MARY LOUISE KELLY, HOST:
Right now in Your Health, we'll examine a different natural phenomenon that's engulfing the northwest of the country. That would be forest fires. It's an unusually bad wildfire season, and for weeks people have been breathing in air thick with smoke. NPR's Jane Greenhalgh reports from Portland, Ore.
JANE GREENHALGH, BYLINE: A thick, smoky haze descended across the city last week, the result of a huge forest fire that's burning a few miles away in the Columbia Gorge. It sent a cloud of ash over the entire region.
TUCKER MACLARAN: My lungs have been really sore. It's hard to breathe. It smells like we're in a campfire. (Laughter).
GREENHALGH: Tucker Maclaran is biking on the city's waterfront. She's wearing a face mask.
MACLARAN: It's hot and sticky, and really chemical-y (ph) and gross.
GREENHALGH: But is her mask doing any good?
UNIDENTIFIED MAN: Step all the way inside. Move all the way forward.
GREENHALGH: To get the answer to that and some other health questions, I'm taking Portland's sky tram...
UNIDENTIFIED MAN: You can move up a little bit up, please.
GREENHALGH: ...Up to Oregon Health and Science University. It's perched on the top of a hill.
GOPAL ALLADA: My name is Gopal Allada. I'm a pulmonary and critical care physician.
GREENHALGH: So basically, lungs are your specialty.
ALLADA: Lungs are my specialty.
GREENHALGH: From the top of the tram, the problem is obvious.
ALLADA: This haze represents a lot of ambient smoke particles and particulate that's just hitting our lungs, hitting our nose and causing problems.
GREENHALGH: Burning eyes, sore throat, headaches, even a little nausea. According to Oregon's Department of Environmental Quality, there's no good air anywhere in the Pacific Northwest, and conditions are similar in parts of Idaho, California and Montana. Allada says the biggest hazard to our lungs is not the ash, but tiny, microscopic particles.
ALLADA: Larger particles actually tend to get lodged in your nose, in your throat and can cause irritating symptoms but won't cause the respiratory symptoms that the fine particulate matter can.
GREENHALGH: For most healthy people, these conditions are unpleasant, but for people with heart conditions or respiratory illnesses it can be a real problem. The elderly, children whose lungs are still developing also need to be extra careful, as do pregnant women. Which means, if you can, stay inside.
ALLADA: Close all windows and doors unless it's really hot, and using the recirculate air button on your - either your car or on your air conditioner so that you're not continually bringing in new particulate matter.
GREENHALGH: Paper masks don't do much good. An N95 mask will offer some protection, but only if it's properly fitted. But if you're worried about long-term damage, Dr. Ann Thomas of the Oregon Health Authority says most people shouldn't be.
ANN THOMAS: I don't want to downplay the significance of the symptoms that many of us are feeling, but the good news is that they do go away. They'll resolve quickly even if it is something that persists for, you know, days to weeks, unless you're in one of these - these high-risk groups.
GREENHALGH: If you are high-risk, you might want to buy a high-efficiency particulate air filter, avoid burning candles, frying meat, even vacuuming, which can add more tiny particles to the air. Jane Greenhalgh, NPR News, Portland.