[kennend3]

Most adults stopped putting strange things in their mouths a long time ago.

But agree, Alpha emitters are a problem if taken internally, which is why i stated breathing/drinking tritium increases cancer risks.

there is not a clear line between "alpha exposure" and "rip-roarding tumour"... See "nuclear medicine", "radioactive tracers" etc for examples of where alpha emitters are intentionally given to patients.

[Gordonjcp]

Yes,-ish but look at the isotopes used for radiotracers in medicine - they typically undergo beta decay and their half-lives are in the order of minutes, mostly, with phosphorus having a half-life of about a fortnight and sulphur about three months.