This link mentions a couple of very young children who began to grow pubic hair (we're talking kindergarten age) because........their father was using a testosterone cream and they absorbed it through their skin. It also offers a list of how you can minimize your own exposure to endocrine-altering chemicals.
http://www.mercola.com/2006/oct/31/why-are-kids-entering-puberty-before-they-enter-school.htm
And here's another one about kids hitting puberty in their very early years:
http://abcnews.go.com/Health/print?id=2610353