[en] Studies carried by us during last three years have produced a map of natural radiation for Spain. The map contains, by administrative region, the respective contributions of terrestrial gamma rays, both outdoors and indoors, cosmic rays and indoor radon. Terrestrial gamma rays have been measured outdoors 'in situ' in more than 1,000 locations. Data for indoor gamma rays were derived from the radioactivity content of more typical spanish building materials as also by 'in situ'measurements in approximately 100 houses. The cosmic ray component is calculated from latitude and altitude. Values for indoor radon exposure have been derived from a national survey and covering more than 2,000 individual measurements employing active and passive detectors. When account is taken of exposures elsewhere, the mean annual effective dose equivalent from these sources is evaluated. Doses from thoron decay products and internal exposure due to natural activity retained in the body from diet are not dealt with in this evaluation. (author)

[en] A method to determine the emanation factor for ²²²Rn in small samples of soils and building materials is proposed. The method is based on the principle of enclosing the sample to be tested in a hermetically sealed modified Lucas cell, designed and built in our laboratory, and subsequently measuring the radon concentration growth in the cell. The method has been tested for a total of 27 samples with different properties, including soils, building materials and phosphate fertilisers, which were previously evaluated for their physical properties and measured by gamma spectrometry to determine their radium activity concentrations. (Author)

[en] Radon proof barriers are used for lowering of radon transport from the soil into the house and the determination of the radon diffusion coefficient is an important parameter to be determined in order to design the minimal thickness of the radon proof insulation. A method has been developed in our laboratory by using modified Lucas cells connected to a radon source and tightly closed onto the top by the tested membranes whose radon diffusion coefficients are being measured. Solving the time-dependent differential equation for radon diffusion in the membrane for well-defined experimental conditions the effective radon diffusion coefficient of the insulating material can be evaluated by comparing the radon concentration decrease in the cell for the first hours with the well-known radioactive decay. First results obtained in several preliminary tests carried out with a parafilm M barrier and two polyethylene membranes are shown in this paper

[en] A method to determine radium contents using gamma spectrometry is developed. Monte Carlo method is used to calculate the detection efficiency corresponding to the peak of 1.76 MeV of Bi-214. Experimental results are presented and discussed. (author)

[en] Field in situ gamma radiation exposure rates and laboratory measured radioactivity contents of 1500 Spanish soils were compared. The main objective was to determine if published theoretically derived conversion factors would yield accurate quantitative activity concentration (Bq kg^-1) for the data carried out in different surveys developed by our laboratory during the last ten years. The in situ external gamma dose rate results were compared to laboratory gamma analysis of soils samples gathered from each site, considering the concentrations of seven radionuclides: ⁴⁰K, ²¹⁴Pb, ²¹⁴Bi, ²¹²Bi, ²¹²Pb, ²⁰⁸Tl and ²²⁸Ac. The coefficient of correlation found between these variables indicate a good relationship. A discussion of the factors contributing to the uncertainties as well as measurement procedure are also given in this paper

[en] The Medical Physics Department in the University of Cantabria, Spain as member belonging to the radiological environmental Monitoring Network has been carried out a series of measures about radioactive elements in air, rain water and soil. This report shows the methodology used and the results obtained in the measurement of the gross-alpha and gross beta activities. ^90Sr and gamma spectrometry in atmospheric aerosols; the activity of ^131I in air; the gross-beta activity ⁹⁰Sr and gamma spectrometry in rain water and dry deposition: and the activity of ^90Sr gamma spectrometer in soils. The average values of the gross-alpha and gross beta activities in air has been 4 x 10^-5 and 32 x10 ^-5Bq/m^3, respectively. The concentration of ^131I has been inferior to the limit of detection in the whole of measurements. Finally, has been found small concentrations of ^90Sr and the ^137Cs in soils samples

[en] Studies carried out over the last 3 years have produced a map of natural radiation for Spain. The map shows the respective contributions of outdoor and indoor terrestrial gamma-rays, of cosmic-rays and indoor radon for each administrative region. Terrestrial gamma-rays were measured outdoors in situ at more than 1000 locations. Data for indoor gamma-rays were derived from the radioactive content of the most typical building materials used in Spain and by in situ measurements in approximately 100 houses. The cosmic-ray component was calculated according to latitude and altitude. Values for indoor radon exposure were derived from a national survey which covered more than 2000 individual measurements employing active and passive detectors. By taking account also of other sources of exposure, the mean annual effective dose equivalent from these and the sources under study has been evaluated. Doses from thoron decay products and internal exposure are not dealt with in this evaluation. (author)

[en] Data for natural radiation from a national survey were used to identify areas in Spain with a high level of natural background radiation. Specific measurements were made in these areas to evaluate indoor radon levels as well as the main sources of this natural gas in houses. Values of indoor radon as high as 800 Bq m^-3 were measured and 39% of the houses showed levels over 150 Bq m^-3. For this area, exhalation rates from soil range from 40 Bq m^-2 h^-1 to 900 Bq m^-2 h^-1. Normal vlaues, lower than 10 Bq 1^-1, for radon dissolved in water were also measured. The results are examined and compared with the values obtained in houses located in other areas of Spain. (author)

[en] Terrestrial gamma ray dose rate has been measured outdoors throughout the whole Spanish territory. This national survey was designed in such a way as to obtain a uniform and representative distribution of the measurement locations. In total, a set of 1053 data is available at this moment. Results obtained are shown in tabular, graphical and cartographical form and are related to the nature of the ground and other influencing factors. The geometric mean terrestrial gamma ray dose rate in outdoors amounts to 44.03 nGy.h^-1 with a geometric standard deviation of 1.72. From this value, the mean annual effective dose equivalent can be calculated when the duration of outdoor exposure is included, as well as the mean annual collective dose equivalent if the distribution of the Spanish population is taken into account. This dose is in addition to those received from other sources of natural radiation. In this way, a study of the correlation between the values of the absorbed dose rate in air found and the presence of radon gas in houses is also made. Finally, the values of the terrestrial gamma ray dose rate theoretically derived from the radioactivity contents in the soil, experimentally measured are compared with the corresponding results obtained from the measurements in situ. (author)

[en] ⁷Be concentrations present in air, rain water and soil have been measured in the region of Cantabria (Spain) during the last 4 yr. There was a relationship between rainfall and the deposited areal activity of the nuclide at the study site which was consistent with observed annual global rainfall and fallout. (author)