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Investigations on the concentration level of heavy metals in the sediments of Cienfuegos bay (Cuba) have been carried out, to reconstruct their "depositional history" by using radionuclide geochronology, to highlight the major changes occurred in the last century and to draw hypotheses on their origin. During two sampling campaigns (1999 and 2001) sediment cores and surface grab samples have been collected in the two basins of the bay. In this paper results on the horizontal and vertical distribution of arsenic, nickel and vanadium are discussed, along with data on concentrations of natural (excess 210Pb) and anthropogenic (137Cs) radionuclides, used as tools to "date" the sediment horizons. Results evidenced that important changes in the sedimentation regime of the bay occurred in the last forty years, in relation to changes in land uses and to the effects of some extreme meteorological events. The distribution of the heavy metals shows the influence of the recent industrialization of the area, as revealed by both the spatial and vertical concentration within the sediment horizons. [ABSTRACT FROM AUTHOR]

The main objective of this work was to evaluate the applicability of this technique to quantify the soil erosion in the tropical region. With this purpose the technique was applied in the tropical soils belonging to a glide parcel, in Cienfuegos province, in Cuba, in the Caribbean area. This allowed us to compare and to demonstrate the good agreement of the results of the soil loss quantification obtained using the 137Cs technique: 37.00 ± 0.80 t.ha-1. year-1 with the obtained using erosion plots in the Soil Experimental Station in Barajagua: 40 t.ha-1. year-1 [ABSTRACT FROM AUTHOR]

The paper shows the experience in the application of 137Cs technique to estimate the erosion rates in cultivated soils classified as ultisol in the west part of the country, and the validation of the technique results by comparison against the results from traditional methods like watershed segments. The proportional, the simplified balance of mass and the balance of mass models were used to calculate the erosion rates, for three segments. In the evaluated area, have been obtained erosion rates from 3.5 to 7.1 t/ha/y for the segment I, from 5.17 to 10.3 t/ha/y for the segment III and from 2.3 to 17 t/ha/y for the segment IX. The conclusions are, the 137Cs technique is reliable for the estimation of erosion rates in the evaluated soil and the mass balance model obtained the nearest values to the estimated by watershed.. segments. [ABSTRACT FROM AUTHOR]

It have been performed a study of the physical-radiological characteristics of sediments of the Havana Bay. The low background spectrometric measurements allowed to quantify the concentrations of the isotopes radioactive gamma emitters 210Pb, 137Cs, 238U, 226Ra, 232Th y 40K. The obtained results will be very useful to the studies on bay contamination, its conditions of sedimentation. [ABSTRACT FROM AUTHOR]

The paper shows the main results obtained in the studies of the ambient radioactive background carried out in the future site of nuclear installations: the Nuclear Research Center La Quebrada, Juraguá nuclear power plant and the northern part of Holguín. The materials and methods used for the work are the recommended by the Center of Radiation Protection and Hygiene and are accepted internationally. From the results obtained, we conclude that dose rate levels due to gamma radiation, as well as natural radionuclide concentrations in different objects of the environment and in foodstuffs within the zones of interest are consistent with those reported in literature for regions without anomalies. The evaluations of the committed effective dose due to the intake of Sr-90 per milk consumption in a year and the external irradiation due to the exposition to Cs-137 existing in soils, gave values between 0.1 and 1.3 µSv for the first and less than 1 µSv/year for the second. [ABSTRACT FROM AUTHOR]

The implementation and calibration of two whole body counters for determination of Cs-137 body activity in children is described. The results of measurements of 4506 children coming from affected areas due to Chernobyl accident from Republics of Ukrainian, Russian and Belaruss, and who received medical atention in Cuba is presented. Instalations, equipment and calibration phantoms used are described. The values of measured activity is relationed with the place of origin groups of age and the form of feeding. The measured activity values range from 1,5 to 565 Bq/kg, and have a log-normal character for each region. [ABSTRACT FROM AUTHOR]