OK. Now you've got me started. My aunt, a nurse, was warning me to be aware that my daughter's cycle could start as early as 8. I was horrified. I told her that I'd only known two girls who started as early as 9 and she went on reassuring me that it was perfectly normal for girls to start at 8-9. She patiently tried to explain to me that "things had changed".
I asked her: If 15% of all the babies born suddenly had an extra arm, would we all calmly smile and nod and say, "Oh! This is so common that it *must* be normal" or would we break down the gates of Hell to figure out what was happening to our kids? She tried to argue that it wasn't the same thing, as all healthy females have cycles. Girls are just starting earlier. So I presented this scenario: What if 10% the 20-25 year old young women were going into menopause? Would *that* be acceptable? She finally got it.
Uh huh. Look at the info/studies about estrogen, and other drugs, in the water supply. I remember first reading about this in the '80's. A portion of most drugs is excreted unchanged from the body. This enters the water supply. Treatment plants are geared to deal with microorganisms, not drugs. There have been a number of reports/ studies about estrogenic effects being found in marine life. So, it's not surprising that girls are entering puberty earlier if the water supply is laced with estrogenic compounds.