Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RADIOACTIVITY”

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.

At least 1,783 records · Page 99Linked to original sources
PubMed1992

Radioactivity in size-separated municipal incinerator ashes.

Radionuclide concentrations of the 238U- and 232Th-decay series, as well as 40K and 137Cs, were determined in size-separated fly ashes and bottom ashes from two municipal incinerators. Secular equilibrium was observed for several of the series' radionuclides, though 222Rn losses during combustion were evident. The fly-ash samples showed increasing enrichment of 40K, 137Cs, and 210Pb as particle diameters decreased, due to their volatility and subsequent condensation, and typically contained higher activities of these volatile radionuclides. Radon emanation from the bottom ashes was not detected but the fly ashes had an emanting power near 7%. Only 40K and 137Cs were found to be water-soluble, with significantly greater solubilities occurring for the fly ashes. Overall concentrations suggest that municipal incinerator ashes contain the equivalent radioactivity of surface soil and substantially less than ashes from coal combustion. It is shown that an incinerator's contribution to the atmospheric radionuclide burden is minimal and, from a radiological viewpoint, their residual ashes can be safely used in construction materials.

Radioactive Pollutants↗
PubMed1996

Model testing using Chernobyl data: II. Assessment of the consequences of the radioactive contamination of the Chernobyl Nuclear Power Plant cooling pond.

The "Cooling Pond" scenario is designed to test models for radioactive contamination of aquatic ecosystems, based on data for contamination of different aquatic media and biota due to fallout of radionuclides into the cooling pond of the Chernobyl Nuclear Power Plant. Input data include characteristics of the cooling pond ecosystem (hydrological, hydrochemical, and hydrobiological conditions) and estimates of the amounts of 137Cs in the cooling pond. Predictions are requested in two stages: (1) calculations for 137Cs concentrations for comparison against actual measurements, including activities of 137Cs in the cooling pond water, in sediment layers, and in fish; and (2) calculations for which actual measurements are not available, including dose and risk estimates for aquatic biota and for humans following hypothetical consumption of contaminated biota. The latter calculations are intended to provide an opportunity for intercomparison among modelers of their results for a simulated assessment problem.

Animals↗
PubMed1980

Radioactive waste: the problem of plutonium.

Systems under development for the recovery of plutonium from spent fuel and its recycling in fresh fuel would not significantly reduce either the total alpha-activity or the amount of fissile plutonium in radioactive waste relative to what is possible with once-through fuel cycles.

Animals↗
PubMed1997

Leukemia in the proximity of a German boiling-water nuclear reactor: evidence of population exposure by chromosome studies and environmental radioactivity.

Exceptional elevation of children's leukemia appearing 5 years after the 1983 startup of the Krümmel nuclear power plant, accompanied by a significant increase of adult leukemia cases, led to investigations of radiation exposures of the population living near the plant. The rate of dicentric chromosomes in peripheral lymphocytes of seven parents of children with leukemia and in 14 other inhabitants near the plant was significantly elevated and indicated ongoing exposures over the years of its operation. These findings led to the hypothesis that chronic reactor leakages had occurred. This assumption is support by identification of artificial radioactivity in air, rainwater, soil and vegetation by the environmental monitoring program at the nuclear power plant. Calculations of the corresponding source terms show that emissions must have been well above authorized annual limits. Bone marrow doses supposedly result primarily through incorporation of bone-seeking beta- and alpha-emitters.

Adult↗
PubMed1987

[Tritium and carbon-14 concentrations around an incinerator for radioactive liquid scintillator waste].

Activity measurements of 3H and 14C in several environmental samples around the incinerator for radioactive liquid scintillator waste at the Radioisotope Center, Kyushu University were carried out to estimate their levels. It was indicated that 3H and 14C concentrations in the atmosphere at 1 m from the outlet were about 0.2% of those estimated at the outlet, respectively. At 6 m away from the outlet, 3H concentration decreased to about one twentieth of that at 1 m and 14C concentration to background level. For soils and plants, 14C concentrations showed negligibly low values. The existence of these nuclides in particle form was not confirmed. It is considered that the result of the higher 3H concentrations as compared to 14C concentrations reflects not only the difference of the waste amounts of their nuclides, but also the discharge of 3H as moisture as well as water vapor.

Carbon Radioisotopes↗
PubMedDate not supplied

[Planning and implementation of protective measures in emergencies during railway transportation of radioactive cargo].

Protective measures in emergencies during railway transportation of radioactive cargoes must be planned in advance, by obligatorily taking into account many factors that influence the scope, nature, specific features and consequences of radiation transport accidents. Of great importance are radiation monitoring, protective regimens, and requirements for decontamination of various objects in liquidating the consequences of a radiation transport accident.

Accidents↗
PubMedDate not supplied

[Physico-chemical and microbiological characteristics of groundwater from observation boreholes of a deep radioactive liquid waste repository].

A radioactive liquid waste repository was found to be a habitat of the rich microbial community with a high catabolic potential. Groundwater from a depth of 162-189 m contained aerobic saprotrophic and anaerobic fermentative, sulfate-reducing, and denitrifying bacteria. Nitrate-reducing bacteria residing in this groundwater were isolated in pure cultures. Based on the results of their physiological studies, 16S rRNA sequencing, and phylogenetic analysis, the microorganisms isolated were ascribed to one phylogenetic branch, the gamma-subclass of gram-negative bacteria. Among six isolates, four belonged to the genus Acinetobacter, whereas two others belonged to the genera Comamonas and Aeromonas. The data obtained indicate that the microflora of the repository can exert a certain effect on the chemical composition of the formation fluids and bearing rocks, as well as on the migration of radionuclides.

Bacteria↗
PubMed1975

Environmental Radioactivity in the Faroes in 1974.

Measurements of fall-out radioactivity in the Faroes in 1974 are presented. Strontium-90 (and 137Cs in most cases) was determined in regularly collected samples of precipitation, grass, milk, fish, sea water, bread, and drinking water. In addition, analyses were made of spotsamples of lamb, potatoes, sea plants, vegetables, eggs, and human bone. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in the Faroes in 1974. Whole body measurements were made on six individuals from the Faroes.

Animals↗
PubMedDate not supplied

[Effects of combined radioactive and pesticide loads on the population health].

Relationships of the magnitude of environmental radioactive and pesticide factors to morbidity were studied. Comparative investigations showed that there was a correlation between the above environmental factors. Hygienic preventive measure for health promotion in ecologically poor areas (exposed to radiation or pesticides) were developed.

Adult↗
PubMed2001

[Children's health in zone of radioactive pollution caused by the Chernobyl accident].

The Chernobyl accident led to contamination of vast territories of Russia by man-made radionuclides. One of such regions is the Tula region. For realization of programs aimed at alleviation of the accident consequences, medical and sanitary measures were taken, including many-year monitoring of radiation pollution in the region and health status of various population groups, primarily children. Complex studies were carried out, making use of radiation, sociohygienic, epidemiological, psychophysiological, anthropometric, clinical laboratory, cytogenetic, immunological, and other methods. Dynamic examinations of children of different age demonstrated that radioactive precipitations at a density of 5-15 Ci/m2 did not directly affect children's health; however essential deviations in the health status, such as changes in morbidity, physical development, and incidence of immunodeficiencies have been revealed. The authors consider that realization of health protection programs should concern primarily children.

Adolescent↗
PubMedDate not supplied

[Level of chromosome aberrations in peripheral blood lymphocytes in evacuees from the 30-kilometer zone of the Chernobyl Atomic Energy Station and residents of radioactively-polluted territories in the long term after the Chernobyl accident].

Eighteen Ukrainian evacuees from the Chernobyl exclusive zone, twenty one inhabitants of radioactively contaminated areas of Belarus and twelve control donors age-matched to the exposed persons were investigated 14-15 years after the Chernobyl accident for chromosomal aberration yields detected in blood lymphocytes by fluorescence in situ hybridisation technique. Unstable aberration yields measured in both Chernobyl cohorts were close to the background frequencies. Positive age-dependence trends in control donors were determined for the all type stable aberration levels. In evacuees the tendency for diminishing the difference between them and controls for stable aberration levels with persons' age increasing was found. The total stable chromosome exchange yields in evacuees 46-55 years old and inhabitants of areas with low contamination level didn't exceed the control values, but for younger evacuees and inhabitants of sufficiently contaminated regions the statistical increase above the age relevant background meanings was detected for this end-point. The advantages of using the FISH-detectable stable aberrations and particularly the total level of stable chromosome exchanges as the end-points for retrospective biological indication of past radiation exposure in Chernobyl cohorts were discussed.

Adolescent↗
PubMedDate not supplied

[Parameters of peroxide oxidation of lipids and the system of its regulation in the tissues of Ellobius talpinus Pall, living on the territory of the East Urals Radioactive Trace].

The peroxide oxidation of lipids and the systems of its regulation was tested in Ellobius talpinus Pall, living on the territory of the East Urals Radioactive Trace with the 90Sr contamination density of 1000 Ci/km2. The degree of sensitivity of the examined tissues and organs was revealed, the most considerable parameters were defined for marking radiosensitivity of the taken species, as well as the complex of parameters, allowing classifying an animal as an inhabitant of the clean or the contaminated territory. The found changes are considered as compensatory mechanisms for forming of nonspecific resistance.

Animals↗
PubMedDate not supplied

[Estimation of rate constant for dissolution of radioactive fuel particles].

Some theoretical of the experimental investigation of solubility of radioactive aerosols were examined. Filters, which were exposed during October-November 1987 in Pripyat town, were studied. Measurements on 22 November 1987 showed that an activity in the air was 12.1-20.8 mBq/m3 for 137Cs, 34.9-89.3 mBq/m-3 for 144Ce, 24.3-30.5 mBq/m-3 for 106Ru. Disperse structure of aerosol hot particles and the number of hot particles on each filter fragment was estimated by radiography. To determine a dissolution rate constant a static system with two 0.14 micron pore size membrane MFE filters (Dubna, Russia) enclosing fragments of Petryanov filters was selected. The composition was held in Gamble's solution lung fluid anf then in 0.1 mol/l HCl as dastic juice simulation. The activity of 90Sr, 238Pu, 239 + 240Pu, 241Am and 244Cm in aerosol filters and solutions was measured by radiochemical methods. It was shown that leaching of radionuclides from aerosol hot particles in lung fluid simulation decreases in line 137Cs > 90Sr >> 239 + 240Pu > or = 241Am, depending om particle diameter and time. Dissolution constants were presented. Dissolution of aerosol particles in 0.1 mol/l HCl is also shown (dissolution time was 3 days). A radionuclide transition to HCl solution decreases in line 90Am 241Am >> 137Cs > 239 + 240Pu. A transition degree reached 21% for 90Sr and extraction of 241Am was 3-17%.

Aerosols↗
PubMedDate not supplied

[Results of dynamic cytogenetic study of children and teenagers living in areas, radioactive by contaminated after the Chernobyl accident].

Results of multiyear cytogenetic study of children and teenagers living in areas, radioactive by contaminated after Chernobyl accident, were adduced. Mean density of 137Cs contamination in two compared living areas were 111 and 200 kBq/m2 and mean external doses accumulated for 1986-2001 were 6.7 and 11.4 mGy correspondingly. Averaged thyroid doses receives by subjects of all age groups in the second area were approximately 1.5 times higher than in the first area; in the youngest group (0-1 year) the doses were 114.3 and 174.3 mGy. During 17 years cytogenetic investigation approximately from 30% to 60% of examined persons were observed the increased level of chromosome aberrations in lymphocytes of peripheral blood. Average frequency of unstable aberrations (acentrics, dicentrics and centric rings) constituted about 0.4 per 100 cells (0.22 per 100 cells in controls) during all period of observation. Level of marker aberrations (dicentrics and centric rings) was increased almost all times of study and varied within 0.04-0.19 per 100 cell (0.03 in control group). The parallel investigation of frequency of stable aberrations by FISH method showed up their level about 3 times exceeding observed dicentrics level. Comparably higher indexes of cytogenetic disturbances were revealed in group exposed in utero during period of accident.

Adolescent↗
PubMedDate not supplied

[Migration characteristics and forms of 90Sr and 137Cs observed in the bottom sediments of certain lacustrine ecosystems on the East Urals Radioactive Trace].

The research findings summarized in the paper include data on the radioecological conditions in two lakes (Large Ighish and Small Ighish) located on the East Urals Radioactive Trace. The focus of the study was on the chemical composition of water and bottom sediments, as well as on the specific features of 90Sr and of 137Cs distribution and the forms in which they occur in silts. Coefficients of radionuclide accumulation in the bottom deposits of the lakes of interest were estimated. A conclusion was drawn about the dependences influencing radionuclide distribution by layers of the lake bottom sediments.

Cesium Radioisotopes↗
PubMed1984

Cancer incidence in an area of radioactive fallout downwind from the Nevada Test Site.

Exposures in southwestern Utah to radioactive fallout (1951 through 1962) from atmospheric nuclear detonations at the Nevada Test Site (NTS) were followed by smaller exposures (1962 through 1979) from venting of underground nuclear detonations. The cancer incidence in a 1951 cohort (4, 125) of Mormon families in southwestern Utah near the NTS was compared with that of all Utah Mormons (1967 through 1975). There were 109 more cases of cancer than expected (288[observed]/179[expected]). Leukemia was most prominent early (1958 through 1966), with 19 cases, five times more than expected (3.6). The excess of leukemia persisted into the later period (1972 through 1980), with 12 cases observed, 3.4 expected. There was an increase in lymphoma. Excess cases of thyroid cancer appeared early and a notable excess appeared later (14/1.7). An excess of breast cancer was noted later (27/14). There were more cancers of the gastrointestinal tract than expected. There was an excess of melanoma (12/4.5), bone cancer (8/0.7), and brain tumors (9/3.9). A subgroup with history of acute fallout effects had a higher cancer incidence. That these cases can be associated with radiation exposures is supported by a comparison between groups of the ratio of cancers of more radiosensitive organs with all other types of cancer.

Adolescent↗
PubMedDate not supplied

[Liquid radioactive waste in health activities: annual dosage to the population].

A survey was taken of the amount of radionuclides, acquired, utilized, and released in one year's time, in the Adige river by the USL (Local Division of the National Public Health System) of Verona. The critical pathways of environmental pollution were analyzed and the individual and collective doses of some critical population groups and the population as a whole were compiled. Some suggestions to reduce the collective doses both from radioactive releases and diagnostic use of radionuclides are given.

Body Burden↗
PubMedDate not supplied

[Calculation of gaseous forms and sizes of aerosol particles 131 Iodine- the radioactive fallout of Chernobyl accident by calculation of inhaled radiation dose].

After the Chernobyl accident the isotopes of radioiodine in air were detected both in aerosol and gaseous forms. In the ICRP publication, No 30 the committed dose equivalent in thyroid per intake of unit activity of 131I, B(ih), were presented. This value holds true only for aerosols with activity median aerodynamic diameter (AMAD) 1 micron. The radioactivity deposition coefficients in human respiratory tract have another values for molecular and organic forms of gaseous radioiodine. In present work the measured AMAD and the proportion between aerosols, molecular and organic forms of 131I in various regions after the accident are given. The correction factors for B(ih) are calculated for the following cases: 1) the radioiodine concentration in air is measured by means of the aerosol filter only, 2) all forms of radioiodine are sampled. The neglection of the gaseous forms of radioiodine could lead to extremely large errors in the determination of inhaled dose radiation: the real value of dose radiation could exceed calculated one by more than 5 times.

Accidents, Occupational↗