CHARACTERIZING POTENTIALLY HARMFUL ENVIRONMENTAL LEGACY ISSUES WITHIN A DECLINING MIDWEST CITY: A STREET SEDIMENT STUDY OF NORTHEASTERN TERRE HAUTE, INDIANA

Urban settings face unprecedented environmental challenges that include legacy issues as well as emerging pollution problems (e.g., micro-plastics) that continually impact the public health of its communities. Determining the baseline abundances of potentially harmful contaminants in soil, sediment, air, and water is essential to protecting residents. This study examines anthropogenic pollution in street sediments collected from three neighborhoods located in northeast Terre Haute, Indiana. Using stereomicroscopy, SEM/EDS, pXRF analyses, and geospatial analysis (GIS), the goal of this work is to characterize the types of pollutants present and place important constraints on their potential sources.

Stereomicroscopy on nine street sediment samples reveals several particle categories that include Fe-rich particles, glass spheres, organic matter, geogenic sediments, and other anthropogenic pollution (e.g., plastics). SEM/EDS analysis reveals Fe-rich spheres (~10 - 50µm), lead chromate (PbCrO₄) paint chips, glass micro-beads (<10 to >100µm), and other minor heavy metal particles. The Fe-rich spheres are consistent with technogenic spheres created by past steel manufacturing activities and possibly coal-fired power generation. We confirm that the lead chromate and glass micro-beads are sourced from weathered road paint chips. Eighteen bulk street sediment samples were analyzed by pXRF at DePauw University. Combined with GIS spatial analysis, we observe high concentrations of heavy metals (Pb, Zn, Cu, and As) that correlate with areas of past and present industrial and manufacturing activities (e.g., Terre Haute Malleable & Manufacturing Co.).

Understanding the types of particulates and their potential sources can be used to safeguard residents within these communities from the potential health hazards associated with long-term exposure to these pollutants.