I'm wondering this too, i couldn't find very much information on the actual risk vectors and required exposure levels and concentrations to trigger an increase

I'm wondering this too, i couldn't find very much information on the actual risk vectors and required exposure levels and concentrations to trigger an increase in lead blood levels, I'm still looking https://news.ycombinator.com/item?id=29487787 https://news.ycombinator.com/item?id=29487787