Monitoring lead deposition around airports using bulk deposition samplers

Piston-engine aircraft that use leaded fuel represent the largest source of atmospheric lead in the United States. Lead levels are elevated in the atmosphere, soil, and in the blood of children that live close to and down-wind from airports. But statistical models examining the health effects of lead exposure near airports indicate that more refined and higher-resolution data are needed to better connect lead sources with human health effects. To address this, we tested the efficacy of bulk deposition samplers for quantifying the deposition of lead around Bellingham International Airport (BLI), an airport that is similar to approximately 1700 single-runway airports in the United States. We measured rates of lead deposition down-wind of BLI (4.8 μg Pb m^-2d^-1) that were twice as high as the average rate of lead deposition south and east of the airport and at a control site 6.7 km away from BLI (average rate, 2.3 μg Pb m^-2d^-1). The spatial pattern of lead deposition was consistent with prevailing winds and aircraft take-off trajectories during the sampling period. These data indicate that bulk-deposition samplers are useful for quantifying the rates and spatial distribution of lead deposition around airports. Their low cost, ease of deployment, and efficiency of sample collection indicate that bulk deposition samplers can generate the high-resolution data on lead deposition necessary for better assessing the transport direction of lead emissions from airports.