Bioavailable Lead in Topsoil Collected from General Aviation Airports

Abstract

Representatives of the aviation community are interested in determining the environmental effects of leaded fuel emissions from general aviation flight operations. Soil is an environmental sink for lead to accumulate over time. This study measured bioavailable lead concentrations in topsoil at three general aviation airports and at one site with no general aviation operations in order to determine if general aviation aircraft operations are contributing to the contamination of airport topsoil at levels that require remediation by law. Bioavailable refers to substances that organisms can absorb, because they have access to them. Topsoil was collected from refueling areas, run-up areas, and approach corridor/departure end runways. The samples were dried and the fine fractions were separated. The fine fractions were suspended in nitric acid to extract the lead for laboratory analysis. A univariate ANOVA was computed comparing the quantity of soluble lead in the topsoil from three general aviation airports (further classified as high, moderate, and low volume of flight operations) and at one site with no general aviation operations (arboretum). A significant main effect for the high volume airport was found (F[2, 24] = 10.966, p < .05), in which the lead in topsoil samples from high volume airports were lower than the samples from the other airports, but similar to the arboretum. Another analysis was calculated comparing quantity of soluble lead in topsoil at sites within airports (refueling areas, run-up areas, and approach corridor/departure end runways). No significant main effect was found among the sites (F[4, 24] = 1.065, p > .05). However, an interaction was observed when comparisons were made between the airport sites (n = 3) and locations sampled at the sites (n = 3) that was significant (F[4, 24] = 2.902, p < .05). Tukey’s HSD was used to determine the nature of the differences. The analysis revealed that concentrations of lead in soil samples collected from the high volume airport refueling area, run-up area, and approach corridor/departure end runway were significantly lower than the moderate volume airport run-up area lead concentrations. The results at the three airports investigated support the conclusions that the risk of ingesting lead from surface soils is low and bioavailable lead in the soil sampled from general aviation airports is not accumulating in quantities that require remediation according to Environmental Protection Agency requirements.