STEVE INSKEEP, HOST:
Good morning. I'm Steve Inkseep. Before yesterday's Beijing marathon, organizers described air quality in China's capital as slight to moderate smog. Competitors thought differently. They called it post-apocalyptic, really dense, almost surreal, like running on Mars. Smog levels were 12 times above what is considered safe, but organizers refused to cancel. Instead, they handed out sponges to clean skin that's been exposed to smog and many runners wore gas masks. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.