First off, playing with Dirt is actually good for you. It’s even sort of edible (in the way that Play-doh and crayons are edible). But some studies have shown that kids who play with Dirt have stronger immune systems than those who don’t. So even if it means doing some more laundry (Dirt is notorious for the stains it causes) it might be worth getting your kids some Dirt.
I don’t mean to brag or anything but I was a serious dirt eater as a kid and I rarely get sick. I plan on letting Charlie roll around in the dirt to her heart’s content. I’ll probably join her, actually.