Editing Radioactive decay (section)

===Radioactive substances===
[[File:Periodic Table Stability & Radioactivity.svg|upright=1.8|right|thumb
|Radioactivity is characteristic of elements with large atomic numbers. Elements with at least one stable isotope are shown in light blue. Green shows elements of which the most stable isotope has a half-life measured in millions of years. Yellow and orange are progressively less stable, with half-lives in thousands or hundreds of years, down toward one day. Red and purple show highly and extremely radioactive elements where the most stable isotopes exhibit half-lives measured on the order of one day and much less.]]
However, the biological effects of radiation due to radioactive substances were less easy to gauge. This gave the opportunity for many physicians and corporations to market radioactive substances as [[patent medicine]]s. Examples were radium [[enema]] treatments, and radium-containing waters to be drunk as tonics. Marie Curie protested against this sort of treatment, warning that "radium is dangerous in untrained hands".<ref>{{cite journal |last1=Rentetzi |first1=Maria |title=Marie Curie and the perils in radium |journal=Physics Today |date=7 November 2017 |issue=11 |page=30676 |doi=10.1063/PT.6.4.20171107a |bibcode=2017PhT..2017k0676R |url=https://physicstoday.scitation.org/do/10.1063/PT.6.4.20171107a/full/ |access-date=3 May 2022|url-access=subscription }}</ref> Curie later died from [[aplastic anaemia]], likely caused by exposure to ionizing radiation. By the 1930s, after a number of cases of bone necrosis and death of radium treatment enthusiasts, radium-containing medicinal products had been largely removed from the market ([[radioactive quackery]]).