And how much polonium would that college lab produce?
Enough to get the job done.
By mass, 210Po is around 250,000 times more toxic than hydrogen cyanide the actual LD50 (lethal dose for 50% of those exposed) for 210Po is less than 1 microgram for an average adult compared with about 250 milligrams for hydrogen cyanide.
A lethal dose may be induced by ingesting about 50 nanograms, or inhaling about 10 ng. One gram of 210Po could thus in theory poison 20 million people of whom 10 million would die. The actual toxicity of 210Po is lower than these estimates, because radiation exposure that is spread out over several weeks (the biological half-life of polonium in humans is 30 to 50 days) is somewhat less damaging than an instantaneous dose. It has been estimated that a median lethal dose of 210Po is 0.089 micrograms, still an extremely small amount.
Thus it will become apparent that acquiring a lethal dose of 210Po does not require one to undertake elicit production as 210Po is widely used in industry, and readily available with little regulation or restriction. In the US, a tracking system run by the Nuclear Regulatory Commission was implemented in 2007 to register purchases of more than 16 curies (590 GBq) of polonium-210 (enough to make up 5,000 lethal doses). The IAEA "is said to be considering tighter regulations... There is talk that it might tighten the polonium reporting requirement by a factor of 10, to 1.6 curie", leaving a purchaser free to obtain say, 500 LD50 for the manufacture of say, anti static brushes.
I mentioned a "university physics lab" because it is possible to produce 210Po at such a facility however producing radioisotopes in a college environment is risky business. It makes much more sense to divert material from commercial sources.
Regards,
GtG