I am directly questioning whether the .22LR bullet creates more lead vapor than any other round as per OP statement.

I haven't measured this but all the ingredients are there: they're unjacketed or copper washed, and they are made from soft lead rather than a hard-cast alloy. You can get a polymer-coated or pure copper round but that's pretty unusual since it goes against the cheap plinking purpose most people are using the .22 for.