Climbing Plot Mountain

This - http://wwwnc.cdc.gov/eid/article/9/8/03-0033_article.htm - is an utterly fascinating article whose premise, ultimately, is Let Them Eat Dirt. As scientific articles go, it’s really very readable, so don’t let the webpage scare you off. Read it to the end, and then take your kids and go out and play in the dirt. It’s good for you.