Originally published 4 December 1995
I’m tired of hearing about the Blue Planet.
We are often reminded that 70 percent of the Earth’s surface is covered with water, as if that makes it beautiful, as if we had something to hide. I mean, you can’t even drink the stuff. And it’s full of sharks. The Blue Planet is fine if you’re a fish.
I’m here to extol the Brown Planet, the 30 percent of the Earth that is covered with dirt.
“The Lord God formed man of the dust of the ground,” says the Bible, echoing many ancient creation myths. We’re made of dirt. We may wash our vegetables before we eat them, but the veggies themselves are just recycled dirt, occasionally recycled again through a chicken or cow before we get it. Where do our atoms come from if not from the soil?
I’ve been watching my grandchildren playing in the sandbox, stuffing sand in their mouths. Kids are drawn to dirt like fish to water. It’s in the blood. We are born with geophilia, the “love of dirt.”
For a child, the best days are those that leave the thickest ring around the tub. Dirty clothes are badges of bliss. When I was a kid our back yard was one great expanse of bare dirt, perfect for play with toy cars and toy soldiers. We were as happy as pigs in a wallow. Then my Dad had the back yard sodded. Whatever grass is good for, it’s not good for kids.
My mother used to fret about our playing in dirt. She was worried about tetanus bacilli, which can enter the body through the gastrointestinal tract. “Not to worry,” my father reassured her. “Half the people in the world eat dirt. A little dirt never hurt anyone.”
My Dad exaggerated, as usual, but he was right about people eating dirt. There’s even a scientific word for it: geophagy. Apparently, geophagy has been practiced for centuries, maybe forever. Plato observed pregnant women eating dirt. Boys in the medieval ages where whipped to break them of the habit. In the 17th century, Spanish noblewomen ate so much dirt the authorities passed laws making the practice illegal. Geophagy has been recorded in every part of the world and in every class of people. Apes do it too, which suggests that the habit might be deeply embedded in our nature.
Kids eat dirt whether we want them to or not, either deliberately or by putting dirty fingers into their mouths. My spouse and I never worried overly much about this when our own kids were young, thinking, without any good scientific reason, that a little dirt might confer resistance to childhood illness.
Ramon Barnes, a chemist at the University of Massachusetts, set out to find out just how much dirt children eat. I will forego describing his experimental procedures, which involved inspecting soiled diapers at the end of the day. Suffice it to say that the average amount of soil ingested was 25 milligrams a day, which is only a few modest spoonfuls a year. However, one child in the study consumed 6 grams of non-food material per day, which can soon add up to a bucketful.
I’m not sure what, if anything, all of this means. A lot more science needs to be done before we know the causes and effects of geophagy. Cultural tradition, hunger, dietary deficiency, parasitical infection, and pregnancy have all been suggested as causes of the dirt-eating habit. In the case of young children, putting the closest available thing into the mouth is as natural as breathing — and the closest thing is often dirt.
A few years ago, the Binney & Smith company introduced Magic Scent Crayolas, with aromas such as chocolate, licorice, cherry, and blueberry. Parents complained that the foody scents might entice the kids to eat their crayons. So the crayon-makers changed to non-food scents, such as dirt, smoke, leather, and lumber, forgetting, apparently, that dirt is one of the things kids are most likely to put in their mouths. In announcing the change, a spokesperson for Crayola got one thing right, however: “Kids love dirt,” she said.
Kids love dirt, indeed. Against the wishes of fastidious parents and the conventions of civilization, kids love to get dirty. Non-dirt floors are a rather recent development in human history; all those millions of years that our soapless ancestors sat in the dirt eating unwashed food with unwashed hands may have left their mark. It is probably worth noting that “human” and “humus” come from the same ancient Indo-European root, dhghem, meaning “earth.”
When my grandchildren come in from outside play covered with dirt from head to toe, I try to be philosophical about it. Ashes to ashes, dust to dust: We came from the soil and to the soil we shall return. We are creatures of the Brown Planet. Cleanliness may be next to godliness, but a child’s layer of backyard grime is next to being human.
