Small-Plane Fuel Raises Lead Levels Up to Sevenfold Near Oregon Airports, Study Finds

Emissions from small aircraft that use leaded aviation gasoline are a significant source of lead pollution in neighborhoods near regional airports, according to a new study by researchers at Oregon State University and Portland State University, published in Communications Sustainability. Lead levels were found to be as much as 7 times higher near two Portland-area regional airports than in other parts of the city, with aviation fuel as the dominant local source.

"While lead was phased out of motor vehicle gasoline decades ago, piston-engine aircraft - small planes such as single-engine trainers, light twin-engine planes, agricultural crop dusters and vintage warplanes - remain the largest remaining source of airborne lead emissions in the country," said Alyssa Shiel, an environmental geochemist at Oregon State University and one of the study's corresponding authors. Lead is highly toxic, and children are particularly vulnerable to exposure, which can cause developmental delays, learning difficulties and behavioral issues.

Shiel and Dean Atkinson, an atmospheric chemist at Portland State University and the study's other corresponding author, collected tree moss from neighborhoods near the Hillsboro and Troutdale airports in Oregon, two of the state's top three lead emitters. Moss absorbs contaminants directly from the surrounding air, giving researchers a ground-level picture of where lead settles. Using a technique called isotopic fingerprinting, which distinguishes lead from different sources by their distinct chemical signatures, the team confirmed aviation fuel as the dominant local source. The highest concentrations were found nearest the runways, but lead from aviation fuel was detected as far as three-quarters of a mile (about 1.2 kilometers) away. More than 19,000 airport facilities nationwide serve piston-engine aircraft.

Shiel said future research will focus on soil testing, since children are primarily exposed to lead through ingesting contaminated soil and dust, and recommended steps such as removing shoes at the door, washing homegrown produce and washing children's hands frequently. The Federal Aviation Administration and private partners are working to eliminate leaded aviation gas in piston-engine aircraft by the end of 2030. The study's lead author is Oluwaseyi Aderinboye, a doctoral candidate at Portland State University.