ESTIMATION OF EXPOSURE TO GAMMA RADIATION OUTDOORS IN THE CITY OF GOIÂNIA – 28 YEARS AFTER THE RADIOLOGICAL ACCIDENT AS CESIUM 137

Leonardo Bastos Lage, Eliane Eugênia dos Santos, Rosangela da Silveira Corrêa, Nivaldo Carlos Silva, Nilson Clementino Ferreira, Ruffo Freitas-Júnior,

Institution: Comissão Nacional de Energia Nuclear

“AbstractOBJECTIVE: Estimate levels of exposure to gamma environmental radiation in the city of Goiania. METHODOLOGY: The ionizing radiation doses were estimated from measurements taken between 2010 and 2014. We used the geographical division of the city in census tracts and Health Districts that characterize the demographic and epidemiological situation of the population. A mobile system for environmental radioactivity measurement was used. The equipment was installed on a motor vehicle to a height of one meter above the ground. Data was collected every second from dose rate measurements absorbed in the air, geographic coordinates, altitude, date and time of acquisition. From the software MobiSys, files were generated and through the ArcGIS platform, was held geospatial assessment survey through the development of thematic and geospatial analysis statistical maps. It included only census tracts in which dose rate measurements were obtained and had the resident population. The average annual effective dose and collective effective dose was estimated from the dose rate and the resident population in the census tract. RESULTS: Of the 1,636 census tracts survey was conducted on 1,405 of these (85.9%). They were obtained 197 811 dose rate measures the air absorbed georeferenced averaging 29.85 nGy/h and range between 9.2 to 629.9 nGy /h. From there, they were estimated average annual effective dose and collective effective dose has been found the values of 0.036 mSv/year and 28.51 ± 11.6 homem.mSv/year respectively. The total estimated population was 1,302,001 inhabitants. Conclusion: The levels of exposure to gamma environmental radiation found in the city of Goiania, they are low and are in agreement with according to established norms and standards of national and international organizations. They do not cause losses to the public and the environment.Ionizing radiation, Risk factor, Environmental monitoring, Public health, Goiania, Brazil”