An NPR analysis of a key air pollutant showed levels have not changed dramatically since the pandemic curbed car traffic in the U.S. NPR science reporter Rebecca Hersher )and NPR climate correspondent Lauren Sommer) explain why — and what really makes our air dirty. Here's their story).Email the show at [email protected]).Learn more about sponsor message choices: podcastchoices.com/adchoices)NPR Privacy Policy)
