Sounds like you're ok as long as you don't eat the brush -- "100% ingested" ?? If you're worried about disposing of it just email the manufacturer. Why would they want you to dispose of it? Maybe so they can sell you a new one?
A quick Google found
this link on the International Atomic Energy site that says:
Quote:
|
Po-210 has a half-life of 138 days. This is the time it takes for the activity to decrease by half due to a process of radioactive decay. Po-210 decays to stable lead-206 by emitting alpha particles, accompanied by very low intensity gamma rays. The majority of the time Po-210 decays by emission of alpha particles only, not by emission of an alpha particle and a gamma ray. Only about one in a 100,000 decays results in the emission of a gamma ray. Alpha spectroscopy is the best method of measuring this isotope.
|
That sounds like the polonium has decayed into lead by this time so the brush is less effective now. Also...
Quote:
|
Po-210 is highly radioactive and chemically toxic element. Direct damage occurs from energy absorption into tissues from alpha particles. As an alpha-emitter Po-210 represents a radiation hazard only if taken into the body. Itīs important to note that alpha particles do not travel very far - no more than a few centimetres in air. They are stopped by a sheet of paper or by the dead layer of outer skin on our bodies. Therefore, external exposure from Po-210 is not a concern and Po-210 does not represent a risk to human health as long as Po-210 remains outside the body. Most traces of it on a person can be eliminated through careful hand-washing and showering.
|
I was kidding about eating the brush but it sounds like that's really the only way you'd become poisoned by the stuff. As old as it is I'd guess you can safely drop it in the trash.