Oregon Health Authority is publishing updated guidance to help families and youth-serving organizations, such as schools and athletic leagues, make decisions about participation in outdoor activities during wildfire smoke and other air pollution events.

The update to the Oregon Air Quality Guide for Children and Youth reflects the increasing scientific evidence that smoke can harm the health of children at lower levels of exposure than previously thought. All children and youth 18 and younger are considered a population sensitive to smoke. Particles in the air measuring less than 2.5 microns, known as PM2.5, can penetrate deep into the lungs and travel through the bloodstream, causing damage throughout the body.

“We fully recognize the importance of outdoor time and exercise for the physical and mental health of children and youth,” said Gabriela Goldfarb, manager of the Environmental Public Health Section at OHA’s Public Health Division. “We offer this guide to support adults making decisions that balance those needs with the reality that children are more likely to be affected by health threats from smoke, because their airways are still developing and because they breathe more air per pound of body weight than adults.”

The guide relies on the familiar air quality index (AQI). PM2.5 is one of the key pollutants tracked by the AQI. AQI categories range from “Good” through “Hazardous” using colors and numbers to communicate risk. The main changes from OHA’s previous guide are:

At Moderate AQI (yellow, AQI 51-100), the updated guide encourages caution for youth with health conditions during short and medium duration activities, and all youth during activities lasting four or more hours. The prior guide stated, “It’s a good day to be active outside” for short duration activities.
At Unhealthy for Sensitive Groups (orange, AQI 101-150), OHA recommends limiting activity intensity for all youth at any activity duration and considering canceling or moving the event if intensity and length of the activity can’t be changed. The previous guide focused on the most sensitive youth with underlying health conditions.
Unhealthy, Very Unhealthy, or Hazardous (red, purple and maroon, any AQI above 150) now has the same guidance at any activity duration: Cancel outdoor activities or move to an area with safer air quality for all children and youth. Previously, that level of health protection was reserved for Very unhealthy or Hazardous at any activity duration.
OHA removed “Infants” from the title of the guide. The guide still applies to everyone under 18, but most of the guide is designed for kids who are over 2 years of age.
Medium length activity duration changed to one to four hours, instead of one to two hours.
The guide emphasizes that exposure can occur during transit, such as walking to school or riding on buses with open windows and advises decision makers to consider total exposure over a day when estimating duration of exposure, if possible.

Source: Oregon Health Authority