They should know better yet they allow this to happen to our children and to us.
They put flouride in the water and then make toothpaste that tastes really good for our children who want to eat it or ingest it and between the mercury and the flouride it's dumbing us all down.
The Bible says that it will only come to poverty the merchants and those that make rich off of us at our expense.
What they do to us is with the permission of our government there is no other away around it and there is enough evidence in history what these toxins do to people so they had to know.
They must have known people would find out eventually when the damage is already done. Knowledge is power in this case.

http://www.fluoridealert.org/health/brain/index.aspx