Iridium 192 in bulk metallic form ,appears to be fairly innocent, aside from if it is in a powdered or form, whereupon handling can become hazardous,
as the substance in that form is an irritant, and can ignite on contact with air. It has various industrial and medical uses, but aside from its
capacity to ignite in air when powdered, it is difficult to see what purpose it would serve to a creep.
Of course, being a radioisotope the usual dangers apply. Accidental exposure to some forms of iridium can cause cancer, radiation burns, and so on
and so forth. Ingestion can cause burning of the various digestive tract components, and the liver tends to fare rather badly when this stuff ends up
flowing through it, as the stuff has a tendancy to collect in that organ, if it is passed through it.
But the same could be said of many other, easier come by, and more abundant substances. Iridium 192 is something in the order of 80 times less
abundant than silver and mercury, there are only three elements that are less abundant in the crustal rock. There is likely to be much more iridium in
the Earths total make up, but because iridium seems to seek iron, it sunk toward the core of the planet, during its formation, and only very small
amounts remain in the crustal rock that we mine.
This means that if the intent of the thief was the creation of some sort of poison, then they chose poorly. The more common a murder weapon, the more
difficult it is to trace, no matter wether you are talking about blunt force trauma, or using radioactivity to poison a target, the rule still
applies.
If the stuff in the van was stolen to order, I would be suprised if it was stolen for the purpose of creating a weapon with it, for either small or
large scale use. There must be some specific, probably industrial requirement involved, if this was anything more than a random theft. Of course,
there is always the random element to consider, and if that is the case, I hope the thief uses his head, and hands this stuff in. While not terrifying
in a "Oh Noes! WMD materialz are loose! We really ARE all gonna die!" kind of way, anyone who comes into close proximity with the unshielded
contents of that container, assuming the gormless fool who stole it was enough of a clod to open it, will be at risk of radiation damage of some sort.
During my looking into the properties of Iridium 192, I came across a segment on one page (which I have helpfully forgotten the name and web location
of, sorry
) that stated that the substance can output both gamma and beta radiation. So, no major concern at this point, but still... I hope this
stuff is either located and reclaimed, or gotten to someplace safe, at least stored responsibly.