There are a billion bacterial cells per gram of soil.
Ah, friends. They're like family but cooler. Fully customizable. Fall and one of them will be right there to pick you back up. But as great as friends can be, they also do a lot of really stupid stuff. Stuff that blows your mind. Like, sometimes it seems crazy that you even hang out with people who make such crappy decisions. Stuff that, were it to get out, would be mortifying for anyone with even a shred of self-respect. Lucky for your friends, they've got you to ask their deepest, darkest questions for them. And lucky for you, we started this column to answer those most embarrassing inquiries.
Your friend is a good dad: He spends plenty of quality time with his kid, lets her watch Moana for the 4,000th time without complaint, and makes sure she's not an asshole to other people. But even when he's playing with her outside in the yard, he doesn't keep his eyes on her 100 percent of the time—and sometimes when his back is turned (or his eyes are on Facebook), his kid manages to shove some dirt in her mouth. Before he can rush over and pull her away from her all-natural snack, she's inevitably swallowed a handful or two.
Naturally, he's worried. After all, can't she contract some brain-eating amoeba? Aren't there harmful bacteria and viruses lurking around? What if the dog shat in the yard and his toddler accidentally ingested some dog poop? At what point should he admit a parenting fail and take her to the hospital? Dirt, especially outside dirt, can be questionable, and who knows what dangers are lurking in your backyard soil.
The Worst That Can Happen
The biggest issue with eating dirt isn't the soil itself, but what it could possibly be contaminated with. If the dirt is near an old house painted with lead paint, for example, then she could potentially swallow some of that toxic lead. But the actual danger comes from chronic exposure, says Jack Gilbert, faculty director of the Microbiome Center at the University of Chicago and author of Dirt is Good: The Advantage of Germs for Your Child's Developing Immune System. Meaning it would only be a health issue if she consumed a lot of it over a period of time. Lead poisoning symptoms include irritability, abdominal pain, vomiting, and seizures, and could result in developmental delay and learning difficulties.
Another problem would be if a bunch of pesticides were sprayed on the soil, which could cause acute poisoning and damage to internal organs if ingested. Symptoms of toxic poisoning include vomiting blood and losing consciousness. If you suspect your child ate something that was contaminated with pesticides or other toxic waste, then seek medical attention immediately.
Even if your kid accidentally eats some dog poop along with that dirt, it's generally harmless, Gilbert says. Unless the dog has some kind of parasite in its feces, in which case she could develop GI issues like stomach pain, fever, and diarrhea, your child is probably fine. Just keep an eye on her to make sure she doesn't develop those negative physical symptoms—if she does, take her to the emergency room ASAP.
What Will Actually Happen
Turns out, eating dirt is almost always completely harmless. "Dirt and soil generally aren't dangerous," Gilbert explains. "There are a billion bacterial cells per gram of dirt, but none of those organisms, or very, very few of them, unless your child is immunocompromised or has a lot of open wounds or sores in their mouth, is going to cause any problem."
And not just harmless, but could actually be beneficial for the kid's overall health. As a small child's immune system is growing, being exposed to everyday benign microbes like what's found in dirt and pet dander will help strengthen a kid's immune system, Gilbert says. His research has shown that kids who don't have as much microbial exposure little have a greater likelihood to develop inflammation such as food allergies, eczema, or asthma.
What You Should Tell Your Friend
"If you're near an industrial wasteland, don't eat all the dirt off the ground. If you're next to a hospital waste pit, don't do it. If you're next to the sewage pipeline, don't do it," Gilbert explains. "But generally if you're out in the bush and as long as you're not eating a bunch of dirt where an animal just crapped, then you're probably fine."
So unless your friend lives next door to a nuclear power plant or has a bunch of feral dogs running around the yard, his kid is probably find munching on some dirt. The other thing Gilbert notes is that since dirt itself doesn't taste very good, kids aren't likely to ingest much of it anyway. Just wash her hands and mouth—sooner or later, she'll figure out it's a better idea to wait for the fruit snacks.
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