The next time you throw something in the trash, think for a moment why you aren’t buried under leaves. Seems silly, right? But really, all trees shed their leaves, even the evergreens as they grow new branches. All the billions of trees in all the world for all the time the Earth has existed. All those leaves! What happened to them? Why did they go away instead of burying everyone and everything? Even though dead leaves get thin and dry and crackly, or brown and break easily, that just means that all of those dead leaves would pile up, only they’d be dust, and really get into everything.
It’s because of the microbes: the little, tiny bacteria and very small creatures that eat leaves after they’ve fallen from the tree. When they are up in the tree, a lot of things eat them: deer, caterpillars, moths, sloths and even horses now and then. And some animals use dead leaves to build their nests. But they eat the living leaves. It’s the microbe’s job to get rid of the dead leaves that no one else could eat, or use.
Now, microbes are very tiny, and they can’t eat big things. And they can’t do things that are too difficult: they can’t eat metal, or plastic or anything like tin foil wrappers. So, when you throw something with metal or plastic in it: the old toy you’re tired of, the shiny wrapper on your food bar or a straw, fork or container from your fast-food lunch, thing: what’s a microbe to do? Microbes can eat paper, yes, and cardboard. But plastic, metal and worse things like polystyrene (the white foamy cups some people drink how liquids in) are way beyond any microbe’s ability to digest.
So, plastic straws and utensils, foam cups and little metal or plastic cars, just take up space in the earth. Metal, at least, rusts and goes away eventually. But plastic hangs around, because it’s not at all like leaves: microbes can’t make it go away.