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PubMed1982

Hyperparathyroidism after radioactive iodine therapy for Graves disease.

The association of external ionizing radiation to the head and neck and the subsequent development of hyperfunctioning parathyroid glands has been documented in recent years. This also has been demonstrated experimentally in animals. Despite the numbers of patients with Graves disease who have been treated with radioactive iodine, there are no reports in the literature of parathyroid surgery for hyperparathyroidism secondary to earlier treatment with radioactive iodine for Graves disease. This report describes the operative and pathologic findings in four patients with hyperparathyroidism. These patients had previously been treated with radioactive iodine for Graves disease. The pathologic findings at surgery included in three cases a single enlarged hyperplastic gland consistent with a parathyroid adenoma. One patient had hyperplasia of all four glands. The two largest glands and halves of the two remaining glands were removed. In a long-term follow-up of children and adolescents treated with radioactive iodine for Graves disease, Levy and Schumacher found calcium elevations in 10 of 159 patients. The increased incidence of hyperparathyroidism following radioactive iodine treatment for Graves disease in children and adolescents would seem several times higher than normal. Whether adults who have radioactive iodine treatment for Graves disease have a similar increase incidence is not known. Meanwhile it would seem reasonable to suggest that patients whose hyperthyroidism is treated with radioactive iodine should have their serum calcium levels determined at 5-year intervals.

Adenoma↗
PubMedDate not supplied

Classification of radioactive pesticide residues in food-producing animals.

Modern analytical methodology, especially radiotracer techniques, makes it possible to detect residues of a foreign compound in animal products at levels seemingly impossible just two decades ago. Unfortunately, the ability to detect "total radioactivity" in a substrate does not assure that the chemical nature of the residues will be elucidated or that their toxicological significance can be properly assessed. Detection without identification has created a number of problems for the residue chemist and toxicologist. Among these is the problem of classifying radioactive residues in a manner that is meaningful to other scientists and which inherently denotes certain characteristics of the residues involved. While such a system is as yet incomplete, a general classification scheme has evolved in recent years that provides a common ground for categorizing radioactive residues, be they known or unknown. The system consists basically of four categories of radioactive residues: (a) free metabolites (b) conjugate metabolites (c) bound pesticide residues and (d) natural constituents. For the most part, the terms are self-explanatory, but precise definitions remain a point of debate among scientists. This paper discusses th criteria for classifying radioactive residues as perceived by the author based upon works of residue and metabolism chemists, especially those dealing with pesticide residues. Utimately, classification is dependent on the identification of total radioactive residues, a situation which is virtually impossible with many xenobiotics. Sound scientific judgment must remain the key ingredient in determining just how far one must go in identifying radioactive residues of drugs, pesticides and other chemicals which may become a component of the human diet.

Animals↗
PubMedDate not supplied

[Radioactivity distribution in the subcellular fractions of reproductive tract and skeletal muscle tissue in rat and rabbit embryos after in vitro exposure to 1 alpha, 2 alpha-3H(p)-testosterone and 5 alpha-dihydro-1 alpha, 2 alpha(p)-testosterone].

In the in vitro experiments the distribution of radioactivity was studied in the subcellular fractions of the reproductive system and muscles of the rat embryos on the 14-, 16- and 18th days and of the rabbit embryos on the 18th and 20-22nd days of development after the preincubation in the medium with 1 alpha, 2 alpha-3H(n)-testosterone (T-3H). The total consumption of T-3H per mg of tissue is higher in the reproductive system than in the muscles and attains the maximum in the rabbit on the 21st and in the rat on the 18th day of development. The ratio of radioactivity in the nuclear and cytoplasmic fractions per mg of protein changes at the critical period of somatic sex differentiation: in the rabbit between the 20th and 21st and in the rat between the 16th and 18th days of development. The radioactivity in the nuclear fraction is markedly higher than in the cytoplasmic one on the 21st day in the rabbit and on the 18th day in the rat and, on the contrary, lower at all preceding times. The radioactivity in the microsomal fraction is higher than in the cytosol. The distribution of radioactivity of 5 alpha-dihydro-1 alpha, 2 alpha(n)-testosterone (DHT-3H) was studied on the 20th and 21st days of development in the rabbit embryos. No changes in the nucleocytoplasmic ratio of radioactivity was found, but the radioactivity decreased in all fractions on the 21st day.

Animals↗
PubMed2002

Survey of natural and anthropogenic radioactivity in environmental samples from Yugoslavia.

The radioactivity of 238U, 226Ra, 232Th, 40K and 137Cs in sediments, soil, turf and honey from Serbia and Kosovo (Yugoslavia) was measured using gamma and alpha spectrometry in order to estimate the radiation hazard from natural and man-made sources, as well as to compile a database for radioactivity levels in those regions. One sample, collected in the vicinity of a "depleted uranium" (DU) shell of the recent Balkan war, revealed a high 238U activity and a non-natural 235U/238U activity ratio, confirming therefore its anthropogenic origin. However, some other soil samples coming from characteristic DU craters did not show any characteristic level of radioactivity. The other sediment and turf samples taken all around the country show low radioactivity levels for all the isotopes here considered. With the aim of obtaining some indication about radioactivity migration in the food chain, several honey samples have been examined too. All samples show very low radioactivity content, often indistinguishable from natural background.

Environmental Monitoring↗
PubMed2005

Characterization and geographic location of sources of radioactivity lost downhole in the course of oil and gas exploration and production activities in Texas, 1956 to 2001.

Case reports describing sources of radioactivity lost downhole in Texas from 1956 to 2001 were obtained from the Texas Department of Health Bureau of Radiation Control and entered into a computerized database. The events of the 45-y period of analysis were characterized, examining aspects such as source type, amount of activity, location of loss, depth, and date of occurrence. Results of the study found that 316 downhole source incidents were reported to the agency during this period of time, representing a total of 426 distinct sources of radioactivity lost downhole within the boundaries of the State of Texas. The sources lost were predominantly AmBe, accounting for 74 TBq of radioactivity at the time of loss, and Cs, accounting for 16.3 TBq of radioactivity. A longitudinal analysis of the data showed the average loss per active oil and gas rig in Texas (known as "rig count") at approximately 24 losses per 1,000 rigs. Specific geographic information was largely missing from many of the records, which prevented the geolocation of wells described to contain lost radioactive sources. As a result, most wells could only be located to the county level, and no comprehensive geographical information system (GIS) map could be accurately created from the data. However, when available, source location information was standardized to permit the characterization of the sources reported as lost. This effort produced the first dedicated compendium of lost downhole sources for the State of Texas and provides an important source of information for regulatory agencies. The ability to provide prompt information about the fate and location of sources of radioactivity is important to regulatory officials, given the recent concerns about radiation source inventory control in the post 9/11 world as it relates to the possible creation of radiological dispersal devices.

Fuel Oils↗
PubMed2006

[Radioactive waste due to electric power and mineral fertiliser production].

Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb has been conducting systematic investigations of radioactive contamination of the Croatian environment by anthropogenic fission products as well as by naturally occurring radioactive material (NORM) since 1963. Several critical sites in Croatia were identified for NORM, that is, for slag and ash repositories from coal-fired power plants and phosphogypsum repository from a mineral fertilizer production plant. As the coals and phosphate ores contain naturally occurring radionuclides, especially the members of the uranium and thorium radioactive chains, utilising these materials in various industries only enhances their natural radioactivity in residual waste. Consequently, the resulting activity concentrations of natural radionuclides in waste material could be several times higher than in the adjacent soil. These deposited materials pose permanent risk of radiation exposure due to the long physical half-life of natural radionuclides (e.g., T 1/2 = 1600 years for 226Ra). Results of scientific investigations related to natural radioactivity are used in the recovery of slag and ash repositories and landfills, as well as in establishing regulatory criteria targeting import of coal and phosphate ores. In consequence, recently measured activity concentrations of natural radioactivity in imported materials used nowadays in coal-fired power plants are significantly lower than in previously used raw materials. Therefore, slag and ash can be used as additive materials in cement production.

Croatia↗
PubMed1990

[Radioactivity of fodder mixtures for poultry and swine].

The investigation was conducted to determine the radioactivities of fodder mixtures and their components for poultry and swine. The total radioactivity, concentrations of potassium, potassium radioisotopes radium and thorium in 273 fodder mixture samples for poultry, 131 fodder mixture samples and concentrates for swine, and 915 component samples of the mixtures were estimated. The radioactivities of fodder mixtures for poultry, swine, and protein concentrates ranged from 212.0 (DKM-2) to 269.0 Bq/kg (DKA-starter), from 206.0 (PT-1) to 233.0 (PP-prestarter), and from 444.0 (KT-1) to 557.0 Bq/kg (Provit), respectively. As to the components of fodder mixture, the radioactivities ranged from 18.0 (fodder phosphate) to 1104.0 Bq/kg (fodder yeasts). The potassium concentrations in fodder mixtures for poultry ranged from 0.82 g/100 g (DKA-starter) to 0.62 g/100 g (KB-1); for swine ranged from 1.97 g/100 g (Provit) to 0.63 g/100 g (PT-1). The highest concentration of potassium was found in fodder yeasts (3.85 g/100 g), and the lowest one in fodder phosphate (0.01 g/100 g). The analysis of the data showed that the radioactivity of the mixtures and their components was mostly conditioned by radiopotassium and revealed correlations between the radioactivities and the total concentrations of potassium. The contamination with the natural radioelements (potassium, radium, thorium) as well as their limited absorption by the gastrointestinal tract, their metabolism in organism, and their radiotoxicological characteristics do not create radiological threat to animals.

Animal Feed↗
PubMed1983

[A system for decontamination of liquid radioactive waste produced in in vitro tests in nuclear medicine].

It is well known that very large storage tanks for radioactive liquids are necessary for the disposal of liquid radioactive waste. In vitro tests in radioimmunoassay in nuclear medicine are rapidly increasing for clinical examination causing marked increase in the volume of liquid radioactive waste. Thus we have developed a system for decontaminating radioactivity from liquid waste. In the first step, the liquid waste is boiled by a sterilizer and, in the second step, this sterilised liquid is filtered by a cylindrical filter (Toyo filter No. 84). After filtration, the liquid waste is passed into a beaded charcoal column and an ion exchange resin (Amberlite IRA 402) column. After these treatments, the radioactivity level of liquid waste is lowered to less than 1% of the original radioactivity. We are now in the planning stages of building an apparatus for practical use.

Filtration↗
PubMed2002

Radioactivity near the sunken submarine "Kursk" in the Southern Barents Sea.

Radioactivity measurements were conducted on seawater, sediment, and biota samples collected in the vicinity of the Russian submarine "Kursk" in September, 2000, within 1 month of the vessel's sinking in the Barents Sea to determine whether leakage of radioactivity from the vessel's two nuclear reactors had occurred and to assess the impact on one of the most productive fishing areas in the world. Levels of radioactivity in surface sediments and biota are within the range of values previously measured in the Barents Sea and can be ascribed to inputs from global fallout, European nuclear fuel reprocessing facilities, and the Chernobyl accident. However, levels of 1291 in seawater in the Southern Barents Sea increased by 500% between 1992 and 2000, and the 129I/137Cs ratio increased by more than an order of magnitude during this time, owing to long-range transport of releases from reprocessing facilities at Sellafield (U.K.) and La Hague (France). Although these results indicate that, at the time of sampling, leakage from the Kursk had a negligible impact on the environment, they also show that regional background levels of artificial radioactivity are varying rapidly on annual timescales and that Europe's nuclear reprocessing facilities are the leading contributor of anthropogenic radioactivity to the region.

Environmental Monitoring↗
PubMed1987

Measurements of induced radioactivity in electron- and photon-irradiated beef.

Samples of beef were irradiated with electrons of approx. 10- and 13.5-MeV energies or with 60Co gamma-ray photons (1.17 and 1.33 MeV). Induced radioactivity was measured with a gamma-ray spectrometer, consisting of a Ge(Li) detector and a multichannel analyzer. No induced radioactivity could be detected in the photon-irradiated samples; also for 10-MeV electrons the activity was below the detection limit. The irradiation by 13.5-MeV electrons, however, resulted in measurable radioactivity and the amount of 13N-activity was in agreement with previously calculated values. These measurements confirm previous conclusions that irradiation of food with electrons at 10 MeV or even at 13.5 MeV does not constitute any health risk due to radioactivity. Part of the induced radioactivity from 13.5-MeV electron irradiation is due to neutron capture, and the results suggest that several neutron sources contribute to the measured radioactivity.

Animals↗
PubMed2005

Radioactivity concentrations in soils of the Xiazhuang granite area, China.

The natural radioactivity of soils at the Xiazhuang granite massif of Southern China has been studied. The radioactivities of 55 samples have been measured with a low-background HPGe detector. The radioactivity concentrations of (238)U and (40)K ranged from 40.2 to 442 and from 442 to 913 Bq/kg, respectively, while the radioactivity concentration of (232)Th varied only slightly. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Ra(eq)), the absorbed dose rate (D ), the annual effective dose rate and the external hazard index (H(ex)) have been calculated and compared with the internationally approved values. The study provides background radioactivity concentrations in a granite area, specifically, the area in the vicinity of a uranium mine in Southern China. The data can be used in exploring granite-type uranium deposits.

Algorithms↗
PubMed1995

Radioactive materials in recycled metals.

In recent years, the metal recycling industry has become increasingly aware of an unwanted component in metal scrap--radioactive material. Worldwide, there have been 35 instances where radioactive sources were unintentionally smelted in the course of recycling metal scrap. In some cases contaminated metal consumer products were distributed internationally. In at least one case, serious radiation exposures of workers and the public occurred. Radioactive material appearing in metal scrap includes sources subject to licensing under the Atomic Energy Act and also naturally occurring radioactive material. U.S. mills that have smelted a radioactive source face costs resulting from decontamination, waste disposal, and lost profits that range from 7 to 23 million U.S. dollars for each event. To solve the problem, industry and the government have jointly undertaken initiatives to increase awareness of the problem within the metal recycling industry. Radiation monitoring of recycled metal scrap is being performed increasingly by mills and, to a lesser extent, by scrap processors. The monitoring does not, however, provide 100% protection. Improvements in regulatory oversight by the government could stimulate improved accounting and control of licensed sources. However, additional government effort in this area must be reconciled with competing priorities in radiation safety and budgetary constraints. The threat of radioactive material in recycled metal scrap will continue for the foreseeable future and, thus, poses regulatory policy challenges for both developed and developing nations.

Brachytherapy↗
PubMed2002

Radioactivity appearing at landfills in household trash of nuclear medicine patients: much ado about nothing?

The U.S. NRC in 1997 removed its arbitrary 1.11 GBq (30 mCi) rule, which had been in existence for almost 50 y, and now many more patients receiving radionuclide therapy in nuclear medicine can be treated as outpatients. However, another problem has the potential to limit the short-lived reality of outpatient treatment unless nuclear medicine practitioners and the health physics community gets involved. Radioactive articles in the household trash of nuclear medicine patients are appearing at solid waste landfills that have installed radiation monitors to prevent the entry of any detectable radioactivity, and alarms are going off around the country. These monitors are set to alarm at extremely low activity levels. Some states may actually hold licensees responsible if a patient's radioactive household trash is discovered in a solid waste stream; this is another major reason [along with continued use of the 1.11 GBq (30 mCi) rule] why many licensees are still not releasing their radionuclide therapy patients. This is in spite of the fact that the radioactivity contained in released nuclear medicine therapy patients, let alone the much lower activity level contained in their potentially radioactive household wastes, poses a minimal hazard to the public health and safety or to the environment. Currently, there are no regulations governing the disposal of low-activity, rapidly-decaying radioactive materials found in the household trash of nuclear medicine patients, the performance of landfill radiation monitors, or the necessity of spectrometry equipment. Resources are, therefore, being unnecessarily expended by regulators and licensees in responding to radiation monitor alarms that are caused by these unregulated short-lived materials that may be mixed with municipal trash. Recommendations are presented that would have the effect of modifying the existing landfill regulations and practices so as to allow the immediate disposal of such wastes.

Humans↗
PubMed1999

Practical methods for reducing radioactive contamination incidents in the nuclear cardiology laboratory.

OBJECTIVE: The purpose of this study was to determine the extent and cause of radioactive contamination in our nuclear cardiology laboratory, and to develop possible solutions to minimize future occurrence. METHODS: We conducted a retrospective review to determine the underlying causes of the 15 minor radioactive contamination events that have occurred in the exercise areas of our laboratory since 1986. Of the 15 documented events, 8 were caused by failure of intravenous apparatus and 7 were due to syringe mishandling. Based on a staff questionnaire, we determined the most prevalent causes of radioactive contamination. Other than problems associated with intravenous setup, the causes were lack of experience by the individual performing the injection, followed closely by radioactive syringe disposal problems, injection technique, and unclear designation of duties during the exercise procedure. RESULTS: Based on these findings, we formulated a 4-part plan: a training program; a closely inspected intravenous apparatus; a mobile radioactive waste container; and a clear designation of duties for personnel to be included in the exercise procedure protocol. CONCLUSION: We have implemented a sensible and practical plan for reducing radioactive contamination, which is currently being evaluated.

Accidents, Occupational↗
PubMedDate not supplied

[Coccidies genus Eimeria as a bioindicator of radioactive pollution of the biocenose].

The data on coccidies of rodents were collected in Chernobil (1989-1991) and in the regions of radioactive pollution in the Bryansk region of Russia (1992-1999). The surface pollution of experimental plots was different and come from 0.11 to 11.8 MBq/m2. 2185 rodent were examined in all. Thirteen types of coccidies p. Eimeria were found out in 525 small animals. The analysis of changes in morphological characters and oocysts sporulation in dependence of the level of radioactive pollution of biocenose was carried out. It was found out that parametric signs (length, width and form index of oocysts) were independent from radioactive pollution. At the some time the radioactive pollution renders a significant influence on the nonparametric signs (different types of capsule deformation and internal texture of oocysts) and the process of sporulation. With the increase of radioactive pollution the part of nonsporulated oocycts increased and the quantity of oocysts, corresponding to the description of given type (normal), decreased. This dependence is well described by the equation of logarithmic regression, that allows to use this indexes in the bioindication of the radioactive pollution of the biocenose.

Animals↗
PubMed1990

[Radioactivity and food].

Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.

Animals↗
PubMed1976

Survey of radioactive agents for in vitro labeling of phagocytic leukocytes. I. Soluble agents.

Twenty-three soluble (nonparticulate) radioactive agents were screened for their ability to label leukocytes in vitro in the presence or absence of plasma and red cells. The degree of cell binding was compared with that of other agents previously reported. Leukocyte binding of 2% or more of the added radioactivity was obtained with ten of these agents. High labeling yields were obtained only with nonpolar lipid-soluble complexes capable of penetrating lipid cell membranes. Unfortunately, this type of labeling tends to be reduced by plasma protein. Some lipophilic radioactive agents tend to elute from the cells after labeling. Compared with radioactive particles, soluble radiopharmaceuticals offer the advantage of easy centrifugal separation of the cell-bound from the residual activity in the suspension fluid. However, the labeling yield tends to be lower than for radioactive particles, and other cellular elements are labeled in addition to the phagocytic leukocytes. In this survey, the most promising soluble agents were 111In or 99mTc complexes of oxine, 111In-tetraphenylporphyrin, DNA labeled with radioactive iodine, and DNA labeled with 77Br and complexed with adriamycin. The ultimate value of any of these agents must await adequate in vivo testing in experimental animals and clinical trials.

DNA↗
PubMedDate not supplied

Radioactivity in municipal sewage and sludge.

OBJECTIVE: To determine the environmental consequences of discharges of radioactivity from a large medical research facility into municipal sewage, specifically 131I activity in sewage sludge, and the radiation exposures to workers and the public when sludges are incinerated. METHODS: The authors measured radioactivity levels in the sludge at the Ann Arbor, Michigan, Waste Water Treatment Plant following radioiodine treatments of two patients at the University of Michigan hospital complex and performed a series of calculations to estimate potential radiation doses due to releases of 131I from incineration of sewage sludge. RESULTS: Approximately 1.1% of the radioactive 131I administered therapeutically to patients was measured in the primary sludge. Radiation doses from incineration of sludge were calculated to be 0.048 millirem (mrem) for a worker during a period in which the incinerator filtration system failed, a condition that could be considered to represent maximum exposure conditions, for two nine-hour days. Calculated results for a more typically exposed worker (with the filtration system in operation and a 22-week period of incineration) yielded a committed effective dose equivalent of 0.066 mrem. If a worker were exposed to both conditions during the period of incineration, the dose was calculated to be 0.11 mrem. For a member of the public, the committed effective dose equivalent was calculated as 0.003 mrem for a 22-week incineration period. Exposures to both workers and the public were a very small fraction of a typical annual dose (about 100 mrem excluding radon, or 300 mrem with radon) due to natural background radiation. Transport time to the treatment plant for radioiodine was found to be much longer than that of a normal sewage, possibly due to absorption of iodine by organic material in the sewer lines. The residence time of radioiodine in the sewer also appears to be longer than expected. CONCLUSION: 131I in land-applied sludge presents few health concerns because sufficient decay occurs before it can reach the public however, incineration, which is done in winter months, directly releases the 131I from sewage sludge to the atmosphere, and even though exposures to both workers and the public were found to be considerably lower than 1% of natural background, incineration of sludge in a pathway for public exposure. Although 131I was readily measurable in sewage sludge, only about 1% of the radioione administered to patients was found in the sludge. The fate of the remaining radioactivity has not been established; some may be in secondary and tertiary residuals, but it is quite likely that most passed through the plant and was discharged in dilute concentrations in plant emissions. The behavior of radioiodine and other radioactive materials released into municipal seweage systems, such as those from large medical facilities, is not yet well understood.

Air Pollutants, Radioactive↗