Just back from the park with 22 month old DS, he fell a couple of times, got soil all over his hands then put his fingers in his mouth while I was trying to wipe the soil off him.
He got quite a lot of soil in his mouth and all I can think about is what I was told when I was little about the dangers of eating soil.
Of course I googled it and am now worrying myself silly about Toxocariasis which you can get from ingesting soil contaminated with un-wormed dog (or cat) poo, public parks are a greater risk than your own garden because not everyone de-worms their dogs!