Thousands of residents in a part of southwestern Oregon—including La Pine—have been advised to stay indoors as elevated levels of fine particle pollution (PM2.5) have reached an “unhealthy” level, as of Tuesday February 3, at 4:45 a.m., according to the Environmental Protection Agency’s (EPA) AirNow Map, which monitors and communicates air quality across America. 

What Should Residents Do When Air Quality Is ‘Unhealthy’? 

The EPA advises that, when the air quality reaches “unhealthy” levels, everyone should take steps to reduce their exposure, especially those in vulnerable groups, which include the elderly, children, and those with existing heart and lung conditions. The EPA says that people in these groups should “avoid long or intense outdoor activities. Consider rescheduling or moving activities indoors.” 

Everyone else should try to reduce the length and intensity of outdoor activities and take more breaks. 

The EPA advises people in affected areas to monitor the AirNow Map for further updates, as conditions can often change rapidly. 

What Is PM2.5 & Where Does It Come From?

Fine particle pollution, otherwise known as PM2.5, is tiny particles of pollution that are each 2.5 micrometers or smaller in size, which is smaller than one strand of hair.

The EPA hasn’t confirmed what is causing the elevated levels of PM2.5 across a part of Oregon on Tuesday, but PM2.5 can come from a variety of sources, including smoke from wildfires and smokestacks, emissions from vehicles or power and industrial plants, and dust from construction sites and unpaved roads. 

Why Are High Levels of PM2.5 Considered ‘Unhealthy’?

The EPA considers PM2.5 to be one of the most dangerous types of air pollution because the partilces or so small they can be unknowingly inhaled, penetrating deep into the lungs and bloodstream, potentially worsening existing health conditions–like asthma—or triggering symptoms ranging from coughing, eyes, throat, and nose irritation to chest tightness and shortness of breath. 

How Does the EPA Measure PM2.5? 

The EPA uses the Air Quality Index (AQI) to report the air quality across America. The AQI is a standardized system that color-codes and categorizes air quality on a scale from “Good” to “Hazardous” based on the level of pollutants—including PM2.5—in the atmosphere: 

Green: If the score is between 0 and 50, the air quality is considered to be “good,” meaning there is little or no health risk to the public.Yellow: If the score is between 51 and100, the air quality is classified as “moderate,” which means the air is acceptable, but some pollutants may pose a minor risk for people who are unusually sensitive.Orange: If the score is between 101–150, the quality of air is “unhealthy for sensitive groups, meaning people with existing health conditions, older adults, children, and teens may experience health effects, but the general public is less likely to be affected.Red: If the score is between 151 and 200, the air quality is “unhealthy,” which means everyone may begin to experience health effects, and sensitive groups may experience more serious effects.Purple: If the score is between 201 and 300, the air is considered to be “very unhealthy” and a health alert is issued as there is an increased likelihood of serious health effects for everyone.Maroon: If the score is between 301+, the air is “hazardous” and health warnings of emergency conditions are immediately issued as the entire population is likely to be affected.