DAVID GREENE, HOST:
As we've been reporting, there are dangerous wildfires burning across the American West. This week, three firefighters were killed in Washington state. Thousands of people have had to evacuate their homes. And then there is the smoke. Rose Olcott lives in Chelan in north-central Washington state. And she says people there are trying to keep the heavy, sometimes black, smoke out of their lungs and also away from their children.
ROSE OLCOTT: It's like going into a very thick fog. There are a lot of places that are now issuing respirator masks because it is something that you don't want to walk outside into. So we are going to be staying inside quite a bit the next few days.
GREENE: And the smoke is spreading. Mark Raminksi (ph) tracks fires and the smoke for the National Oceanic and Atmospheric Administration.
MARK KAMINSKI: It would be an understatement to say that there's a lot of smoke. It pretty much covers most of the western third of the U.S. So northern California, Nevada, Washington, Oregon, Idaho, Montana, Wyoming - even though there's not many fires burning in Wyoming. The smoke has drifted that far east.
GREENE: And we learned this from Raminski (ph) as well. Smoke is not just moving across the United States.
KAMINSKI: Depending on how high the smoke gets into the atmosphere, then it can go transcontinental. We routinely see smoke from fires that are burning in Siberia come across the Pacific and across the U.S. because they get lofted so high. And once the smoke gets up into the atmosphere, it can stay there for a very long time.
GREENE: Now national firefighting officials are telling us there are 74 large active fires in eight Western states. For the first time in nearly a decade, active duty U.S. troops have been called in to help, along with experts from Canada, Australia and also New Zealand. Transcript provided by NPR, Copyright NPR.