Application of Field Portable X-Ray Fluorescence and GIS Spatial Analysis techniques for soil metal analysis in Northwest Indiana
Abstract
There are many metals present in industrial processes and these metals can be discharged into the environment through air and water, which can then deposit out onto soil. Exposures to metals in concentrations greater than the recommended standards present the potential for overexposure to members of the surrounding community which can develop into unwanted negative health effects. Some metals that create an impact on health from overexposures are Pb, Mn, Cd, As, Zn, and Hg. In areas where metal production manufacturing processes such as steel mills and foundries are present Pb and Mn contaminants are often of greatest concern. The main objective of this study is to investigate whether environmental soil metal concentrations in Northwest Indiana can be used as a surrogate indicator for community exposures to metals, by: 1) measuring Mn and Pb soil concentrations to see if they are greater than criteria and background levels in the designated study area within Lake County; 2) investigating whether Mn and Pb soil levels will increase with decreasing distance to industrial sites; 3) determining Mn and Pb isopleths concentration gradients using Spatial Analysis techniques; 4) calculating the number of people residing in areas with greater than background levels; and 5) determining if a correlation exists between air and soil levels. The concentrations of Pb and Mn were analyzed in 135 randomly chosen soil samples located throughout Northwest Indiana using a Field Portable X-Ray Fluorescence (FP-XRF) device. The results show that Pb and Mn concentrations are greater than background levels, and Pb and Mn concentration gradient isopleths do correlate with distance from potential industrial sources. The environmental exposure assessment shows that 6494 people reside in areas with to Mn concentrations greater than 900 ppm and 25,692 people reside in area with Pb concentrations greater than 25 ppm.
Degree
M.S.
Advisors
Zimmerman, Purdue University.
Subject Area
Environmental Health|Public health
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