[en] The natural radioactivity of coals mined in Hungary is 5 to 10 times that of the world average. As coal-slag, ash and fly-ash have often been used as backfill or insulation material in building houses, in some regions the population is exposed to excessive radiation. In the region of Ajka, houses are found with indoor radon concentrations in the range of 400 to 1200 Bq/m³. (A.K.)

[en] According to an ICRP recommendation, the exposure of jet aircraft crew to radiation should be considered as occupational exposure when the annual equivalent doses are liable to exceed 1 mSv. Many new data on this type of exposure collected since 1991 are presented and analyzed. The dose equivalent rates established are fitted as a function of flight altitude. An analysis of data from cosmic ray monitors has shown that the presence of cosmic rays in the Earth's atmosphere is rather stable since early 1992. An estimation was therefore made of the possible influence of the solar cycle phase by means of a transport code. The results obtained are compared with experimental data

[en] The construction is described of a personal dosemeter making it possible to measure an occupational exposure of 50 Bq/m³ with an accuracy of 20% during one working month. A combination of track-etch dosemeter and activated charcoal was used. Different types of activated charcoal were tested in combination with a Makrofol detector. Charcoal Carboxen-564 was found to be optimal, with an optimal layer thickness of 2.1 mm. For this detector, the adsorption and desorption constants for radon and water at various relative humidities were determined

[en] The risk of mammographic examination was estimated. It is concluded that a mean glandular dose (MGD) of 1 mGy per exposure can be associated with a risk of 1 radiation-induced carcinoma per less than 100 positive detected by the preventive examination. The variability of actual MGD at various hospitals can be quite large. Although the majority of measurements were made on phantoms it is assumed that the national MGD average will exceed 3 mGy for the average breast size of 55 mm

[en] The effect of the Krsko nuclear power plant on the level of ⁹⁰Sr and ¹³⁷Cs in the Sava River and in ground water was examined. The level of the radionuclides is not elevated on account of the normal operation of the plant. Any major release, however, would soon cause pollution of the ground water and drinking water

[en] The median activity concentrations in the Danube water (free of suspended matter) was about 1.2, 75, and 2.0 mBq/l for Cs-137, K-40 and Ra-226, respectively. In the sediment and suspended matter, the values for K-40 and Ra-226 are about 600 and 50 Bq/kg dry weight, respectively. The average Cs-137 activity concentration in sediments decreased from 100 Bq/kg in June 1993 to 70 Bq/kg in June 1996. The concentration in suspended matter was about 1.67 higher than in bottom sediments. Suspended matter and sediments were also examined with respect to the transport of Pb-210 and Cs-137, as well as of K-40 and U-238. The annual radioactivity load of the Austrian segment of the Danube (dissolved in water and bound to suspended matter), as calculated based on the activity concentrations and daily suspended matter flow rate, was about 6, 0.3, and 0.5 TBq for K-40, Ra-226, and Cs-137, respectively. (P.A.)

[en] Background gamma radiation from soil sources were measured at 42 sites in Montenegro by in-situ spectrometry. The medians are 223, 19, 19, and 152 Bq/kg for ⁴⁰K, ²³²Th, ²³⁸U, and ¹³⁷Cs, respectively. Ground contamination by ¹³⁷Cs roughly follows the topographical map of Montenegro: it is negligible on the Montenegrin Coast and reaches 74 kBq/m² in the mountains. Radiocesium is mostly retained by the surface layer of uncultivated soil, to a depth of 6 cm in average

[en] Approximately 90% of the Secondary Standard Dosimetry Laboratories (SSDLs) provide users with calibrations of radiation protection instruments, and the IAEA is taking every necessary effort to insure that SSDLs measurements are traceable to Primary Standards. The Agency has proper radiation sources available to provide traceable calibrations to the SSDLs involved in measurements on diagnostic x-ray generators, including an x-ray unit specifically for mammography dedicated to standardization procedures. The different photon beam qualities and calibration procedures available in the Agency's Dosimetry Laboratory are described

[en] A study was performed with the aim to examine whether the progeny of cells that had been repeatedly irradiated with low doses of gamma rays will change their sensitivity to cytotoxic agents. Four mammalian cell lines were used in the experiment. It was found that the progeny of cells irradiated in this way do not change their sensitivity to gamma rays but would change their sensitivity to various cytostatics drugs. (A.K.)

[en] Recently an analytical method was developed to compute radiation doses deposited by ²²²Rn progeny alpha particles in 1 μm spheres located at different depths in bronchial epithelium. The same method was now applied to alpha particles emitted from ²²⁰Rn progeny deposited in bronchial airway surfaces. Results of the computations are presented in graphs. The mean cellular doses imparted by ²²⁰Rn progeny to basal and secretory cell nuclei were compared with those produced by ²²²Rn progeny; due to differences in alpha energies, radon progeny doses were found to be generally higher than those for thoron progeny. (A.K.)