[teraflop]

As I understand it, the "solder smoke" produced during hand-soldering does not actually contain metallic solder itself, except maybe in trace amounts. It primarily consists of vaporized organic compounds from the rosin flux core of the solder wire.

It's still not good to inhale (chronic exposure can cause asthma and other respiratory issues) but it's not really an issue of leaded vs. lead-free.

And for what it's worth, I've always anecdotally heard that solder paste is what you really want to be worried about, rather than solder wire, because it's much easier for small amounts to get smeared onto objects/surfaces and contaminate them.