[lutorm]

Thanks for those numbers. As a contrast, the lead content in lead-based paint can be up to 50% by weight for really old paint, down to 0.5% before lead was banned. A single house full of old lead paint can easily contain many kg of lead.

It's true that as long as that paint is in good condition and isn't disturbed, it's not harmful. However, paint deteriorates and chips, is disturbed when remodeled, etc. One tiny paint chip of old paint can easily have more lead than that Cessna dispersed around the airport, and it's concentrated in a single article.

There's a crap ton of lead paint still around and sooner or later it's going to be mobilized. It's a fiction to think that an EPA-approved hazmat team will be dispatched whenever one of these old houses are torn down or remodeled. I'm much more worried about paint than a little avgas spread out evenly across the landscape.

[ineedasername]

How many planes land & take off every day though? Over the course of a decade, sitting in small quantities on literally ever outdoor surface...

Comparing it to lead paint is the wrong comparison. Take a look at what lead in the water supply, even at small concentration, can do to people. That's more comparable to air dispersal.

[lutorm]

If lead from avgas was an acute problem, literally everyone who lives near GA airports would have high lead levels. I've not heard of such a situation, though.

I think that evidence points to plenty of cases of lead poisoning from lead paint and, yes, lead in water. I have yet to hear of anyone getting lead poisoning from living near a GA airport.

Do note that lead paint also leads to contamination of surfaces and soils, as deteriorating paint turns into dust.

I don't think water contamination is similar to air dispersal at all. People consume a certain amount of water out of the tap every day, and whatever is in the water ends up in the body. There is a much less clear absorption chain from lead emitted into the air to the body.

Edit: I did the math based on the numbers above: Within 1 mile of an airport (typical pattern size) with 100 take-offs per day, each using 1 gallon of avgas so emitting 1g of lead will, over a decade, deposit ~50ug of lead per m^2.

If we say a yard is 100m^2, that's 5mg of lead. That's the equivalent lead content of < 1g of lead-based paint.

I'm not disputing that if you live in a new house, far away from a highway, but near a GA airport, avgas might be the major contribution to your lead exposure. But compared to the lead exposure risk from houses still containing lead paint, it seems completely insignificant.