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1.
This work discusses the production and management of liquid radioactive wastes as excretas from patients undergoing therapy procedures with 131I radiopharmaceuticals in Spain. The activity in the sewage has been estimated with and without waste radioactive decay tanks. Two common therapy procedures have been considered, the thyroid cancer (4.14 GBq administered per treatment), and the hyperthyroidism (414 MBq administered per treatment). The calculations were based on measurements of external exposure around the 244 hyperthyroidism patients and 23 thyroid cancer patients. The estimated direct activity discharged to the sewage for two thyroid carcinomas and three hyperthyroidisms was 14.57 GBq and 1.27 GBq, respectively, per week; the annual doses received by the most exposed individual (sewage worker) were 164 μSv and 13 μSv, respectively. General equations to calculate the activity as a function of the number of patient treated each week were also obtained.  相似文献   

2.
Liquid discharges from the use of radionuclides in medicine (diagnosis)   总被引:1,自引:1,他引:0  
The production and discharge of liquid radioactive wastes as excreta from patients undergoing Nuclear Medicine Diagnostic (NMD) in a hospital were studied. Instantaneous and accumulated activity, discharged from the hospital to the sewage system, has been estimated keeping in mind radionuclide decay. This study would enable estimation of the environmental impact due to NMD procedures. Annual accumulated activities of 2.2GBq ((131)I), 1.847GBq ((99m)Tc), 0.743GBq ((123)I), 0.337GBq ((67)Ga), 0.169GBq ((111)In) and 0.033GBq ((201)Tl) result from our model when applied to a European hospital. A comparison is made with calculations by other authors that do not consider the radionuclide decay and who overestimate by two orders of magnitude. Doses to critical people as sewage treatment workers are also significantly reduced. So, our results stress the importance of including the decay in the calculations.  相似文献   

3.
Indoor environments contribute to gamma radiation in the general population. The aims of the present study were to investigate average gamma radiation doses in a rural and an urban area of Sweden, compare indoor dose rates with personal exposure, and study the effects of building characteristics on radiation levels. Radiation was measured with thermoluminescence dosimeters (TLDs). Repeated measurements were performed with TLDs worn by participants (n=46) and placed in their dwellings. Personal dose rates were 0.092muSv/h (rural) and 0.096muSv/h (urban). The mean effective gamma dose rates in dwellings were 0.091muSv/h (rural) and 0.11muSv/h (urban), which are higher than the world average. Dose rates in apartments were higher than in detached houses and higher for concrete than wooden dwellings. Personal dose rates were strongly associated with dwelling dose rates (r(p)=0.68, p<0.01) and could be modelled. Within-participant variability was low.  相似文献   

4.
The distribution of radioactive contamination at three island sites downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC) was studied with the objectives of mapping contamination levels, interpreting radionuclide distributions through consideration of alluvial processes and determining radionuclide inventories. Contamination was measured using in situ gamma spectrometry and landforms characterised using topographic surveying methods. Maximum (137)Cs contamination densities (700 kBq m(-2)) were found on low- and middle-level floodplains and low-lying interconnecting areas of Beriozovy Island (16 km from the KMCC). On Mikhin Island (180 km from the KMCC) maximum total (60)Co, (152)Eu and (154)Eu activity concentrations (30-40 kBq m(-2)) occur in low-lying areas inundated during flooding. Maximum (137)Cs and total (60)Co, (152)Eu and (154)Eu contamination densities on Cheriomukhov Island (250 km from the KMCC) were 390 and 50 kBq m(-2), respectively. Estimated (137)Cs inventories were 145, 148 and 16GBq for Beriozovy, Mikhin and Cheriomukhov Islands, respectively.  相似文献   

5.
A dynamic linear compartment model of the global iodine cycle has been developed for the purpose of estimating radiological impacts on the world population from releases of 129I to the environment. The time-invariant fractional transfer rates, which describe the transport of 129I between environmental compartments comprising the atmosphere, hydrosphere, lithosphere, and terrestrial biosphere, are estimated from an analysis of available data on concentrations for naturally occurring stable iodine and data on the global hydrologic cycle. The global radiological impacts on man from a given release of 129I are estimated from the calculated compartment inventories as a function of time and models for the intake of iodine by a reference adult. For a constrant population of 12.2 billion, the estimated worldwide complete population dose commitment to the thyroid is 76 man-Sv/GBq (2.8 × 105 man-rem/Ci) released. Estimated values of the incomplete population dose commitment at various times after a global-scale release to the atmosphere are also presented.  相似文献   

6.
Air radon concentration was measured in summer and winter at 11 points along the tourist guided route in the Gadime Cave in Kosovo using alpha scintillation cells and etched track detectors. At two points in summer, values higher than 1700Bqm(-3) were observed; they otherwise were in the range 400-1000Bqm(-3). Values were lower in winter. The effective dose received by a person during a 90min visit is 3.7muSv in summer and 2.5muSv in winter. For a tourist guide the annual effective dose is less than 3.5mSv.  相似文献   

7.
Disposal of sewage sludge from waste water treatment plants is a serious environmental problem of increasing magnitude. Waste water treatment generates as much as 70 g of dry solids per capita per day. Although one of the disposal solutions for this waste is through incineration, still almost 30% of sludge solids remain as ash. This paper presents results related to reuse of sewage sludge ash in concrete. The sludge was characterised for chemical composition (X-ray flourescence analysis), crystalline phases (X-ray diffraction analysis) and pozzolanic activity. The effects of incineration on crystal phases of the dry sludge were investigated. Two water/cement (W/C) ratios (0.55 and 0.45) and three sludge ash percentages (5%, 10% and 20%) per cement mass were used as filler. The mechanical performance of sewage sludge ash concrete (SSAC) at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests and capillary water absorption. Results show that sewage sludge ash leads to a reduction in density and mechanical strength and to an increase in capillary water absorption. Results also show that SSAC with 20% of sewage sludge ash and W/C = 0.45 has a 28 day compressive strength of almost 30 MPa. SSAC with a sludge ash contents of 5% and 10% has the same capillary water absorption coefficient as the control concrete; as for the concrete mixtures with 20% sludge ash content, the capillary water absorption is higher but in line with C20/25 strength class concretes performance.  相似文献   

8.
This paper presents and discusses the results of (239+240)Pu determinations in different components of Gdańsk bay and Gdańsk basin ecosystem, as well as estimated sources and inventories of plutonium in these basins. The total plutonium (239+240)Pu activities deposited in Gdańsk bay and Gdańsk basin sediments are 1.18 TBq and 3.77 TBq, respectively. Two rivers, the Vistula and Neman rivers, and atmospheric fallout were distinguished as the main sources of plutonium in these basins. In seawater (with suspended matter included) there is about 2.33 GBq (239+240)Pu (0.2% of total activity) in Gdańsk bay and 9.92 GBq (239+240)Pu (0.3% of total activity) in Gdańsk basin. In both cases, 56% of (239+240)Pu is associated with suspended matter. Organisms contain 3.81 MBq in Gdańsk bay and 7.45 MBq (239+240)Pu in Gdańsk basin. From this value in Gdańsk bay 82.1% of plutonium is associated with zoobenthos, 13.6% with phytobenthos, 1.6% with phytoplankton, 1.5% with zooplankton and 1.2% with fish. In Gdańsk basin, 83.2% is associated with zoobenthos, 7.5% with phytobenthos, 3.6% with phytoplankton, 3.2% with zooplankton and 2.5% with fish.  相似文献   

9.
The Swedish regulations concerning disposal of clinical radioactive waste are currently under revision and a graded approach is proposed for risk limitation purposes. To assist the revision procedures, a screening study was performed to estimate public exposures from liquid releases from hospitals to public sewers. The results showed that doses to sewage workers were above the dose constraint of 100muSva(-1) especially for (131)I and (99m)Tc. Hence, a dynamic model, LUCIA, was developed for realistic assessments in which radionuclide transportation in sewers was modelled. Probabilistic simulations were performed to obtain probability distributions of radionuclide concentrations in sludge. Concurrently, estimates of the effective doses to sewage workers decreased significantly and were below 10muSva(-1) except for (111)In and (131)I. However, the Kd-coefficients representing the partition of radioactivity between water and sludge in sewers are highly uncertain for (111)In. As shown by sensitivity studies, these values are the major determinant of the exposures in sewers.  相似文献   

10.
Plutonium isotopes in the Rh?ne River originate from both the weathering of the catchment basin contaminated by global atmospheric fallout, and the liquid effluents released from the Marcoule reprocessing plant since 1961. Due to a new treatment process applied to the liquid effluents, a decrease of two orders of magnitude in the industrial plutonium discharged into the River Rh?ne has been registered from 1991. Today, 238Pu industrial inputs to the River Rh?ne are still about 10 times higher than those derived from global fallout, while 239+240Pu inputs from industrial and global fallout sources are of similar importance, i.e. 1 GBq y(-1). Our results indicate that the river sedimentary compartment act either as a sink or a delayed-source term of plutonium for the freshwaters depending on the hydraulic regime and flood events. This compartment may then represent an important industrial delayed-source term for the River Rh?ne freshwaters in the coming years as the Marcoule reprocessing plant is being dismantled. These results were obtained from samples collected from the lower course of the River Rh?ne over the 1987-1998 period and analysed for 238Pu and 239+240Pu activities. Both river sedimentary inventories of plutonium isotopes and effective outputs from the River Rh?ne towards the Gulf of Lions have been estimated for each year over the 1945-2000 period. Regarding 239+240Pu, the sedimentary inventory accumulated since 1945 is estimated to be 172+/-35 GBq. If mobile, this amount represents a significant delayed-source term of plutonium on the scale of the Rh?ne watershed.  相似文献   

11.
Various sources contribute to the radioactive contamination of the Moselle River, among which the French NPP Cattenom with four units of 1300 M We represents the most important. Appropriate operational precautions were taken in order to monitor the nuclide transfer on different pathways under normal and accidental conditions and the effectiveness of these measures has been tested using natural (214Pb/214Bi, 7Be, 40K) and artificial radionuclides. (3H, 58Co, 60Co, 131I, 137Cs) as tracers. Measurements of suspended matter have revealed that the inputs of natural nuclides exceed the discharges of the NPP Cattenom. In 1992 the annual loads of 7Be and 40K in suspended matter at Palzem amounted to 21 and 130 GBq year−1, whereas the emission rates of 60Co and 137Cs were about 2.6 and 1.0 GBq year−1. The total nuclide load of 137Cs at Palzem reached 6.2 GBq year−1, which is about six times the quantity emitted by the NPP Cattenom in the same year. This excess is due to the accident at Chernobyl and to a lesser extent to prior atmospheric weapons tests.  相似文献   

12.
Due to the relatively high activity concentrations of (210)Po and (210)Pb that are found in tobacco and its products, cigarette smoking highly increases the internal intake of both radionuclides and their concentrations in the lung tissues. That might contribute significantly to an increase in the internal radiation dose and in the number of instances of lung cancer observed among smokers. Samples of most frequently smoked fine and popular brands of cigarettes were collected from those available on the Egyptian market. (210)Po activity concentrations were measured by alpha spectrometry, using surface barrier detectors, following the radiochemical separation of polonium. Samples of fresh tobacco, wrapping paper, fresh filters, ash and post-smoking filters were spiked with (208)Po for chemical recovery calculation. The samples were dissolved using mineral acids (HNO(3), HCl and HF). Polonium was spontaneously plated-out on stainless steel disks from diluted HCl solution. The (210)Po activity concentration in smoke was estimated on the basis of its activity in fresh tobacco and wrapping paper, fresh filter, ash and post-smoking filters. The percentages of (210)Po activity concentrations that were recovered from the cigarette tobacco to ash, post-smoking filters, and smokes were assessed. The results of this work indicate that the average (range) activity concentration of (210)Po in cigarette tobacco was 16.6 (9.7-22.5) mBq/cigarette. The average percentages of (210)Po content in fresh tobacco plus wrapping paper that were recovered by post-smoking filters, ash and smoke were 4.6, 20.7 and 74.7, respectively. Cigarette smokers, who are smoking one pack (20 cigarettes) per day, are inhaling on average 123 mBq/d of (210)Po and (210)Pb each. The annual effective doses were calculated on the basis of (210)Po and (210)Pb intake with the cigarette smoke. The mean values of the annual effective dose for smokers (one pack per day) were estimated to be 193 and 251 microSv from (210)Po and (210)Pb, respectively.  相似文献   

13.
The radioactive cloud from the Chernobyl nuclear reactor accident arrived in northeast Italy on 30 April 1986. Ground-level air activities detected in Padua reached maximum values of 28·6, 19·2, 3·3, 1·7 and 7·5 Bq m−3 for 131I, 132Te(132I), 137Cs and 103Ru, respectively, on 1 May; about 10 days later, the activities had fallen to less than 1% of peak values. Considerations of cloud homogeneity are reported.The distribution of fallout radionuclides in Padua was evaluated on the basis of radioactivity detected on natural surfaces. The average committed dose equivalent to the thyroid for adult people in Padua through 131I inhalation was estimated at 0·37 mSv. Soil activity was monitored daily in samples collected in Padua during the first weeks of May 1986. Fallout deposition over northeast Italy was measured on 75 surface soil samples collected during June 1986 and long-lived radionuclide distribution maps were derived.  相似文献   

14.
分别选取了贵州省7个主要城市的10个典型污水处理厂脱水污泥样品进行检测,统计了2009~2012年污泥中重金属Cu、Zn、Pb、Cd、Ni、Cr、As、Hg的含量。结果表明,城市污泥中重金属含量受到各地区工矿业发展的影响,部分重金属在某一污水处理厂出现了远大于其它地区的极值,具有明显的地域特征。2009~2012年贵州省城市污泥重金属的变化表现为As、Hg呈升高趋势,其它重金属变化趋势不明显,As、Hg升高可能是因为贵州省近年来燃煤消耗量增加,烟气排放污染所致。对污泥重金属的农用风险评价显示,贵阳中部(S2)、黔西地区(S9)污泥农用重金属的生态风险较高,不推荐直接施用,其它各地区污泥农用风险较低,可以进行农用,建议各污水处理厂应根据本地区污泥重金属特征制定合理的污泥处置措施  相似文献   

15.
在介绍污水处理厂的基础建设程序及环境影响评价的发展概况的基础上,以京溪污水处理厂为例,指出城市规划部门在规划制定过程中,应加大环境影响评价工作的深度,以使污水厂的建设程序得以顺利开展。同时指出城市的卫生、地质、规划、国土、环保等职能部门在制定本部门的法规政策过程中,应发挥协调机制,在工程建设的相关方面达成共识,以确保污水处理厂等市政项目的建设顺利开展,促进城市更好的发展。  相似文献   

16.
Radioactivity in some Tunisian thermo-mineral springs (11 hot mineral springs and one cold spring) has been determined for the first time in Tunisia using radiochemical separation procedures. The obtained results show that 238U activity concentrations vary between 1.5 and about 43 mBq/l. The measured activities of 234U and 226Ra range from 1.1 to about 82.2 mBq/l and 34-3,900 mBq/l. respectively. The radioactive disequilibria in these waters are in excess of concentration of 234U compared to that of 238U. The 226Ra/234U activity ratios are high and in the range of 9.0-691.0). U, Th and Ra activities are similar to those published for other non-polluted regions of the world. Radioactivity in the only cold mineral water from A?n Oktor is very low, and thus health hazards due to the consumption of this water are not expected.  相似文献   

17.
Wastewater has proved to be a significant source of polybrominated diphenyl ethers (PBDEs) in the environment. Seventeen congeners from tri- to deca-BDEs were determined to characterize the occurrence, fate, and transport of PBDEs in two sewage treatment plants in the Pearl River Delta, South China. The PBDE concentrations varied substantially from 13.3 to 2496.4 ng L(-1) in the raw wastewater, depending on the wastewater types and contents of the suspended particulate matter (SPM). The concentrations declined to 0.9 to 4.4 ng L(-1) in the treated effluent and were closely associated with SPM contents. BDE-209 was the predominant congener in the wastewater and sewage sludge. Most of PBDEs might have ended up in the sewage sludge, with <4.7% being discharged with the treated effluent. The results revealed that PBDEs were not significantly degraded by biological treatment and chlorination in the STPs. An annual release of PBDEs was estimated at 2280 kg/year through wastewater from the Pearl River Delta.  相似文献   

18.
As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography-electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56-379.9 microg/kg, 0.16-4.88 mug/kg, 0.037-2.013 microg/L and 0.30-9.1 microg/L, respectively. The results show that perchlorate has been widespread in China.  相似文献   

19.
This work presents a quantitative assessment of nonsmokers' risk of lung cancer from passive smoking. The estimates given should be viewed as preliminary and subject to change as improved research becomes available. It is estimated that U.S. nonsmokers are exposed to from 0 to 14 mg of tobacco tar per day, and that the typical nonsmoker is exposed to 1.4 mg per day. A phenomenological exposure-response relationship is derived, yielding 5 lung cancer deaths per year per 100,000 persons exposed, per mg daily tar exposure. This relationship yields lung cancer mortality rates and mortality ratios for a U.S. cohort which are consistent to within 5% with the results of both of the large prospective epidemiological studies of passive smoking and lung cancer in the United States and Japan. Aggregate exposure to ambient tobacco smoke is estimated to produce about 5000 lung cancer deaths per year in U.S. nonsmokers aged ≥ 35 yr, with an average loss of life expectancy of 17 ± 9 yr per fatality. The estimated risk to the most-exposed passive smokers appears to be comparable to that from pipe and cigar smoking. Mortality from passive smoking is estimated to be about two orders of magnitude higher than that estimated for carcinogens currently regulated as hazardous air pollutants under the federal Clean Air Act.  相似文献   

20.
Environmental contamination by pesticides has been documented in biotic and abiotic components. These persistent organic pollutants are lipid soluble, nonbiodegradable, and endocrine disrupters. The present study was therefore planned to determine whether the levels of these pesticides like DDT and its metabolites DDD and DDE, dieldrin, heptachlor, and HCH and its isomers (alpha, beta, and gamma) were higher in blood of breast cancer patients when compared with normal women who did not suffer from major diseases like blood pressure, tuberculosis, diabetes, thyroid dysfunction, arthritis, cancer, etc. and had not undergone any major surgery. The results indicated that organochlorine pesticides taken for analysis were found significantly high in breast cancer patients irrespective of age, diet, and geographic distribution.  相似文献   

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