dunno about the evidence, but I kinda figured post-combustion lead is more atmospheric than pre-combustion lead. Elemental lead doesn't really absorb through the skin (and gas doesn't evaporate too well at low temperatures) as far as I know.

Lead added to fuel is in the form of an organic compound, so I'd expect the opposite effect. Obviously there's more distribution post combustion, but from a bio-availability standpoint spraying tetraethyl lead around in equivalent quantities would be a much more severe problem.

Naively (without looking at data for concentrations in various environments), I could buy that people regularly handling / being around leaded aviation fuel are worse off than those breathing the (dilute) exhaust products.

I realize this is an anecdote, not data, but after flying my own plane for 5 years and getting >500 hours of flight time, plus soldering off and on for 30 years with leaded solder, my lead levels were fine at my last physical. I don’t drink avgas or anything, but don’t take precautions other than attempting to avoid getting it on bare skin.

We got one of them fancy lads what drinks the jet A, boys. Thinks the 100LL ain’t good enough, no doubt!

:)