Can Mud Runs Make Me Sick?

My mom always said to stay inside during dust storms because the dirt could make me sick. Can racing a muddy, dusty event make me ill?


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If you or your mom have been poking around the Internet, you might’ve found stories like this one about kids in Louisiana contracting E. coli after playing in a mud pit. Or this one about a deadly soil-based bacteria that can get stirred up after heavy rains. Or this one about a few hundred people who got nasty rashes after hanging out in the mud at a festival. It’s enough to make you question your choice of weekend activities.

However, we posed your query to Dr. Gerald Callahan, an immunology professor at Colorado State University and author of this great big article on eating dirt published in the Emerging Infectious Disease Journal in 2003. He said not to worry too much about getting dirty.

“If the mud was set up outside a toxic waste dump, then I would be concerned,” he says. “Otherwise it poses the same risks you expose yourself to by going swimming in untreated water.” And many of those risks, including E. coli and skin infections, come from fecal contamination, which one would hope is not going to be an issue at your event.

“If you’ve got a functional immune system and your skin’s intact, for the most part you’re going to be okay,” says Callahan, who’s actually a fan of the dirt. “Regular exposure of our immune systems to pathogens—bacteria especially—seems to keep our immune systems stronger and healthier,” he says. The only thing that would keep him from doing a mud run isn’t the exposure to mud, it’s the scary obstacles, like jumping over fire.

Also in your favor: the fact that you’re racing in the U.S. “We don’t have a number of the water-borne parasites and bacteria that they do in tropical regions of the world,” Callahan says, that cause illnesses like cholera. In the American Southwest, there is always a risk of getting Valley Fever from breathing in a fungus found in the soil there. If you grew up in the desert, that’s likely why your mom made you stay inside during dust storms.

A few more suggestions to avoid any post-race problems: Don’t chug the mud, and don’t hang out in it longer than necessary. Researchers who looked into some nasty skin infections (pustular follicular dermatitis, to be exact) that students in Seattle contracted after wrestling each other in fecally contaminated mud found that the more time students spent in tainted mud, the higher their risk for developing a skin infection. And that risk goes up even more if you have any cuts or scrapes, so if you snag yourself on barbed wire, make sure to clean out your cut ASAP.

And if you’re truly concerned about what might be lurking in the dirt, run in the first wave of your race before thousands of other bodies plunge into the muck and kick up the dirt around you.

THE BOTTOM LINE: Yes, hanging out in the mud can make you ill, but if you don’t have any cuts and your immune system is strong, you generally shouldn’t worry too much about getting sick. Exposure to dirt can actually help strengthen your immune system.  

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