40K, 226Ra AND 228Ra SERIES IN BOVINE AND POULTRY FEED AND IN DICALCIUM PHOSPHATE (DCP) SAMPLES BY GAMMA-RAY SPECTROMETRY

The aim of this study is to determine the amounts of radionuclides' activity present in samples of feed for young and adult chicken and feed for dairy and beef cattle, as well as in dicalcium phosphate (DCP) (CaHPO4), used as a nutritional supplement for animal feed. Radioactivity in these samples is due to the presence of the 238U and 232Th radioactive series, as well as their daughter. In addition, as it is for environmental samples, the activity of 40K should be an important source of radioactivity in all analyzed samples. Gamma rays were measured using a standard spectroscopy system, with a high-resolution HPGe detector. Measured activities in feed samples ranged from 0.23 to 1.51 Bq.kg-1, 0.67 to 4.21 Bq.kg-1, 0.29 to 1.63 Bq.kg-1 and 236 to 402 Bq.kg-1 for 226Ra, 228 Ra, 228 Th and 40K, respectively. Measured activities in DCP samples were 46.6 Bq.kg-1, 83 Bq.kg-1, 4.20 Bq.kg-1 and 16.61 Bq.kg-1 for 40 K, 226 Ra, 228 Ra and 228 Th, respectively. Although 40K activity has reached hundreds of Becquerel in feed samples, it should not represent a risk to human health, not even to animals, since potassium is an essential mineral to living organisms.

Niveles de radionúclidos naturales y metales pesados en suelos urbanos de la ciudad de Cienfuegos, Cuba / Heavy metal and natural radionuclide levels in urban soils from Cienfuegos city, Cuba

Se determinan las concentraciones de metales pesados y radionúclidos naturales en suelos superficiales (0-10 cm) de la ciudad de Cienfuegos, Cuba, mediante las técnicas de fluorescencia de rayos X y espectrometría gamma respectivamente. Los resultados de la medición de metales pesados mostraron que las concentraciones promedio de Ni, Cu, Zn y Pb en los suelos estudiados son superiores a los valores correspondientes de fondo. El cálculo del Índice de Polución Integral permitió determinar que estos suelos presentan una contaminación severa por metales pesados. Las concentraciones de , y en los suelos urbanos de Cienfuegos se encuentran en los intervalos de 8.3-32.7, 3.7-10.7 y 129-356 , con promedios de 22.6, 6.3 y 272 respectivamente, valores que son similares a los reportados para la zona Centro-Sur de Cuba. La tasa de dosis absorbida en aire y la dosis equivalente efectiva anual que recibe la población local producto de la radiación natural es inferior a los límites establecidos internacionalmente. Se determinaron correlaciones positivas significativas de -Cu y -Zn, indicando la posible presencia de una fuente de contaminación por estos elementos en la zona.

Concentrations of heavy metals and natural radionuclides in topsoil (0-10cm) from Cienfuegos city, Cuba, were determined by using X-ray fluorescence analysis and gamma ray spectrometry, respectively. The measured results of heavy metals show that the mean concentrations of Ni, Cu, Zn and Pb in the studied soil samples are higher than their corresponding background values. The calculated results of integrated pollution index of heavy metals indicate that the studied soils present severely heavy metal contamination. The concentrations of , and in the studied soil samples range from 8.3 to 32.7, 3.7 to 10.7 and 129 to 356 with an average of 22.6, 6.3 and 272 , respectively, which are similar than the average concentrations reported for South-central Cuban soils. The air absorbed dose rate and the annual effective dose equivalent received by the local residents due to the natural radionuclides in soil are lesser than the worldwide established limits. A significantly positive -Cu and -Zn correlations were determined, indicating the possible existence of a source of pollution due to the presence of these elements in the area.

Investigation the natural radioactivity in local and imported chemical fertilizers

In order to assess the radioactive level in the environment, the specific activities of 238U, 232Th and 40K were measured by using a gamma ray spectrometer based on a NaI(Tl) detector. The results showed that the specific activities of 238U, 232Th and 40K were 12.846-88.585, 1.304-26.656 and 11.598-2275.896 Bq/kg respectively. The radium equivalent activity was also calculated which varied from 0.893 to 175.244 Bq/kg. The radium equivalent average values were lower than the world average. In general, the highest level of radium equivalent value was in leafy type NPK fertilizers. The urea type had no radionuclide. The specific activity and absorbed dose rate at 1m above the ground surface (nGy/h) after NPK fertilizers agricultural applications were calculated and the maximum value of dose rate was 0.15 percent of the world average outdoor exposure due to terrestrial gamma radiation.

Evaluación de la carga radiacional sobre pacientes y trabajadores en el balneario Elguea, Cuba / Radiological impact assessment on patients and workers at Elguea spa

RESUMEN Los balnearios de aguas termales procedentes de capas geológicas profundas se han identificado como escenarios típicos de exposición a radiaciones de origen natural, tanto para los pacientes que se someten a los tratamientos como para los trabajadores de estas instalaciones, debido a la permanencia en lugares con niveles incrementados de radiación. Por ello se realizan en estos balnearios estudios de caracterización dirigidos a evaluar el impacto radiológico que producen sobre estas categorías poblacionales. El balneario de Elguea, ubicado en la costa norte de Villa Clara, está equipado para brindar servicios que emplean las aguas termales y los lodos en la zona del balneario. Las aguas de este balneario contienen niveles significativos de radón. En este trabajo se presentan las estimaciones de dosis realizadas a partir de la caracterización radiológica del balneario y su entorno, tanto para los trabajadores como para los pacientes que reciben tratamientos. Los valores de dosis estimados se encontraron en el intervalo de 1,01 a 180 μSv/año para los trabajadores, que resultó ser el grupo más irradiado, y no indicaron la necesidad de adoptar medidas o regulaciones especiales de protección.

ABSTRACT The use of hot spring waters from deep geologic layers in spas has been identified as typical scenarios of exposure to natural radiation. These scenarios can affect the patients under treatment, as well as the workers of these facilities. Therefore, characterization studies are being undertaken in these spas in order to evaluate the radiological impact they produce on these categories of population. The Elguea Spa, located on the northern coast of Villa Clara, Cuba, is equipped to provide services by using hot spring waters and mud existing in the zone of the spa. Its waters contain significant levels of radon. Present paper shows the dose estimates made from the radiological characterization of the spa and its surroundings, both for workers and the patients receiving treatment. The dose values are in the range of 1,01 to 180 μSv/year for workers, the most irradiated group, and these results suggest that there is no need for special protection measures or regulations.

Impacto radiológico de las fuentes naturales y artificiales de radiación. El informe UNSCEAR 2008 / Radiological impact of artificial and natural radiation sources. UNSCEAR 2008 Report

RESUMEN Se presentan los resultados del informe del Comité Científico de Naciones Unidas para el Estudio de los Efectos de las Radiaciones Atómicas presentado en el 56período de sesiones de julio del 2008 y se comparan los valores obtenidos según los tipos de fuentes naturales o artificiales y de acuerdo con el efecto sobre las personas. Se concluye que el cambio más significativo en la situación entre informes fue el aumento en la exposición médica debido al incremento de los exámenes de tomografía computarizada.

ABSTRACT The present paper shows the results of the report from the United Nations Scientific Committee on the Effects of Atomic Radiation, presented at the 56th session on July 2008. The values obtained according to the types of natural or artificial sources and their effect on people are compared. It is concluded that the most significant change in the situation has been the increase in medical exposure due to the increase in CT examinations.

Study on the ecological association between natural radioactivity and childhood leukemia in Guangdong province / 中华流行病学杂志

Objective This study was undertaken to evaluate the ecological association between terrestrial natural radionuclide,indoor radon concentration,natural radioactivity and leukemia incidence among children under 18 years of age.Methods Data were gathered from the disease surveillance program and literature reading while software SPSS 13.0 was used to calculate the Spearman's correlation.Results The incidence rates of childhood(0-18 year)leukemia showed significant differences in different places with the highest as 3.13/105in Jiangmen area and the lowest as 0.42/105 in Maoming area.The incidence in Jiangmen was 7.45 times higher than that in Maoming.There was a rank correlation between the incidence of childhood leukemia and the mean concentrations of natural radio-nuclides in soll(226Ra and 232Th),with a Positive correlation observed for overall leukemia(rs=0.70,P=0.011;rs=0.66,P=0.02 for226 Raand 232Th respectively)and acute lymphoblastic leukemia(ALL)(rs=0.66,P=0.019;rs=0.64,P=0.025 for 226 Ra and 232Th respectively).Associations between the incidence of childhood leukemia and the indoor γ radiation dose rate,the total annual average effective dose equivalent from natural background radiation were also analyzed(both rs=0.59,P=0.042).Conclusion The natural radioactivity was likely to be a causative factor for childhood leukemia in Guangdong.