If you're truly concerned about lead in the environment you'd be best served going after old structures with leaded paint -- not Avgas.
Do I understand correctly that leaded paint is harmless until scratched or otherwise dispersed?
http://www.aopa.org/News-and-Video/All-News/2013/December/3/...
http://www.networkworld.com/community/blog/faa-wants-all-air...
They knew lead was a poison.
Even the Romans knew lead was a poison so it wasn't like asbestos where suddenly a realisation was made.
Yet everyone pretended it did not matter. Everyone did what everyone else did. Nobody thought to avoid driving past schools because they weren't sure about the ethics of covering kids in a cloud of lead (with NO2, CO, O3, PAH's and maybe some invisible micro particles thrown into the mix).
Air pollution from cars kills 50,000 a year in the UK [0]. Apparently closer to 200,000 a year in the US.
But it's even worse than that. 1.24 million each year are killed directly by motorists.[1] There are more young people killed directly by motorists than malaria or aids.
And yet many people are happy to continue driving around.
It's not like this is unavoidable. Electric cars are here, we could move the pollution out of cities. We could design our cities to be safer for walking and cycling. We could invest in public transport and pass on the cost of some of the externalities of cars to motorists.
[0] http://www.theguardian.com/environment/2010/mar/22/air-pollu... [1] http://www.who.int/mediacentre/factsheets/fs358/en/
So just to be clear... you're complaining that the US has five times the population of the UK but four times the deaths from air pollution?
Your overall point is right, though, that mid-20th-century motorist pretty much behaved like an oblivious jerk for decades.
You're saying that had something to do with fear of lead poisoning?
AV gas is being replaced step by step but since leaded gas has its advantages, the replacement process takes time – and there is no really convincing alternative. Anyway, the amount of lead is probably no significant factor in air pollution, there is simply not enough general aviator flying for that.
It's true that if you average the consumption of avgas over the service of the planet you get a pretty small number, but that's no consolation to the family at the end of the airfield who actually gets all of that stuff deposited in their back yard.
I've been active in general aviation for years, and I've never met one these pro-lead strawmen you write about. Since you seem to have all the answers, can you put forward a rational solution to the problem (that isn't "Just throw away all the airplanes")?
The older cars that were originally designed for leaded fuel were either retrofitted with hardened valve seats that didn't require the lubrication of lead, were simply run on unleaded to their deaths, or in some cases (Mercedes-Benz comes to mind, though there may have been others) never needed lead to begin with.
Perhaps we could do the same for small planes, but clearly it would take a lot of research and testing to make sure it's safe. If someone is willing to pay for that testing, it's probably doable.
I'm sure it won't be cheap. And this isn't just an abstract cost to me; although it won't hit me nearly as hard as some, I do belong to a flying club which owns two airplanes that would need the work. On the other hand, owning an airplane is painfully expensive anyway. Perhaps I'm off base, but it sounds like the unleaded retrofit wouldn't be too painfully expensive when, say, combined with a 2000-hour overhaul.
I'm sure there will be a number of aircraft owners who couldn't afford it and would have to sell their plane at a discount once the fuel cut over. I'd feel bad for them. On the other hand, they (we) are running pretty dirty machines that emit some nasty pollution, and it shouldn't be a big surprise that they (we) can't get away with that forever.
On one hand, the small size of the GA fleet means that this is a tiny problem compared to leaded gas use in cars. On the other hand, the general reduction in pollution in the US means that it's substantial relative to what's left. Leaded fuel used by GA accounts for almost half of all lead emissions in the country now, and that seems worth fixing.
But it is also incorrect to draw a parallel to cars, because there was enough volume for cars to transition gently to unleaded gas; you could get both for a while. There is not enough volume of 100LL for FBOs to have two tanks, so, the switchover will have to be all at once. That's why the "drop-in replacement fuel" search is going on... Don't know if it will come to fruition, but if it does, sure makes the problem a lot easier.
Today, though, it's frustrating to have an airplane that I know could run fine on ethanol-free, lead-free 92 octane motor gas, but am required by law (unless I buy an STC) and by practicality (what airports sell) to use leaded fuel.
I guess I'm assuming that an engine that's been converted for unleaded will still work on 100LL. Obviously that's the case for yours, but I suppose it may not be the case for all. If so, that would complicate things severely.
Most normally aspirated engines will work fine (in some cases, better) on a high grade unleaded auto gas.
Most turbo-charged engines lack sufficient detonation margin when run with that "premium" auto fuel, and need some form of octane boost to provide adequate detonation margins for a high-temp, max performance takeoff run. Several groups, including Swift, GAMI, and Shell, are working on drop-in zero-lead replacements for 100LL. All are flying the fuel in experimental applications as I understand it. None appear "close" to certification.
The real problem is that the bulk of gallons burned are burned by airplanes that are turbo-charged. So, even if 75% of the engines can be readily converted (in many cases, a paperwork-only STC), those 75% of airplanes likely represent fewer than 25% of the gallons burned.
I've been to GAMI in Ada, OK and seen them run their no-lead fuel in a lab setup. It's impressive and looks like it would work. They still face a steep and long uphill battle with the FAA, as do Swift, Shell and the others...