Still, one atom probably won't kill you. Various sources talk about blood lead concentration thresholds of concern between 0.5 ug and 10 ug per dL. It's 3.5 ug for children and 10 ug in the USA presently. But it's likely that even below 1 ug per dL has small but real negative health consequences over a population, at least showing up statistically.
"The median concentration of lead in the blood of children between the ages of 1 and 5 years dropped from 15 µg/dL in 1976–1980 to 0.7 µg/dL in 2015–2016" - https://www.epa.gov/americaschildrenenvironment/ace-biomonit...
Honestly? Yeah, it seems most of my parent's generation likely has a touch of minor lead poisoning. Much, possibly most of my generation too, though less so. Even the generation coming up will have a few.
> I can only speak to gasoline specifics in the US
Lead was used in gasoline in most places at some point or other. And gasoline isn't the only use of lead that causes widespread human exposure. It has been used historically (and still in some countries) in some pesticides, explosives, industrial chemicals, and paints. It does seem that blood lead levels are much higher in children in poor industrial countries than in the US or Western Europe.
> Are we being lead by a bunch of Caligulas?
It is a seriously argued theory that the 70s - 90s crime wave in the USA is a consequence, at least in part, of mass lead poisoning. One which we would not have quite fully recovered from yet. Sure. Maybe it helps explains the government, too.
Where I live there is a secondary airport that mostly flies Cessna's etc where people go to learn to fly.
It's surrounded by residential and depending where you live planes every three minutes endlessly doing circuits, quite low in some places. At one stage I think it was the busiest airport in the world.
I avoid living in the suburbs under the approach, seems to be a dirty secret about the fuel.