/oss/taxonomy/term/725/all en /oss/article/health-general-science-you-asked/what-hormesis <p>Just about every textbook of toxicology pays homage to Paracelsus, the sixteenth century alchemist. Why? Because he introduced the idea that “only the dose makes the poison.” It makes no sense to talk about the toxicity of a substance, Paracelsus said, without talking about the extent of exposure. A high dose can be lethal, but minute amounts of the same substance may be perfectly safe. This really is the approach authorities take today to determine the toxicity of substances to which we are likely to be exposed.</p> Sat, 25 Jan 2020 00:21:22 +0000 Joe Schwarcz PhD 8092 at /oss