title: Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.
abstract: Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.
authors.affiliation: Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Perif. Francisco R. Almada km 1, 31415 Chihuahua, Mexico. sergio7_mex@hotmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: Luevano-Gurrola
authors.affiliation: Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Perif. Francisco R. Almada km 1, 31415 Chihuahua, Mexico. angelicapereztapia0308@gmail.com.
authors.forename: Angelica
authors.initials: A
authors.lastname: Perez-Tapia
authors.affiliation: Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Perif. Francisco R. Almada km 1, 31415 Chihuahua, Mexico. cpinedo@uach.mx.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Pinedo-Alvarez
authors.affiliation: Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Mexico. carrillo@cimav.edu.mx.
authors.forename: Jorge
authors.initials: J
authors.lastname: Carrillo-Flores
authors.affiliation: Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Mexico. elena.montero@cimav.edu.mx.
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Montero-Cabrera
authors.affiliation: Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Perif. Francisco R. Almada km 1, 31415 Chihuahua, Mexico. mrenteria@uach.mx.
authors.forename: Marusia
authors.initials: M
authors.lastname: Renteria-Villalobos
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D001417:Background Radiation; D002947:Cities; D005720:Gamma Rays; D006801:Humans; D008800:Mexico; D011197:Potassium Radioisotopes / Q000032:analysis; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011883:Radium / Q000032:analysis; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma; D013910:Thorium / Q000032:analysis
chemical_list: D000396:Air Pollutants, Radioactive; D011197:Potassium Radioisotopes; D012990:Soil Pollutants, Radioactive; D013910:Thorium; D011883:Radium
keywords: Chihuahua; health risk; kriging; radiation dose; radioactivity mapping