Radiation actually appears to exhibit hormesis- small doses of ionizing radiation likely activate some protective response, which decreases rather than increases cancer risk.
I think allergens, and compounds which initiate autoimmune disease (gluten in coeliacs) are a good example of something which remains toxic at low doses. There hasn’t been a lot of research into it, but even extremely low doses of gluten seem to be harmful to coeliacs.
Radiation actually appears to exhibit hormesis- small doses of ionizing radiation likely activate some protective response, which decreases rather than increases cancer risk.
I think allergens, and compounds which initiate autoimmune disease (gluten in coeliacs) are a good example of something which remains toxic at low doses. There hasn’t been a lot of research into it, but even extremely low doses of gluten seem to be harmful to coeliacs.