I am probably responsible for all of this, since I'm from Sweden. But, seriously. Lead is poisonous. I've had, as many mixed success with lead-free products; I have a Stannol lead-free roll I avoid using, because it is not very helpful. With good temperature control, it is quite OK, though.
For repair of old gear, lead is of course quite necessary. I have a bunch of rolls leaded, but I restrict use of it to old stuff, to make it last and to minimise exposure and contamination.
New builds are lead-free through and through, regardless of what I'm doing. I've, through other members here, found that Balver Zinn unleaded is extremely good, and a bunch of us managed to score a group buy. It feels like the old days.
I've also stopped using Freon, Asbestos, and DDT. Quit smoking. I do drink, though. There are limits. But I can, OTOH, keep drinking for longer now that I've optimised wear and tear on myself.

Edit: What Bassman wrote. 10 times over.