Air quality in the Los Angeles region has plummeted due to smoke from the ongoing wildfires. With all that smoke comes possible risks to human health. So what actually is smoke and why is it so harmful? Jessica Gilman, an atmospheric chemist with the National Oceanic and Atmospheric Administration, explains what smoke is made of, how it behaves in the atmosphere and smoke's role in climate change. Plus, tips for how to lessen your exposure. Check out the CDC's recommendations for avoiding smoke inhalation here. Read more of NPR's coverage of the fires.Questions, story ideas or want us to dig more into the science underpinning natural disasters? Email us at shortwave@npr.org — we'd love to hear from you!Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy