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Portland-area air quality getting worse, annual report card shows

New data released from IQAir shows smoke from wood stoves and pollution caused by other sources can also be a problem during the winter
Wildfire smoke filling the Willamette Valley in September 2017, and increasingly bad wildfire seasons are contributing to overall worsening air quality in the Pacific Northwest, a new report finds. | U.S. FOREST SERVICE
March 15, 2023

Despite a relatively mild wildfire season in 2022 for smoke in the Portland metro region, overall air quality decreased throughout the Pacific Northwest region compared to the previous year.

New data released from IQAir — a Swiss-based global air quality tracking company contracted by the World Health Organization (WHO) — breaks down the 2022 Annual Air Quality Report Card.

The report looks specifically at a type of pollution known as PM 2.5, which is a category that includes the type of particulate pollution that hangs in the air from wood smoke.

While the smoky conditions are most pronounced during wildfire season, and the 2022 report notes that monthly average particulate readings spiked during wildfire season, smoke from wood stoves and pollution caused by other sources can also be a problem during the winter.

Bowl-shaped areas like the Tualatin Valley have a more pronounced winter inversion effect, further contributing to pollution hanging in the air.

IQAir utilizes a vast network of ground-level air quality sensors — many of which are managed by government agencies, but also many that are overseen by private companies or community organizations — to aggregate PM 2.5 readings.

Local air getting worse

While the United States’ overall levels of pollution decreased in 2022, the Pacific Northwest trended in the opposite direction.

Major metropolitan areas in the Pacific Northwest suffered lower-than-ideal readings last year, which IQAir attributed to wildfires driven by climate change.

“Wildfires in the United States are becoming a year-round challenge,” IQAir’s report states. “Increasing emissions from wildfires in recent years are quickly erasing air quality improvements gained over the past decade. Research studies observe improvement in particulate matter air quality in the United States in the past decade except in wildfire-prone areas like the Pacific Northwest.”

Portland saw its annual average PM 2.5 pollution increase from 2021, with an annual average of 9.9 micrograms of pollution per cubic meter of air.

In 2021, the number was 7.0 micrograms.

In 2020, which saw a particularly bad season for wildfire smoke, the number was 11.2 micrograms per cubic meter.

Gresham fared better in its 2022 average, with an average of 8.5 micrograms per cubic meter.

Clackamas and Milwaukie were the two communities in the Portland metro area that fared the worst in 2022 average air quality as reported by IQAir, with 11.8 and 11.7, respectively. That represents a yellow annual average, which IQAir defines as being two or three times the recommended value, based on WHO guidelines.

On the Washington County side, Aloha was the only community to receive a yellow annual average, recording a 11-micrograms-per-cubic meter PM 2.5 rating.

Beaverton, Hillsboro and Tigard were in the green, with annual averages of 9, 9.7 and 9.7, respectively.

Important to note, however, is that even green readings in IQAir’s report card are considered higher than the World Health Organization’s recommended annual levels.

The WHO sets the standard at an annual average of just 5 micrograms per cubic meter.

The daily guideline states that PM 2.5 is unhealthy if it is over 15 micrograms.

The West Haven-Sylvan area went from being the only metro area community recording a blue level — within recommended levels of PM 2.5 pollution — to having a dip down to the green level with an 8.5-microgram annual average in 2022.

Some of the loss of progress in 2022 can be attributed to abnormally low readings for 2021, which saw significant dips in air pollution as a result of the COVID-19 pandemic. For most of that year, community shutdowns and overall reduced travel meant fewer pollutants in the air than in a typical year, while northwest Oregon saw far less wildfire smoke than it did in 2020.

“We were, just through behavior, able to affect air pollution,” said Glory Dolphin, chief executive of IQAir North America. “Our air quality dramatically improved … so it really just shows that we are the cause of air pollution.”

Health impacts

The WHO, the U.S. Environmental Protection Agency and the American Lung Association all agree that exposure to even moderate levels of air pollution can lead to serious health impacts.

The particulate pollution tracked is called PM 2.5 because it represents particles that are smaller than 2.5 microns in diameter.

To put that in perspective, the IQAir report contains a graphic showing how these particles compare to a strand of human hair, which is 50 to 180 microns in diameter. Even respiratory droplets found in our lungs are bigger than the particles being tracked, ranging from 5 to 10 microns in diameter.

As such, tiny particles can easily penetrate the body’s cells, and when inhaled into the lungs, these particles are delivered quickly into the system.

The report notes that the result is increased risk of heart and lung disease; high blood pressure; increased risk of asthma; irritation of the eyes, nose and throat; and even increased depression and anxiety.

In short, inhaling pollution leads to lower lifespans.

Experts are pushing for regulatory agencies to update their messaging to the public about what is considered an acceptable level of PM 2.5 or overall AQI.

In the U.S., the AQI chart bases unhealthy readings at lower levels — yellow, orange and red — mostly around the health impacts to sensitive groups, like the elderly and those with existing lung conditions.

But new studies show that even at “healthier” levels of PM 2.5, otherwise healthy people are actually still seeing health impacts.

“If you look at what is considered ‘good’ air quality … if you were to average that out over a year, it would be unhealthy according to the WHO standard,” Dolphin said.

Better tracking

Governments and nonprofits are prioritizing more investments in up-to-date air quality measurements and reporting, so people can adjust their behavior in real time.

The WHO updated its PM 2.5 guidelines in 2021, on which this latest IQAir report is based.

In the United States, the EPA is also undertaking an effort to overhaul its guidelines and alter public messaging around air pollution, the 2022 report card notes.

The Inflation Reduction Act, passed by Congress in July 2022, also sets aside millions for the EPA to make new investment in air quality monitoring and reporting.

During days where the AQI is at higher than recommended levels, experts recommend limiting time spent outdoors and wearing approved masks — those rated N95, KN95 or FFP2 — if you need to be outside.

You can track AQI readings through the website or through IQAir.

Troy Shinn, a reporter for The Portland Tribune, can be reached at [email protected]. This article is used with permission of Pamplin Media Group. Read more from Oregon’s largest source of independent local news at