[Intergrated assessment of the radioecological state of the biota in Moscow water objects].

The paper presents the results of studying the regularities and distribution pattern of natural radionuclides (potassium-40, thorium-232), as well as the representatives of the uranium family (radium-226, polonium-210) and the technogenic isotope cesium-137 in different objects of the water ecosystem in the North-Western District of Moscow (bottom sediment, hydrobiota). Some radiation parameters of these objects (the total alpha- and beta-activities of the radionuclides, their specific effective activity are given. On the basis of the experimental findings, the authors have made an assessment of the radioecological situation in the water pool of the district examined.

[Studying patterns of distribution of 137Cs and natural radionuclides in bottom sediments of water ecosystem in Moscow region].

The authors evaluated distribution of technogenic isotope cesium-137 and natural radionuclides (radium-226, thorium-232 and kalium-40) in bottom sediments of water ecosystem in Moscow region. Radiation parameters of the sediments appeared to be similar to background values of soils and grounds in the region.

[Estimation of the levels of plutonium isotopes in soil and bed deposits during environmental radiological monitoring]. / Otsenka soderzhaniia izotopov plutoniia v pochve i donnykh otlozheniiakh pri radioékologicheskom monitoringe okruzhaiushchei sredy.

The paper deals with the development of a highly sensitive method for determining plutonium isotopes (238Pu, 239Pu + 240Pu, 242Pu) in the solid samples of environmental objects with preliminary radiochemical preparation. The chosen conditions for preparation of samples permit effective separation of plutonium from mixing alpha-radiating radionuclides and allow plutonium to release in the radiochemically pure form to a sample to be calculated. Spectrometric measurements of the calculated samples and identification of isotopes were made on a "Progress-alpha" alpha-spectrometric unit having a silicon semiconductor detector. The developed procedure is rather reliable in identifying and estimating the content of major plutonium isotopes in the soil and bed deposits at their background values (1 Bc/kg or higher). The paper presents the results of analysis of samples of the soil selected during radioecological monitoring in the South-Western Okrug of Moscow, as well as the alpha-spectra obtained.

[The pattern of distribution of polonium-210 in the superficial soil layer in Moscow]. / Zakonomernosti raspredeleniia radioizotopa poloniia-210 v poverkhnostnom sloe pochvy goroda Moskvy.

The pattern of distribution of 210Po, 226Ra, 232Th, and 40K was studied in the superficial soil layer of Moscow. There was a correlation between the soil levels of the natural uranium decay products 210Po and 226Ra. The ratio of specific 210Po, 226Ra activities was 1.3 +/- 2.6 in the soil samples. There is a close correlation between the soil levels of 210Po and its organic substance. The specific activities of the natural radionuclides in the Moscow soil were as follows: 210Po 30-50 Bk/kg, 226Ra 10-30 Bk/kg, 232Th 10-30 Bk/kg, and 40K 200-400 Bk/kg. These levels are no greater than those of those of natural radionuclides in the Earth's crust.

[A radiation hygiene assessment of the use of the deicing preparation Kama-M in Moscow]. / Radiatsionno-gigienicheskaia otsenka primeneniia protivogololednogo preparata "Kama-M" v usloviiakh Moskvy.

The content of radionuclides and metals in the agent to control the ice-crusted ground Kama-M was determined. An investigation has shown that the radioactive background of the agent is caused only by the presence of 40K as part of KCl. Small quantities of 226Ra and 232Th are present in the insoluble sediment. The concentrations of metals are very low and produce no environmental effects. The levels of superficial pollutions vary from 1.3 to 4.8 beta-particles per cm2/min and the power of an exposure dose is at the level of background values (9-20 microR/hour), which is no greater than the permissible ones.