issued alerts Thursday for Arizona, California, Oregon, Washington and Idaho.
The smoke component is tied to wildfires in Canada, which are sending fine particles south into the Pacific Northwest. At the same time, hot weather and stagnant air are helping ozone build to dangerous levels in the Southwest and Southern California.
Where the alerts are concentrated
In Oregon, Washington and Idaho, smoke alerts are expected to remain active through Friday in some areas, with Eastern Okanogan County singled out as especially concerning because of its proximity to active fires. Officials said air quality there could fall to the “Very Unhealthy” or even “Hazardous” range.
Arizona has separate advisories for the Phoenix and Tucson metro areas through Friday evening, while Southern California faces an ozone alert that could last until 8 p.m. Monday. The South Coast Air Quality Management District also extended warnings across the Inland Empire, Orange County, mountain communities and parts of the Los Angeles basin.
The health risks behind smoke and ozone
The danger comes from what people cannot see. Wildfire smoke carries fine particulate matter, known as PM2.5, which can travel deep into the lungs and enter the bloodstream. Ozone is also harmful because it can irritate airways and make breathing more difficult, especially during heat…