Moss biomonitoring and isotopic signatures reveal aviation fuel as local lead source near Oregon airports

Lead emissions from piston-engine aircraft using leaded aviation gasoline (avgas) remain a significant source of environmental contamination near regional airports, posing potential health risks to nearby communities. Passive biomonitoring using the epiphytic moss Orthotrichum lyellii was combined with lead isotope fingerprinting to quantify lead concentrations and distinguish between legacy leaded gasoline and current avgas emissions near Hillsboro and Troutdale airports in Oregon. Here we show that lead levels are elevated by up to 50 times the rural background near airports, with isotopic signatures confirming avgas as a dominant local source. These findings indicate that avgas use contributes substantially to environmental lead burdens in adjacent residential neighborhoods. Moss biomonitoring offers a cost-effective approach for detecting and mapping lead pollution from airport emissions, supporting efforts to evaluate exposure risks and inform regulatory actions aimed at reducing lead exposure from aviation sources. Lead near airports rises up to 50 times above background with isotopic evidence identifying aviation gasoline as the dominant source, indicating substantial residential contamination, according to moss biomonitoring using Orthotrichum lyellii and lead isotope fingerprinting in Hillsboro and Troutdale, Oregon.