Should I Give a Crumb About Crumb Rubber?
#EcoAdvice from our expert
Dear Dr. Donley,
The playground near our house just replaced the wood mulch with what looks like small chunks of rubber under all the play equipment. I’m not exactly sure what this stuff is and am wondering if it’s safe for my kids?
Signed,
Rubber Chicken
Rubber and children should go together like peas in a pod. In fact, when I find myself awake at 6 a.m. watching my toddler awkwardly knock into every obstacle as he races toward the stairs, I often fantasize about having an entire room made of rubber, where he could bounce off the walls while I sawed logs on the couch. But until RubberRoom™ becomes a thing, I have to settle with following this madman around the house while he tries to harm himself in the craziest and — to give credit where credit is due — most creative ways possible.
But you didn’t ask to hear the half-baked inventions of a sleep-deprived brain. You want to know whether tossing a bunch of old tires in a wood chipper and having your children play on the resulting carnage is safe. For those who aren’t in the know, many schools and municipalities have switched to using crumb rubber as a play surface instead of good ol’ fashioned wood chips from the days of yore.
Crumb rubber can exist as tiny granules the size of a pinhead that are laid down in a sheet like asphalt, or as larger chunks that are sometimes dyed to resemble wood chips. It also forms the underlayer for most types of artificial turfs, to give them added cushioning. What all crumb rubber has in common is that it’s made from old, discarded automotive tires.
Chances are you’re a stones-throw away from a playground that uses it. In the United States alone, 14 million discarded tires are ground up and spread over children’s playgrounds each year — double that if you include sports surfaces like athletic fields and tracks. It’s estimated that roughly 4 million children in this country run, skip and tumble on toxic tire waste that many states won’t even allow in their landfills.
Tires are generally made of a mix of natural rubber and synthetic rubber made from plastics. About 30 percent of a tire consists of carbon black, which is similar to the soot that lines the inside of your fireplace. The rest is vulcanizing agents, manufacturing byproducts, fillers and heavy metals. It’s a laundry list of names no one can pronounce, and there’s no need to. The only thing that matters is that many have been associated with disease in people and can really harm the environment.
The simple act of manufacturing rubber is recognized by the World Health Organization’s cancer research agency as “Carcinogenic to Humans,” the most conclusive designation it has. It’s even advised that workers wear respirators when laying crumb rubber — though I can’t recall signs posted at any playground I’ve visited urging kids to don dust masks to climb the jungle gym.
Exposure to the dust that’s formed when these tire fragments slowly break down and are kicked up during play is concerning, as is the off-gassing of many of the volatile compounds when the playground is exposed to high temperatures on a hot, sunny summer day. A child or athlete running around and playing on playgrounds or athletic fields is going to be breathing rapidly and taking in a lot more of these contaminants than the average person out on a leisurely stroll. And just because you’d never stuff your mouth full of rubber granules doesn’t mean your toddler may not be a little curious (in the words of the late Rutger Hauer, “I’ve seen things you people wouldn’t believe”).
After it rains, the particles that slough off from tires can make their way into nearby rivers and streams. There they have been associated with serious environmental harms, like fish mortality.
Basically, athletic fields and playgrounds are terrible places to throw our garbage. Wanting to divert tires from garbage heaps is a worthy cause. They provide breeding grounds for mosquitos, and tire fires don’t just happen in the Simpsons — they happen in the real world, and it’s absolutely devastating when they do.
But crumb rubber is a solution in search of a problem. Engineered wood fiber (think wood chips that won’t give you splinters and can be compacted to provide good cushioning and wheelchair accessibility) and pesticide-free fields work just fine and are so much better in just about every way. There are other ways to recycle tires — and with the United States tossing out nearly 300 million of them every year, it’s something we have to do — but the only real path forward is to reduce the amount of waste we produce in the first place.
If your school or local playground keeps it real (literally), then it’s worth a call or letter thanking them for using natural materials and imploring them to keep it that way. Otherwise, some good tips are to make sure your child washes her or his hands after playing on a crumb-rubber playground, takes off shoes before coming inside, and limits activity when the sun’s beating down and the temperature’s high.
Wheel-y hope this helps.
Stay wild.
Dr. Donley
Dr. Nathan Donley is a scientist at the Center for Biological Diversity who answers questions about how environmental toxins affect people, wildlife and the environment. Send him your questions at AskDrDonley@biologicaldiversity.org
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