PORTLAND, Ore. (KOIN) – The number of unhealthy air quality days in Oregon due to wildfire smoke continues to grow, according to the recently published Wildfire Smoke Trends and the Air Quality Index report by the Oregon Department of Environmental Quality. 

The annual report summarizes the state’s air quality monitoring during fire seasons. This latest report covers air quality during the 2022 wildfire season.

According to the new report, Southern and Central Oregon have been experiencing the most significant impacts of worsening air quality due to wildfire smoke. 

Oakridge in Lane County had 27 days where the air quality was considered either unhealthy for sensitive groups or hazardous in 2022. That’s more than it’s ever had and more than anywhere else in the state in 2022. 

Air quality that’s unhealthy for sensitive groups means that people with heart or lung disease may experience symptoms. Older adults, pregnant women and children are also most at risk of respiratory symptoms.

Another example of worsening air quality can be seen in Bend where from 1989 to 2016, the city only had 10 days where the air quality was considered unhealthy for sensitive groups due to wildfire smoke. From 2017 to 2022, that number jumped to 58 days. 

At unhealthy air quality levels, everyone may begin to experience health effects.

Bend also reached hazardous AQI levels for the first time in 2020 when it recorded six days of air quality at this harmful level. 

Hazardous air quality means the entire population is more likely to be affected.

Before 2015 in Portland, the city had never had a single day with air quality that was at or worse than a level that qualified as being unhealthy for sensitive groups. Air quality monitoring began in 1985. 

From 2015 to 2022, Portland had 26 days where the air quality was unhealthy for sensitive groups. In 2020, Portland had its first day when the AQI reached the unhealthy level; it recorded three unhealthy days and five hazardous days. In 2022, the city had three days where the AQI was unhealthy for sensitive groups. 

The air quality index measures particulate matter, or PM2.5, which are tiny particles or droplets in the air that are two and a half microns or less in width. Particulate matter this small is especially dangerous because it can be inhaled deeply into the lungs and some of it might even reach the bloodstream, according to the Oregon Health Authority. 

Wildfire smoke emits several pollutants that are measured as particulate matter, including black carbon, nitrogen dioxide, carbon monoxide, volatile organic compounds, polycyclic aromatic hydrocarbons and metals. 

The AQI is considered unhealthy for sensitive groups when the PM2.5 measures between 35.5 and 55.4. 

Unhealthy AQI is when the PM2.5 is between 55.5 and 150.4. 

Very unhealthy AQI has PM2.5 that ranges from 150.5 to 250.4. 

Hazardous AQI is when the PM2.5 is greater than 250.5. 

After comparing the average number of days when the AQI level was at or above unhealthy for sensitive groups from 2003-2012 to 2013-2022, the Oregon DEQ found that wildfire smoke impacts are increasing across the state. The most significant impacts from fires are in Southern Oregon. 

“The data shows that AQI categories from wildfire smoke have been increasing starting around 2012, with more frequent days at more ‘unhealthy’ or worse levels, including the record-breaking events of September 2020. If these trends continue, Oregon should expect to see an increasing number of days with an AQI ≥ [unhealthy for sensitive groups] during the summer,” the Oregon DEQ wrote in the conclusion of its report. 

Researchers predict these increasing number of days with unhealthy air quality won’t just impact Southern Oregon, but the entire state, including places like the north coast area, the Willamette Valley and the Portland metro area. 

In recent years, fires in Pacific Northwest forests have become more massive and burned more acres, according to the National Interagency Fire Center. 

Historically, Oregon’s wildfire season started in late July and continued into early September. However, more recently, fires have been starting in mid-July and lasting until early October.