SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Radon is the most serious cause of human irradiation and can accumulate indoors in large quantities. The authors examine some aspects of human exposition to natural radioactivity, survey the Italian and international literature on indoor radon concentrations, and finally, set out some guidelines for prevention and control of radon pollution.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
An important part of the practice of occupational medicine is directed toward the control of the industrial, physical, chemical and biological environments which may adversely affect health. This concern with the effect of environment on health has moved out of industry and has become a major area of public health practice, as evidenced by interest in pesticides, air pollution and radioactive fallout. The discipline of occupational health is a natural resource and springboard for the development of the skills necessary to control these environmental hazards. Occupational health is supplying trained and experienced personnel in the applied technical and administrative phases. It also can provide a basis for graduate teaching and research programs in environmental health. At the University of California's School of Public Health in Berkeley, curricula are being developed for educating teachers and research personnel in the environmental health sciences.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Working processes using zircon sand in a factory producing refractory material were studied from the point of view of radiation protection. Zircon sand contains high concentrations of natural radionuclides and is a typical example of an enhanced source. Using various techniques the characteristics of the original material were analysed and environmental radioactivity was measured in the different significant points of the process. Finally, a first assessment was made of effective dose equivalent values in the areas of highest risk.
Coal- and lignite-fired power plants produce significant amounts of ashes, which are quite often being used as additives in cement and other building materials. In many cases, coal and lignite present high concentrations of naturally occurring radionuclides, such as 238U, 226Ra, 210Pb, 232Th and 40K. During the combustion process, the produced ashes are enriched in the above radionuclides. The different enrichment of the various radionuclides within a radioactive series, such as that of 238U, results in the disturbance of radioactive secular equilibrium. An extensive research project for the determination of the natural radioactivity of lignite and ashes from Greek lignite-fired power plants is in progress in the Nuclear Engineering Department of the National Technical University of Athens (NED-NTUA) since 1983. This paper presents detailed results for the natural radioactivity, the secular radioactive equilibrium disturbance and the radon exhalation rate of the fly-ash collected at the different stages along the emission control system of a lignite-fired power plant as well as of the bottom-ash. From the results obtained so far, it may be concluded that 226Ra radioactivity of fly-ash in some cases exceeds 1 kBq kg(-1), which is much higher than the mean 226Ra radioactivity of surface soils in Greece (25 Bq kg(-1)). Furthermore, the radioactivity of 210Pb in fly-ash may reach 4 kBq kg(-1). These results are interpreted in relation to the physical properties of the investigated nuclides, the temperature in the flue-gas pathway, as well as the fly-ash grain size distribution. It is concluded that towards the coldest parts of the emission control system of the power plant, the radioactivity of some natural nuclides is gradually enhanced, secular radioactive equilibrium is significantly disturbed and the radon exhalation rate tends to increase.
The contribution of 222Rn to the background in a low background experiment with a germanium detector has been estimated. We have also checked the efficacy of a standard radon cleaning system. The cleaning reduces the radon concentration two orders of magnitude with respect to the air in the laboratory. The residual 222Rn represents at most 12.5% of the background in the low energy region, a value low enough for the purpose of our experiment. A detailed study of the radioactive background is presented.
Explore the source record for details and available documents.
The spatial and temporal distributions of the anthropogenic radionuclides (137)Cs and (90)Sr, originating from nuclear bomb testing and the Sellafield reprocessing plants in the Irish Sea, are simulated using a global version of the Miami Isopycnic Coordinate Ocean Model (MICOM). The physical model is forced with daily atmospheric re-analysed fields for the period 1950 to present. Comparison of temporal evolution of observed and simulated concentrations of (137)Cs have been conducted for the regions east of Scotland, west of central Norway and at the entrance of the Barents Sea. It follows that the radionuclides from the Sellafield discharge reach the Barents Sea region after 4-5 years, in accordance with observations. The simulation provides a detailed distribution and evolution of the radionuclides over the integration time. For the Atlantic waters off the coast of Norway and in the southern Barents Sea, the atmospheric fallout dominates over the Sellafield release up to the mid 1960s and from the early 1990s, whereas Sellafield is the main source for the two radionuclides in the 1970s and 1980s. It is furthermore argued that model systems like the one presented here can be used for future prediction of radioactive contaminations in the Nordic Seas and the Arctic Ocean, for instance under various global warming scenarios.
The transit of an air mass containing radioactive gas released from the Three Mile Island reactor was recorded in Albany, New York, by measuring xenon-133. These measurements provide an evaluation of Three Mile Island effluents to distances greater than 100 kilometers. Two independent techniques identified xenon-133 in ambient air at concentrations as high as 3900 picocuries per cubic meter. The local gamma-ray whole-body dose from the passing radioactivity amounted to 0.004 millirem, or 0.004 percent of the annual dose from natural sources.
Results of measurements of radionuclide and disperse compositions of aerosols in ventilation system "Bypass" of the object "Shelter" of the Chernobyl NPP are presented. The Bypass is used for releasing contaminated air from the destroyed reactor of Block-IV to the atmosphere. In aerosols, the experimentally found ratio of 137Cs concentration to the sum of beta-emitting radionuclides more than 1.5 times exceeds the calculated ratio for nuclear fuel (in December, 2003). Using the data of meteorological station "Chornobyl", which situated 15 km SE from the Chernobyl NPP, we found that the wind with mean velocity of 4-5 m/sec or more and gusts of 10-11 m/sec led to increasing the aerosol concentration in the Bypass by more than power of magnitude. With the help of filter pack technique sizes of aerosol particles--the carriers of Chernobyl's radioactivity--were measured. It was found that the range of activity median aerodynamical diameter (AMAD) is 2-5 microns.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The formulas and manufacture technology of the prophylactic syrups for population living in zones of radioactive pollution were developed. The basic raw material for syrups were infusions of herb having various radioprotective properties. As additional raw material was used food supplement "Adaptin".
The size distributions of 38Cl and 39Cl aerosols formed from the irradiation of argon gas containing di-octyl phthalate (DOP) aerosols by 65 MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive aerosols in high-energy radiation fields. Both the number size distribution and the activity-weighted size distribution were measured using an electrical low-pressure impactor. It was found that the 35Cl and 39Cl aerosols are formed by attachment of the radioactive atoms generated by the neutron-induced reaction to the DOP aerosol particles.
Results obtained from radiometric research carried out from 1980-81 in the region of U mines in the Val Vedello are provided. Data are presented on 222Rn, 226Ra and natural U concentrations in spring and surface waters. Concentrations were found to be relatively low. There is some increase in the vicinity of the exploratory U mine but this is, at least up to the present, only of a local character. Data are presented on external gamma exposure, 210Pb and 210Po in foodstuffs and in the urine of normal and exposed population as well as 226Ra in milk and vegetable samples. The aim of this study is to outline a preliminary map of natural radioactivity on the site before starting the mining activity. This will enable us later to detect changes caused by the U mining, milling and mill-tailing disposal operations.