The recent NIH meta-study indicated there may be neurotoxic effects at concentrations within an order of magnitude of the recommended drinking water level (perhaps even at just 2x the recommendation), I wouldn't call that "very low".
The best research I've seen on this, from NZ, suggests the neurocognitive effect in typical fluoridation programs is about as close to zero as you can get.
I admit I think people were stigmatized for raising concerns about it before, and find it sort of weird it was added without more safety data, but by the same token I think the most rigorous evidence suggests its pretty safe at the typical concentrations of most fluoridation programs.
I actually consider myself "on the left," but find their turn to a sort of scientistic blind trust of anything remotely billed as "public health" during COVID to have been disastrous.
I thought I was on the left but there’s no way I want to be associated with people who have such blind trust in institutions and have such pride in their lack of critical thinking.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6923889/