Arsenic presents complex spatial occurrence trends that can be difficult to identify andunderstand. The objective of this study was to understand geographic trends in arsenic occurrence using avisualization technique. The approach taken was to link geospatially referenced arsenicconcentration information from a water quality database with elevation data contained in DigitalTerrain Elevation Data (DTED) files. DTED files are available for all land masses across theworld for public download. This allows for the development of three-dimensional plots ofarsenic concentration and topography. The plots developed in this manner show that high arsenicis associated with the transition from plains to piedmont in New Jersey. In Oklahoma, higharsenic is found along the North Canadian River Valley. In New Mexico, concentrations aregenerally high in the Rio Grande Valley, but there is also an area of low concentration in the southernportion of this valley. In California, arsenic concentrations are high in the middle of the CentralValley, but moderate somewhat toward the edges. These results are consistent with mobilizationof arsenic by reductive processes in the organic-rich sediments of river valleys, but furtherstatistical analysis is required to confirm the significance of this association. The visualizationsoftware used here is broadly applicable, and a user guide for this software is available onrequest. Includes 9 references, figures.
