“But what about glass?”

Will the barefoot runner who has ever sliced his or her foot on a piece of glass please stand up? If you’re able, of course. Because I’d love to meet you, mysterious and mythical stranger that you are. Anyone who runs without shoes is constantly asked about All That Dangerous Glass Out There! Take this comment from Kevin Kirby, the angry podiatrist who pops up  whenever natural-style running is discussed.

KEVIN KIRBY I have no problem with people who occasionally run barefoot on a safe surface as a supplement to their normal training. But in today’s society, we don’t have a lot of grassy fields. We have a lot more asphalt, concrete, glass, and nails. So I worry that barefoot running is going to produce injuries, such as puncture wounds, infections, and even lacerations of vital structures at the bottom of the foot. I would hate to see someone who wouldn’t get injured in shoes go out barefoot running and get a serious injury.

But I’ve never heard from any barefoot runners, ever, who have cut themselves. One reason, of course, is that by keeping your stride short and feet under your hips, it’s easy to dodge around any debris in your path.

And there’s an even simpler explanation. All That Dangerous Glass Out There… ain’t out there. According to this nationwide study of America’s litter (caution, it’s a slow-loading PDF), our streets are pretty darn pristine, at least when it comes to sharp stuff. Overall, litter is down by 61% since 1969. Glass has decreased by a whopping 86.4 percent. In fact, glass makes up only 4.5% of all street litter.

So what is out there? Soft stuff, mostly. Cigarette butts (37.7%), paper (21.9%), plastic (19.3%), and my favorite category: “organic” (4.2%), which I’m guessing is survey-speak for dog dumpers. Which means that even if you wanted to cut your foot or step in Marley’s final steaming pile, you’d need a serious masochistic streak and the eyes of a hawk just to find something to do the job.