[downrightmike]

If you look at Chandler Az's small airport, you'll see it is now in the middle of a dense sprawl of suburbs, who no doubt have no idea leaded fuel it burnt over their heads day and night. Minimum house price in the areas wasn't less that $500k last time I looked, and those were few. Intel is just to the west. https://www.google.com/maps/place/Chandler+Municipal+Airport...

[toomuchtodo]

I’m somewhat surprised, based on state lead disclosure laws, that this too isn’t required to be disclosed to buyers of properties within proximity to airports that provide 100LL from their FBOs. It’s worse than lead paint (typically stable if not disturbed) in that it’s in the air and on the soil.

You might expect the noise, but you’d have to be versed in general aviation to know you’re being exposed to lead from combustion pollution.

[jliptzin]

I had no idea leaded fuel was still used anywhere

[tialaramex]

It may also be used for some very old cars. "This should be in a museum" (and maybe is) level cars may have been impossible to adapt to unleaded gasoline. So, one option is you just don't run them - after all these are very old cars they're both unsafe and inefficient by modern standards with few creature comforts. But if you're exhibiting cars in working condition you've got two practical options:

1. Add a lead additive, you don't need very much, and since this isn't exactly your daily driver it's not so terribly inconvenient, you can buy this over the Internet. You just pour a measured ammount in to the tank each time you re-fuel. I don't think this is illegal in the US, but I don't know if it's common. At population scale it isn't a big nuisance.

2. Choose a substitute additive, which is likewise added to fuel. There are several, but whether they work for you is a question and of course the manufacturers are not interested in insuring your potentially unique 100+ year old car for damage from their cheap additive product. If you suffer mechanical problems that's your problem.

There's a lot more piston plane flight than there are people still driving a classic era car on any particular day.

[dreamcompiler]

It's limited to general aviation: Small piston-driven private airplanes. Lead is not used in jets.

[tialaramex]

And importantly in this context: The magic word is "piston-driven". Lots of aircraft you see look to a lay person like they don't have a jet engine, because there are propellers just like on a piston-engined plane. But a https://en.wikipedia.org/wiki/Turboprop is a very efficient jet engine that just happens to be driving a propeller and so they're running on JetA fuel which never had lead in it. (There are still lots of reasons not to exhaust that into the sky either, but at least it doesn't have lead in it)

[zardo]

Also still used in (some formulations) of race gas.

[heresie-dabord]

Pertinent references:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230438/

https://www.smgov.net/uploadedFiles/Departments/Airport/News...

[refurb]

Do you have a source that’s it’s worse?

[ineedasername]

It would make sense that lead aerosolized in the air has more access to human biology than lead in undisturbed paint.

Degraded lead paint consumed by unknowing children would probably deliver high concentrations, but a lot of that will travel unabsorbed through the intestinal track. Aerosolized lead paint would be unavoidable with a higher proportion passing into the bloodstream through the lungs, and therefore on a more express route northwards where it can pass between the blood-brain barrier.

[slimsag]

Concentration could make a huge difference, though. Paint is in enclosed spaces without ventilation, often. Aeroplanes are not in the context of suburb effects.

[refurb]

Aviation 100LL is 0.56g of lead per gallon. Small Cessna 172 burn ~10 gal/hr in flight.

Presumably taxiing and take off burn a few gallons, so 1gm of lead dispersed over a pretty wide area. So at any given point in the area your overall exposure is low.

[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.

[jandrese]

With hundreds of GA flights per day this will add up over time. One of the terrible things about lead is how hard it is to get out of the environment.

[BurningFrog]

I wonder how that compares living near traffic in the 1970s when all cars ran on lead.

I'm (wildly) guessing 0.1% of those lead levels.

[Cerium]

I could not find any data on the actual levels, but there is data available on the effect on children.

By the late 1970s "88% of children had a level exceeding 10 μg/dl" [1] while current data from near the Reid-Hillview Airport shows that there is no particularly noticable effect [2] with just 1.7% of children having a blood level above 4.7 ug/dl. On average around 2% of children in the US regardless of location have a blood lead level around that number.

[1] https://www.jci.org/articles/view/28232 [2] https://sanjosespotlight.com/san-jose-airport-lead-levels-ar...

[nimish]

No level of lead is safe in children, so even that is concerning.

[BurningFrog]

If levels at the airport aren't higher than the "background level" elsewhere, our concern should focus on other factors.

[VLM]

Actually no, not for policy decisions.

Guaranteed kids will have levels medically too high is a policy problem. Immediately downwind of the interstate in the 70s was apparently a very bad place for kids to be, and policy fixed that (more or less).

Almost no kids will have high levels now, and those few with higher levels experimentally are from uncountable random sources rather than the point source airport, is not a useful aviation policy problem.

[nimish]

The issue is high level = any detectable level above zero, especially if man made and easily preventable.

Allowing leaded avgas has always been a policy decision to cater to GA over the health of, among others, children.

[BurningFrog]

The main lead sources now are old water pipes and paint.

Both seem very countable and fixable.

[Tagbert]

Yes, we live just a couple of miles from the airport in downtown Renton, WA (Seattle suburb). Small planes burning leaded fuel takeoff and land over the town and over Lake Washington. We are not in the flight path, but it’s very concerning for everyone who is and for all the fish in that lake.

[Spooky23]

I’d rather have Cessnas above me than a fab upwind. There is and has been some very nasty stuff in types of plants.

[downrightmike]

Arizona gives you both!

[skybrian]

I don’t know enough to judge how bad a problem it is either. What’s a good way to find out more?

[dpe82]

Santa Clara County did a study, found there was not much of a difference: https://sanjosespotlight.com/san-jose-airport-lead-levels-ar...

[lotsofpulp]

https://www.cdc.gov/nceh/lead/default.htm

[skybrian]

I’m already aware of lead’s environmental effects in general. I was wondering what we know about the scope of the problem from burning 100LL?