AN INDUCTIVELY COUPLED PLASMA-MASS SPECTROSCOPY (ICP-MS) AND ELECTRON MICROSCOPY ANTHROPOGENIC POLLUTANT CHARACTERIZATION OF POST-INDUSTRIAL GREAT MIAMI RIVER SEDIMENT IN HAMILTON, OHIO

In the Midwest, riverside manufacturing cities are plentiful and with the decline of industry a majority of these cities are experiencing a deterioration of their infrastructure along with general economic downturn. Hamilton, Ohio is a characteristic example of a post-industrial Midwestern city which has experienced the decline of manufacturing and industry within the city limits. The Great Miami River (GMR) runs through Hamilton and many of the city’s industrial buildings are lying vacant along its banks, including one paper mill and two coal-fired power plants; however, no extensive pollution studies have been carried out on the river sediment. In order to assess the extent of pollution present in the GMR sediment, samples were collected along the length of the river that runs through the city and separated into “bulk” and “fine” (≤40 µm). Through ICP-MS analysis a higher concentration of anthropogenic metals was identified in the fine fraction of the sediment. Electron microscopy (Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) and Scanning Transmission Electron Microscopy(STEM)) aided in identifying anthropogenic particulate within the river sediment. SEM analysis identified multiple pollution particulates including lead, barite, antimony, PbCrO₄ and coal spherules. Further elemental relationships were investigated using STEM which indicated a correlation between anthropogenic metals and Mn and Fe on phyllosilicates. A statistical analysis confirmed that a higher concentration of metals are present in the fine fraction of the sediment and identified six metals which were significantly above the concentrations observed in the reference materials: Zn, Sn, Sb, Cu, Pb and Sr. This study has proven that anthropogenic pollution can be identified in river sediment despite low levels of anthropogenic pollutants and that the pollutants found are of concern. Additionally, the electron microscopy added another dimension to this pollution study, allowing for the characterization of particles and identification or tentative identification of sources for pollution identified within the river sediment. Overall, this investigation lays the foundation for future detailed studies regarding the source and extent of pollution in the GMR and other post industrial river environments.