Nitrogen dioxide (NO₂) in the atmosphere is a harmful pollutant that is principally generated from combustion of fossil fuels, and contributes to acid rain, photochemical smog, and lung irritation. Measurement of atmospheric NO₂ with simple diffusion-based sensors at several locations provides data that can be mapped to give spatial representations. In this research NO₂ levels were measured at several different locations in the Emporia, Kansas area. Sensors were systematically placed on the corners of 1.0 x 0.5 mile grids to ensure the inclusion of industrial, high traffic and rural areas. Measurements were taken at ten-day intervals and weather conditions were monitored. Sensor coordinates and measured concentrations of NO₂ at each location were placed in a geographic information system (GIS), and maps were created to show the spatial distribution of the pollutant. Most locations exhibited stable results, but some gave erratic concentrations. This poster presents results, and predicts possible NO₂ sources.