Wildfires have broken out across the Western U.S. this week, many of them triggered by lightning strikes in heat-dried vegetation, and tens of thousands of people have been forced to evacuate. Living in the smoke downwind from one can be eerie. The sky casts a yellow-orange glow on everything, and when the wind blows, flecks of ash glitter in the air like dirty snow.

Watching the haze from wildfires raging a few miles from where I live in California, I wondered: What’s actually in that smoke and ash, and how hazardous is it? I tracked down Luke Montrose, an environmental toxicologist at Boise State University, to explain the hazards of wildfire smoke, what it can do to your lungs and how to protect your health.

Also today:

Stacy Morford

General Assignments Editor

The health impact of wildfire exposure depends in part on the fire itself and how much smoke a person breathes in, how often and for how long. AP Photos/Noah Berger

What’s in that wildfire smoke, and why is it so bad for your lungs?

Luke Montrose, Boise State University

Wildfires blanketing several Western cities are creating hazardous health conditions. Don't count on cloth masks to protect your lungs.

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