RESUMO
In a 55-year-old woman, the medial medullary syndrome developed owing to infarction of the left medullary pyramid, ventromedial portion of the inferior olivary nucleus, medial lemniscus, and hypoglossal nerve. The previously reported 14 cases of the medial medullary syndrome are reviewed, and their clinical features and topography of the medullary lesions are discussed. Like the lateral medullary syndrome, the medial medullary syndrome is closely associated with hypertension and atherosclerosis but has a higher incidence of bilateral involvement and a worse prognosis.
Assuntos
Infarto Cerebral/complicações , Encéfalo/patologia , Encefalopatias/etiologia , Encefalopatias/patologia , Infarto Cerebral/patologia , Feminino , Hemiplegia/etiologia , Humanos , Bulbo/patologia , Pessoa de Meia-Idade , SíndromeRESUMO
Members of the public are becoming increasingly interested in understanding risks associated with their exposure to radionuclides and chemicals in the environment. They also want to be more involved in decision making about future exposures to risks. This paper reviews one community's involvement in decisions about technical methods to calculate soil cleanup criteria for the Rocky Flats Environmental Technology Site near Denver, Colorado. The public anticipated that much of the site would be available for their use following cleanup. Final decisions regarding the future use of the site have yet to be made; however, the soil action levels were developed for this eventuality. When the public expressed considerable concern about cleanup standards for the site in 1996, a community group met to focus efforts on reviewing the cleanup standards. Later, the U.S. Department of Energy officially established the community panel to oversee an independent calculation of radionuclide soil action levels that would be used as the basis for cleanup at Rocky Flats. The primary radionuclide of concern was 239+240Pu. The Radionuclide Soil Action Level Oversight Panel (Panel) was substantively involved in all aspects of the work, from selecting the contractor, approving the computer code that formed the basis of the calculation, and assisting in developing the exposure scenarios, to selecting the values for the numerous input parameters. Communicating the uncertainties to the public, which was a major component of the analysis of soil action levels, presented a unique challenge. Over the course of the 18-mo project, the Panel and interested members of the public gained an understanding of the technical elements of the calculation and the sensitivities of the different parameters. This project serves as an excellent model of the effectiveness of public involvement in science and decision making for the future. It also illustrates the public expectations, difficulties, and time commitments encountered when making scientific decisions in a public forum. Although the process was time consuming for the scientists responsible for the calculations, a more technically defensible as well as publicly acceptable soil action level emerged. The technical approach developed during the project has been recommended for use as a decision-making tool for cleanup of the site.
Assuntos
Participação da Comunidade , Tomada de Decisões , Poluentes Radioativos , ColoradoRESUMO
The Feed Materials Production Center, northwest of Cincinnati, processed uranium concentrates and uranium compounds recycled from other stages of nuclear weapons production, as well as some uranium ore and thorium. Particulate releases were primarily uranium (natural, depleted, and slightly enriched. In addition, two large silos containing radium-bearing residues were emission sources of radon and its decay products. The Fernald Dosimetry Reconstruction Project was undertaken to help the Centers for Disease Control and Prevention to evaluate the impact of the Feed Materials Production Center on the public from radionuclides released to the environment from 1951 through 1988. At this point in the study, the project has estimated the quantities of radioactive materials released to air, surface water, and in groundwater; developed the methodology to describe the environmental transport of the materials; developed mathematical models to calculate the resulting radiation doses; and evaluated environmental monitoring data to verify that the estimates of releases and transport are reasonable. Thorough review of historical records and extensive interaction with former and current employees and residents have been the foundation for reconstructing routine operations, documenting accidents, and evaluating unmonitored emission sources. The largest releases of uranium to air and water occurred in the 1950's and 1960's. Radon releases from the silos remained elevated through most of the 1970's. The quantity of uranium released to surface water was much less than that released to air. Best estimates of releases are reported as median values, with associated uncertainties calculated as an integral part of the estimates. Screening calculations showed that atmospheric pathways dominate the total dose from Feed Materials Production Center releases. Accordingly, the local meteorology, effluent particle size and chemical form, and wet and dry deposition, were particularly important in this study. The final goal of the project is the calculation of radiation doses to people living in the study domain, which is represented by a circle with radius of 10 km centered on the Feed Materials Production Center production area.