BEND, Ore. -

Wildfires sent thick smoke streaming across northern areas of the High Desert Friday, sending DEQ air pollution readings soaring to "hazardous" levels in Madras and "very unhealthy" in Prineville late in the day.

Here's a DEQ release issued earlier in the day

People in Deschutes, Jefferson, Crook, Wheeler, Grant and Harney counties should protect themselves from poor air quality caused by potential smoke from ongoing wildfires, the Oregon Oregon Department of Environmental Quality said Friday.

This week, the DEQ has recorded elevated fine particulate levels from monitors located in Burns, John Day, Bend, Madras, Prineville and Sisters.

DEQ urges residents and people visiting Deschutes, Jefferson, Crook, Wheeler, Grant and Harney Counties to take the following precautions:

-- Be aware of smoke concentrations in your area and avoid the places with highest concentrations.

--Avoid smoke either by leaving the area or protecting yourself by staying indoors, and by closing windows and doors

--Avoid strenuous outdoor activity in smoky conditions.

--People exposed to smoky conditions and who suffer from asthma or other respiratory problems should follow their breathing management plans or contact their healthcare providers.

Monitoring locations are limited and pollution levels may be higher in some areas, especially those closer to a wildfire.

People can conduct a visual assessment of nearby smoke to quickly get a sense of air quality levels.

Generally, if you can see up to 15 miles, the air quality is probably good. If you can see less than one mile, the air quality is very unhealthy and everyone should avoid outdoor activities.

Refer to the descriptions below for more information based on how far you can see in various conditions:

Between 5-15 miles: Air quality is moderate and beginning to deteriorate, and is generally healthy, except possibly for smoke sensitive persons. The general public should avoid prolonged exposure if conditions are smoky to the point where visibility is closer to the 5 mile range.

If under 5 miles: The air quality is unhealthy for young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness. These people should minimize outdoor activity.

If under 3 miles: The air quality is unhealthy for everyone. Young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness should avoid all outdoor activities.

If under 1 mile: The air quality is very unhealthy, and in some cases may be hazardous. Everyone should avoid all outdoor activities.

For more information on using the visibility index during wildfires, visit http://www.deq.state.or.us/aq/burning/wildfires/visibility.htm.

For information on smoke and wildfires in Oregon, visit http://oregonsmoke.blogspot.com/.