Orange and soot-filled skies overshadowed a devastated landscape in rural Siskiyou County, California on August 1, 2022. By Monday morning, wind had whipped the 55,493 acre McKinney wildfire into the largest wildfire of the 2022 California wildfire season to date (1). Plumes of noxious wildfire smoke imperiled air quality hundreds of miles north into neighboring Oregon.

Just three days earlier, the uncontained fire sparked in the Klamath National Forest near Yreka, California, forcing thousands of evacuations. An unknown number of homes were destroyed and two people were killed by the blaze (2).

Nearby air quality monitoring stations measured hazardous concentrations of PM2.5 (pollution particles 2.5 microns in diameter or smaller) at 5 PM on Sunday, peaking at 840 micrograms per cubic meter (µg/m3) at a Delphic Road, Montague air quality monitoring station. The daily concentration of PM2.5 measured at the station was 320 µg/m3, 21 times higher than the World Health Organization’s (WHO) guideline for daily averageexposure to PM2.5 of 15 µg/m3 or less.

An air quality monitoring station near Yreka, California shows a sudden spike in PM2.5 concentrations being measured on July 31. Source: IQAir AirVisual.

Wildfire and unhealthy air quality visualized near Yreka, California. High concentrations of PM2.5 were measured by multiple air quality monitors. Source: IQAir AirVisual.

PM2.5 is a deadly airborne pollutant associated with wildfire smoke, vehicle exhaust, and industrial pollution among other sources. It is linked to many health problems, including heart and lung disease, asthma, and emphysema.

While we initially experience wildfire smoke through smell, coughing, and throat and lung irritation, the damage to human organs can be serious. PM2.5 is tiny, as are even smaller ultrafine particles; when we breathe them in, fine particles enter the lungs and are distributed to every organ in the body.

Wildfire smoke blankets Oregon

Harm from the McKinney fire spread far beyond California’s borders.

Wildfire smoke from California wildfires impacted air quality across multiple Oregon cities east of the Cascade Mountains. Bend, Medford, Ashland, and Klamath Falls, Oregon were the worst affected Oregon cities, reporting US AQI values ranging from moderate to unhealthy due to high PM2.5 concentrations.

Poor air quality was experienced across nearly all of Oregon east of the Cascade Mountains on Monday morning August 1, 2022. Source: IQAir AirVisual.

The air quality at one station in Medford was so poor that at 11 am on Sunday PM2.5 concentrations measured 342 µg/m3. Measurement of PM2.5 concentrations over 250 are hazardous; everyone should avoid going outdoors in those conditions.

Moderate to unhealthy concentrations of PM2.5 were measured in Medford, Oregon. Source: IQAir AirVisual.

Moderate to unhealthy concentrations of PM2.5 was also measured by air quality stations throughout Bend, Oregon. Source: IQAir AirVisual.

Unhealthy concentrations of PM2.5 were measured by air quality monitoring stations in and around Klamath Falls, Oregon. Source: IQAir AirVisual.

Poor air quality isn’t unknown to these communities. In August 2021, Ashland, Medford, and Klamath Falls all experienced average PM2.5 concentrations that were considered hazardous. Klamath Fall’s average PM2.5 concentration in August was 101 μg/m3. Bend’s air quality was only slightly better, though very unhealthy.

Air quality was so poor in 2021 that Altamont, Oregon, a neighborhood of Klamath Falls, had the 15th worst air quality in the country with a PM2.5 concentrations of 24 μg/m3. Klamath Falls was 32nd with PM2.5 concentrations of 22 μg/m3.

For both 2021 and 2022, Oregon’s poor air quality came down to major wildfire outbreaks in the Pacific Northwest and California.

The takeaway

Though as of August 1, 2022 it’s the biggest California wildfire of the year, the McKinney fire has the potential to get worse before it gets better. And it may not be the worst fire, as the wildfire season is far from over. Extreme drought conditions persist across the American and Canadian west, raising concerns that more wildfires are to still to come.

As the McKinney fire drew firefighting resources from surrounding communities, there were ten additional smaller fires in the Klamath National Forest. On August 1, large-scale fires were also recorded in Idaho, Montana, Portugal, and France (3,4).

Our changing climate means hotter, drier conditions not only in summer but year-round. Wildfires are getting more intense and larger in scale. This means that accompanying wildfire smoke presents a serious threat to people wherever they may live, as smoke travels for miles beyond its source.

“Wildfires really can no longer be considered as local, or even regional, pollution events that only affect geographically collocated communities,” said Dr. Christi Chester Schroeder, Air Quality Science Manager at IQAir.

“Data collected during the 2021 wildfire season indicated migrating smoke plumes from wildfires in the western United States elevated PM2.5 concentrations across northern states from Minnesota all the way to New York.”

When air quality conditions become dangerous, it’s important to run an air purifier for wildfire smoke that seeps inside and avoid outdoor exposure to smoke. Anyone who must go outdoors should wear a face mask. Owning an outdoor air quality monitor will also help to notify you whether air quality is dangerous outside.