In my workshop, I have three gallons of a deadly blend of methanol, toluene and methyl ethyl ketone. It's explosively flammable, it's a breathing hazard and a suspected carcinogen. Why, in a society that prides itself on protecting its citizens from undue hazards, am I allowed to have this stuff?
Because it's otherwise known as lacquer thinner and I use it as a solvent to cut lacquer-based paints. The can is festooned with warning labels and, evidently, we've decided that the benefits of its use outweigh the hazards. Or maybe it's just that environmental groups haven't gotten around to convincing the government to declare lacquer thinner a controlled dangerous substance. After all, one could make the argument that one gallon of lacquer thinner is one gallon too many.
I submit that lead in aviation gas ought to bebut is nottreated similarly. When lead was phased out of autogas during the 1980s, it was, without question, the right thing to do. Millions of cars were spewing tons of lead byproducts into the air, and the larger issue was that lead emissions fouled the catalytic converters that have substantially reduced air pollution and photochemical smog.
Now we come to the same juncturefinallywith leaded avgas. Or maybe not. The numbers aren't nearly so convincing. Avgas accounts for less than one percentway lessof all the light motor fuel burned in the U.S., so airplane emissions are a tiny fraction of the total vehicle-originated pollution load. True, avgas might account for a large portion of the total lead pollution, but these days, that's not much.
So the question is, is it still too much? The Friends of the Earth say it is, thus they are petitioning the EPA to regulate lead out of existence as an octane additive. And that brings us up to date, as the EPA has ordered lead emission studies at a number of U.S. airports in advance of rulemaking to eliminate lead. This may turn out to be as much politics as science, but that's how things go these days.
First, Friends of the Earth. This group is a network of environmental activists, and it is not without resources. As card-carrying members of our own special interest group targeted by FOE, we might dismiss them as environmental wackos but this is, in my view, an infantile characterization. These are serious people. They have their agenda, we have ours. It's not impossible that they're right.
At issue is how airborne lead affects public health in general and children specifically. The FOE and EPA are arguing that epidemiological studies show that small differences in lead content can measurably impact IQ scores. By measurable, we are talking about 0.08 IQ point which, extrapolated to a larger population, means this: At a lead content of .06 micrograms per cubic meter, the number of children with IQs below 80 would rise to 10.66 percent from 10.56 percent if the same air were lead free.
While I consider myself sensitive to environmental issues, I'm not buying the science on this one. My J-school education was short on epidemiology, but I've covered enough of these issues to sense that this just doesn't add up. There are too many variables involved in IQ determination to split the hairs into tenths, never mind hundredths, even among large population groups. And how strong is this supposed correlation? Has it proven to be repeatable? Have other factors been ruled out?
I'm open-minded and willing to be convinced, but so far, no sale. To me, the science isn't a credible enough foundation upon which to build public policy. Further, the EPA hasn't been forthcoming on the methods used to measure airborne lead content around airports it has examined. Without that data, the science is ever more suspect.
One idea floating around is the so-called "Oshkosh experiment." This would involve placing lead monitors around the airport during AirVenture which is, arguably, the most intense piston GA event on the planet. While it sounds appealing, I'd be a little careful with this idea unless we as an industry are prepared to confront what we might find. Suppose the measured lead content is twice the .06 value? Or 10 times or 100 times? Now what? If those undertaking such an experiment are confident the lead value would be below the background noise, I'm all for it. If not, better be prepared for an answer you might not like.
My guess is that at times, there's enough activity at Oshkosh to spike a well-designed lead monitoring network. (Think about 30 or 40 airplanes idling on departure day.) But at typical airports in the U.S.even busy onesI seriously doubt lead pollution is significant. That's my gut feel for it. Yours might be different.
So, if I were setting public policy here, I'd leave lead in avgas alone. There are much larger public health issues to addresstobacco and obesity come to mindthan this one. If, on its own, the industry determines that unleaded fuels have other benefits, not the least of which is lower cost, then we should let lead go. But that's a market solution, not a regulatory one. I see that as a good thing.
You do hear this argument a lot: Well, there's only one source of TEL in the world and it's threatened. That's a reference to the Octel plant in the U.K. But let's wake up and smell the coffee. If that plant is phased out and there's still money to be made making and selling TEL, the Chinese will fall all over themselves to capture the market, if they aren't already.
TEL manufacture is nasty business, which may alone argue for phasing it out. But in my view, the public health case hasn't been made. What I'm sensing is a feel-good, group think momentum that accepts the notion that the only good lead is no lead when there may be no science to support that.
Over to you, FOE.