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5-3-1 Visibility Chart Helps Determine Air Quality

Oregon Department of Environmental Quality (DEQ) monitors air pollution throughout the state to ensure that air quality standards are being met. Since wildfires often occur in remote areas, air monitoring equipment may not be available. Smoke levels can rise and fall rapidly, depending on weather factors including wind direction. Making visual observations is a simple way of estimating smoke levels and what precautions to take. While this method can be a useful tool, persons should always use caution and avoid going outside if visibility is limited, especially persons who may be sensitive to smoke.

Wondering what the quality of air is?  Use the chart below to estimate air quality in your area.

5-3-1 Visibility Guide to Smoke and Air Quality*

If You Are:
Or You Have:
AQI Category (24-hr average PM2.5 in ug/m3
Visibility Index
(How far
you can see)
*An Adult
*A Teenager
*An Older Child
*Age 65 or older
* Pregnant
*A Young Child
* Asthma
* Respiratory Illness
*Lung or Heart Disease
(0-12 ug/m3)
over 15 miles
Air quality is generally good
(13-35 ug/m3)
5 – 15 miles
Air quality is moderate.  Avoid prolonged exposure to smoke where visibility is closer to 5 mile range.
These smoke sensitive persons may begin to notice deterioration of air quality and should minimize outdoor activity.
Unhealthy for Sensitive Groups
(36-55 ug/m3)
3 – 5 miles
Avoid prolonged exposure to smoke.
Unhealthy air quality.  Minimize exposure by staying inside where air is cleaner
(56-150 ug/m3)
1 – 3 miles
Unhealthy air quality.  Minimize exposure by staying inside where air is cleaner
Avoid all outdoor activity – stay inside where air quality is clean.
Very Unhealthy
(151-250 ug/m3)
1 – 3 miles
(>251 ug/m3)
Less than 1 mile
Everyone should avoid all outdoor activities.  Relief from heavy smoke conditions is best accomplished by leaving for cleaner air. 
No matter how far you can see, if you feel like you are having health effects from smoke exposure, take extra care to stay inside or get to an area with better air quality.  You should also see your doctor or other health professional as needed.

* adapted from Oregon Wildfire Response Protocol for Severe Smoke Episodes, version 2.0, June 3, 2014