Lead paint was banned in the United States in the 1970s. Leaded gasoline was slowly phased out over the next 20 years. Those efforts drove one of the great public–health improvements of the past century. The amount of lead found in human bloodstreams has dropped 90 percent.
But across the nation, hundreds of thousands of engines still run on leaded gas. Why is anyone still burning fuel with such a brain–damaging substance in it? John Ryan brings us this KUOW investigation.
TRANSCRIPT
I'm lying on my back on a picnic table in a tiny county park called Ruby Chow Park. It's in south Seattle, and it's not your typical county park. It actually sits right next to the state's largest source of a very toxic kind of pollution.
Sound: (Small plane overhead)
Ruby Chow sits right next to Boeing Field airport. More lead goes into the air here at Boeing Field than anywhere else in Washington state. Boeing Field is the state's busiest airport for the small planes that still use fuel with lead in it.
Sound: (Fuel pump)
At the north end of Boeing Field, tanker trucks pump two kinds of airplane fuel into underground tanks. Most of that fuel is jet fuel. Jet fuel doesn't have any lead. But the aviation fuel known as "avgas" does. The lead gives the fuel extra oomph.
Gary Molyneaux is the head planner at King County International Airport, also known as Boeing Field. We spoke about avgas on the tarmac at Boeing Field.
Molyneaux: "It represents a really small proportion of our fuel usage here at the airport."
That's also true nationwide. Avgas accounts for less than 1 percent of the nation's liquid fuel use. Yet enough piston&ndas;engine planes fly enough miles on avgas to belch out half of all the lead going into the nation's air.
John Ryan: "So I wonder if anybody at King County is concerned about lead emissions from one of its facilities?"
Molyneaux: "Concerned? Yes. Watch it? Yes. But right now, there is simply not enough data in the stream to understand it. It may be the largest, but does it reach the federal standard?"
Ryan: "Is anybody monitoring lead emissions or concentrations here?"
Molyneaux: "Here at the airport? No."
In fact, monitoring of airborne lead in the Puget Sound region stopped back in 1999. That was a year after a lead smelter on Seattle's Harbor Island shut down. The Puget Sound Clean Air Agency says, "Airborne lead is no longer a public health concern in the Puget Sound region."
But recent research has found lead is harmful at much lower levels than previously thought. And it's most harmful to children.
Sound: (Children squeal and laugh)
It's recess at Van Asselt Elementary on Seattle's Beacon Hill. First–graders squeal over the whoosh of I–5 and the occasional plane taking off from Boeing Field, just downhill and across the highway. As the crow — or the small plane — flies, it's just a quarter mile from Boeing Field to the school.
Researchers say that's close enough to raise the levels of lead in children's blood. Marie Lynn Miranda is an environmental health scientist and a dean at the University of Michigan. She's examined the lead exposure of children living within a kilometer of airports in North Carolina. That's about twice the distance from Boeing Field to Van Asselt Elementary.
Miranda: "Living close to an airport can increase your blood lead level anywhere from 2 to 4 percent. That's small. But we're getting more and more evidence that indicates even very small amounts of lead is bad."
Small doses of lead can damage young brains and nervous systems in lots of ways.
Miranda: "Decreases in IQ, changes in test scores, changes in attention, hearing threshold, all sorts of things like that."
Miranda says lead from crumbling paint in old buildings remains a much bigger threat to children's health.
Miranda: "But the reality is that exposure to aviation gasoline contributes to children's exposure to lead, something that we have known for a very, very long time is bad for children."
Earlier this month (January), an expert panel advising the Centers for Disease Control and Prevention cut in half the levels of lead in children that should alarm parents or doctors. Researchers have yet to find any level of lead exposure that doesn't cause harm.
Sound: (Small plane overhead)
Hundreds of small airports and airstrips are scattered across the Northwest. Washington state ranks fifth in the country for lead emissions from airplanes. Per person, all the Northwest states use more avgas than the national average.
But remember that America's air and Americans themselves contain a lot less lead than they did before the 1980s.
Researchers say the effects of lead in low doses can be subtle. Michael Kosnett is a medical toxicologist at the University of Colorado.
Kosnett: "In any one child, it's not something that's going to necessarily cause them to display any kind of signs and symptoms. But if you can lower the lead exposure of a population of children, you're going to give that population more of an opportunity to have gifted children and to have children who have higher IQs, and that's certainly a desirable public health goal."
Marie Lynn Miranda says lead is especially a problem for the low–income families that are most likely to live near airports.
Miranda: "Anything we can do to drive down children's exposure to this substance that we know is bad for them is something that we as a country should be pursuing."
Ryan: "But to reduce exposure to the last atom of lead is not possible. Is there a point beyond which you just have to say, 'We've done enough, and we should focus our efforts on some other public health problem?'"
Miranda: "Yes, but we're not at that point."
Man: "Clear!"
Sound: (Float plane engine starts)
Rob Richey: "These are air–cooled engines, so you have to warm them up slowly on a morning as cold as this."
Rob Richey stands on the dock at Kenmore Air Harbor on Lake Washington. It's a little below freezing as his crew starts up a float plane. Richey is Kenmore Air's director of maintenance. All of Kenmore's float planes are decades old, some going back to the 1950s.
Ryan: "Why is that?"
Richey: "There actually isn't a plane currently made that can do what these old airplanes can do. Their capability, short takeoff and landing, safety."
Richey says the old Canadian–built planes just go and go and go.
Richey: "Everybody who works here just loves these planes. So it is a bit like a taxi company operating a 1956 Checker cab."
Richey says about half of Kenmore's business depends on planes that burn leaded fuel.
Richey: "Honestly, if leaded fuel without an alternative is removed, our industry will be dead. If a fuel could be developed that was lead–free, it's fine with us. But because our market is so small, whether the big refiners go to the trouble to make it, that's the big question."
Lars Hjelmberg says there's no need to wait for unleaded avgas. Three European companies, including his, already sell it.
Hjelmberg: "Our fuel is about 40 cents cheaper per US gallon, and it has been so for three decades."
Ryan: "Cheaper?"
Hjelmberg: "Yes. The lead compound which is added into the fuel is a very expensive compound, and it's toxic. It's dangerous to work with, and it's a really awful compound to handle."
Hjelmberg owns Hjelmco Oil in Stockholm. He says Hjelmco sells unleaded avgas at about 90 airports in Scandinavia and Japan. But he's had no luck trying to break in to the much bigger American market.
Hjelmberg: "Because no one thinks that there will be demand for an unleaded–grade aviation gasoline."
Unleaded fuel doesn't work in all small planes. But Hjelmberg says it's approved for use in 90 percent of the world's airplanes that now burn leaded fuel.
Almost every nation on earth has banned lead in motor gasoline. The United Nations Environment Programme expects the six holdouts, including Iraq and North Korea, to follow suit this year or next.
But there's no end in sight for the use of lead in small airplanes.
The group Friends of the Earth petitioned the US Environmental Protection Agency (EPA) five years ago to get the lead out of aviation fuel. In just the past month, the EPA has started a pilot project to monitor airborne lead at 15 airports. The list includes two in the Northwest: Harvey Field in Snohomish and Auburn Municipal Airport south of Seattle.
Auburn KinderCare, Cascade Middle School and Dick Scobee Elementary all sit less than half a mile from the Auburn runway.
The EPA has told the aviation industry that there's no timeline for making any decisions on the lead in aviation fuel.
