Another fellow on the forum said a friend who had access to lead test gear had checked out his work areas. No lead contamination problem at the loading bench. None at the casting bench (lead vapor from normal casting temperatures is actually very low). The place it did show up? Around the case tumbler. That's primer dust. It's the bad stuff, and it's enough to make you want to use a wet tumbling medium. Doing your tumbling and media separating outdoors turns out to matter more than casting and other activities except maybe indoor shooting. I use a respirator for that. No big deal.