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At least 1,099 records · Page 61Linked to original sources
PubMed1991

[Influence of radioactive contamination and iodine prophylaxis after the Czernobyl disaster on thyroid morphology and function of the Poznan region].

The radioactive contamination of Poznań Region was recognized after Chernobyl accident as average. The predicted values of minimal (inhalation) and maximal (inhalation and ingestion) committed dose equivalent to the thyroid varied from 2.5 (min) to 24.7 (max) mSv in different groups of adults and children. To follow up the results of iodine prophylaxis and some aspects of possible thyroid gland morphological and functional changes 11086 persons were carefully investigated clinically and biochemically. Among these 11086 persons were 42.6% males and 57.4% females both adults from 17 till 40 year and children up do 16 years. The following parameters were reviewed: pregnancy, time of residence in the region, thyroid abnormalities, family history concerning thyroid diseases, iodine intake in April and May 1986 with possible side effects, changes in the thyroid size observed before and after 1986, degree and kind of thyroid enlargement, serum concentration of T3, T4, TSH, ATMA and ATG titre and finally the effectiveness of thyroid blockade at 24, 48 and 72 h after ingestion of Lugol's solution. Side effects of the ingestion of potassium iodide from 30-70 mg were observed in 153 cases, 36 of them consulted medical doctors but in no case the side effects (dominated by vomiting) threatened the life. In the investigated group were 144 pregnant women. Majority, because 88% of them delivered the baby on or after time and 6.9% before time, 4.9% of natural abortions were noted but non artificial. In the group of children thyroid gland abnormalities before 1986 were reported in 3 cases in 23 after 1986 it is after Chernobyl accident. This information is interesting but needs more precise analysis of different dependencies occurring. The data obtained indicated the existence in Poznań. Region the goiter endemy because 27.5% of investigated children and adults had goiter classified as grades O-B, I, II and III. The elevation or diminution of T3 values were noted in 1164 cases, for T4 in 418 cases and for TSH in 1412 cases. The presence of antimembrane and antithyroglobulin antibodies were observed in 303 cases. All persons with changes observed in thyroid morphology and function are periodically controlled and the results will be published separately. The investigations performed and results presented concern the early aspects of radioactive contamination and effects of iodine prophylaxis. The answer regarding late effects including thyroid cancer needs further multi year studies for which the clinical material investigated in different parts of Poland and well documented should be used as model group for further periodical studies.

Adolescent↗
PubMedDate not supplied

[Late changes in the body function of the inhabitants in the area of the eastern Urals radioactive trace].

Using a mathematical methodology based upon the theory of pattern recognition, the adequacy of this methodology being confirmed by the corroborative results obtained with neuro-net non-parametric methods of analysis, it proved possible to discriminate reliably between generalized organism's statuses, as described with a big number of laboratory indices, of the inhabitants of different areas of a big industrial city which differ in levels of radioactive and non-radioactive environmental pollution.

Adolescent↗
PubMed1996

Analytical microscopy and environment. Current developments using bioindicators of pollution by stable and radioactive elements.

Ecotoxicological investigations were performed on three sets of bioindicators. The first one concerns marine pollution of invertebrates (molluscs: the mussel Mytilus edulis and related species, crustaceans: the crab Liocarcinus puber and related species), contaminated by stable or radioactive elements originating from wastes discharged into sea water. The second one concerns freshwater pollution of vertebrates (fish: the brown trout Salmo trutta fario), contaminated by aluminium dissolved in rivers, as a consequence of an atmospheric pollution by acid rain. The third one concerns the atmospheric pollution of trees by plutonium (Casuarina equisetifolia). Mechanisms involved in the uptake, storage and elimination processes of these toxicants were studied, with a special emphasis on cellular and subcellular aspects of concentration sites. Two microanalytical methods were employed: Secondary Ion Mass Spectrometry (SIMS), using the ion microscope and the ion microprobe, and X-ray spectrometry using the electron microprobe (EMP). In marine organisms, the target organs and tissues of bioaccumulation of stable and radioactive elements (238U, 239Pu and 241Am), were shown to be mainly digestive gland, gill and exoskeleton. The target organelles were shown to be spherocrystals and lysosomes. Amoebocytes, enzymatically equipped with lysosomal phosphatase, were involved in the phagocytic clearance of metal pollutants. In trout, insolubilisation of Al phosphate within lysosomes and a high metal concentration within bones were observed. The tree Casuarina equisetifolia exhibits a particular ability to concentrate atmospheric plutonium within its leaves.

Air Pollution↗
PubMedDate not supplied

[Consequences of radioactive pollution of forests in the zone affected by the accident at the Chernobyl power plant].

The effect of forests on the radionuclide primary distribution in different components of the contaminated ecosystems is considered by the example of Chernobyl accident. A basic mathematical model is developed describing 137Cs biogeochemical cycling under conditions of quasi-steady state radionuclide redistribution in the ecosystem. The radionuclide fluxes between different ecosystem components are estimated. Forest ecosystems are proved to diminish radionuclide migration in the environment, and forest should be regarded as an important sanitary factor. The contribution of contaminated forests and forest products to the total irradiation dose to local population is estimated. Special countermeasures are elaborated in order to diminish unfavorable consequences of forest radioactive contamination. A long-term dynamics of radioactive situation in the forest ecosystems is forecasted and further studies on the subject are drafted.

Cesium Radioisotopes↗
PubMedDate not supplied

[The cytogenetic effects in natural populations of Crepis tectorum L. growing in the region of the eastern Urals radioactive trace].

Genetic consequences of a prolonged action of ionizing radiation were analyzed in five natural Crepis tectorum populations growing at the radioactively contaminated territory of the East-Ural radioactive track. In these populations about 40 years after the start of a chronic irradiation an increased frequency of chromosome aberrations was found out. An additional acute gamma irradiation at the dose of 20 Gy did not reveal any changes of radioresistance of the plants investigated.

Asteraceae↗
PubMedDate not supplied

[Influence of radioactive pollution on the character of the distribution of wild mouselike rodents according to the measure of lipid antioxidant activity in their organs].

The estimation of the degree of the radioactive contamination effect on the antioxidative status in tissues of rodents from natural populations is done by means of biometric methods. It is shown, that the character of distribution and variability of the lipids antioxidant activity (AOA) differs significantly depending of species and age of animals, the degree of contamination on areas where wild rodents were caught and time during which the radioactive factor affected. The change in character of the animals distribution in AOA of the brain lipids for the more radioresistant Clethrionomys glareolus Schreb, occurs the later than for the more radiosensitive Apodemus agrarius and especially for Microtus oeconomus Pall. The data obtained make possible to suppose, that the long-term effect of the low intensive ionizing radiation results the qualitative changes in the rodents natural populations state.

Age Factors↗
PubMed1975

Radioactive contamination of the environment and the possible consequences.

To find the optimum solution to the problem of how to protect the environment from pollution by industrial waste, it is necessary, first and foremost, to obtain information on the existing levels of various forms of pollution and the damage caused by them. In this review data are given on all the main sources of contamination of the environment by radioactive substances. The pathways by which these substances reach and affect the human body are discussed, the doses incurred are characterized and the possible consequences of existing levels of exposure are assessed in the light of the latest data on the dose-effect relationship. The wisdom of treating the evaluation of radiation hazards arising from the use of atomic energy not in isolation but as part of a whole complex of ecological factors - including the use of conventional fuels for power generation and transport - is duly noted.

Adult↗
PubMed2000

Pneumotoxic effects of radioactive dust (RD) from a nuclear power plant in Kozloduy, Bulgaria.

BACKGROUND: Airborne radioactive particles isolated from the reactor halls of nuclear power plants are a potential risk to the respiratory system of the working staff. Such radioactive dust (RD) from the Nuclear Power Plant, Kozloduy, Bulgaria was investigated. METHODS: The RD was administered intratracheally to 60 male Wistar rats as an aqueous suspension and the biological effects are estimated, using sensitive biological markers in bronchoalveolar lavage fluid (BALF) and important parameters of the pulmonary antioxidant defense. RESULTS: The results obtained show that RD increases the total cell number, the activities of the lactate dehydrogenase and alkaline phosphatase as well as the protein content in BALF. The activities of superoxide dismutase and catalase in lung homogenate are decreased while activity of the glutathione peroxidase and the content of non-protein sulfhydrils is elevated. CONCLUSIONS: It is concluded that the RD causes transitory toxic effect on lung tissue and changes the correlation between the elements of the pulmonary antioxidative defense.

Air Pollutants, Radioactive↗
PubMed2002

Application of extracorporeal immunoadsorption to reduce circulating blood radioactivity after intraperitoneal administration of indium-111-HMFG1-biotin.

BACKGROUND: Extracorporeal immunoadsorption (ECAT) is a method of reducing activity in radiosensitive organs by removing excess monoclonal antibodies (MAbs) from the blood. Previously, the authors experimentally evaluated ECAT based on the avidin-biotin concept after intravenous administration of radioimmunoconjugates. The aim of the current study was to determine whether ECAT could be used to reduce activity after intraperitoneal (i.p.) administration of indium-111((111)In)-HMFG1-biotin in rats, and to compare the pharmacokinetics of (111)In-HMFG1 with or without attached biotin after i.p. injection. METHODS: HMFG1, a murine immunoglobulin G(1) MAb that recognizes an epitope on the polymorphic epithelial mucin (PEM) antigen, was labeled with (111)In and then biotinylated. ECAT was explored from unseparated blood using an avidin-agarose adsorption column. Thirty rats were used as controls and 13 underwent ECAT. The whole-body (WB), blood, and organ activity were monitored. RESULTS: The binding capacity of (111)In-HMFG1-biotin to avidin was high. Biotinylation did not enhance the excretion of HMFG1. When ECAT was employed, the WB and blood radioactivity were reduced by 35-40% (P < 0.05) and 75--86% (P < 0.01), respectively. After the completion of ECAT, the activity uptake in organs was significantly decreased. CONCLUSIONS: ECAT was successfully applied after i.p. injection of the (111)In-HMFG-biotin MAb to reduce the radioactivity in the WB, blood, and radiosensitive organs. Due to redistribution of the radiolabeled MAbs during and after the completion of ECAT, the adsorption may have been prolonged or repeated. Biotinylation did not significantly change the biodistribution of the (111)In-HMFG1 in rats after intraperitoneal injection.

Animals↗
PubMedDate not supplied

National survey of elements and radioactivity in municipal incinerator ashes.

An analytical survey of fly ashes, bottom ashes and mixtures of the two for 36 elements, soluble salts and radioactivity was conducted. The ashes were taken from approximately one-fourth of the municipal solid waste incinerators presently operating in the United States. The concentrations of a number of toxic elements such as As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, and Zn in specific ashes were high. The levels of radioactivity were not significant from a health standpoint. A number of ashes were exceedingly high in organic matter, indicating grossly inadequate conditions during incineration. Soluble salt content was appreciable in the ashes. The possible sources of elements in refuse and their behavior and fate during refuse incineration are discussed with respect to their chemical forms and properties and incinerator operating parameters. Variability of metal concentrations in ash with time of sampling and their solubilization in landfills are also considered.

Carbon↗
PubMed1991

Genetic damage in a population of slider turtles (Trachemys scripta) inhabiting a radioactive reservoir.

Turtles inhabiting a radioactive reservoir appear to experience genetic damage due to environmental exposure to low concentrations of long-lived radionuclides. Total body burdens for the 50 reservoir turtles examined in the survey ranged from 164.7-4679.3 Bq for cesium-137 and from 462.6-5098.3 Bq for strontium-90. Flow cytometric (FCM) assays of red blood cell nuclei demonstrated significantly greater variation in DNA content for the reservoir turtles than for turtles from a nearby, non-radioactive site. Furthermore, two of the reservoir turtles possessed FCM profiles that are indicative of aneuploid mosaicism. These data strongly suggest that exposure to low-level radiation may involve a sensitive genetic response in a natural population.

Animals↗
PubMed2006

The contents and forms of solid-phase species of radioactive strontium and cesium in Taiwan soils.

This study was to investigate the activities and contents of (137)Cs in the profiles of selected arable and forest soils in Taiwan and various solid-phase species of (85)Sr and (137)Cs in selected arable soils in Taiwan. The gamma (gamma) ray spectra of the collected soil samples and some of the soils amended with (85)Sr and (137)Cs were measured. The data indicate that the arable soils from Sanhsing series, Sanhsing Township and Chuangwei series, Chuangwei Township, Ilan County, and from Tunglochuan series, Pinglin Township, Taipei County shows significantly higher radioactivity of (137)Cs (ND - 11.0 +/- 0.2 Bq kg(-1)). Furthermore, the radioactivity of (137)Cs in the mountain soils (1.24 +/- 0.07 - 42 +/- 1 Bq kg(-1)) from Yuanyang Lake Nature Preserve among Ilan, Taoyuan, and Hsinchu Counties is the highest among the investigated mountain forest soils. This may be mainly attributed to the fact that Ilan County is located in the northeastern part of Taiwan and faces the northeastern and northern seasonal winds with lots of precipitation annually from mid-autumn through mid-spring next year and is receiving greater amount of fallouts yearly. Due to longer reaction period (>or=3 y) of (137)Cs with soil components, (137)Cs was mainly in the forms bound to oxides and to organic matter in the soil amended with (137)Cs and in the soil contaminated with (137)Cs. On the contrary, due to shorter reaction period (<60 d) of (85)Sr with soil components, (85)Sr was mainly in exchangeable form and partially in the forms bound to carbonates and oxides in the soils amended with (85)Sr.

Cesium↗
PubMed1990

MIC-III--an integrated software package to support experiments using the radioactive microsphere technique.

MIC-III is a versatile program system to support gamma spectrometry data management and data collection for experiments using the radioactive microsphere technique. It is mainly written in PASCAL and running on a minicomputer. Hierarchical organ dissection schemes are used for unique classification and identification of samples. For each series of experiments, up to 12 different nuclides and up to 20 different organ dissection schemes can be handled simultaneously. Sample weights are collected on-line and sample radioactivities are measured automatically by gamma spectrometry under process control. The spectra with a resolution of 1022 channels are analyzed using a modified linear regression technique and a strategy to compensate for global spectrum shifts. The spectrum deconvolution algorithm was evaluated by calculating the recovery indices for known nuclide mixtures and compared to the stripping method, matrix method and a linear regression technique using window counts. Recovery values produced by MIC-III are better balanced than those of the other methods. MIC-III showed the smallest dispersion of the recovery index and exhibited least error accumulation in case of spectrum shift. MIC-III computes regional blood flow and arterio-venous shunt, and provides interfaces to customized programs or statistical software packages for further analysis. It has successfully been employed in more than 140 experiments.

Animals↗
PubMed1993

Transpalatal insertion of radioactive gold grain for the treatment of persistent and recurrent nasopharyngeal carcinoma.

PURPOSE: To evaluate the efficacy of radioactive gold grain implant via the split palate approach in the control of locally recurrent or persistent nasopharyngeal carcinoma. METHODS AND MATERIAL: Forty-three patients, 10 for persistent NPC, 28 for first relapse in the nasopharynx, and five for second relapse in the nasopharynx, were treated. The diameter of the tumors at the time of gold grain implant ranged from 0.5 to 5 cm, the number of gold grains inserted varied from 4 to 14, the median number was seven. RESULTS: There was no significant difference in the control of the primary tumor for persistent disease (80% at 5 years), first relapse (61% at 5 years) and second relapse (80% at 3 years), p = 0.8845. The difference in survival between the three subgroups of patients, however, was highly significant (p = 0.0040). Thirty patients had CT evaluation before gold grain implant and the tumor was found confined to the nasopharynx in 21, in the remaining nine patients erosion of the sphenoid sinus or other parts of the base of skull was noted. The difference in the control between those patients with tumors confined to the nasopharynx and those patients with extranasopharyngeal extension of tumor almost reached statistical significance (81% and 44% respectively at 5 years, p = 0.0554). For the six patients who developed local recurrence after gold grain implant and were evaluable for the pattern of failure, the recurrent tumors were considered originating from another region of the nasopharynx in four, and in-field failure in the other two cases. CONCLUSION: Radioactive gold grain implant as salvage treatment provides satisfactory control of persistent and recurrent nasopharyngeal carcinoma. The local control was better when the tumor was localized to the nasopharynx, thus underlines the importance of close follow-up for early recognition of relapse and persistent tumor. However, such patients still suffered from high incidence of regional and distant failure, the pathophysiology and management of which require further investigation.

Adult↗
PubMed1987

Measurement of 99Tc in low-level radioactive waste from reactors using 99mTc as a tracer.

A radiochemical procedure has been developed for measuring 99Tc in major low-level radioactive waste streams from commercial nuclear power facilities which contain numerous potential contaminants. Separation was by alkaline precipitation and anion exchange chromatography; trace amounts of 60Co and other radioactive contaminants were removed by solvent separation. Pure separations were obtained with average radiochemical yield of 47.3 +/- 4.3% determined by a 99mTc tracer. The lower limit of detection for 99Tc was found to be 0.16 pCi/g based on 10-g sample and a 100-min counting time.

Alkalies↗
PubMed2004

Self-absorption correction for beta radioactivity measurements in water samples.

Two methods were used to apply self-absorption corrections for the determination of beta radioactivity in water samples (either for an identified radionuclide or for monitoring trends). One method was performed by estimating the absorption coefficient by assuming an exponential behaviour of absorption using external absorbers, while the other method was performed by preparing empirical curves using standards of different mass. In the first method, a relationship between absorption coefficient and maximum beta energy was also derived. In the second method, self-absorption curves for 90Sr/90Y standard were prepared with several sodium salts (carbonate, nitrate and sulphate salts) and, for 40K standard using a potassium salt. Both beta emitters are usually necessary to calibrate detectors for beta radioactivity measurements. This study showed that, for 90Sr/90Y, results using standards of different mass were more accurate than using external absorbers. Furthermore, it is highly recommended to melt sodium nitrate salts in order to perform a self-absorption curve for 90Sr/90Y because standards were stable in time and homogeneously distributed. For 40K, a self-absorption curve may be easily derived using paper absorbers of different thickness, instead of performing a time consuming self-absorption curve using a set of varying thickness of 40K standards. In order to test the two methods, the gross beta activity of several environmental water samples was analysed.

Absorption↗
PubMed2005

Ion exchangers in radioactive waste management: natural Iranian zeolites.

Five samples of natural zeolites from different parts of Iran were chosen for this study. In order to characterize and determine their structures, X-ray diffraction and infrared spectrometry were carried out for each sample. The selective absorption properties of each zeolite were found by calculating the distribution coefficient (K(d)) of various simulated wastes which were prepared by spiking the radionuclides with (131)I, (99)Mo, (153)Sm, (140)La and (147)Nd. All the zeolite samples used in this study had extremely high absorption value towards (140)La; clinoptolite from Mianeh and analsite from Ghalehkhargoshi showed good absorption for (147)Nd; clinoptolite from Semnan and clinoptolite from Firozkoh showed high absorption for (153)Sm; mesolite from Arababad Tabas showed good absorption for (99)Mo; and finally mesolite from Arababad Tabas, clinoptolite from Semnan and clinoptolite from Firozkoh could be used to selectively absorb (131)I from the stimulated waste which was prepared. The natural zeolites chosen for these studies show a similar pattern to those synthetic ion exchangers in the literature and in some cases an extremely high selectivity towards certain radioactive elements. Hence the binary separation of radioactive elements could easily be carried out. Furthermore, these zeolites, which are naturally occurring ion exchangers, are viable economically and extremely useful alternatives in this industry.

Absorption↗
PubMed2006

Natural radioactivity measurement in pumice samples used raw materials in Turkey.

The activity concentrations of 232Th, 226Ra, and 40K in different pumice samples have been determined by high-resolution gamma-ray spectrometry using a 110% HpGe detector. The radium equivalent activities (Raeq), external hazard index (Hex), and internal hazard index (Hin) associated with the natural radionuclides and representative level index (Igamma r) are calculated to assess the radiation hazard of the natural radioactivity in the pumice samples. The mean values of the measured radioactivity concentrations of 232Th, 226Ra, and 40K for pumice samples from the region of lakes (ROL) are 232.4+/-8.0, 196.9+/-7.8, and 1325.8+/-20.4 Bqkg(-1) and for pumice samples from Cukurova region (CR) 16.3+/-4.0, 16.1+/-4.9, and 479.7+/-170.4 Bqkg(-1), respectively. The calculated Raeq values vary from 435.9+/-12.5 to 883.6+/-41.5 Bqkg(-1) with a mean of 630.9+/-20.2 Bqkg(-1) for the ROL samples and from 49.7+/-3.3 to 101.9+/-7.2 Bqkg(-1) with a mean of 76.3+/-23.7 Bqkg(-1) for the CR samples. For the ROL samples, Raeq are above the limit of 370 Bqkg(-1), equivalent to external gamma dose of 1.5 mSv yr(-1), recommended for the safe use of construction materials by NEA-OECD, while for the CR samples, Raeq values are lower than the limit.

Environmental Pollutants↗