MINERALOGY OF LEAD IN LEAD-CONTAMINATED SOILS IN PHILADELPHIA, PA

The purpose of our study is to determine the mineralogical composition of soil samples collected from the city of Philadelphia using powered x-ray diffraction. These samples have been previously analyzed for the abundances of elemental heavy metals using the handheld x-ray fluorescence analyzer and were found to contain various concentrations of lead (Pb) that reached a peak of 3300ppm, over 8 times the EPA Standard for Pb in residential soil where children are exposed. There was a general correlation between the amount of lead in a surface soil sample and two different factors: historical usage of the land and the age of the structure adjacent to the sampling site. These mineralogical data will further our investigation of the identified Pb by getting a better understanding of its sources, being either natural or anthropogenic. By obtaining more information on the sources of Pb, we can begin to determine the biological availability of the Pb and ultimately, its fate in the environment.