A new Oregon study shows that small planes that burn leaded fuel may be leaving behind a much larger footprint than nearby residents realize.
According to the research, moss growing near two regional airports in the Portland area contained lead at levels up to seven times higher than moss sampled elsewhere in the city, and researchers traced most of that contamination to aviation gas.
Here's what to know
In the study, published by Communications Sustainability, scientists from Oregon State University and Portland State University sampled tree moss in neighborhoods surrounding the Hillsboro and Troutdale airports.
As Oregon State University revealed in a news release, they then used isotopic fingerprinting to separate lead from aircraft fuel from remnants of older pollution sources such as past car gasoline.
Corresponding author Alyssa Shiel said piston-engine aircraft account for a significant share of lead pollution.
"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 war planes — remain the largest remaining source of airborne lead emissions in the country," Shiel said in the release.
TCD Picks » Quince Spotlight
💡These best-sellers from Quince deliver affordable, sustainable luxury for all
Fellow corresponding author Dean Atkinson said the moss samples showed where pollution was settling on the ground.
"Using moss as a natural sensor gives us a clear, ground-level picture of where airborne lead settles in nearby communities," he explained.
The study found the highest lead readings nearest the runways, though aviation-related lead was measurable as far as three-quarters of a mile away.
More background
The release noted that more than 19,000 airport facilities across the United States serve piston-engine aircraft that emit lead. Shiel said regional airports can produce more of this kind of pollution than major international airports because they get more traffic from planes that use leaded gas.
Exposure is not limited to breathing polluted air, as lead that falls onto soil and dust can create another route of contact. Children are especially vulnerable to lead, a toxic metal that can contribute to developmental delays, learning difficulties, and behavioral problems.
Shiel said the contamination can persist.
"These emissions don't simply break down over time, they stay in the soil until it's remediated or removed," Shiel noted in the release. "People can be exposed to lead from aviation emissions in two ways: directly from the air or through lead that accumulates in local dust and soil."
Though lead contamination at airports is already well documented, this study offers a clearer picture of how it affects nearby neighborhoods at ground level.
What can be done?
The Federal Aviation Administration, together with private partners, is working to move piston-engine aircraft away from leaded aviation gasoline. The goal is to end its use by the end of 2030.
Residents can use an interactive website created by Shiel to look up airport lead levels near their neighborhoods and read about possible exposure risks. The site also outlines ways families can reduce contact with contaminated soil and dust.
Suggested precautions include taking shoes off at the door, washing homegrown produce, and reminding children to wash their hands frequently, especially after outdoor play and before eating. If parents near these airports fear their kids are exposed, Shiel encourages action.
"Seeking a blood lead level test or soil testing would be a reasonable course of action for concerned families," Shiel said in the release.
Where can I learn more?
Air pollution doesn't affect every neighborhood the same way. These articles look at how other communities are dealing with toxic pollution and how transportation systems can shape public health.
• In California, disadvantaged communities are still suffering from health problems despite cleaner air.
• In Southern communities, a cesspool of pollution has intensified concerns over ethylene oxide exposure.
• In the Netherlands, bicycle-friendly infrastructure can improve health, safety, and daily mobility.
Seen alongside Portland's airport lead problem, these stories show that neighborhood health risks often come from several overlapping sources. They also help explain why it matters to know who is most exposed and how communities respond.
Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.
