Data-base construction for a computerized radiological-risk investigation system

Oak Ridge National Laboratory developed a Computerized Radiological Risk Investigation System (CRRIS) to assess chronic exposures from atmospheric radionuclide releases. Previously, CRRIS population and agricultural data were tabulated on 1/2 degree square grid cells, which resulted in anomalies, such as population in water bodies and agriculture in cities. These difficulties were overcome by using Thiessen polygons to apportion an area to individual census enumeration districts and exclude population from unpopulated areas (e.g., large water bodies). This article discusses the data base construction using examples from Tennessee and Pennsylvania. 10 refs., 5 figs