It’s not necessary to be an expert on fluoride to have an informed opinion because experts write articles and books as well as do NZ public lecture tours to educate the public. There is also wealth of information on the internet for those who wish to be more knowledgeable. Most of those speaking out against fluoride are informed and concerned because fluoride is a highly toxic chemical and it has detrimental effects on some people’s health.
https://fluoridefree.org.nz/about/