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At least 775 records · Page 43Linked to original sources
PubMed1987

Simultaneous determination of radioactive and stable isotopes of cobalt in environmental samples by the isotopic exchange method.

The isotopic exchange method is studied for the simultaneous determination of radioactive and stable isotopes of cobalt in environmental samples. Radioactive cobalt is isotopically exchanged with Co-CyDTA in HC1 solution of the sample. The solvent extraction method is used for the separation of Co2+ and Co-CyDTA species from each other. The amounts of radioactive and stable cobalt isotopes are calculated with activities of Co and Co-CyDTA at the exchange equilibrium. The methods for eliminating interfering ions are discussed. The results are in good concordance with those obtained by the conventional analytical methods.

Cobalt Isotopes↗
PubMed2003

[Introduction of manual for the management radioactive medical waste].

Societies concerned with radioactive rays and nuclear medicine have recently highlighted the necessity of managing radioactive medical waste resulting from nuclear medicine examinations. We introduce a manual that we have created and explain its use in decision-making and management practices aimed at the reduction of radioactive medical waste at hospitals that have not yet solved this problem. We hope that our manual will help in reducing this medical waste.

Japan↗
PubMedDate not supplied

On the production of radioactive stents.

In the last few years, radioactive stents has been proved to inhibit neointima formation. This paper describes the actual status of producing such radioactive stents. After a short discussion of the different radioisotopes suitable for radioactive stents, potential production methods are discussed. The ion beam implantation of P-32 applied at the Karlsruhe Research Centre shall be described in more detail.

Animals↗
PubMed1999

Birds as objects in bioindication of radioactive pollution.

This article is a review the recent results of research in the accumulation of natural and artificial radionuclides in birds from Russia (Adigea, Krasnodar, Rostov, Astrahan and Moscow regions, Novaya Zemlya isles), Ukraine, Vietnam, Poland, Ethiophia and Mongolia after global precipitation and local pollution, such as in the East-Urals radioactive region and radioactive zones after the Chernobyl accident. Resident birds reflect local level of radionuclide contamination. The 90Sr concentration in the food of the Pied Flycatcher had a tendency to increase in dependent of age. The Common Jay and the Mallard were the most contaminated with 137Cs in the Bryansk region. The total content of various radio-isotopes of plutonium in bird bones from Southwest Russia were hundred and thousand times more, than in Mongolia. Activity levels in specimens from Ethiopia bear record to Ethiopia can notbe a "pure" control site in radioecological research and radioactive background since it does not significantly differ from Turkmenia and Mongolia.

Animals↗
PubMed1998

Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste. A report of The International Commission on Radiological Protection.

(79) Waste, by definition, has no benefit. It should be viewed as one aspect of the beneficial practice that gave rise to it. Furthermore, radioactive waste management should be placed in the context of the management of society's waste in general. (80) A major issue in evaluating the acceptability of a disposal system for long-lived solid radioactive waste is that doses or risks may arise from exposures in the distant future. There is uncertainty surrounding any estimate of these doses or risks due to lack of knowledge about future conditions. Such exposures are treated as potential exposures as their magnitude depends on future processes and conditions that have probabilities associated with them. (81) Nevertheless, the Commission recognises a basic principle that individuals and populations in the future should be afforded at least the same level of protection from the action of disposing of radioactive waste today as is the current generation. This implies use of the current quantitative dose and risk criteria derived from considering associated health detriment. Therefore, protection of future generations should be achieved by applying these dose or risk criteria to the estimated future doses or risks in appropriately defined critical groups. These estimates should not be regarded as measures of health detriment beyond times of around several hundreds of years into the future. In the case of these longer time periods, they represent indicators of the protection afforded by the disposal system. (82 Constrained optimisation is the central approach to evaluating the radiological acceptability of a waste disposal system; dose or risk constraints are used rather than dose or risk limits. By this transition from limitation to optimisation, the needs of practical application of the radiological protection system to the disposal of long-lived solid waste disposal are met: determination of acceptability now for exposures that may occur in the distant future. Optimisation should be applied in an iterative manner during the disposal system development process and should particularly cover both site selection and repository design. (83) Two broad categories of exposure situations should be considered: natural processes and human intrusion. The latter only refers to intrusion that is inadvertent. The radiological implications of deliberate intrusion into a repository are the responsibility of the intruder. Assessed doses or risks arising from natural processes should be compared with a dose constraint of 0.3 mSv per year or its risk equivalent of around 10(-5) per year. With regard to human intrusion, the consequences from one or more plausible stylized scenarios should be considered in order to evaluate the resilience of the repository to such events. (84) The Commission considers that in circumstances where human intrusion could lead to doses to those living around the site sufficiently high that intervention on current criteria would almost always be justified, reasonable efforts should be made at the repository development stage to reduce the probability of human intrusion or to limit its consequences. In this respect, the Commission has previously advised that an existing annual dose of around 10 mSv per year may be used as a generic reference level below which intervention is not likely to be justifiable. Conversely, an existing annual dose of around 100 mSv per year may be used as a generic reference level above which intervention should be considered almost always justifiable. Similar considerations apply in situations where the thresholds for deterministic effects in relevant organs are exceeded. (85) Compliance with the constraints can be assessed by utilising either an aggregated risk-oriented approach, with a risk constraint, or a disaggregated dose/probability approach, with a dose constraint, or a combination of both. A similar level of protection can be achieved by any of these approaches; however, more information may

Hazardous Waste↗
PubMed2000

[Effects of one cycle of inhalation crenotherapy with radioactive fluoridated oligomineral].

The objective of the study was to test the effects of inhalation crenotherapy using the radioactive, fluoridated oligomineral waters from the Merano Spa on both subjects with specific upper respiratory tract phlogosis and normal subjects. The double-blind study was performed on a population of 27 adults of both sexes treated with radioactive-fluoridated water (group A) and 20 subjects, suffering from the same chronic catarrh pathology, selected with the same criteria but treated with inhalation of steam and an aerosol using drinking water from the municipal water supply (group C). In addition, a group of 13 subjects--which in terms of age and sex were statistically comparable to groups A and C but who did not show any signs of acute or chronic upper respiratory tract pathologies (group B) were also treated with the radioactive-fluoridated waters. All subjects included in the study underwent the following tests before and after the cycle of crenotherapy: Objective E.N.T. examination. Computerized Active Anterior Rhinomanometry. Detection of the ciliary mucous transport (CMT) time. Nasal cytology. Physical and immunochemical examination of the nasal mucous. The results of this study--seen in the trend in some parameters monitored both before and after the cycle of crenotherapy using Merano Spa water--clearly show that that the crenotherapy studied had an effect on aspecific chronic phlogosis of the upper respiratory tract. In fact, among other things, group A showed decreased nasal resistance, increased nasal respiratory flow, normalized mucociliary transport, decreased bacterial flora and an increased number of plasma cells in the rhinocytogram. In addition there was an increase in the following values in the nasal mucous: Albumin, non-secretory Immunoglobulin and the secretory portion of secretory Immunoglobulin A. None of these variations are seen in the results from the control group treated with municipal drinking water. After treatment with Merano spa water, the pathology-free subjects showed variations in the parameters in line with those found for group A. This biological reality can most likely be attributed to the favorable response of the respiratory mucosa, promoting anti-infection defenses.

Acute Disease↗
PubMed2002

Analysis of radioactive pollution in the Gulf of Palermo.

PURPOSE: Sea water represents more than three quarters of the whole world. The radioactive fall out caused by nuclear experiments, radioactive drosses from nuclear power plants and other pollution sources, are able to contaminate the world ecosystems, and especially the sea water. The aim of this work is the evaluation of a possible radioactive pollution in the Gulf of Palermo. MATERIAL AND METHODS: The Gulf of Palermo was divided into 5 homogeneous hydrological parts, in which fish and water were collected. The dosage of 131I e del 137Cs was mainly assessed because they have a long half-life and their presence in the water can be due to nuclear accidents but also to a wrong removal of the waste materials of nuclear medicine procedures; the other radioisotopes assessed (144Ce, 106Rh, 140La) are due only to nuclear fall-out. Gamma spectrometry technique was used for the evaluation of the radioisotopes' concentration after an adequate treatment of the samples. RESULTS AND CONCLUSIONS: The concentration of the examined radionuclides was below the instrumental capability apart from the 137Cs, whose dose was increased, and can be due to nuclear accidents and explosions. The radionuclide levels detected do not determine a higher risk than normal for the population's health even regard the eatablity of ittical species.

Animals↗
PubMed2002

[Radioactivity for 137Cs, 125I, 131I, 59Fe, y 57Co windows from foods included in the basic alimentary basket and in the water, consumed in the state of Carabobo, Venezuela].

One of the input ways of radionucleids into the organism is through food intake. The aim of the present study is to measure the radioactivity levels in food and water samples within energy windows corresponding to 137Cs, 125I, 131I, 59Fe, and 57Co. Samples were taken from local and imported food belonging to the venezuelan basic alimentary basket and included: beef meat, hen egg, chicken bone, tomato, black bean, rice, powder milk from local dealers or imported from Italy and New Zeeland, potable water from the Valencia city aqueduct and bottled water from local sources or imported from Portugal. Radioactivity was measured with a well type Nal (TI) scintillation counter. Analyzed foods and water presented levels lower than the minimal detectable activity for 137Cs, 131I, 59Fe, 57Co, but it was detected in the Valencia city aqueduct water and in bottled water imported from Portugal, levels greater than the minimal detectable activity for the 125I energy window. These results strongly suggest the need of repeated multienergy windows monitoring of radioactivity of basic alimentary basket foods and potable water.

Animals↗
PubMed1964

STUDIES ON INHIBITION OF INTESTINAL ABSORPTION OF RADIOACTIVE STRONTIUM. II. EFFECTS OF ADMINISTRATION OF SODIUM ALGINATE BY OROGASTRIC INTUBATION AND FEEDING.

A method is reported that enables selective suppression of absorption of radioactive strontium from ingested food material, permitting calcium to remain available to the body. Studies were carried out by measuring blood levels and bone uptake of Sr(89) and Ca(45) at different time intervals after orogastric intubation of rats. The addition of sodium alginate, derived from brown marine algae, to the radioactive isotopes increased the overall physiological discrimination against strontium by amounts up to 60% after 24 hours. This discrimination was further increased by feeding sodium alginate mixed with standard diet in the proportions of 20:80 and 30:70. The observed ratio was reduced by administration of sodium alginate from 0.25 to 0.09.Determination of the limiting dosage in rats is restricted to the amounts which rats will consume. In the event of an inadvertent release of radioactive strontium, human subjects probably could increase their intake of alginate at will, permitting a greater effectiveness of sodium alginate than could be obtained in experimental animals.

Absorption↗
PubMed1964

STUDIES ON THE INHIBITION OF INTESTINAL ABSORPTION OF RADIOACTIVE STRONTIUM. 3. THE EFFECT OF ADMINISTRATION OF SODIUM ALGINATE IN FOOD AND IN DRINKING WATER.

A method is reported which permits selective suppression of absorption of radioactive strontium from ingested food material, permitting calcium to be available to the body. Studies were carried out by measuring bone uptake of Sr(89) and Ca(45) when various amounts of sodium alginate were fed with the diet. Long-term studies were made in which two different levels of radioactivity were used, to determine the pattern of Sr(89) deposition with continuous intake of binding agent. It was found that administration of sodium alginate as a jelly overcomes the problem of constipation and effectively reduces Sr(89) uptake, up to 83%. This fact represents a significant finding with respect to the use of the compound in human subjects. Addition of sodium alginate to drinking water is effective with low levels of Sr(89) intake.This naturally occurring water-soluble macromolecular substance possesses several advantages in use for the suppression of absorption of radioactive strontium when compared with synthetic ion exchange resins: there is no disturbance of electrolyte balance; efficiency is not reduced by treatment over a prolonged period of time; and finally, the product is palatable.

Alginates↗
PubMed2005

[Details in relation to emergency planning in case of undesired dispersion of radioactivity].

In the present context of terrorist threat and the multiple uses of radioactive sources for many applications, one cannot exclude the probability of a contamination with radioactive products in the public domain. The most probable scenario is the loss or theft of a source, or a source showing up in some unexpected location (orphan sources). Terrorist actions may lead to a similar problem (radiological dispersion devices, RDD). If the radiological situation is serious, the Belgian emergency plan will be declared, aiming at protecting the population as adequately as possible. However, the emergency plan has mainly been conceived for an accident in a nuclear facility; as exercises are organised frequently and as the technical possibilities can be studied in advance, the experts are better prepared for such accidents. But a radioactive contamination in some other location would lead to modifications to be made, which may result in less effective response. Indeed, the very first stage--an alert--will presumably be missing. Or the contamination may occur in a town not involved in radiological emergency exercises, leading to a local lack of means. The main concern is that this should not lead to a degradation of the response. It is essential that all decision makers at all levels know how to deal with the situation, or at least know whom to call for support (Mayors, emergency workers) A special focus on medical staff who could be involved with potentially strong (yet local) fields of radiation, injured people with contamination, but also (and presumably especially) with the psychological impact of large groups of population feeling concerned about the potential health or societal (and economic) consequences for themselves or their children. Whether the probability of such an event is large in Belgium or not is in that sense less relevant: the probability surely isn't zero, and as such an adapted preparation scheme is absolutely necessary.

Disaster Planning↗
PubMed2006

[Modyfying complex additives in technologies for cementing radioactive waste].

The article presents results obtained in studies concerning properties of cement compounds with radioactive waste, if made with modifying complex additive. Modifying complex additive was proved to influence positively on technologic parameters of cementing liquid and solid radioactive waste, on possible lower volume of cemented waste vs. the volumes obtained through traditional cementing methods without the modifying complex additive, on regulated qualities of end cement compounds with radioactive waste and prevention of biologic corrosion in presence of the modifying complex additive.

Construction Materials↗
PubMedDate not supplied

[Distribution and activity of microorganisms in the deep repository for liquid radioactive waste at the Siberian Chemical Combine].

The physicochemical conditions, composition of microbial communities, and the rates of anaerobic processes in the deep sandy horizons used as a repository for liquid radioactive wastes (LRW) at the Siberian Chemical Combine (Seversk, Tomsk oblast), were studied. Formation waters from the observation wells drilled into the production horizons of the radioactive waste disposal site were found to be inhabited by microorganisms of different physiological groups, including aerobic organotrophs, anaerobic fermentative, denitrifying, sulfate-reducing, and methanogenic bacteria. The density of microbial population, as determined by cultural methods, was low and usually did not exceed 10(4) cells/ml. Enrichment cultures of microorganisms producing gases (hydrogen, methane, carbon dioxide, and hydrogen sulfide) and capable of participation in the precipitation of metal sulfides were obtained from the waters of production horizons. The contemporary processes of sulfate reduction and methanogenesis were assayed; the rates of these terminal processes of organic matter destruction were found to be low. The denitrifying bacteria from the underground repository were capable of reducing the nitrates contained in the wastes, provided sources of energy and biogenic elements were available. Biosorption of radionuclides by the biomass of aerobic bacteria isolated from groundwater was demonstrated. The results obtained give us insight into the functional structure of the microbial community inhabiting the waters of repository production horizons. This study indicates that the numbers and activity of microbial cells are low both inside and outside the zone of radioactive waste dispersion, in spite of the long period of waste discharge.

Bacteria↗
PubMed1990

Low-level radioactive wastes. AMA Council on Scientific Affairs.

Under a federal law, each state by January 1, 1993, must provide for safe disposal of its low-level radioactive wastes. Most of the wastes are from using nuclear power to produce electricity, but 25% to 30% are from medical diagnosis, therapy, and research. Exposures to radioactivity from the wastes are much smaller than those from natural sources, and federal standards limit public exposure. Currently operating disposal facilities are in Beatty, Nev, Barnwell, SC, and Richland, Wash. National policy encourages the development of regional facilities. Planning a regional facility, selecting a site, and building, monitoring, and closing the facility will be a complex project lasting decades that involves legislation, public participation, local and state governments, financing, quality control, and surveillance. The facilities will utilize geological factors, structural designs, packaging, and other approaches to isolate the wastes. Those providing medical care can reduce wastes by storing them until they are less radioactive, substituting nonradioactive compounds, reducing volumes, and incinerating. Physicians have an important role in informing and advising the public and public officials about risks involved with the wastes and about effective methods of dealing with them.

Physician's Role↗
PubMed1989

Low-level radioactive wastes. Council on Scientific Affairs.

Under a federal law, each state by January 1, 1993, must provide for safe disposal of its low-level radioactive wastes. Most of the wastes are from using nuclear power to produce electricity, but 25% to 30% are from medical diagnosis, therapy, and research. Exposures to radioactivity from the wastes are much smaller than those from natural sources, and federal standards limit public exposure. Currently operating disposal facilities are in Beatty, Nev, Barnwell, SC, and Richland, Wash. National policy encourages the development of regional facilities. Planning a regional facility, selecting a site, and building, monitoring, and closing the facility will be a complex project lasting decades that involves legislation, public participation, local and state governments, financing, quality control, and surveillance. The facilities will utilize geological factors, structural designs, packaging, and other approaches to isolate the wastes. Those providing medical care can reduce wastes by storing them until they are less radioactive, substituting nonradioactive compounds, reducing volumes, and incinerating. Physicians have an important role in informing and advising the public and public officials about risks involved with the wastes and about effective methods of dealing with them.

Environmental Monitoring↗
PubMedDate not supplied

After Chernobyl--how U.S. physicians respond to radioactive fallout.

On April 26, 1986, a reactor unit at the Soviet Union's Chernobyl Power Station exploded, and substantial amounts of radioactive material were released. Fallout from this incident was deposited in the United States and elsewhere. Radioactive fallout is a major concern for obstetricians and pediatricians; their patients are the most vulnerable to the adverse effects of radiation. This study addresses the question: What are these physicians' perceptions and beliefs about fallout and its effects on their patients? A questionnaire was developed to measure these perceptions and beliefs. This instrument was mailed in November 1986 to all obstetricians and pediatricians listed in the telephone directory for western Massachusetts. A factor analysis of the physicians' responses yielded five factors: concern for patients, management of risk, effect of fallout, physicians' role in prevention, and guidance on advising patients. The physicians' responses to patients' inquiries were categorized as giving information, reassurance, and prescription. The authors recommend that the study be replicated with a more representative sample, that professional medical groups provide reliable information to members, and that physicians ask their professional organizations to address the issue of physician participation in the national planning process relevant to their concerns about radioactive fallout.

Accidents↗
PubMed1985

Disposal of low-level radioactive waste. Impact on the medical profession.

During 1985, low-level radioactive waste disposal has become a critical concern. The issue has been forced by the threatened closure of the three commercial disposal sites. The medical community has used radioactive isotopes for decades in nuclear medicine, radiation therapy, radioimmunoassay, and biomedical research. Loss of disposal capacity for radioactive wastes generated by these activities, by the suppliers of radioisotopes, and by pharmaceutical companies will have a profound impact on the medical profession.

Legislation as Topic↗
PubMed1977

[Studies on the lymph drainage of the eye. 2. Drainage of lymph-dependent radioactive substances from the anterior chamber. (author's transl)].

In order to study lymph drainage from the eye colloid solutions (198Au-colloid and 99mTc-sulfur-colloid) were injected into the right anterior chamber of the eye in 12 rabbits. The distribution of the radioactivity was measured in vivo with an Anger-type camera and in vitro with a sodium iodine crystal well-counter after dissection. The drainage of radioactivity from the anterior chamber had an average half-life of 36 min. The drained activity could be found mainly in blood, liver, kidney, and bone tissue. Moreover, a concentration of radioactivity significantly surpassing the concentration in blood was measured in the right retrobulbar space in 75% of the cases and in the cervical lymph nodes in 50% of the cases. These findings substantiate a communication between the anterior chamber of the eye and the retrobulbar space in the form of a lymphatic or a prelymphatic-lymphatic flow.

Animals↗