CDC Facts About Lewisite
http://www.bt.cdc.gov/agent/lewisite/basics/facts.asp
http://www.bt.cdc.gov/agent/lewisite/index.asp
Even more on google.
The latest news I could find on this bus incident, take a look at what this says the ingredients are (???)
Thu, May 27, 2004
Bus illness stymies B.C. investigators
By CP
VANCOUVER -- The mystery of what caused riders of a transit bus to become ill has deepened with the discovery that some small brown pellets found on board turned out to be thyme, mud and a pine substance. There were early reports the brown pellets were a form of phosphine -- a fumigant that, in pellet form, releases a toxic gas when it comes in contact with humid air. Phosphine is an industrial pesticide, and can cause nausea, vomiting, bronchitis, shortness of breath, convulsions and death.
A woman on the bus said that as a man was leaving the bus he asked the driver how his day was going.
The driver said it was fine and the witness said the man then replied it wouldn't be for long.
http://www.canoe.ca/NewsStand/CalgarySun/News/2004/05/27/475004.html