The litany of cases you posted makes for interesting raw data, but what point are you making? Is there any evidence of a connection among these incidents?
"Is there any evidence of a connection among these incidents?"
Perhaps you should field this one, Kahn.
BTW, whatever became of your better half, whatshername?
I don't know, but since TownCryer seems to think so, let's stipulate a connexion between some of these incidents and the 2001 anthrax letters, and see where it leads us.
If these are the same people, the first Question to ask is Why would they stop sending anthrax, swiching instead to other agents?
Anwser 1 - They have run out of anthrax/
Anwser 2 - The weaponisation method has been much less effective than they had expected, so they decided to try some different things/
Either Anwser 1 or Anwser 2 is possible. Anwser 2 gets some support from the dud anthrax attack around 24 February 2003 - click here and here.
Whether the Anwser to the Question is 1 or 2, they are sitting on a weaponisation method in search of an application. So they try one chemical agent after another, weaponise it with their method, and do a test mailing, to see which agents could be effectively weaponised via their method. The good thing is- So far none.
Disclaimer: This entire chaine of reasoning is contingent on the stipulated Assumption of a connexion between the 2001 anthrax letters and some of the chemical mailings. I know no strong argument for or against this Assumption.