Let's look hard at this because Alum is what is used in canning foods and treating the water we drink.
There are parts of the U.S, where the rural population is much greater than the urban numbers.. The folks in these locations have a lot of problems with teeth because of a "lack" of fluoride in well water because it's higher in Alum treated city water.
I don't want to see this being used as a means of keeping people from using it when it's consumed every day by humans in various sources.

www.aquaticspecialties.info
May God be with the Overton's Family.