Holy shit...
Exotic professions like being spies and agents sound super fun until you read some shit like this!

Man...
As if acid attacks weren't bad enough.
A "mystery" substance "BLOWN" at them?!
How would you even see something like that coming!?
You fucking wouldn't.
When they do it in public like that it must be to send a message to any others as a warning dont think about selling state secrets for money
Walking past someone and blowing a cloud of plutonium at their face is all it takes. It will get in through the nostrils and/or mouth if you don´t react in time.
Realistically if they did this to kill, they used a radioactive material. If it´s not radioactive, it would seem more like a scare tactic.