Interesting.
But don't tell Sparky you have that! He's sure to correlate it with an eminent mass extinction event. All radiation is super deadly forever, right? Especially old record cleaning brushes originally doped with spy killing poisonous radioisotopes.
gettng back to the theme of 1977..... I still use it to clean the stylus and headshell.
I bought one of these back then as my dusting brush, the StaticMaster 500. It is a soft natural hair dusting and destat brush.
It came complete with a Caution warning:
Radiation from Polonium is dangerous if solid material is ingested or inhaled. Do not touch under the grid. Keep away from children. See instructions.
Guarantee until May 1977
Here's the real deal-
Polonium is quite active radiologically, having a half-life of just 138 days, meaning it's radioactivity drops by half every 4-1/2 months or so. But you still shouldn't lick the brush. What little polonium was originally vapor deposited on the base metal under the brush grid decayed long ago into lead. Regardless I suspect it's still done a fine job a brushing dust away for the last 4 decades since May of '77. And without a doubt, the StaticMaster 500 would be ideal for dealing with fallout dust accumulating on cold-war era LPs in any underground backyard bunker.
The type of radiation emitted by polonium-210 is high-energy alpha particles which are completely blocked by a few sheets of paper or the top layer of our skin rendering it externally harmless. But deadly tissue damage can occur if sufficient quantities are introduced internally though inhalation, ingestion, or entry through skin abrasions or wounds, in which case it becomes a deadly poison. The US and all other countries except the USSR stopped producing polonium in the late 1970s.
Some reading this may recall the infamous murder of MI6 agent and former Soviet/Russian spy Alexander Litvinenko in London in 2006 by polonium poisoning. He is thought to have ingested the polonium orally via a cup of tea, which would have hidden the heat generated by the radioisotope. The perpetrator(s) of his murder would have needed recent access to a reactor capable of producing and irradiating materials, a radiochemical laboratory to convert metallic polonium-210 into liquid, and would have had to smuggle it to London prior to its decay. Buying pure polonium from legitimate sources would not be feasible since it is sold in such tiny quantities, something like 15,000 orders would have to be placed to obtain sufficient quantities for a lethal poisoning, and the dose of polonium used to kill Litvinenko was exceptionally large. The only place remaining in the world with a polonium production line and the last remaining source of commercial polonium is a closed nuclear facility known as Avangard south-east of Moscow. Polonium was likely used because it was unlikely to be detected given that it emits alpha rather than more penetrating gamma radiation. Indeed, it was only hours before Litvinenko's death that polonium-210 was discovered as the poison that was killing him.
Although polonium-210 can clearly be extremely dangerous in certain circumstances, commercial application onto devices which remove static was done in such a way to make it infeasible to separate the polonium for use as a poison, and its use in such applications has since been replaced by non-radioactive technology.
http://www.medicalnewstoday.com/articles/58088.php