An official website of the United States government
Here's how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Data from 5,594 samples collected from 1931 through 2006 were used to describe naturally occurring fluoride concentrations in freshwater aquifers in Louisiana. Statistical analyses were used to summarize fluoride concentrations in the aquifers.