{sup 222} Rn exposure assessment in the caves of Parque Estadual Turistico do Alto Ribeira (PETAR); Avaliacao da exposicao ao {sup 222} Rn nas cavernas do Parque Estadual Turistico do Alto Ribeira (PETAR)

Energy Technology Data Exchange (ETDEWEB)

Alberigi, Simone

2006-07-01

In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Touristic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Agua Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005.The {sup 222}Rn concentrations lay in a range from 153 Bq.m{sup -3} to 6607 Bq.m{sup -3} and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a{sup -1} for the Couto cave, strongly ventilated, to 4.0 mSv.a{sup -1} for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a{sup -1}. All assessed effective doses received by the tour guides are bellow 20 mSv.a{sup -1} suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990). (author)

Correlation among the terrestrial gamma radiation, the indoor air 222Rn, and the tap water 222Rn in Switzerland

International Nuclear Information System (INIS)

Buchli, R.; Burkart, W.

1989-01-01

The external gamma radiation and the indoor air Rn (222Rn) concentration were measured in 55 houses of the South East Grisons, the Urseren valley, and the Upper Rhine valley (crystalline subsoils) and in 39 houses of the Molasse basin and the Helvetic nappes (sedimentary subsoils). In homes located on a crystalline subsoil, a mean cellar gamma level of 1.40 mGy y-1 was measured, which is twice the mean gamma level of 0.70 mGy y-1 found in homes built on a sedimentary subsoil. The cellar 222Rn gas concentration is about six times higher in houses with a crystalline subsoil (1232 Bq m-3) than in houses with a sedimentary subsoil (201 Bq m-3). Although a weak correlation is observed between the mean gamma radiation levels and mean cellar 222Rn gas concentrations for the five subregions investigated, the gamma levels and the 222Rn gas concentrations do not correlate for single homes. For the population living on the ground floor of a house with a crystalline subsoil, the gamma radiation and the indoor air 222Rn lead to estimated mean exposures of 1.16 mSv and 9.44 mSv effective dose equivalent per year, respectively. In houses with a sedimentary subsoil, these mean exposures lead to 0.68 mSv y-1 and 3.22 mSv y-1, respectively. A mean tap water 222Rn content of 38.3 Bq L-1 and 10.4 Bq L-1 was measured in 31 villages with a crystalline subsoil and 73 villages with a sedimentary subsoil, respectively. Radon-222 degasing from the tap water into the indoor air leads to an additional exposure of about 0.11 mSv y-1 and 0.03 mSv y-1 in homes with a crystalline subsoil and homes with a sedimentary subsoil, respectively

Estimation of exposure to 222Rn from the excretion rates of 21πPb

International Nuclear Information System (INIS)

Holtzman, R.B.; Rundo, J.

1981-01-01

A model is proposed with which estimates of exposure to 227 Rn and its daughter products may be made from urinary excretion rates of 210 Pb. It is assumed that 20% of all the 210 Pb inhaled reaches the blood and that 50% of the endogenous excretion is through the urine. The estimates from the model are compared with the results of measurements on a subject residing in a house with high levels of radon. Whole body radioactivity and excretion data were consistent with the model, but the estimates of exposure (WL) were higher than those measured with an Environmental Working Level Monitor

Occupational exposure of phosphate mine workers: airborne radioactivity measurements and dose assessment

International Nuclear Information System (INIS)

Khater, Ashraf E.; Hussein, M.A.; Hussein, Mohamed I.

2004-01-01

Under the Egyptian program for radiation safety and control, airborne radioactivity measurements and radiological dose assessment were conducted in some phosphate and uranium mines. Abu-Tartor mine is one of the biggest underground phosphate mines in Egypt. Airborne radioactivity, radon ( 222 Rn) and its short-lived decay products (progenies) and thoron ( 220 Rn), were measured in selected locations along the mine. The environmental gamma and workers dose equivalent rate (mSv/y) were measured inside and outside the mine using thermo-luminescence dosimeters (TLD). The results were presented and discussed. The calculated annual effective dose due to airborne radioactivity is the main source of occupational exposure and exceeding the maximum recommended level by ICRP-60 inside the mine tunnels. A number of recommendations are suggested to control the occupational exposures

Internal exposure to 222Rn progeny of the underground workers in Bulgarian uranian mines in 1958-1989

International Nuclear Information System (INIS)

Dimitrov, M.; Presiyanov, D.

1998-01-01

The results of more than 50000 measurements of 222 Rn and 22R n progeny measurements made in 1958-1989 in 9 large Bulgarian uranium mines (namely: '9 septemvri', 'Seslavci', 'Eleshnitsa 1, 2, 3', 'Smolyan', 'Byalata voda', 'Balkan' and 'Smolyanovtsi') have been summarized. The average WLM-exposures have been determined for each of the mines. The results make possible to estimate internal WLM exposure of any miner, provided that his underground working experience is known

Occurrence of 222Rn and progeny in natural gas processing plants in western Canada

International Nuclear Information System (INIS)

Drummond, I.; Boucher, P.; Bradford, B.; Evans, H.; McLean, J.; Reczek, E.; Thunem, H.

1990-01-01

In Western Canada, there are many plants that process natural gas to remove impurities (CO 2 , H 2 S, H 2 O) and recover natural gas liquids (propane, butane, etc.). Trace quantities of 222 Rn present in the inlet stream are concentrated in streams rich with propane. Potential hazards to plant operators include direct inhalation of 222 Rn and progeny; exposure to gamma radiation from short-lived progeny deposited inside equipment; or inhalation of 210 Pb when contaminated equipment is opened for repair. Twenty-four plants operated by seven companies cooperated to assess these potential hazards. The findings indicate a substantial flux of 222 Rn and progeny passing through the plants, but little accumulation of radionuclides. In no case was there evidence of significant exposure of plant operators or maintenance personnel to ionizing radiation. Further investigation of pipeline operations, and chemical operations using natural gas liquids as feed stock, is recommended

Measurements of Rn-222, Rn-220 and their decay products in the environmental air of the high background radiation areas in Yangjiang, China

International Nuclear Information System (INIS)

Yuan Yongling; Shen Tong; Morishima, Hiroshige; Koga, Taeko; Wei Luxin; Sugahara, Tsutomu

2000-01-01

For the renewal of dose estimation from internal irradiation in the high background radiation areas (HBRA) of Yangjiang, the measurements of radon, thoron and their decay products in the environmental air were conducted, including: integrating measurements of Rn-222 and Rn-220 concentrations; equilibrium factor F for Rn-222 and alpha-potential energy value of Rn-220; external gamma radiation in places where radon measurements were undertaken; cumulative exposure to indoor radon for each family in a case-control study on lung cancer. The Rn-Tn cup monitor method was used for the integrating measurement of Rn-222 and Rn-220 concentration. An alpha track detector was used for the integration measurement of Rn-222 concentration in the case-control study on lung cancer. The results of measurements show that although the investigated areas are located between the Equator and the Tropic of Cancer, and that people live in well-ventilated dwellings, the concentrations of radon, especially of Rn-220 are significantly higher in the indoor air of HBRA than those in the control area. The value of equilibrium factors for Rn-222, the alpha potential energy of decay products from Rn-222 and Rn-220 are determined. (author)

Epidemiological analysis of the relationship between exposure to Rn progeny, smoking and bronchogenic carcinoma in the U-mining population of the Colorado Plateau--1960-1980

International Nuclear Information System (INIS)

Saccomanno, G.; Yale, C.; Dixon, W.; Auerbach, O.; Huth, G.C.

1986-01-01

This study investigates the relationship between exposure to radioactive Rn decay products during U mining and milling operations, cigarette smoking and age, on the incidence and mortality rates of lung cancer among U workers of the Colorado Plateau during the 20-yr period from 1960-1980. A case control sample was taken from an extensive data base of 9,817 men accumulated by one author (Saccomanno). A preliminary hypothesis had been made that a possible synergistic or at least additive effect might exist when the risk factors of exposure to Rn decay products and smoking were simultaneously present. This study would seem to indicate that a synergistic effect is not present. In this work, a total of 489 cases, defined as men having a cytological diagnosis of moderate or worse atypical squamous-cell metaplasia, and a random sample of 992 ''non-cases'' were selected retrospectively from the dynamic cohort of workers. These data analyzed from three different perspectives indicate significant effects due to Rn-decay-product exposure in excess of the expected incidence due to age and smoking history. The data also indicate that Rn-decay-product accumulations of less than 300 working level months (WLM) is not carcinogenic in non-cigarette smokers

A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China

International Nuclear Information System (INIS)

Shang Bing; Cui Hongxing; Wu Yunyun; Zhang Qingzhao; Su Xu

2008-01-01

Objective: To measure levels of 222 Rn and 220 Rn in typical non-uranium mines, China, and to estimate dose from the occupational radon exposure in the miners. Methods: Using typical sampling scheme, 44 mines were selected in 12 provinces, which can be classified into 4 categories and 17 types of mines. The radon-thoron discriminative detectors were used to measure 222 Rn and 220 Rn concentrations in mines. Result: The concentration of 222 Rn or 220 Rn was log-normally distributed. The arithmetic mean (AM) concentration and geometric mean (GM) concentration of 222 Rn and 220 Rn in 25 metal mines (n=147) were estimated to be (1211 ±2359) Bq/m 3 (AM) and (311 ± 5.5) Bq/m 3 (GM), and (269 ±700) Bq/m 3 (AM) and (71 ± 4.4)Bq/m 3 (GM), respectively. The mean concentrations of 222 Rn and 220 Rn in 18 non-metal mines (n=118) were (98 ± 207) Bq/m 3 (AM) and(55 ± 2.5) Bq/m 3 (GM), and (60 ± 76) Bq/m 3 (AM) and (38 ± 2.4) Bq/m 3 (GM) respectively. In total, we measured 222 Rn concentration in 44 underground mines, 6 of them, accounted for 15%, with the mean radon concentration exceeding 1000 Bqm -3 (limit of workplace in China). Approximately 7% of radon concentration in mines measured were higher than 3700 Bq/m 3 (current limit in uranium mine in China), some points even exceeded 10 000 Bq/m 3 . Based on this typical measurements, the equilibrium factor for 222 Rn was estimated to be 0.33 ± 0.15 in underground mines and 0.47 ±0.18 in nearby houses. Equilibrium factor for 220 Rn ranged from 0.001 to 0.032. Using the data obtained in this typical survey, the average annual effective dose of underground miners exposed to radon and thoron was estimated to be 8.15 mSv/a. Conclusions: High levels of 222 Rn exists in metal mines, such as copper, tin, lead and zinc, gold, and aluminum mines among others. More study and administrative measures are needed to address the radiation protection of workers occupationally exposed to high radon in mines. (authors)

In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

International Nuclear Information System (INIS)

Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

1995-01-01

It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne 222 Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee's work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of 210 Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of 210 Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring 210 Pb in the heads of former uranium miners has been accomplished

Health effects assessment in population exposed to 222Rn in drinking water

International Nuclear Information System (INIS)

Burkhardt, R.; Mocsy, I.; Muntean, N.

1996-01-01

The carcinogenetic effect produce by ionizing radiation upon human health, mainly by drinking water consumption with an elevated 222 Rn content is well documented. The objective of the paper was to demonstrated the possible relationship between the incidence of pulmonary and gastric cancer and 222 Rn presence in water and indoor air. The 222 Rn content was assessed by the standard method in drinking water sampled in two sources in Transylvania area from located in Tirgu Mures and Miercurea Ciuc towns. The 222 Rn concentration in indoor air was indirectly determined. On the basis of the registered values the pulmonary and gastric internal dose received by the residents of the towns was calculated. In parallel was performed a retrospective epidemiological study (1980-1992) regarding the incidence of gastric and pulmonary cancer in two towns in terms of morbidity, mortality and lethality indices. By comparing the estimated carcinogenic risk for this type of cancer with the specific mortality rate registered in our study, we estimate the contribution of 222 R to the cancer mortality percentage in the two towns, as follows: 0.47% for Tirgu Mures and 0.01% for Miercurea Ciuc town for pulmonary cancer and 0.23% and 0.015% for gastric cancer. (author)

In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

Energy Technology Data Exchange (ETDEWEB)

Guilmette, R.A.; Laurer, G.R. [New York Univ. Inst. of Environmental Medicine, Tuxedo, NY (United States); Lambert, W.E.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

1995-12-01

It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

An assessment method of dose equivalent due to indoor 220Rn progeny by using 220Rn concentration measured at a 20 cm distance from wall

International Nuclear Information System (INIS)

Iida, T.; Ikebe, Y.; Okamoto, K.; Guo, Q.; Yamasaki, T.

1996-01-01

A pair of passive cup monitors with a different air exchange openings was developed for measuring simultaneously 222 Rn and 220 Rn concentrations. Indoor 220 Rn concentrations were very high in traditional Japanese dwellings with soil walls. The 220 Rn concentration decreases exponentially with the distance from wall. The effective diffusion coefficient of 220 Rn in dwelling and the exhalation rate of 220 Rn from wall were evaluated from the distribution of the 220 Rn concentrations. Then, indoor 220 Rn progeny concentration could be estimated from the 220 Rn concentration at a 20 cm distance from wall. From the results of the surveys. the average annual effective dose equivalent due to 220 Rn progeny was expected to be 0.67 mSv/year in the traditional Japanese dwellings. (author)

222Rn alpha dose to organs other than lung

International Nuclear Information System (INIS)

Harley, N.H.; Robbins, E.S.

1991-01-01

The alpha dose to cells in tissues or organs other theft the lung has been calculated using the solubility coefficients for 222 Rn measured in human tissue. The annual alpha dose equivalent f rom 222 Rn and decay products in most tissues is a maximum of 30% of the annual average natural background dose equivalent (1 mSv) for external and internally deposited nuclides. The dose to the small population of lymphocytes located in or under the bronchial epithelium is a special case and their annual dose equivalent is essentially the same as that to basal cells in bronchial epithelium (200 mSv) for continuous exposure to 200 Bq M -3 . The significance of this dose is uncertain because the only excess cancer observed in follow up studies of underground miners with high 222 Rn exposure is bronchogenic carcinoma

Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

Science.gov (United States)

Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

2015-09-01

In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radon exposure system for mammalian cells in culture: Design, operation, and dosimetry

International Nuclear Information System (INIS)

Seed, T.M.; Kretz, N.D.; Schlenker, R.A.

1991-01-01

A novel system for Rn gas exposure of mammalian cells in culture has been designed, constructed, and used to directly assess both the magnitude and the nature of chronic, low-dose Rn/Rn daughter toxicity of exposed vital lung cells isolated from normal pulmonary tissue, propagated and exposed in vitro. Direct correlations between atmospheric Rn concentrations, alpha-particle fluences, and macro- and microdoses of absorbed radiation doses by lung cells provide for a heretofore unavailable assessment of critical doses to vital cells

Potable water as a source of airborne 222Rn in US dwellings: a review and assessment

International Nuclear Information System (INIS)

Nazaroff, W.W.; Doyle, S.M.; Nero, A.V.; Sextro, R.G.

1987-01-01

Using a long-term-average, single-cell model and available data for U.S. housing, the concentration of 222 Rn in indoor air due to the use of potable water is assessed. The ratio of the airborne 222 Rn concentration to the concentration in water is represented by a lognormal distribution with geometric mean and geometric standard deviation of 0.65 X 10(-4) and 2.88, respectively, in fair agreement with the previously reported results of direct measurements of the ratio in 13 houses. By combining this result with data on 222 Rn concentrations in U.S. water supplies, potable water is estimated to contribute an average of 24, 1.3, and 0.1 Bq m-3 to the airborne 222 Rn concentration in residences served by private wells, public ground water, and surface water supplies, respectively

Development, implementation and utilization of 210Pb in vivo measurement techniques as indicator of human being exposure to 222Rn - evaluation of associated parameters

International Nuclear Information System (INIS)

Dantas, Ana Leticia Almeida

2005-01-01

Radon and its decay products are present in the atmosphere and are the most important contributors for the internal exposure of humans to natural radiation. The execution of in vivo measurements of 210 Pb in the population and in individuals occupationally exposed in underground mines has been studied and recommended as one of the procedures for the estimation of the exposure to 222 Rn. The metabolism of 210 Pb and its distribution within the human body, mainly deposited in the bone tissue, suggests the regions of skull and knee as the most suitable for the in vivo monitoring of such radionuclide. A radiological survey in non uranium mines in Brazil indicated that an underground coal mine in the State of Parana, in the south of Brazil, had high radon concentration. The aim of this work were: (1) To investigate whether underground coal miners may also have elevated 210 Pb in the skeleton as a result of occupational exposure to radon in the coal mine; (2) To estimate the committed equivalent dose and the committed effective dose in different incorporation scenarios using a computer code. The calibration and the in vivo measurements of underground coal miners were performed in the IRD-CNEN Whole Body Counter shielded room using an array of four high resolution germanium detectors. The detection system was positioned at the head and knee geometries. The minimum detectable quantity of 210 Pb in the skeleton using this methodology was (50 Bq) and the positive results were verified using a mathematical method that applies a moving median smoothing function to the total spectrum for each measurement. In vivo measurements of 210 Pb in 6 out of the 32 underground coal miners ranged between 83 Bq and 164 Bq suggesting that these workers received significant occupational cumulative exposure to 222 Rn. The simulation of some exposure patterns of 222 Rn progeny and 210 Pb incorporation showed that the most important contribution for 210 Pb skeleton deposition was the intake of

Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

Science.gov (United States)

Borak, T B

1986-04-01

Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

Determination and assessment of Rn in mineral springs of Shandong province

International Nuclear Information System (INIS)

Xu Jia'ang; Li Fusheng; Chen Yingmin; Chen Yue; Deng Daping; Yuan Ming; Song Gang; Zhang Lianping

2002-01-01

Objective: The concentrations and its changes of 222 Rn in mineral springs of Shandong were determined in order to evaluate the committed equivalent dose for people drinking the water. Methods: Scintillation flask method is used for the measurement of 222 Rn concentrations in mineral springs. Results: The concentrations of 222 Rn in mineral springs of Shandong ranged from 0.51 Bq·L -1 to 807.20 Bq·L -1 , the geometric average of it was 22.09 Bq·L -1 . The relationship between the ratios of 222 Rn remains in the water under the natural conditions (P) and the period of time exposed in air (T) was discovered, which is fits for the following function relation: P = 46.666 T -0.517 (0.117 h≤T≤9 h). The committed equivalent dose resulting from 222 Rn concentrations was estimated to be 9.68 x 10 -2 mSv·a -1 , Which is due to drinking the water. Conclusion: The analyses of data indicate that there is no over-burden dose from 222 Rn for people who drink the water of mineral springs of Shandong

Primary measuring of equipment factor of 222Rn/220Rn indoor

International Nuclear Information System (INIS)

Liu Yanyang; Liu Fudong; Wang Chunhong; Sheng Mingwei

2010-01-01

The activity concentration of 222 Rn, 220 Rn and their progenies of certain working places and dwellings in Baotou city were measured simultaneously. Based on these results, the equipment factor of 222 Rn is 0.35 for working places and 0.43 for dwellings, while equipment factor of 220 Rn measured at 20 cm distance from wall is 0.030 for both working places and dwellings. Preliminary results show that the temporal change of 220 Rn equilibrium equivalent concentration is same as 222 Rn which is high in midnight and low in afternoon,and significant difference between instant and accumulated measure result of 222 Rn, 220 Rn activity concentration is found, with the factor of 2.1 and 1.7. (authors)

Simultaneous determination of Rn-220 and Rn-222 concentrations in atmospheres by cellulose nitrate ionographic detectors

International Nuclear Information System (INIS)

Lobao, N.

1977-01-01

A method for the indoor determination of airborne radon and radon daughters is described, based in the utilization of cellulose nitrate (CN) ionographic detectors (LR-115-Kodak-Pathe) These track-etching detectors are coupled to an air sample and to a difusion chamber respectively. In the first system ambient air is pulled through a fiber glass filter for collection of airborne radon daughters (Flow: 230 ml/min). In the second system, the cellulose nitrate detectors is coupled/min). In the second system, the cellulose nitrate detectors is coupled to a difusion chamber electrostatic precipitator arrangement. Here the CN detector will register only the alpha particles given off by the decay products of Rn-222 formed within the sensitive volume of electrostatic precipitator. The construction of calibration curves for the two systems using adequate steady-state concentrations of Rn-220 and Rn-222 in an exposure chamber (1 cubic meter), will allow the use of the system for measurement of measurement of averaged integrated radon concentrations. The CN attached to the CN attached to the air sampler is exposed in the reference atmosphere with and without a mylar filter for discrimination of alpha particles with different energies Field sampling indicated however, that efficiency of the two systems are still low for the measurement of environmental levels of Rn-220 and Rn-222 within houses of the AENR, recommendations for efficienty improvement of the system are proposed [pt

Study of natural radioactivity and 222Rn exhalation rate in soil samples for the assessment of average effective dose

International Nuclear Information System (INIS)

Bangotra, P.; Mehra, R.; Jakhu, R.; Sahoo, B.K

2016-01-01

The natural radioactivity in soil is usually determined from the 226 Ra (Radium), 232 Th (Thorium) and 40 K (potassium). 222 Rn and 220 Rn are produced in soil as a result of the presence of these radionuclides. As 226 Ra decay, the newly created 222 Rn radionuclide recoil from the parent grain and then exhale through the soil. Since 98.5% of radiological effects of 238 U series are produced by 226 Ra and its daughter products. The assessment of gamma radiation dose from natural sources is of particular importance as natural radiation is the largest contributor to the external dose of the world population. Authors are advised to maximize the information content utilizing the full space available. The main objective of the present study is to measure the level of natural radioactivity 226 Ra, 232 Th, 40 K and 222 Rn exhalation rate in the soil samples for health risk assessment

Thoron (RN-220) interference in the determination of RN-222 exhalation rate of soils

Energy Technology Data Exchange (ETDEWEB)

Amaral, Déric S.; Farias, Emerson E.G.; Santos, Mariana L.O.; Silva, Karolayne E.M.; Hazin, Clovis A.; França, Elvis J., E-mail: emersonemiliano@yahoo.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, João A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Geologia

2017-07-01

The transport of Rn-222 from the soil to the atmosphere known as exhalation is influenced by meteorological conditions and soil geophysical parameters. In closed and poorly ventilated rooms, this radioactive gas can reach high activity concentrations, in which the energy of alpha particles released by this radionuclide and its progeny is the second leading cause of lung cancer. Soil exhalation rate is an important parameter for assessing human health risks associated with radon. For radon determination using an exhalation chamber, an ionization chamber detector is used to count the electrical pulses generated by the interaction between the alpha particles produced by Rn-222 and its progeny and the air inside the chamber. In this work, the interference of thoron (Rn-220) in the determination of soil exhalation rate of Rn-222 was studied. For this, the RadonBOX exhalation chamber and the AlphaGuard ionization chamber detector were utilized for analyzing the same soil during two hours on different days under similar meteorological conditions. From zero up to approximately 2,400 s, the radon activity concentrations decreased. After 40 minutes, the radon concentrations started to increase, thereby allowing the calculation of soil exhalation rate. This initial decreasing could be explained by a high Rn-220 than Rn-222 presence in the soil, in which, because of its short half-life, after 40 minutes, most thoron present in the chamber has undergone so that the main alpha emitter become Rn-222. In order to confirm this, Rn-220 activity was estimated by the Ra-228 concentration in the soil determined after 30 days using High Resolution Gamma-Ray Spectrometry with HPGe detectors. Therefore, the thoron interference in the determination of soil radon exhalation rate was considered negligible after 40 minutes of measurement time for the analyzed soil. (author)

222Rn in wine cellars in Hungary

International Nuclear Information System (INIS)

Csige, I.; Hunyadi, I.; Szerbin, P.; Juhasz, L.

2004-01-01

We measured seasonal average 222 Rn activity concentrations in the air of 60 wine cellars in the Tokajhegyalja and Villany wine regions of Hungary using Radamon type etched track radon detectors. The exposure period was 3 months, matching the seasons of 2003-2004. We also used an ionization chamber-type continuous 222 Rn-monitor (AlphaGUARD PQ222, Genitron Instruments, Germany) to study temporal variations of 222 Rn activity concentration in a selected wine cellar in the Tokajhegyalja wine region. This instruments also recorded temperature, atmospheric pressure and relative humidity data. The etched track detector data revealed that the 222 Rn activity concentrations in the air of wine cellars spread over a wide range, from the ambient outdoor concentration of 6 Bq.m -3 up to 6 kBq.m -3 characteristic of natural caves. The temporal variation of 222 Rn activity concentration in the air of the selected cellar varied inversely with the variation of the atmospheric pressure. Earlier we observed similar phenomena in natural karstic caves connected to the surface with vertical shafts only. This suggests that relatively large volume of pore space of the embedding rock communicates with the volume of the cellar induced by the variation of the atmospheric pressure

Environmental thoron (220Rn): a review

International Nuclear Information System (INIS)

Ramachandran, T.V.

2008-01-01

Studies on natural background radiation is a topic, which evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true from the recent studies resulted in observing high 220 Rn levels in living environments and work places in various countries and it is increasingly felt that it may be necessary to have data on 220 Rn levels in environment for obtaining a complete picture of inhalation dose. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products, like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. Due to this it was necessary to supplement the external component with inhalation component. This component is not

Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

Science.gov (United States)

Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

2011-04-01

This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessment of Human Exposures to Natural Sources of Radiation in Kenya

International Nuclear Information System (INIS)

Mustapha, A.O.; Patel, J.P.

1999-01-01

Levels of exposures to different components of natural background radiation in Kenya were assessed from measured data and published conversion factors. Among them, the average annual per capital effective dose from terrestrial external radiation is 0.76 mSv and the annual per capital effective dose from external exposure to cosmic radiation at ground levels is 0.41 mSv. The total average annual effective dose is greater than the global average. Also among the measured data, concentrations of radon ( 222 Rn) vary from 5 to 1200 Bq m -3 in indoor air of dwellings, and from 1 to 410 KBq m -3 in drinking water. An unusual pathway to internal exposure was discovered among the female population who engage in consumption of some earth materials, some of which are rich in thorium

Contribution of 222Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

International Nuclear Information System (INIS)

Song Gang; Wang Xinming; Chen Diyun; Chen Yongheng

2011-01-01

This study investigates the contribution of radon ( 222 Rn)-bearing water to indoor 222 Rn in thermal baths. The 222 Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM 10 and PM 2.5 ) and carbon dioxide (CO 2 ) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m -3 of 222 Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which 222 Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average 222 Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor 222 Rn levels were influenced by the 222 Rn concentrations in the hot spring water and the bathing times. The average 222 Rn transfer coefficients from water to air were 6.2 x 10 -4 -4.1 x 10 -3 . The 24-h average levels of CO 2 and PM 10 in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM 2.5 . Radon and PM 10 levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: → 222 Rn-bearing water is the main contributor to indoor radon in hot spring hotel. → The PM 2.5 and CO 2 are also the main indoor pollutants in the hotel rooms. → Higher radon and PM levels might have significant negative health effects to human. → The radon transfer coefficients are consistent with the published data.

Detection of 222Rn and 226Ra in environmental samples by scintillation method

International Nuclear Information System (INIS)

Zafimanjato, J.L.R.; Raoelina Andriambololona; Mobius, S.

2009-01-01

222 Rn is considered as the major source of radiological exposure of natural radiations to the population. It represents about the half of exposures of natural radiation sources in the world (UNSCEAR, 1993). 222 Rn gets into human body with inhaled air and sometimes with drinking water. Then, the objective of this work is to know the 222 Rn concentrations in water and in indoor atmosphere, and the risk in order to set up a method of monitoring and to identify high radon level areas. A specific method of detection using liquid scintillation with special emphasis on α/β discrimination, the use of solvent extractive and enrichment of radionuclides have been developed for the determination of both 222 Rn and 226 Ra in water. The method is simple, rapid and sensitive. It was shown that the proposed method was suitable for a large scale monitoring and routine analysis. Considerable concentrations of 222 Rn were found in water and air samples from Vinaninkarena - Antsirabe. 222 Rn concentrations obtained by in situ and in laboratory measurements have been compared to the results of an international intercomparison campaigns organised by the German Society for Liquid Scintillation Spectrometry in 2001. An assesment model of the dose due to ingestion and liberation of radon from water is presented and compared with other models especially to the Crawford Brown's model.

Evaluation of occupational exposure in a underground coal mine by environmental measures of 222Rn and in vivo measurements of 210Pb in bones

International Nuclear Information System (INIS)

Dantas, A.L.A.; Veiga, L.H.S.; Dantas, B.M.; Melo, V.P.

2005-01-01

A radiological survey performed in an underground coal mining in the State of Parana, southern Brazil, has indicated the occurrence of high levels of concentration of radon and its decay products. The levels of 222 Rn concentration measured in the basement of this mine, in the period from 1999 to 2003 ranged from 2000 to 7000 Bq m -3 . It is estimated, for these workers, an average annual exposure of 2.1 WLM ranging from 0.2 to 7.2 WLM. A retrospective mortality study conducted with 2856 miners of this mining indicated a risk of lung cancer mortality greater than the one expected for the male population of the State. In this study the cumulative exposure to radon cannot be estimated since there was no radon measures in other periods. In this way, the cumulative exposure can be evaluated by through 210 Pb activities monitored in the skeleton. The measures of 210 Pb in skeleton ranged from 83 to 164 Bq, indicating that these workers were significantly exposed to 222 Rn. These results show that cumulative exposure to radon has been higher than estimated based on recent measures of the activity concentration of radon in the workplace and is compatible with the risk determined in the epidemiological study

Contribution of {sup 222}Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

Energy Technology Data Exchange (ETDEWEB)

Song Gang, E-mail: songg2005@126.co [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Xinming [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Diyun; Chen Yongheng [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China)

2011-04-15

This study investigates the contribution of radon ({sup 222}Rn)-bearing water to indoor {sup 222}Rn in thermal baths. The {sup 222}Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM{sub 10} and PM{sub 2.5}) and carbon dioxide (CO{sub 2}) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m{sup -3} of {sup 222}Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which {sup 222}Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average {sup 222}Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor {sup 222}Rn levels were influenced by the {sup 222}Rn concentrations in the hot spring water and the bathing times. The average {sup 222}Rn transfer coefficients from water to air were 6.2 x 10{sup -4}-4.1 x 10{sup -3}. The 24-h average levels of CO{sub 2} and PM{sub 10} in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM{sub 2.5}. Radon and PM{sub 10} levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: {yields} {sup 222}Rn-bearing water is the main contributor to indoor radon in hot spring hotel. {yields} The PM{sub 2.5} and CO{sub 2} are also the main indoor pollutants in the hotel rooms. {yields} Higher radon and PM levels might have significant negative health effects to human. {yields} The radon transfer coefficients are consistent with the published data.

Relationship of 220Rn and 222Rn progeny levels in Canadian underground U mines

International Nuclear Information System (INIS)

Bigu, J.

1988-01-01

Radon-222 and 220 Rn progeny are found in some Canadian underground U mines. Because both can contribute to lung dose, their experimental determinations are important. The relationship between 222 Rn progeny Working Level [WL(Rn)] and 220 Rn progeny Working Level [WL(Tn)] has been investigated in U mines. Experimental measurements extended from 1981 to 1986 and consisted of about 700 measurements of each WL(Rn) and WL(Tn). The data were analyzed by standard linear and power-function regression analysis. A power-function relationship between WL(Rn) and WL(Tn) seemed to fit the experimental data best. The relationship obtained permits the calculation of WL(Tn) from experimental values of WL(Rn). The relationship is useful for lung-dose-calculation purposes and in mine-ventilation-engineering calculations

Calibration factor determination for solid nuclear track detectors CR-39 type exposed to Rn-222

International Nuclear Information System (INIS)

Cazula, Camila Dias; Campos, Marcia Pires de; Mazzilli, Barbara Paci

2014-01-01

In the detection method with solid nuclear track detector, when a heavy particle rests on the detector surface, causes a breakdown in their molecular structure forming a trace. One of the typical applications of these detectors is the measurement of the concentration of Rn -222 in air, a noble radioactive gas, part of the U-238 series, emitting alpha particles and important in epidemiological studies to protect individuals from natural radiation. To determine the concentration of Rn -222 in the air in a room is necessary to know the density of lines (traces / cm 2 ) on the detector surface, the exposure time and the calibration factor. The determination of the calibration factor for CR-39 detectors was taken from the exposure of these to a known concentration of Rn-222. Therefore, the detectors were placed inside a cell of Lucas adapted and subsequently exposed to a concentration of Rn-222 15 kBq / m 3 , by means of the apparatus RN-150 Pylon Electronics Incorporation, which has a source of Ra-226 and releases known concentrations of Rn-222. Six calibration factor determinations were performed, the average value obtained was 0.0534 ±0.0021 (traces / cm 2 per Bq / m 3 day). The results are consistent with literature values for the same type of detector and showed good reproducibility

Standards, calibration and quality assurance of 222Rn measurements in Sweden

International Nuclear Information System (INIS)

Falk, R.; Hagberg, N.; Mjoenes, L.; Moere, H.; Nyblom, L.; Swedjemark, G.A.

1994-01-01

Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure to the general population. Limits have been introduced in Sweden, and recommendations were made in 1980 for decreasing indoor 222 Rn concentration. The need for the coordinated calibration of measuring instruments as well as for quality assurance was obvious for both health and economic reasons. 222 Rn measurements in Sweden are based on standards traceable to the National Institute of Standard and Technology (NIST) through the use of standard reference material 226 Ra. Standards for both 222 Rn and short-lived 222 Rn progeny are described together with the reference instrument adopted for these studies. The calibration of field instruments was performed in a ''radon room'', a climate chamber in which it is possible to vary and monitor the concentration of 222 Rn as well as other characteristics of the indoor air such as temperature, humidity, ventilation rate and aerosol concentration. The rules and regulations for field measurements imply a calibration of the instruments yearly, as well as accreditation and training for the companies that carry out the measurements. Examples are given of the official measurement protocols used for the different types of instruments. (orig.)

Relation between 222Rn concentration in outdoor air and lower atmosphere

International Nuclear Information System (INIS)

Kataoka, Toshio; Mori, Tadashige; Yunoki, Eiji; Michihiro, Kenshuh; Sugiyama, Hirokazu; Shimizu, Mitsuo; Tsukamoto, Osamu; Sahashi, Ken.

1991-01-01

Using the height of the surface-based inversion layer obtained by the acoustic sounder returns and the variation of the 222 Rn concentration in the outdoor air during the presence of the surface-based inversion layer, the exhalation rate of 222 Rn is estimated to be 0.020 Bq·m -2 ·s -1 , which is observed elsewhere on land. Furthermore, the exposure rate at 1 m above the air-ground interface due to the short-lived 222 Rn daughters in the outdoor air during the presence of the surface-based inversion layer can be estimated using the height of the surface-based inversion layer and the 222 Rn concentrations in the outdoor air at the ground level before and after the onset of the surface-based inversion layer. From these treatment, it is clearly demonstrated that the monostatic acoustic sounder is useful as a supplementary method for a weather survey which forms a part of monitoring around the nuclear facilities. (author)

A multi-detector continuous monitor for assessment of 222Rn in the coastal ocean

International Nuclear Information System (INIS)

Dulaiova, H.; Peterson, R.; Burnett, W.C.

2005-01-01

Radon-222 is a good natural tracer of groundwater discharge and other physical processes in the coastal ocean. Unfortunately, its usefulness is limited by the time consuming nature of collecting individual samples and traditional analysis schemes. An automated multi-detector system is demonstrated that can be used in a continuous survey basis to assess radon activities in coastal ocean waters. The system analyses 222 Rn from a constant stream of water delivered by a submersible pump to an air-water exchanger where radon in the water phase equilibrates with radon in a closed air loop. The air stream is fed to 3 commercial radon-in-air monitors connected in parallel to determine the activity of 222 Rn. By running the detectors out of phase, it is possible to obtain as many as 6 readings per hour with a precision of approximately ±5-15% for typical coastal seawater concentrations. (author)

Allometric methodology for the assessment of radon exposures to terrestrial wildlife

International Nuclear Information System (INIS)

Vives i Batlle, J.; Copplestone, D.; Jones, S.R.

2012-01-01

A practical approach to calculate 222 Rn daughter dose rates to terrestrial wildlife is presented. The method scales allometrically the relevant parameters for respiration in different species of wildlife, allowing inter-species calculation of the dose per unit radon concentration in air as simple base-and-exponent power functions of the mass. For plants, passive gas exchange through the leaf surface is assumed, also leading to specific power relationships with mass. The model generates conservative predictions in which the main contributor to the dose rate of target tissues of the respiratory system is from α radiation arising from 222 Rn daughters. Tabulated 222 Rn DPURn values are given for 69 species used by the England and Wales Environment Agency for habitats assessments. The approach is then applied to assess the authorised discharges of 222 Rn from sites in England, demonstrating that, from a whole-body dose perspective, the biota considered are protected from effects at the population level. - Highlights: ► Allometric method developed to calculate radon daughter doses to 69 species of terrestrial wildlife. ► Model satisfactorily compared with previous studies of lung dose rates for mammals. ► The main contributor to the dose rate of the respiratory system is internal α-radiation from the 222 Rn daughters. ► Air immersion is the principal contributor to the external dose rate. ► Assessment for 7 authorised sites in England suggests that wildlife populations are adequately protected from the anthropogenic radon emissions considered in this study.

A novel design of a personal nuclear track detector for ambient Rn

International Nuclear Information System (INIS)

Margaliot, M.; Even, O.; Herman, R.

1997-01-01

In some occupations, workers spend a part of their time underground, in closed and unventilated spaces, while most of their time is spent in the open air. The case in hand is a group of the 'Bezek' telephone technicians, whose work includes spending a few hours daily in small, coarsely finished and unventilated tunnels in which telephone branching boxes are located. The rest of their time they work outdoors, and a small part of it is spent in offices. The Rn levels in a few telephone branching tunnels were measured and were found to be rather high (levels of 3000 - 5000 Bq/m 3 are common). The average exposure of the workers is however much lower, due to short time spent in the tunnels, versus the longer time spent outdoors, and the low Rn level there. To obtain a well founded estimation of their actual commutative Rn exposure, a new integrative Rn detector was designed, which is attached to the workers clothing during the whole working day, and serves as a personal Rn detector, rather than as the a conventional area monitor. The detector element itself consists of a Nuclear Track Detector made of dosimetry grade CR-39. The function of the detector is how ever dependent mainly on the geometrical design of the housing of the detector. The properties of these detectors are, however, highly dependent on the design of the detectors housing.The design itself, it's theoretical efficiency, it's actual calibration process and it's calibration factor are presented. Mechanical reliability has been established in some 3 years of operation both as a fixed area monitor and as a personal portable detector. (authors)

Distribution of 222Rn in dwellings around proposed uranium mining site at Rohil, Rajasthan

International Nuclear Information System (INIS)

Jha, V.N.; Kumar, Rajesh; Singh, M.K.; Patnaik, R.L.; Sahoo, S.K.; Jha, S.K.; Tripathi, R.M.

2018-01-01

Prior to commissioning of uranium ore mining and processing facility baseline radiological monitoring vis-a-vis public exposure assessment is required. Such information are utilized for developing control measures during operational phases to ascertain the minimal impact on the surrounding areas. Among the various pathways the inhalation component far exceeds the other component in the natural background of a region. Further, in inhalation component also the contribution of 222 Rn is almost 50%. The main sources of indoor radon are geological features, soil characteristics, construction materials of the dwellings, water utilization pattern, use of natural cooking gas, climatological/weather variables. As part of preliminary radiological assessment exercise twenty three dwellings were selected in this region comprising of different types of construction design/materials and passive radon dosimeters were provided of evaluation of radon level and inhalation exposure. The results presented in the text are part of the said radiological assessment exercise

Analytical FcRn affinity chromatography for functional characterization of monoclonal antibodies

Science.gov (United States)

Schlothauer, Tilman; Rueger, Petra; Stracke, Jan Olaf; Hertenberger, Hubert; Fingas, Felix; Kling, Lothar; Emrich, Thomas; Drabner, Georg; Seeber, Stefan; Auer, Johannes; Koch, Stefan; Papadimitriou, Apollon

2013-01-01

The neonatal Fc receptor (FcRn) is important for the metabolic fate of IgG antibodies in vivo. Analysis of the interaction between FcRn and IgG in vitro might provide insight into the structural and functional integrity of therapeutic IgG that may affect pharmacokinetics (PK) in vivo. We developed a standardized pH gradient FcRn affinity liquid chromatography method with conditions closely resembling the physiological mechanism of interaction between IgG and FcRn. This method allows the separation of molecular IgG isoforms, degradation products and engineered molecules based on their affinity to FcRn. Human FcRn was immobilized on the column and a linear pH gradient from pH 5.5 to 8.8 was applied. FcRn chromatography was used in comparison to surface plasmon resonance to characterize different monoclonal IgG preparations, e.g., oxidized or aggregated species. Wild-type and engineered IgGs were compared in vitro by FcRn chromatography and in vivo by PK studies in huFcRn transgenic mice. Analytical FcRn chromatography allows differentiation of IgG samples and variants by peak pattern and retention time profile. The method can distinguish: 1) IgGs with different Fabs, 2) oxidized from native IgG, 3) aggregates from monomer and 4) antibodies with mutations in the Fc part from wild-type IgGs. Changes in the FcRn chromatographic behavior of mutant IgGs relative to the wild-type IgG correlate to changes in the PK profile in the FcRn transgenic mice. These results demonstrate that FcRn affinity chromatography is a useful new method for the assessment of IgG integrity. PMID:23765230

Thoron (220Rn) in the indoor atmospheric environment

International Nuclear Information System (INIS)

Ramachandran, T.V.

2006-01-01

Naturally occurring background radiation is a topic, which has evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Many locations around the world have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It has been estimated that inhalation of 222 Rn, 2 20 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. In the Indian context, in an earlier national survey, the external gamma radiation dose rates have been more or less well mapped using thermo luminescent dosimeters covering more than 214 locations, which has yielded a national average of 775 mGy/y. Of this, nearly 48.7% contribution of the dose rate is from 40 K and the rest from the uranium (33.6%) and thorium (17.7%) series. A good database pertaining to the country wide levels of uranium, thorium and potassium in geological materials also exists. Thus, there exists a good database on the total external gamma radiation level across the country. Since the contribution from inhalation of 222 Rn, 220 Rn and their short lived progenies contributes more than 54% of the total background radiation dose, it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for the country so far on national level. With this in mind, a national survey has been executed by this center involving a large number of universities and other allied research institutions from different parts of the country for the estimation of inhalation component of the dose

Measurement of 222Rn and 220Rn exhalation rate from soil samples of Kumaun Hills, India

Science.gov (United States)

Semwal, Poonam; Singh, Kuldeep; Agarwal, T. K.; Joshi, Manish; Pant, Preeti; Kandari, Tushar; Ramola, R. C.

2018-03-01

The source terms, i.e., exhalation and emanation from soil and building materials are the primary contributors to the radon (222Rn)/thoron (220Rn) concentration levels in the dwellings, while the ecological constraints like ventilation rate, temperature, pressure, humidity, etc., are the influencing factors. The present study is focused on Almora District of Kumaun, located in Himalayan belt of Uttarakhand, India. For the measurement of 222Rn and 220Rn exhalation rates, 24 soil samples were collected from different locations. Gamma radiation level was measured at each of these locations. Chamber technique associated with Smart Rn Duo portable monitor was employed for the estimation of 222Rn and 220Rn exhalation rates. Radionuclides (226Ra, 232Th and 40K) concentrations were also measured in soil samples using NaI(Tl) scintillation based gamma ray spectrometry. The mass exhalation rate for 222Rn was varying between 16 and 54 mBq/kg/h, while the 220Rn surface exhalation rate was in the range of 0.65-6.43 Bq/m2/s. Measured gamma dose rate for the same region varied from 0.10 to 0.31 µSv/h. Inter-correlation of exhalation rates and intra-correlation with background gamma levels were studied.

Interview med børn

DEFF Research Database (Denmark)

Interview med børn handler om børneinterview i forbindelse med forskning. Bogen er tænkt som inspiration til og afsæt for metodiske refleksioner i forbindelse med inddragelse af børn som informanter.......Interview med børn handler om børneinterview i forbindelse med forskning. Bogen er tænkt som inspiration til og afsæt for metodiske refleksioner i forbindelse med inddragelse af børn som informanter....

Effects of air conditioning, dehumidification and natural ventilation on indoor concentrations of 222Rn and 220Rn

International Nuclear Information System (INIS)

Lee, Thomas K.C.; Yu, K.N.

2000-01-01

A bedroom was selected for detailed measurements on 220 Rn and 222 Rn concentrations and environmental parameters including CO 2 concentration, temperature and relative humidity. To simulate different sealing conditions, five conditions were artificially created in the sampling period of 25 consecutive days. It was concluded that natural ventilation is the most efficient way to lower the 222 Rn levels, while air conditioning is the next. Dehumidification provides only a marginal reduction of 222 Rn levels. The 220 Rn concentrations are not affected by natural ventilation, air conditioner or dehumidification, and were all around 10 Bq m -3 . There are no significant correlations between the 220 Rn and 222 Rn concentrations and environmental conditions such as CO 2 concentrations, temperature, relative humidity and pressure

Allometric methodology for the assessment of radon exposures to terrestrial wildlife

Energy Technology Data Exchange (ETDEWEB)

Vives i Batlle, J., E-mail: jordi.vives.i.batlle@sckcen.be [Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Copplestone, D. [School of Biological and Environmental Sciences, University of Stirling (United Kingdom); Jones, S.R. [SJ Scientific Ltd, 13 Fern Bank, Cockermouth, Cumbria (United Kingdom)

2012-06-15

A practical approach to calculate {sup 222}Rn daughter dose rates to terrestrial wildlife is presented. The method scales allometrically the relevant parameters for respiration in different species of wildlife, allowing inter-species calculation of the dose per unit radon concentration in air as simple base-and-exponent power functions of the mass. For plants, passive gas exchange through the leaf surface is assumed, also leading to specific power relationships with mass. The model generates conservative predictions in which the main contributor to the dose rate of target tissues of the respiratory system is from {alpha} radiation arising from {sup 222}Rn daughters. Tabulated {sup 222}Rn DPURn values are given for 69 species used by the England and Wales Environment Agency for habitats assessments. The approach is then applied to assess the authorised discharges of {sup 222}Rn from sites in England, demonstrating that, from a whole-body dose perspective, the biota considered are protected from effects at the population level. - Highlights: Black-Right-Pointing-Pointer Allometric method developed to calculate radon daughter doses to 69 species of terrestrial wildlife. Black-Right-Pointing-Pointer Model satisfactorily compared with previous studies of lung dose rates for mammals. Black-Right-Pointing-Pointer The main contributor to the dose rate of the respiratory system is internal {alpha}-radiation from the {sup 222}Rn daughters. Black-Right-Pointing-Pointer Air immersion is the principal contributor to the external dose rate. Black-Right-Pointing-Pointer Assessment for 7 authorised sites in England suggests that wildlife populations are adequately protected from the anthropogenic radon emissions considered in this study.

High-spin yrast isomers in 211Rn and 212Rn with enhanced E3 decays

International Nuclear Information System (INIS)

Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.

1990-01-01

New isomeric states with J π =69/2 + ,τ m = 13 (1) ns in 211 Rn and J π =33 - ,τ m = 7(1) ns in 212 Rn have been identified. They decay by enchanced E3 transitions with strengths of 33(3) and 43(6) single particle units to the known 63/2 - and 30 + isomers 211 Rn and 212 Rn, respectively. The excitation energies and transition strengths agree well with predictions of the multi-particle, octupole-vibration coupled model. 13 refs., 2 tabs., 3 figs

Concentration of {sup 222}Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose; Concentracion de {sup 222}Rn en agua potable de la Ciudad de Zacatecas, medida por centelleo liquido y dosis asociada

Energy Technology Data Exchange (ETDEWEB)

Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A., E-mail: cesar_arevalob@outlook.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

2017-09-15

A study was carried out to determine the concentration of {sup 222}Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The {sup 222}Rn radioactive gas is a product of the decay series of {sup 238}U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The {sup 222}Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that {sup 222}Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing {sup 222}Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of {sup 222}Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of {sup 222}Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of {sup 222}Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of {sup 222}Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m{sup 3} and 1,463 μ Sv a, respectively. (Author)

Concentration of 222Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose

International Nuclear Information System (INIS)

Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A.

2017-09-01

A study was carried out to determine the concentration of 222 Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The 222 Rn radioactive gas is a product of the decay series of 238 U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The 222 Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that 222 Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing 222 Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of 222 Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of 222 Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of 222 Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of 222 Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m 3 and 1,463 μ Sv a, respectively. (Author)

Assessment of uncertainty associated with measuring exposure to radon and decay products in the French uranium miners cohort

International Nuclear Information System (INIS)

Allodji, Rodrigue S; Leuraud, Klervi; Laurier, Dominique; Bernhard, Sylvain; Henry, Stéphane; Bénichou, Jacques

2012-01-01

The reliability of exposure data directly affects the reliability of the risk estimates derived from epidemiological studies. Measurement uncertainty must be known and understood before it can be corrected. The literature on occupational exposure to radon ( 222 Rn) and its decay products reveals only a few epidemiological studies in which uncertainty has been accounted for explicitly. This work examined the sources, nature, distribution and magnitude of uncertainty of the exposure of French uranium miners to radon ( 222 Rn) and its decay products. We estimated the total size of uncertainty for this exposure with the root sum square (RSS) method, which may be an alternative when repeated measures are not available. As a result, we identified six main sources of uncertainty. The total size of the uncertainty decreased from about 47% in the period 1956–1974 to 10% after 1982, illustrating the improvement in the radiological monitoring system over time.

Delebørn i tal

DEFF Research Database (Denmark)

Ottosen, Mai Heide; Mathilde Hansen Stage, Sofie

Hvordan påvirker samværsordninger børns hverdagsliv? Fungerer forældresamarbejdet anderledes, når der er en deleordning, og trives børn med udstrakt samvær bedre eller dårligere end andre skilsmissebørn? Med udgangspunkt i SFI’s Børneforløbsundersøgelse, som følger 6000 børn fra 1995, bliver der ...

Environmental thoron (220Rn): a review

International Nuclear Information System (INIS)

Ramachandran, T.V.

2013-01-01

Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment and considerable data is generated on the levels of 222 Rn in the environment across the worlds and is periodically reported by UNSCEAR. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. Many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. This component is not adequately estimated for any country so far on a national level. 220 Rn problem will also be a problem in industries which uses thorium nitrate. Including India lamps using thoriated gas mantles are being still used for indoor and outdoor lighting and hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this article current status of 220 Rn levels in the indoor environment workplaces as well as in other industries where large amount of 232 Th is being handled are being summarized. (author)

Measurement uncertainties of long-term 222Rn averages at environmental levels using alpha track detectors

International Nuclear Information System (INIS)

Nelson, R.A.

1987-01-01

More than 250 replicate measurements of outdoor Rn concentration integrated over quarterly periods were made to estimate the random component of the measurement uncertainty of Track Etch detectors (type F) under outdoor conditions. The measurements were performed around three U mill tailings piles to provide a range of environmental concentrations. The measurement uncertainty was typically greater than could be accounted for by Poisson counting statistics. Average coefficients of variation of the order of 20% for all measured concentrations were found. It is concluded that alpha track detectors can be successfully used to determine annual average outdoor Rn concentrations through the use of careful quality control procedures. These include rapid deployment and collection of detectors to minimize unintended Rn exposure, careful packaging and shipping to and from the manufacturer, use of direct sunlight shields for all detectors and careful and secure mounting of all detectors in as similar a manner as possible. The use of multiple (at least duplicate) detectors at each monitoring location and an exposure period of no less than one quarter are suggested

Selection of design parameters of diffusion barrier in a passive 222Rn sampler based on activated charcoal adsorption

International Nuclear Information System (INIS)

Wei Suxia

1992-01-01

A method concerning selection of design parameters of diffusion barrier in a passive 222 Rn sampler based on activated charcoal adsorption. The proper parameter value of diffusion barrier is obtained by means of linearization of 222 Rn adsorption versus the exposure time. Thus, the influence of temperature on measured results may be greatly decreased, and higher sensitivity of the detector may be maintained

Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

International Nuclear Information System (INIS)

Greg J. Shott, Vefa Yucel, Lloyd Desotell Non-Nstec Authors: G. Pyles and Jon Carilli

2007-01-01

Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory

Measurement of 222Rn, 220Rn and their decay products in high background radiation area in Yangjiang

International Nuclear Information System (INIS)

Yuan Yongling

2000-01-01

The investigators have measured concentrations of Rn-222, rn-220 and their decay products in high background radiation area (HBRA) and the neighboring control area (CA), as well as the equilibrium factor F for Rn-222. The average concentrations of Rn-222 in the air indoors and outdoors in the HBRA are 42.6 and 17.3 Bq/m 3 respectively, and CA, 13.2 and 11.7 Bq/m 3 , respectively. The average α-potential energy concentrations for daughters of Rn-222 indoors and outdoors in HBRA are 0.109 and 0.051 μJ/m 3 , CA, 0.045 and 0.041 μJ/m 3 , respectively. The average α-potential energy values for daughters of Rn-220 indoor and outdoor in HBRA are 0.249 and 0.053 μJ/m 3 , CA, 0.051 and 0.025 μJ/m 3 , respectively. With regard to equilibrium factor F for Rn-222, the authors have also measured 52 points of 10 hamlets in HBRA (indoor 31, outdoor 21), 9 points of 2 hamlets in CA (indoor 5, outdoor 4), respectively. These figures are 0.46, 0.53, 0.62 and 0.64, respectively

Dosimetry of Rn-222 in the air in environments located above and below ground level; Dosimetria de Rn-222 no ar em ambientes localizados acima e abaixo do nivel do solo

Energy Technology Data Exchange (ETDEWEB)

Cazula, Camila Dias

2015-07-01

Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m{sup 3} for homes and 1000 Bq/m{sup 3} for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y{sup -1}, lower than the annual dose limit for the general public of 1 mSv y{sup -1}. (author)

Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2

Directory of Open Access Journals (Sweden)

S. van der Laan

2016-11-01

Full Text Available We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC, to estimate regional-scale surface fluxes of 222Rn from tower-based observations of 222Rn activity concentration, CO2 mole fractions and direct CO2 flux measurements from eddy covariance. For specific events, the regional (222Rn surface flux is calculated from short-term changes in ambient (222Rn activity concentration scaled by the ratio of the mean CO2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels and space (i.e. over the footprint of the observations. The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longer-term (e.g. seasonal or annual means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW and Lutjewad station (LUT. For LUT, which is an intensive agricultural site, we estimated a mean 222Rn surface flux of (0.29 ± 0.02 atoms cm−2 s−1 with values  > 0.5 atoms cm−2 s−1 to the south and south-east. For CBW we estimated a mean 222Rn surface flux of (0.63 ± 0.04 atoms cm−2 s−1. The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222Rn surface fluxes. Practical applications furthermore include

Seasonal and spatial variations in Rn-222 and Rn-220 in soil gas, and implications for indoor radon levels

International Nuclear Information System (INIS)

Sharman, G.

1992-01-01

Rn-222 enters dwellings as a component of soil gas drawn from the soil by mass flow driven by the pressure difference between the house and soil beneath. In a site on Northampton Sand Ironstone (Aalenian), a preferred path of emanation (hotspot) was found. A difference of 63 Bq L -1 Rn-222 was recorded in July between this point and another 3 m away. Rn-222 in this hotspot shows 12% less variation annually than the surrounding rock. During winter, Rn-222 values within 1.6 m of the house were 44% lower than those at more than 4 m away. Rn-222 showed a 99.5% negative correlation with wind run, showing that on this soil wind pressure can significantly reduce radon in the soil at 500 mm depth. Rn-220 in soil gas correlated positively at the 99.5% level with grass and air temperatures. Rn-220 was not associated with the hotspot. (Author)

Matérn thinned Cox processes

DEFF Research Database (Denmark)

Andersen, Ina Trolle; Hahn, Ute

2016-01-01

and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...

Matérn thinned Cox processes

DEFF Research Database (Denmark)

Andersen, Ina Trolle; Hahn, Ute

of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...

Stressede børn

DEFF Research Database (Denmark)

Tonseberg, Signe

2016-01-01

Stressede børn får det bedre, når deres krop får lov at tale. Fysioterapeut Pernille Thomsen lærer børn at bruge kroppen, så de trives bedre. Og der er ingen hokuspokus, for det hele bygger på naturvidenskabelig forskning i kroppens hormoner og stress....

Minoritetsdanske børn i dagtilbud

DEFF Research Database (Denmark)

Tireli, Üzeyir

2015-01-01

Dagtilbud skal fremme børns trivsel, sundhed, udvikling og læring, Dette er et lovmæssig krav, som gælder for alle børn i Danmark. Minoritetsdanske børn anderledes grundvilkår giver dog store udfordringer for dagtilbuddene - for hvordan sikrer man, at også børn fra kulturelle minoriteter får opti...

Rn daughter exposure to U miners

Energy Technology Data Exchange (ETDEWEB)

Cohen, B L

1982-04-01

Radon exposures to U.S. uranium miners under present conditions average about 1.3 WLM per year approximately or equal to 60 WLM per full working lifetime. This is intermediate between the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer, and there are many other occupations and industries with far higher SMR for lung cancer than that from radon exposure to miners.

Soil as a source of indoor 220Rn

International Nuclear Information System (INIS)

Li, Y.; Schery, S.D.; Turk, B.

1992-01-01

Two suggestions for sources of indoor 220Rn (thoron) have appeared in the literature: (1) building materials and outside air, and (2) soil beneath the house. Due to the difficulty of 220Rn measurement and limited data, both suggestions lack sufficient supporting evidence. We have investigated sources of indoor 220Rn in seven occupied houses in northern New Mexico, U.S. A two-filter system was used to measure indoor 220Rn levels continuously, and 220Rn progeny were measured with single filters and specialized alpha-track detectors. The amount of 220Rn entry from soil was curtailed by cutting off soil gas flow to the indoor air with subfloor depressurization mitigation systems. Four of the houses showed significant reductions in 220Rn with mitigation systems on. The average effect for these houses was to reduce indoor 220Rn levels by 70%. The other three houses had no clear reductions but in one of these houses, the mitigation system was not effective for stopping soil gas flow. Our results provide some of the most clear evidence to date supporting soil as an important source of indoor 220Rn

Estimated doses related to 222Rn concentration in bunker for radiotherapy and storage of radioisotopes

International Nuclear Information System (INIS)

Mestre, Freddy; Carrizales-Silva, Lila; Sajo-Bohus, Laszlo; Diaz, Cruz

2013-01-01

It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39®). The concentration of 222 Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm 2 equivalent to 0,434 Bqm -3 per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10 -6 mSv h -1 by Bqm -3 , it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva -1 and 150 micro risk cancer

Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

Energy Technology Data Exchange (ETDEWEB)

Greg J. Shott, Vefa Yucel, Lloyd Desotell

2007-06-01

Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory.

Mere Musik til Byens Børn

DEFF Research Database (Denmark)

Holst, Finn

Førsteårsrapport på København Kommunes treårige projekt Mere Musik til Byens Børn - et pilotprojekt med henblik på at sikre, at flere børn i København får mulighed for at deltage i forskellige former for frivillig musikundervisning. Særligt fokuseres der på at fremme, at alle børn i hele byen...

Assessment of the radiological impact of gamma and radon dose rates at former U mining sites in Tajikistan

International Nuclear Information System (INIS)

Lespukh, E.; Stegnar, P.; Yunusov, M.; Tilloboev, H.; Zyazev, G.; Kayukov, P.; Hosseini, A.; Strømman, G.; Salbu, B.

2013-01-01

An assessment of the radiological situation due to exposure to gamma radiation, radon ( 222 Rn) and thoron ( 220 Rn) was carried out at former uranium (U) mining and processing sites in Taboshar and at Digmai in Tajikistan. Gamma dose rate measurements were made using various field instruments. 222 Rn/ 220 Rn measurements were carried out with field instruments for instantaneous measurements and then discriminative 222 Rn/ 220 Rn solid state nuclear track detectors (SSNTD) were used for longer representative measurements. The detectors were exposed for an extended period of time in different outdoor and indoor public and residential environments at the selected U legacy sites. The results showed that gamma, 222 Rn and 220 Rn doses were in general low, which consequently implies a low to relatively low radiological risk. The radiation doses deriving from external radiation (gamma dose rate), indoor 222 Rn and 220 Rn with their short-lived progenies did not exceed national or international standards. At none of the sites investigated did the average individual annual effective doses exceed 10 mSv, the recommended threshold value for the general public. A radiation hazard could be associated with exceptional situations, such as elevated exposures to ionizing radiation at the Digmai tailings site and/or in industrial facilities, where gamma and 222 Rn/ 220 Rn dose rates could reach values of several 10 mSv/a. Current doses of ionizing radiation do not represent a hazard to the health of the resident public, with the exception of some specific situations. These issues should be adequately addressed to further reduce needless exposure of the resident public to ionizing radiation

Contribution of 222Rn in domestic water supplies to 222Rn in indoor air in Colorado homes

International Nuclear Information System (INIS)

Lawrence, E.P.; Wanty, R.B.; Nyberg, P.

1992-01-01

The contribution of 222Rn from domestic water wells to indoor air was investigated in a study of 28 houses near Conifer, CO. Air concentrations determined by alpha-track detectors (ATDs) and continuous radon monitors were compared with the predictions of a single-cell model. In many of the houses, the water supply was shown to contribute significantly to levels of indoor 222Rn. The data from the ATD study were augmented with a continuous monitoring study of a house near Lyons, CO. The well water in that house has the highest known concentration of 222Rn in water yet reported (93 MBq m-3). The temporal pattern in the indoor 222Rn concentration corresponds to water-use records. In general, it is difficult to quantify the proportion of indoor radon attributable to water use. Several lines of evidence suggest that the single-cell model underestimates this proportion. Continuous-monitoring data, although useful, are impractical due to the cost of the equipment. We propose a protocol for 222Rn measurement based on three simultaneous integrating radon detectors that may help estimate the proportion of indoor 222Rn derived from the water supply

Randon daughter exposure of the U.K. population

International Nuclear Information System (INIS)

Cliff, K.D.

1980-01-01

The highest dose to the body tissues from natural radioactivity is that to the bronchial epithelium arising predominantly from the short-lived daughters of 222 Rn with a lesser contribution from the daughters of 220 Rn. This paper discusses the estimation of current United Kingdom population exposure to these nuclides. At present the exposure for an average member of the population of the UK is 0.15 WLM y -1 when the winter ventilation rate is 0.8 h -1 . This will increase to 0.58 WLM y -1 if the winter ventilation rate is reduced to 0.2 h -1 . The use of electrostatic precipitators would decrease the measured WL but would not affect the unattached fraction of 222 Rn daughter products, which determines the dose to the epithelium. Other methods of reducing 222 Rn daughter concentrations under investigation include prevention of the ingress of 222 Rn from the subsoil and the coating of construction materials with a radon barrier

Radon exposure, cigarette smoking, and other mining experience in the beaverlodge uranium miners cohort

International Nuclear Information System (INIS)

L'Abbe, K.A.; Howe, G.R.; Burch, J.D.; Miller, A.B.; Abbatt, J.; Band, P.; Choi, W.; Du, J.; Feather, J.; Gallagher, R.

1991-01-01

A nested case-control study within the Beaverlodge Uranium Miners Cohort was undertaken to assess any possible contribution of confounding by smoking and other mining experience to the risk estimate derived from the original cohort study. Next of kin have been interviewed for 46 lung cancer cases and 95 controls enrolled in the Beaverlodge Uranium Miners Cohort Study who died between 1950 and 1980. Confounding by cigarette smoking and other mining experience appears unlikely to have contributed to the relative risk coefficient for exposure to Rn decay products derived in the parent study. Data for smoking and exposure to Rn decay products are consistent with a multiplicative model, although considerable caution must be applied to this interpretation

Energy-dependent etching-related impacts on CR-39 alpha detection efficiency for the Rn-222 and Rn-220 decay chains

Science.gov (United States)

Tan, Y.; Yuan, H.; Kearfott, K. J.

2018-04-01

CR-39 detectors are widely used to measure environmental levels of Rn-222, Rn-220 and their progeny. Prior research reported the CR-39 detection efficiency for alpha particles from Rn-222, Rn-220 and their progeny under a variety of etching conditions. This paper provides an explanation for interesting observations included in that work, namely that the critical incidence angle decreases with the increasing particle energy and the detection efficiency for 8.78 MeV alpha particles is zero. This paper explains these phenomena from a consideration of the interaction of alpha particles with the CR-39 detectors and the physics of etching dynamics. The proposed theory provides a rationale for an approach to optimizing the etching conditions of CR-39 detector for measuring Rn-222, Rn-220 and their progenies.

Estimated doses related to {sup 222}Rn concentration in bunker for radiotherapy and storage of radioisotopes; Dosis estimada por concentraciones de {sup 222}Rn en bunker de radioterapia y de almacenamiento de isotopos radiactivos

Energy Technology Data Exchange (ETDEWEB)

Mestre, Freddy; Carrizales-Silva, Lila, E-mail: freddymest@gmail.com, E-mail: lcarriza@ivic.gob.ve [Instituto Venezolano de lnvestigaciones Cientificas, Caracas (Venezuela, Bolivarian Republic of); Sajo-Bohus, Laszlo, E-mail: sajobohus@gmail.com [Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear; Diaz, Cruz, E-mail: cruzediaZ@gmail.com [Universidad Pedagogica Experimental Libertador, Barquisimeto (Venezuela, Bolivarian Republic of). Instituto Pedagogico

2013-07-01

It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39 Registered-Sign ). The concentration of {sup 222}Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm{sup 2} equivalent to 0,434 Bqm{sup -3} per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10{sup -6} mSv h {sup -1} by Bqm{sup -3}, it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva{sup -1} and 150 micro risk cancer.

Dosimetry of Rn-222 in the air in environments located above and below ground level

International Nuclear Information System (INIS)

Cazula, Camila Dias

2015-01-01

Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m 3 for homes and 1000 Bq/m 3 for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y -1 , lower than the annual dose limit for the general public of 1 mSv y -1 . (author)

Seasonal variations of radon and the radiation exposure levels in Nerja cave, Spain

International Nuclear Information System (INIS)

Duenas, C.; Fernandez, M.C.; Canete, S.; Perez, M.; Gordo, E.

2011-01-01

222 Rn concentrations in the air in Nerja cave (Spain) (3 o 52'35''W 36 o 43'50''N) were measured by continuous monitoring using Alpha-Guard, Genitron instrument equipment. The 222 Rn measurements were carried out for a complete annual cycle in the different halls: Vestibule hall from July 2003 to June 2004, Ballet hall from July 2004 to June 2005 and Mirador hall from July 2005 to June 2006. Starting from the entrance of the cave we successively find the Vestibule hall, the Ballet hall and the Mirador hall. The range of 222 Rn levels were of 8-627 Bq m -3 for the Vestibule hall, 28-575 Bq m -3 for the Ballet hall and 38-578 Bq m -3 for the Mirador. The aim of this study was to detect seasonal variation patterns of 222 Rn concentrations. The seasonal variations of 222 Rn concentrations are discussed in relation to various meteorological factors measured inside and outside the cave. The radiation exposure levels for workers and tourists with different equilibrium factors have been evaluated. The radiation exposure levels for workers and tourists only represent a low percentage of the exposure guides for the general population. - Highlights: → The aim of the study was to detect seasonal variation of 222 Rn concentrations. → 222 Rn concentrations in the air-cave were measured by continuous monitoring. → The 222 Rn measurements were carried out in the different halls of the cave. → The radiation exposure levels for workers and tourists have been evaluated.

Risk assessment of radiation carcinogenesis

International Nuclear Information System (INIS)

Kai, Michiaki

2012-01-01

This commentary describes the radiation cancer risk assessed by international organizations other than ICRP, assessed for radon and for internal exposure, in the series from the aspect of radiation protection of explaining the assessments done until ICRP Pub. 103. Statistic significant increase of cancer formation is proved at higher doses than 100-200 mSv. At lower doses, with use of mathematical model, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported the death probability due to the excess lifetime risk (ELR) at 100 mSv of 0.36-0.77% for solid tumors and 0.03-0.05% for leukemia, and NRC in US, the risk of exposure-induced prevalence and death (REID) per 100 thousands persons of 800 (male)/1,310 (female) and 410/610, respectively. Both are essentially based on findings in A-bomb survivors. The assessment for Rn is described here not on dose. UK and US analyses of pooled raw data in case control studies revealed the significant increase of lung cancer formation at as low level as 100 Bq Rn/m3. Their analyses also showed the significance of smoking, which had been realized as a confounding factor in risk analysis of Rn for uranium miners. The death probability until the age of 85 y was found to be 1.2 x 10 -4 in non-smokers and 24 x 10 -4 in smokers/ Working Level Month (WLM). Increased thyroid cancer incidence has been known in Chernobyl Accident, which is realized as a result of internal exposure of radioiodine; however, the relationship between the internal dose to thyroid and its cancer prevalence resembles that in the case of external exposure. There is no certain evidence against the concept that risk of internal exposure is similar to and/or lower than, the external one although assessment of the internal exposure risk accompanies uncertainty depending on the used model and ingested dose. International Commission on Radiological Protection (ICRP) recommendations hitherto have been important and precious despite

Estimation of 222Rn flux and its effect on the atmospheric 222Rn concentration at Hachijo-jima Island, Japan

International Nuclear Information System (INIS)

Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao

2010-01-01

222 Rn fluxes from the ground surface and 226 Ra contents in soil were measured on Hachijo-jima Island, which is a solitary island in the Pacific Ocean located about 200 km to the south of the main island of Japan, to evaluate fractional contributions of the locally exhaled 222 Rn and the long-range transported one to the surface air concentration measured on this island. Averages of 222 Rn flux and 226 Ra content in dry soil were evaluated to be 0.9±0.4 mBq m -2 s -1 and 6.8±0.2 Bq kg -1 , respectively. These are considerably smaller than the respective values of 9.7±0.8 mBq m -2 s -1 and 23.2±0.4 Bq kg -1 measured at Nagoya as a reference. The lower value of the 226 Ra content and the even lower 222 Rn flux on this island can be attributed to the basaltic geology and the soil's coarse texture moisture, respectively. A simple model calculation assuming a typical nocturnal condition showed that the measured 222 Rn flux would cause only a small increase in the surface air concentration by 0.035 to 0.072 Bq m -3 (relative contribution of 1 to 12%) in addition to the long-range transported 222 Rn under a typical nocturnal condition. The contribution of the local flux would be smaller than that under nocturnal condition. This local 222 Rn component is negligible as compared with the concentration of the long-range transported 222 Rn (0.6 to 3.6 Bq m -3 ). It is, therefore, concluded that Hachijo-jima Island is suitable for measuring the long-range transported atmospheric 222 Rn in East Asia region. (author)

Dependence of indoor 222Rn level on building materials

International Nuclear Information System (INIS)

Tso, M.W.; Ng, C.; Leung, J.K.C.

1993-01-01

The radionuclide contents of typical building materials used in Hong Kong were studied by γ spectroscopic analysis. The physical properties of these building materials affecting the production and transportation of 222 Rn to the surrounding air were examined; these include the emanation coefficient of 2 '2 2 Rn of the material, the diffusion coefficient of 222 Rn in the material and the effect of surface coating and temperature on the rate of 222 Rn exhalation. Results obtained in this study explain the indoor 222 Rn concentration observed in our previous surveys and also suggest that the main source of indoor 222 Rn in Hong Kong is building material. (3 figs., 4 tabs.)

Variations of Rn-222 concentration in the Bratislava air

International Nuclear Information System (INIS)

Holy, K.; Bohm, R.; Polaskova, A.

1996-01-01

222 Rn is produced by alpha decay of 222 Ra in roil. A small fraction of totally produced 222 Rn escapes from coil particles into soil air. Then 222 Rn is transported predominantly by molecular diffusion into outdoor atmosphere. The radon concentration in the outdoor atmosphere is not stable. It varies irregularly depending on meteorological conditions. However there were found out regular daily and remand variations of 222 Rn concentration in outdoor atmosphere. These variations were measured in numerous works and results are summarized f.e. in work of Gesell. A simple model described the annual variations of 222 Rn concentration war published by Minato. A mathematical analysis of daily course of 222 Rn concentration in outdoor atmosphere was realized by Garzon et al. Some results of our study of 222 Rn variations in outdoor atmosphere of Bratislava are shown in this report. (author)

Retirement Financial Planning and the RN: An Integrative Literature Review.

Science.gov (United States)

Keele, Shanna; Alpert, Patricia T

2015-10-01

This integrative literature review examined the current research on RN retirement. The review identified 3 critical gaps in knowledge: (a) minimal knowledge regarding the economic impact on RN retirement, (b) incomplete information regarding the demographics of RN retirement, and (c) a scarcity of prospective longitudinal RN workforce studies. Future research must address these gaps to better address RN workforce sustainability.

222Rn flux and soil air concentration profiles in West-Germany. Soil 222Rn as tracer for gas transport in the unsaturated soil zone

International Nuclear Information System (INIS)

Doerr, H.; Muennich, K.O.

1990-01-01

Measurements of the 222 Rn activity concentration profile in the soil and the 222 Rn flux in West-Germany are presented. The spatial pattern of the 222 Rn flux depends more on soil type than on the 226 Ra activity of the soil material. The average 222 Rn flux from sandy soils is 1000-2000 dpm m -2 h -1 and 4000-6000 dpm m -2 h -1 froam loamy and clayey soils. Weekly 222 Rn flux measurements during a period of 1 year at a sandy site show no significant temporal variations. At a clayey site, the 222 Rn flux tends to be higher in summer than in winter. The permeability coefficient P Rn , obtained from simultaneous 222 Rn flux and concentration profile measurements in various soils, can be expressed as a function of the soil parameters total porosity ε 0 , soil moisture F, tortuosity k and the molecular diffusion coefficient D 0 of 222 Rn in air: P = D 0 ((ε 0 -F)/k-const.). The flux of any other gas into or out of the soil can thus be calculated from its measured concentration profile in the soil and from the 222 Rn permeability coefficient, replacing the molecular diffusion coefficient of 222 Rn by that of the specific gas under consideration. As an example, this method of flux determination is demonstrated for the soil CO 2 flux to the atmosphere and for the flux of atmospheric CH 4 into the soil. (author) 14 refs

Studies on 222Rn concentration in ground water using smart radon monitor and assessment of the radiation dose to the population of Mysuru city

International Nuclear Information System (INIS)

Chandrashekara, M.S.; Pruthvi Rani, K.S.

2017-01-01

Radioactive elements originate from the earth's crust and make their way into air, water, food and eventually in to the living system. Even though 75% of the Earth's surface is covered by water, only about 0.3 % of the total water on the Earth is available for public use. The ground water contains trace amounts of radioactive elements and these radionuclides contribute significant amount of dose to living beings, through intake of water into the human body. Radon dissolved in water is released into air when it is used for cooking, drinking, bathing and washing purposes. Exposure of population to higher concentrations of radon and its progeny for a long time causes occurrence of lung cancer and pathological effects like respiratory functional changes. Radon is a main source of ionizing radiation of natural origin and the studies on radon concentrations in drinking water are of importance. A systematic study of 226 Ra and 222 Rn concentration in the drinking water samples was carried out in Mysuru city. The concentration of 226 Ra and 222 Rn was estimated in water samples using emanometry method employing scintillation cells and alpha counting system. The 222 Rn concentration in water was also measured using a Smart Radon Monitor (SRM) for comparison of the results. SRM is a technologically advanced real time, portable, radon monitor developed at BARC, Mumbai

Utility of a human FcRn transgenic mouse model in drug discovery for early assessment and prediction of human pharmacokinetics of monoclonal antibodies

Science.gov (United States)

Avery, Lindsay B.; Wang, Mengmeng; Kavosi, Mania S.; Joyce, Alison; Kurz, Jeffrey C.; Fan, Yao-Yun; Dowty, Martin E.; Zhang, Minlei; Zhang, Yiqun; Cheng, Aili; Hua, Fei; Jones, Hannah M.; Neubert, Hendrik; Polzer, Robert J.; O'Hara, Denise M.

2016-01-01

ABSTRACT Therapeutic antibodies continue to develop as an emerging drug class, with a need for preclinical tools to better predict in vivo characteristics. Transgenic mice expressing human neonatal Fc receptor (hFcRn) have potential as a preclinical pharmacokinetic (PK) model to project human PK of monoclonal antibodies (mAbs). Using a panel of 27 mAbs with a broad PK range, we sought to characterize and establish utility of this preclinical animal model and provide guidance for its application in drug development of mAbs. This set of mAbs was administered to both hemizygous and homozygous hFcRn transgenic mice (Tg32) at a single intravenous dose, and PK parameters were derived. Higher hFcRn protein tissue expression was confirmed by liquid chromatography-high resolution tandem mass spectrometry in Tg32 homozygous versus hemizygous mice. Clearance (CL) was calculated using non-compartmental analysis and correlations were assessed to historical data in wild-type mouse, non-human primate (NHP), and human. Results show that mAb CL in hFcRn Tg32 homozygous mouse correlate with human (r2 = 0.83, r = 0.91, p PK studies, enhancement of the early selection of lead molecules, and ultimately a decrease in the time for a drug candidate to reach the clinic. PMID:27232760

Blinde børn - integration eller isolation?

DEFF Research Database (Denmark)

Bengtsson, Steen; Cayuelas Mateu, Nuria; Høst, Anders

Blinde børn har i de senere årtier været integreret i den almindelige skole. Men betyder det, at de bliver bedre forberedt til et integreret liv som voksne? Det er langt fra sikkert, viser denne undersøgelse af blinde børn. Skolen sørger for, at de blinde børn har en støttelærer, så de får det he...

Fremtidens biblioteksbetjening af børn

DEFF Research Database (Denmark)

Høyrup, Helene

2008-01-01

Rapporten er resultatet af et tværministerielt udvalgsarbejde nedsat af Kulturministeriet.  Kommissoriet har været at nytænke biblioteksbetjeningen af børn, så den passer til vidensamfundet.  Udvalgsarbejdet munder ud i ti bud for fremtidens biblioteksbetjening af børn....

IL1RN and KRT13 Expression in Bladder Cancer: Association with Pathologic Characteristics and Smoking Status

Directory of Open Access Journals (Sweden)

Thomas S. Worst

2014-01-01

Full Text Available Purpose. To validate microarray data on cytokeratin 13 (KRT13 and interleukin-1 receptor antagonist (IL1RN expression in urothelial carcinoma of the urinary bladder (UCB and to correlate our findings with pathologic characteristics and tobacco smoking. Methods. UCB tissue samples (n=109 and control samples (n=14 were obtained from transurethral resection and radical cystectomy specimens. Immunohistochemical staining of KRT13 and IL1RN was performed and semiquantitative expression scores were assessed. Smoking status was evaluated using a standardized questionnaire. Expression scores were correlated with pathologic characteristics (tumor stage and grade and with smoking status. Results. Loss of KRT13 and IL1RN expression was observed in UCB tissue samples when compared to controls (P=0.007, P=0.008 in which KRT13 and IL1RN expression were high. IL1RN expression was significantly reduced in muscle-invasive tumors (P=0.003. In tissue samples of current smokers, a significant downregulation of IL1RN was found when compared to never smokers (P=0.013. Conclusion. Decreased expressions of KRT13 and IL1RN are common features of UCB and are associated with aggressive disease. Tobacco smoking may enhance the loss of IL1RN, indicating an overweight of proinflammatory mediators involved in UCB progression. Further validation of the influence of smoking on IL1RN expression is warranted.

Etched track technique to measure sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn fluxes on soil surface

CERN Document Server

Csige, I

2003-01-01

sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn in the human environment are considered to be a risk factor because of the radiation dose due to the inhalation of their short-lived daughters. Main source of radon is usually the soil; therefore the measurement of fluxes of sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn on soil surfaces is often a relevant parameter to characterise building site radon potential. An etched track detector technique was developed to measure long-time average sup 2 sup 2 sup 2 Rn and sup 2 sup 2 sup 0 Rn fluxes. (R.P.)

Recent Swedish experiences in 222Rn control

International Nuclear Information System (INIS)

Swedjemark, G.A.; Maekitalo, A.

1990-01-01

Swedish local authorities are responsible for decreasing 222 Rn progeny concentrations in homes in their municipalities. To obtain an overall view of their experiences, concerned national authorities sent a questionnaire in 1986 to local authorities. The results were intended to form one basis for decisions by the government regarding revised statements on financial contributions, limits, etc. The results were also intended to be of use to national authorities in determining limits and recommendations and to local authorities in their field work. One result of the survey was an enhanced interest in the Rn problem among Swedish politicians and the mass media. This increased attention resulted in new plans for continued work to decrease Rn levels indoors during 1987-1989, on both a national and a local level. The experiences of the local authorities show that Rn progeny concentrations decreased to below the design level in 95% of newly built houses investigated. It was also found that Rn progeny concentrations were below the limit for reconstruction in 53% of existing homes that previously had levels exceeding the limit

Transitioning the RN to Ambulatory Care: An Investment in Orientation.

Science.gov (United States)

Allen, Juliet Walshe

2016-01-01

Registered nurses (RNs) struggle when transitioning from the inpatient setting to the outpatient clinical environment because it results in a diverse skill-set shift. The RN, considered an outpatient revenue source, experiences a decrease in peer-to-peer relationships, changes in leadership responsibilities, and changes in workgroup dynamics (supervision of unlicensed clinical personnel who function under the direction of the physician, not the RN). Ambulatory organizations find themselves implementing clinical orientation programs that may not delineate the attributes of the RN. This diminishes their value while emphasizing the unlicensed technical skill set. Creating a core RN orientation program template is paramount for the transition of the RN to the ambulatory setting. The literature reveals several areas where improving the value of the RN will ultimately enhance recruitment and retention, patient care outcomes, and leverage the RN role within any organization. Eleven 30-minute in-depth telephone interviews were conducted in addition to 4 nurse observations to explore the lived experience of the RN in ambulatory care. The findings disclosed an overarching theme of nurse isolation and offered insightful underpinnings for the nurse leader as ambulatory growth continues and nurse leaders further endorse the RN presence in the ambulatory setting.

(222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

Science.gov (United States)

Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

2014-10-01

One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. Copyright © 2014 Elsevier Ltd. All rights reserved.

Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

International Nuclear Information System (INIS)

Haquin, G.; Lang, B.; Even, O.; Asael, Y.; Shamai, Y.; Margaliot, M.; Shirav, M.

2002-01-01

Radon gas ( 222 Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to ( 222 Rn and its progeny in epidemiological studies. Measurements of implanted 210 Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210 Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210 Po in spongy, porous materials ( 210 Po volume traps). Other approach is in-vivo measurements of 210 Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210 Po concentration in glasses exposed to 222 Rn using alpha spectrometry

Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

Science.gov (United States)

Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

2009-11-15

Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

Effects of RN Age and Experience on Transformational Leadership Practices.

Science.gov (United States)

Herman, Susan; Gish, Mary; Rosenblum, Ruth; Herman, Michael

2017-06-01

This study reported the evolution of transformational leadership (TL) practices and behaviors across years of age, management experience, and professional nursing practice within a professional nursing leadership organization. Recent studies of CNO TL found valuations peak near age 60 years. This study reported on a wider range of management positions, correlating years of RN practice and management experience and age to TL metrics. This study used Kouzes and Posner's Leadership Practices Inventory-Self-Assessment (LPI-S) to survey a nursing leadership organization, the Association of California Nurse Leaders (ACNL). Anonymous responses were analyzed to identify leadership trends in age and years of professional service. On average, LPI-S metrics of leadership skills advance through years of management, RN experience, and age. The TL scores are statistically higher in most LPI-S categories for those with more than 30 years of RN or management experience. Decade-averaged LPI-S TL metrics in the ACNL survey evolve linearly throughout age before peaking in the decade from age 60 to 69 years. A similar evolution of TL metrics is seen in decades of either years of management experience or years of RN experience. Transformational leadership increased with nursing maturity particularly for LPI-S categories of "inspire a shared vision," "challenge the process," and "enable others to act." In the ACNL population studied, decade-averaged leadership metrics advanced. Leadership evolution with age in the broader RN population peaked in age bracket 60 to 69 years. The LPI-S averages declined when older than 70 years, coinciding with a shift from full-time work toward retirement and part-time employment.

Transforming RN education: clinical learning and clinical knowledge development.

Science.gov (United States)

Benner, P

1993-04-01

Transforming RN education has the potential for transforming clinical teaching and learning for all students. The returning RN student offers possibilities for clinical learning that the generic student does not have, but this should not cause us to limit the returning RN student to the generic level. Where possible innovative programs should be developed to move the RN student from baccalaureate level to the Master's level. As educators, we should take the opportunity to increase the numbers of nurses who are educationally prepared to move into advanced levels of practice. The returning RN student offers a rich human resource for the profession, and a rich resource for improving our clinical teaching as well as our practice.

A long range transport model of Rn-222

International Nuclear Information System (INIS)

Ikebe, Y.; Kojima, S.; Shimo, M.

1993-01-01

In this report, we propose an analytical treatment about temporal variation of 222 Rn concentration in the atmosphere with an aim to clarify origin and transport of 222 Rn. Based on the results of numerical simulation of radon, we separate the 222 Re concentration measured at Nagoya into the following two components : (1) 222 Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. From numerical simulation of radon, it has been shown that the measured diurnal variation can be explained by this component. (2) 222 Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose here a one layer transport model using air mass trajectory technique. By this model we can explain the temporal variation of background component and seasonal variation of 222 Rn at Nagoya. (3 figs.)

Indoor "2"2"2Rn concentration in the exhibition and storage rooms of Polish geological museums

International Nuclear Information System (INIS)

Długosz-Lisiecka, Magdalena; Krystek, Marcin; Raczyński, Paweł; Głuszek, Ewa; Kietlińska-Michalik, Barbara; Niechwedowicz, Mariusz

2017-01-01

The radon exhaled from radioactive mineral collections exhibited in five Polish geological museums may influence its total indoor concentration. Radon concentrations measured in the exhibition halls do not pose a risk for visitors or museum staff. However, air exceeding the action limit for workers (equal to 300 Bq/m"3) was noted in the storage rooms of two museums. Significant"2"2"2Rn activity concentrations equal to more than ~300 kBq/m"3were measured inside lead containers where radioactive minerals were stored. - Highlights: • In this "2"2"2Rn radionuclide measurements in 5 Polish geological museums have been done. • The review of "2"2"2Rn activity in the air in areas containing radioactive geological collections is not a routine protocol, and is not included in the national radon monitoring program. • Therefore the radiological exposure for museum staff resulting from inhalation of gaseous radon and its products has been including.

Experimental setup for radon exposure and first diffusion studies using gamma spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Maier, Andreas, E-mail: a.maier@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Beek, Patrick van [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Hellmund, Johannes [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Durante, Marco [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany)

2015-11-01

In order to measure the uptake and diffusion of {sup 222}Rn in biological material, an exposure chamber was constructed where cell cultures, biological tissues and mice can be exposed to {sup 222}Rn-activities similar to therapy conditions. After exposure, the material is transferred to a gamma spectrometer and the decay of {sup 214}Pb and {sup 214}Bi is analyzed. From the time kinetics of these decays the total amount of the initial {sup 222}Rn concentration can be calculated. In this paper the design and construction as well as first test measurements are reported.

Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

Science.gov (United States)

Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

2014-02-01

This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

A survey of 222Rn in drinking water in mexico city

International Nuclear Information System (INIS)

Vasquez-Lopez, C.; Zendejas-Leal, B. E.; Golzarri, J. I.; Espinosa, G.

2011-01-01

In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l -1 for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a 222 Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l -1 . 222 Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken. (authors)

Overview of Hazard Assessment and Emergency Planning Software of Use to RN First Responders

Energy Technology Data Exchange (ETDEWEB)

Waller, E; Millage, K; Blakely, W F; Ross, J A; Mercier, J R; Sandgren, D J; Levine, I H; Dickerson, W E; Nemhauser, J B; Nasstrom, J S; Sugiyama, G; Homann, S; Buddemeier, B R; Curling, C A; Disraelly, D S

2008-08-26

There are numerous software tools available for field deployment, reach-back, training and planning use in the event of a radiological or nuclear (RN) terrorist event. Specialized software tools used by CBRNe responders can increase information available and the speed and accuracy of the response, thereby ensuring that radiation doses to responders, receivers, and the general public are kept as low as reasonably achievable. Software designed to provide health care providers with assistance in selecting appropriate countermeasures or therapeutic interventions in a timely fashion can improve the potential for positive patient outcome. This paper reviews various software applications of relevance to radiological and nuclear (RN) events that are currently in use by first responders, emergency planners, medical receivers, and criminal investigators.

Unit type differences in RN workgroup job satisfaction.

Science.gov (United States)

Boyle, Diane K; Miller, Peggy A; Gajewski, Byron J; Hart, Sara E; Dunton, Nancy

2006-10-01

Using cross-sectional data from the 2004 National Database of Nursing Quality Indicators (NDNQI) RN Satisfaction Survey, differences in RN workgroup job satisfaction were examined among 10 unit types--medical-surgical, step-down, critical care, pediatric, maternal-newborn, psychiatric, emergency department, rehabilitation, surgical services, and outpatient clinics and labs. The national sample included RN workgroups in 2,900 patient care units (55,516 RNs; 206 hospitals in 44 states). Workgroup satisfaction across all unit types was moderate. RN workgroups in pediatric units were the most satisfied, whereas those in surgical services and emergency department unit types were least satisfied. A consistent finding across all unit types was high satisfaction with the specific domains of nurse-to-nurse interaction, professional status, and professional development versus much lower satisfaction with task, decision making, and pay. Findings can be used to inform and develop investigations that examine specific aspects of the work environment for RN workgroups in various unit types.

RN-to-BSN Students' Quality Improvement Knowledge, Skills, Confidence, and Systems Thinking.

Science.gov (United States)

Trent, Peggy; Dolansky, Mary A; DeBrew, Jacqueline Kayler; Petty, Gayle M

2017-12-01

Little evidence demonstrates that RN-to-baccalaureate nursing (BSN) graduates have met The Essentials of Baccalaureate Education for Professional Nursing Practice-specifically, evidence of the graduates' organizational and systems leadership related to quality care and patient safety. This BSN Essentials reflects the QSEN quality improvement (QI) competency. The purpose of this pilot study was to develop and test an assessment strategy to measure RN-to BSN students' QI competence and their perception of QI knowledge and skills. Students (N = 59) from six RN-to-BSN programs participated in a Qualtrics survey e-mailed during the last semester of their program. The majority of students (60%) reported that they did not experience QI content in their program. Scores on QI knowledge, skills, and systems thinking were low, yet the students self-reported that they were confident in their ability to perform QI. This pilot study provides an assessment strategy to measure students' competence related to QI. Nursing education has an opportunity to integrate and measure QI competence to ensure that nurses have the knowledge and skills to continually improve patient care. [J Nurs Educ. 2017;56(12):737-740.]. Copyright 2017, SLACK Incorporated.

RN-BSN Students' Perceptions of the Differences in Practice of the ADN- and BSN-Prepared RN.

Science.gov (United States)

Matthias, April D; Kim-Godwin, Yeoun Soo

2016-01-01

This study explored RN-BSN students' perceptions of practice differences between nurses prepared with an ADN and BSN. Five themes were identified in 20 students' discussion posts: "a nurse is a nurse" at the bedside, beyond the bedside, BSN wanted, digging deeper, and appraisal. Results illustrate the need for educators to assist nurses in translating the differentiated educational competencies to the practice role of the bedside RN.

Integrated Environmental Assessment Part III: ExposureAssessment

Energy Technology Data Exchange (ETDEWEB)

McKone, Thomas E.; Small, Mitchell J.

2006-06-01

Human exposure assessment is a key step in estimating the environmental and public health burdens that result chemical emissions in the life cycle of an industrial product or service. This column presents the third in a series of overviews of the state of the art in integrated environmental assessment - earlier columns described emissions estimation (Frey and Small, 2003) and fate and transport modeling (Ramaswami, et al., 2004). When combined, these first two assessment elements provide estimates of ambient concentrations in the environment. Here we discuss how both models and measurements are used to translate ambient concentrations into metrics of human and ecological exposure, the necessary precursors to impact assessment. Exposure assessment is the process of measuring and/or modeling the magnitude, frequency and duration of contact between a potentially harmful agent and a target population, including the size and characteristics of that population (IPCS, 2001; Zartarian, et al., 2005). Ideally the exposure assessment process should characterize the sources, routes, pathways, and uncertainties in the assessment. Route of exposure refers to the way that an agent enters the receptor during an exposure event. Humans contact pollutants through three routes--inhalation, ingestion, and dermal uptake. Inhalation occurs in both outdoor environments and indoor environments where most people spend the majority of their time. Ingestion includes both water and food, as well as soil and dust uptake due to hand-to-mouth activity. Dermal uptake occurs through contacts with consumer products; indoor and outdoor surfaces; the water supply during washing or bathing; ambient surface waters during swimming or boating; soil during activities such as work, gardening, and play; and, to a lesser extent, from the air that surrounds us. An exposure pathway is the course that a pollutant takes from an ambient environmental medium (air, soil, water, biota, etc), to an exposure medium

Assessment of human exposures

Energy Technology Data Exchange (ETDEWEB)

Lebret, E. [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

1995-12-31

This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

Assessment of human exposures

Energy Technology Data Exchange (ETDEWEB)

Lebret, E [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

1996-12-31

This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

Development of a PIN diode based on-line measurement system for Radon (222Rn) and Thoron (220Rn) in environment

International Nuclear Information System (INIS)

Ashokkumar, P.; Chaudhury, Probal; Sumesh, C.G.; Sahoo, B.K.; Gaware, J.J.; Mayya, Y.S.

2014-01-01

Radon, thoron and their progenies are universally present in outdoor air, and can reach higher levels in indoor air due to poor ventilation. Several instruments have been developed for accurate measurement of radon and thoron in the environment. Semiconductor detector based system employing spectroscopic method has been proved to be the best among them. A PIN diode based electrostatic collection type online real-time instrument has been developed in Bhabha Atomic Research Centre for simultaneous measurement of radon and thoron in an environment while both 222 Rn and 220 Rn are present. This system can be used for determination of radon and thoron concentrations at residence or workplace. Furthermore, since the 222 Rn and 220 Rn are differentiated from each other through spectroscopy, this monitor can be used even in a mixed radon/thoron environment

Margus Pärn : turuliidri koht on Maximale jõukohane 4-5 aastaga / Margus Pärn ; interv. Viljar Rääsk

Index Scriptorium Estoniae

Pärn, Margus

2008-01-01

Leedu jaekaubandusketi Maxima Eesti juht Margus Pärn vastab küsimustele, mis puudutavad Eesti jaekaubandusturgu ja Maxima positsiooni selles, ettevõtte laienemist ning turuliidri rolli saavutamise võimalust. Lisa: Margus Pärn. Tabel: Maxima

Application of {sup 222} Rn as a tracer of groundwater discharge at the coastal zone of Ubatuba, Sao Paulo State, Brazil; Aplicacao de {sup 222} Rn como tracador da descarga de aguas subterraneas na regiao costeira de Ubatuba, Sao Paulo

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Joselene de; Farias, Luciana A.; Mazzilli, Barbara P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Radiometria Ambiental]. E-mail: jolivei@net.ipen.br; Burnett, William C. [Florida State Univ., Tallahassee, FL (United States); Saraiva, Elisabete de S.B. e; Furtado, Valdenir V. [Sao Paulo Univ., SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Quimica e Geologica

2002-07-01

Submarine groundwater discharge (SGD) and recycled seawater can provide chemical constituents to coastal zone, representing an important material flux pathway from land to sea in some areas. Geochemical tracers, like {sup 222} Rn and {sup 226} Ra, are advantageous for regional-scale assessment of SGD, because their signals represent values integrated through the water column that removes small-scale variations. These radionuclides are usually enriched in groundwater compared to seawater, can be measured at very low concentrations and are conservative. This work reports preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil, covering latitudes between 23 deg 26{sup '}S and 23 deg 46{sup '}S and longitudes between 45 deg02{sup '}W and 45 deg 11{sup '}W. The main aims of this research were to set up an analytical method to assess {sup 222} Rn and {sup 226} Ra activities in seawater samples and to apply the excess {sup 222} Rn inventories obtained to estimate the submarine groundwater discharge. Measurements made during 2001/2002 included {sup 222} Rn and {sup 226} Ra in seawater, {sup 222} Rn in sediment, seawater and sediment physical properties. (author)

222Rn determination in mineral waters from the Pocos de Caldas Plateau in Brazil

International Nuclear Information System (INIS)

Taddei, M.H.T.; Silva, N.C.; Cipriani, M.

2002-01-01

It is estimated that 50% of the radioactive effective dose equivalent to man comes from radon and its radioactivity daughters. The main 222 Rn sources are the soils, building materials and potable waters. There is an especial interest in spas waters with high natural radioactivity. It's considered that the use of these waters as drinking waters is a significant radiation exposure factor, and it is worthwhile to assess the consequent dose. Such estimation has been made for the Pocos de Caldas Plateau, which is a region of high natural radioactivity, from volcanic origin, containing several spas (Aguas da Prata, Caldas, Pocos de Caldas and Andradas). The 222 Rn content was determined in 23 spring waters in Pocos de Caldas and neighboring cities. In water sampling, modified Marinelli flasks were used. The determinations were effected with a high resolution gamma ray spectrometer. High concentration variations were observed in the collected mineral waters, the highest values having been found in Fonte Villela's waters, in Aguas da Prata town (926 Bq/l); Grande Hotel's in Caldas Town (420 Bq/l) and COLAB's in Pocos de Caldas region (289 Bq/l). The annual whole body effective dose equivalent estimate for adult due to water ingestion, using the Crowford-Brown's biokinetic model's adult dose conversion factors, was higher than 1 mSv/year in 61% of the analyzed waters. (author)

Determine concentration radon 222Rn in the air inside and outside the buildings at the summer province of Baghdad

International Nuclear Information System (INIS)

Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

2010-01-01

In this study, Was use of solid-state nuclear track detectors in the measurement of concentrations of radon 222 Rn inside and outside of the buildings in the summer and winter of the Baghdad province and because of the high features of the technical sensitivity and efficiency to record track of charged particles (such as protons and alpha particles and fission fragments) . Is the radon of Environmental Pollutions that is caused health problems , that was seemed the concern at the problem of pollution, radon gas 222 Rn and thoron gas 220 Rn and the considerable risk resulting from exposure to these isotopes by alpha particles emitted which have proved the relationship between exposure to emitted alpha particles with the incidence of disease of lung cancer. In this study, measured the concentration of radon 222 Rn inside and outside buildings in the summer and winter in several areas from the Baghdad province and as showed in the attached tables. Been studied the environmental radioactivity and measurement of the concentration of radon gas in the air in different parts of the city of Baghdad. the highest concentration was Found in the second Orf ali (A) (of the Sadr City) for the summer and was (37.973 Bq/m3) outside the building and ((53.400 Bq/m3 inside the building, either for the winter season was (55.773 Bq/m3) outside the building and (Bq/m3 58.148) inside the building for the same region and This is the concentration within the limits allowed

Thoron (220Rn) in the indoor environment and work places

Science.gov (United States)

Ramachandran, T. V.; Sahoo, B. K.

2009-08-01

Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222Rn and its progeny, there was a great upsurge of interest in the measurement of 222Rn in the environment. Subsequently, considerable data is being generated on the levels of 222Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220Rn in indoors and workplace environment is scaree due to the genral perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon (222Rn), and thoron (220Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222Rn, 220Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232Th is being handled is being summarized. Methods of measurement and

Thoron (220Rn) in the indoor environment and work places

International Nuclear Information System (INIS)

Ramchandran, T.V.; Sahoo, B.K.

2009-01-01

Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scaree due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220 Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220 Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232 Th is being handled is being summarized. Methods of

AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

Science.gov (United States)

Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

2018-05-16

Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

Comparison of methods and instruments for 222Rn/220Rn progeny measurement

International Nuclear Information System (INIS)

Liu Yanyang; Shang Bing; Wu Yunyun; Zhou Qingzhi

2012-01-01

In this paper, comparisons were made among three methods of measurement (grab measurement, continuous measurement and integrating measurement) and also measurement of different instruments for a radon/thoron mixed chamber. Taking the optimized five-segment method as a comparison criterion, for the equilibrium-equivalent concentration of 222 Rn, measured results of Balm and 24 h integrating detectors are 31% and 29% higher than the criterion, the results of Wl x, however, is 20% lower; and for 220 Rn progeny, the results of Fiji-142, Kf-602D, BWLM and 24 h integrating detector are 86%, 18%, 28% and 36% higher than the criterion respectively, except that of WLx, which is 5% lower. For the differences shown, further research is needed. (authors)

Measurement of 222Rn in soil concentrations in interstitial air

International Nuclear Information System (INIS)

Duenas, C.; Fernandez, M.C.; Carretero, J.; Liger, E.

1996-01-01

Measurements of 222 Rn soil concentrations were made by inserting stainless-steel sampling tubes into the soil. The samples of the soil interstitial air were taken in to pre-evacuated 1 L glass flasks. The glass flasks are cylindrical and coated with a film of ZnS(Ag). 222 Rn was measured by counting the alpha particles emitted by 222 Rn and its daughter products, 218 Po and 214 Bi, when they reached radioactive equilibrium. Measurements of 222 Rn gas concentrations in the soil air interstices by the method at different depths were used to calculate the diffusion coefficient of the 222 Rn in the soil air. This study has been carried out for diverse soils. (Author)

Jørn Utzon’s Maritime Origins

DEFF Research Database (Denmark)

Jaeger, Thomas Arvid

2014-01-01

Article about Jørn Utzons and the influence on his architecture comming from his early years with sailing, and learning about boat construction and the design principles from his father - the yacht designer Aage Utzon.......Article about Jørn Utzons and the influence on his architecture comming from his early years with sailing, and learning about boat construction and the design principles from his father - the yacht designer Aage Utzon....

Ontologies in a project by Jørn Utzon

DEFF Research Database (Denmark)

Jørgensen, Lars Botin

2003-01-01

The paper has an overall theoretical and philosophical view on the actual topic: the architecture of Jørn Utzon, whereas Utzon himself often has stated that theories and hermeneutic approaches does not interest him at all. It is the aim of this paper to inscribe Jørn Utzon in a theoretical...... tradition where nature and the real is in the core of everything and furthermore to throw a light on the paradoxical non-modern and non-Cartesian aspect of the architectural practice of Jørn Utzon....

Theoretical study of the diffusion 222Rn gas on activated charcoal

International Nuclear Information System (INIS)

Lopez, Fabio O.; Canoba, Analia C.

2001-01-01

The 222 Rn adsorption coefficient is the fundamental parameter characterizing activated carbon's ability to adsorb 222 Rn . In this work, it has been determined the 222 Rn coefficient adsorption for 222 Rn activated carbon detectors. Scintillation vials were used as detectors. The measurement of the 222 Rn activity adsorbed in activated carbon was made by a liquid scintillation measurement of its alpha-beta progeny decay. On the other hand, in this work a diffusion and adsorption model has been developed for the transport of 222 Rn in an activated carbon porous bed. The equation that describes these processes is a partial differential equation, of the second order with respect to axial coordinate, and the first order with respect to time. The equation was numerically solved using a finites differences method. With this model the 222 Rn activity adsorbed in the detector, for several situations, was calculated. The results were tested with the data obtained from series of experiences made in our laboratories. (author)

The ventilation influence on the spatial distribution of Rn-222 and its decay products in human inhabited environments

International Nuclear Information System (INIS)

Munoz, S.N.M.; Hadler, J.C.; Paulo, S.R.

1996-01-01

For the determination of the ventilation influence (directional flux of air induced by a fan) on the spatial distribution of Rn-222 and its decay products (daughters) present in human inhabited environments, a group of experimental results were obtained by means of the fission nuclear tracks left by α-particles over adequate plastic detectors CR-39). The exposure of these detectors was done in a closed environment considering the influence of ventilation for different angles, velocities and distances from fan. The results show that a relative quantity of daughters of Rn-222 are pulled out of the environment due to the effects of ventilation and plat-out

Extremal RN/CFT in both hands revisited

International Nuclear Information System (INIS)

Kuo, En-Jui; Yang, Yi

2016-01-01

We study RN/CFT correspondence for four dimensional extremal Reissner–Nordstrom black hole. We uplift the 4d RN black hole to a 5d rotating black hole and make a geometric regularization of the 5d space–time. Both hands central charges are obtained correctly at the same time by Brown–Henneaux technique.

Evaluate transport processes in MERRA driven chemical transport models using updated 222Rn emission inventories and global observations

Science.gov (United States)

Zhang, B.; Liu, H.; Crawford, J. H.; Fairlie, T. D.; Chen, G.; Chambers, S. D.; Kang, C. H.; Williams, A. G.; Zhang, K.; Considine, D. B.; Payer Sulprizio, M.; Yantosca, R.

2015-12-01

Convective and synoptic processes play a major role in determining the transport and distribution of trace gases and aerosols in the troposphere. The representation of these processes in global models (at ~100-1000 km horizontal resolution) is challenging, because convection is a sub-grid process and needs to be parameterized, while synoptic processes are close to the grid scale. Depending on the parameterization schemes used in climate models, the role of convection in transporting trace gases and aerosols may vary from model to model. 222Rn is a chemically inert and radioactive gas constantly emitted from soil and has a half-life (3.8 days) comparable to synoptic timescale, which makes it an effective tracer for convective and synoptic transport. In this study, we evaluate the convective and synoptic transport in two chemical transport models (GMI and GEOS-Chem), both driven by the NASA's MERRA reanalysis. Considering the uncertainties in 222Rn emissions, we incorporate two more recent scenarios with regionally varying 222Rn emissions into GEOS-Chem/MERRA and compare the simulation results with those using the relatively uniform 222Rn emissions in the standard model. We evaluate the global distribution and seasonality of 222Rn concentrations simulated by the two models against an extended collection of 222Rn observations from 1970s to 2010s. The intercomparison will improve our understanding of the spatial variability in global 222Rn emissions, including the suspected excessive 222Rn emissions in East Asia, and provide useful feedbacks on 222Rn emission models. We will assess 222Rn vertical distributions at different latitudes in the models using observations at surface sites and in the upper troposphere and lower stratosphere. Results will be compared with previous models driven by other meteorological fields (e.g., fvGCM and GEOS4). Since the decay of 222Rn is the source of 210Pb, a useful radionuclide tracer attached to submicron aerosols, improved

Indoor {sup 22}Rn and {sup 222}Rn concentration measurements inside the Teotihuacan pyramids using NTD and E-PERM methodologies

Energy Technology Data Exchange (ETDEWEB)

Espinosa, G. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico)]. E-mail: espinosa@fisica.unam.mx; Golzarri, J.I. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico); Martinez, T. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Navarrete, M. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Bogard, J. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6480 (United States); Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, Xicotencatl y General Anaya s/n, 04120 Mexico, D.F. (Mexico); Juarez, F. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)

2005-11-15

Measurements of {sup 22}Rn (Thoron) and {sup 222}Rn (Radon) concentrations, inside the Sun and Moon pyramids of Teotihuacan's archeological zone in Mexico, are reported in this work. Two well-established methods, nuclear track detectors (NTDs), using open-close end cups with internal and external detectors of CR-39 polymer, and electret-passive environmental radon monitoring (E-PERM) were used for the measurements. This experiment had two objectives: to obtain better confidence in the {sup 22}Rn and {sup 222}Rn measurements inside the archeological tunnels, and to compare the data obtained in each one of the two methods. This experiment is specially interesting because of the very peculiar conditions where the measurements are made: high humidity, labyrinths with air currents, but almost constant temperature inside of the pyramid tunnels and galleries, notwithstanding of the temperature changes between the day and the night outside of the pyramid body. The {sup 222}Rn concentrations found in both the pyramids were lower than the action level proposed by the ICRP-65. These tunnels are not open to the public, but researchers from the Anthropology Institutions spend part of their time working there, in periods varying from 3 to 5 months.

On the 221 Rn → 221 Fr decay scheme

International Nuclear Information System (INIS)

Gromov, K.Ya.; Norseev, Yu.V.; Samatov, Zh.K.; Fominykh, V.I.; Chumin, V.G.; Kudrya, S.A.; Sergienko, V.A.

2002-01-01

The results of investigating the 221 Rnβ - - decay and the 225 Ac α-decay are compared. It is shown that 221 Fr levels at 145.9 and 393.2 keV are excited at the 221 Rn decay. Intensities and reduced probabilities of the β - - decay to the 221 Fr levels are determined. A conclusion is drawn that the parity of the 221 Rn ground state is positive

Børn af veteraner

DEFF Research Database (Denmark)

Frederiksen, Signe; Lausten, Mette

Siden starten af 1990’erne har Danmark sendt over 30.000 soldater og andet personel på internationale missioner – langt de fleste til Eks-Jugoslavien, Afghanistan og Irak. Denne undersøgelse handler om de børn, hvis fædre har været udsendt på militære missioner i udlandet. For hvordan håndterer...... spørgsmål er fokus for undersøgelsen. Undersøgelsen bygger på en spørgeskemaundersøgelse blandt børn af veteraner på henholdsvis 7, 11 og 15 år. Undersøgelsen er gennemført for og i samarbejde med Veterancentrets Videncenter, som er en del af Forsvarsministeriets Personalestyrelse....

Measurements of indoor 222Rn concentration in two art galleries

International Nuclear Information System (INIS)

Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

2009-01-01

It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

Assessment of Human Exposure to ENMs.

Science.gov (United States)

Jiménez, Araceli Sánchez; van Tongeren, Martie

2017-01-01

Human exposure assessment of engineered nanomaterials (ENMs) is hampered, among other factors, by the difficulty to differentiate ENM from other nanomaterials (incidental to processes or naturally occurring) and the lack of a single metric that can be used for health risk assessment. It is important that the exposure assessment is carried out throughout the entire life-cycle as releases can occur at the different stages of the product life-cycle, from the synthesis, manufacture of the nano-enable product (occupational exposure) to the professional and consumer use of nano-enabled product (consumer exposure) and at the end of life.Occupational exposure surveys should follow a tiered approach, increasing in complexity in terms of instruments used and sampling strategy applied with higher tiers in order tailor the exposure assessment to the specific materials used and workplace exposure scenarios and to reduce uncertainty in assessment of exposure. Assessment of consumer exposure and of releases from end-of-life processes currently relies on release testing of nano-enabled products in laboratory settings.

Annual effective dose equivalents arising from inhalation of 222Rn, 220Rn and their decay products in high background radiation area in China

International Nuclear Information System (INIS)

Zhang Zhonghou

1985-01-01

The author presents the data of on-the-sport investigations in the high background radiation area in Yangjiang County in 1975 and 1981. Monazite sand is contained in the soil of this area. The average concentrations of 222 Rn in the air indoors and out doors of the high background radiation area are 31.8 and 16.4 Bqm -3 respectively, which are equal to 2.9 and 1.5 times the average concentrations in the control area. The average concentrations of 220 Rn in the air indoors and outdoors of the high background area are 167.5 and 18.4 Bqm -3 , corresponding to 9.6 and 4.8 times those of the control area respectively. The average potential alpha energy concentrations for daughters of 222 Rn indoors and outdoors are 0.1 and 0.097 μJm -3 , which are equal to 2.6 and 2.2 times those of the control are respectively. The average potential alpha energy concentrations for daughters of 220 Rn indoors and outdoors are 0.255 and 0.053 μJm -3 , corresponding to 3.7 and 2.7 times those of the control area respectively. The average annual effective dose equivalents arising from inhalation of 222 Rn, 220 Rn and their decay products in high background radiation area are estimated to be 2.8 mSv per caput, in which 40.5% arise from 220 Rn and its decay products. This result is about 3 times that in the neighboring control area

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [CNRS/IN2P3, Universite de Nantes, SUBATECH, IMT Atlantique, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Lombardi, F.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Messina, M. [Columbia University, Physics Department, New York, NY (United States); New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Pienaar, J. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Ramirez Garcia, D. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Reuter, C. [University of Zurich, Physik-Institut, Zurich (Switzerland); Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Lavina, L.S. [Universite Paris Diderot, CNRS/IN2P3, LPNHE, Universite Pierre et Marie Curie, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Weber, M. [Columbia University, Physics Department, New York, NY (United States); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Wei, Y. [University of Zurich, Physik-Institut, Zurich (Switzerland); University of California, Department of Physics, San Diego, CA (United States); Collaboration: XENON Collaboration

2018-02-15

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ({sup 222}Rn), thoron ({sup 220}Rn) and krypton ({sup 85}Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

International Nuclear Information System (INIS)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Zhang, Y.; Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A.; Agostini, F.; Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S.; Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M.; Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I.; Barrow, P.; Baudis, L.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J.; Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B.; Berger, T.; Brown, E.; Piro, M.C.; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z.; Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N.; Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von; Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S.; Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M.; Fei, J.; Lombardi, F.; Ni, K.; Ye, J.; Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C.; Fulgione, W.; Lindemann, S.; Messina, M.; Naganoma, J.; Shagin, P.; Pienaar, J.; Ramirez Garcia, D.; Reuter, C.; Lavina, L.S.; Stein, A.; Wang, H.; Trinchero, G.; Tunnell, C.; Weber, M.; Wei, Y.

2018-01-01

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ( 222 Rn), thoron ( 220 Rn) and krypton ( 85 Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

Diesel oil removal by immobilized Pseudoxanthomonas sp. RN402.

Science.gov (United States)

Nopcharoenkul, Wannarak; Netsakulnee, Parichat; Pinyakong, Onruthai

2013-06-01

Pseudoxanthomonas sp. RN402 was capable of degrading diesel, crude oil, n-tetradecane and n-hexadecane. The RN402 cells were immobilized on the surface of high-density polyethylene plastic pellets at a maximum cell density of 10(8) most probable number (MPN) g(-1) of plastic pellets. The immobilized cells not only showed a higher efficacy of diesel oil removal than free cells but could also degrade higher concentrations of diesel oil. The rate of diesel oil removal by immobilized RN402 cells in liquid culture was 1,050 mg l(-1) day(-1). Moreover, the immobilized cells could maintain high efficacy and viability throughout 70 cycles of bioremedial treatment of diesel-contaminated water. The stability of diesel oil degradation in the immobilized cells resulted from the ability of living RN402 cells to attach to material surfaces by biofilm formation, as was shown by CLSM imaging. These characteristics of the immobilized RN402 cells, including high degradative efficacy, stability and flotation, make them suitable for the purpose of continuous wastewater bioremediation.

A survey of ²²²Rn in drinking water in Mexico City.

Science.gov (United States)

Vázquez-López, C; Zendejas-Leal, B E; Golzarri, J I; Espinosa, G

2011-05-01

In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l(-1) for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a (222)Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l(-1). (222)Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken.

Jørn Utzon -Influences and Reinterpretation

DEFF Research Database (Denmark)

Carter, Adrian

2012-01-01

The Paper presents a study of Jørn Utzon's architecture, in terms of its response to both local context and transcultural influences. The paper shows Utzon to have been a precursor and direct influence upon subsequent developments within contemporary regional architecture.......The Paper presents a study of Jørn Utzon's architecture, in terms of its response to both local context and transcultural influences. The paper shows Utzon to have been a precursor and direct influence upon subsequent developments within contemporary regional architecture....

Vibrations in the urban environment controlling 222Rn migration in soils

International Nuclear Information System (INIS)

Wiegand, J.

1998-01-01

Comparable to investigations looking for a connection of 222 Rn and earthquakes, this study shows the influence of subsurface vibrations on the 222 Rn concentration of the soil-gas in urban environments. Generally, the 222 Rn concentration increases through vibrations induced by trains, street-traffic and activities at project sites. The spatial radius of the 222 Rn increase due to vibrations reach highest values at project sites where piled foundations or metal panels are rammed into the ground (> 60 m). Along railway tracks the radius is wider (> 30 m) than along heavy traffic roads ( 222 Rn concentrations in soil-gas due to vibrations is the highest at project sites (53%). Along heavy traffic roads the increase of 222 Rn concentrations by motor vehicle traffic is higher (37%) than that by railway traffic (11.5%). The maximum increase of 400% was observed in a distance of 1 m from a railway track. In the vicinity of railway tracks a difference of the vibration influence according to unconsolidated rock (11.1%) or solid rock (11.8%) was not noticed. Beside this vibration effect, the overall 222 Rn level decreases with increasing distance to the vibration source, but only at locations laying above solid rocks. The observation of the increase of 222 Rn concentrations can be explained by a 'pump effect': the mechanical vibration of soil and mineral particles leads to an upward motion of the whole volume of soil-gas. Therefore, 222 Rn is pumped out of the soil to the atmosphere and as a result the upward transport is increased. (author)

Characteristics of the Nursing Practice Environment Associated With Lower Unit-Level RN Turnover.

Science.gov (United States)

Nelson-Brantley, Heather V; Park, Shin Hye; Bergquist-Beringer, Sandra

2018-01-01

The aim of this study is to examine characteristics of the nursing practice environment associated with lower RN turnover. Identifying characteristics of the practice environment that contribute to lower RN turnover is important for meeting the national quality strategy priority of reducing healthcare costs. Data from 1002 adult care units in 162 National Database of Nursing Quality Indicators participating hospitals were analyzed using multivariate linear regression. The Practice Environment Scale of the Nursing Work Index was used to measure practice environment characteristics. RN turnover was measured at the unit level. Nursing units with higher overall ratings of the nursing practice environment had lower rates of RN turnover. Units with higher RN perceived staffing and resource adequacy experienced significantly lower RN turnover. Unit managers and hospital administrators should consider RN perception of staffing and resource adequacy and the overall practice environment when developing targeted strategies for decreasing RN turnover.

Accelerated second-degree nursing students: predictors of graduation and NCLEX-RN first-time pass rates.

Science.gov (United States)

Penprase, Barbara B; Harris, Margaret A

2013-01-01

It is important to understand and identify factors that affect students' academic performance before entry into a nursing program and as they progress through the program. The authors discuss a study, and its outcomes, that assessed accelerated second-degree nursing students' prenursing and core nursing grades that served to predict their success at completing the nursing program and passing NCLEX-RN on first attempt. Strategies were identified to help at-risk students to be successful in the program and with first-time passage of NCLEX-RN.

Systematic Review: Bridging the Gap in RPN-to-RN Transitions.

Science.gov (United States)

Suva, Grace; Sager, Shelley; Mina, Elaine Santa; Sinclair, Nancy; Lloyd, Monique; Bajnok, Irmajean; Xiao, Sarah

2015-07-01

To review the evidence examining the influences of successful education and professional role transition for registered practical nurses (RPNs) pursuing a baccalaureate degree in nursing (BScN) and registered nurse (RN) licensure through RPN-to-RN bridging programs. Systematic review of papers published between 1995 and 2014 that evaluated students' education and professional role transitions from RPN to RN. Thirty-nine papers were selected that observed or studied the change or transition in designation from RPN to RN, or its equivalent, through bridging programs and analyzed thematically according to Meleis, Sawyer, Im, Hilfinger Messias, and Schumacher's transition model. Personal, community, and social conditions related to preparation for entry, program enrolment, and postgraduate clinical integration influence successful education and professional role transitions for RPN-to-RN bridging students. Providing key transition supports may enhance the potential for successful student transition into and throughout a bridging program, but further research is necessary to enhance this understanding and to recommend best practices for optimizing students' success. The evidence from this review identifies facilitators and barriers to successful education and professional role transition for RPN-to-RN bridging students, and identifies important considerations for future research. © 2015 Sigma Theta Tau International.

Challenges and perspectives of nanoparticle exposure assessment.

Science.gov (United States)

Lee, Ji Hyun; Moon, Min Chaul; Lee, Joon Yeob; Yu, Il Je

2010-06-01

Nanoparticle exposure assessment presents a unique challenge in the field of occupational and environmental health. With the commercialization of nanotechnology, exposure usually starts from the workplace and then spreads to environment and consumer exposure. This report discusses the current trends of nanoparticle exposure assessment, including the definition of nanotechnology relevant terms, essential physicochemical properties for nanomaterial characterization, current international activities related nanomaterial safety, and exposure assessment standard development for nanotechnology. Further this report describes challenges of nanoparticle exposure assessment such as background measurement, metrics of nanoparticle exposure assessment and personal sampling.

Radiation exposure and dose to small mammals in radon-rich soils

International Nuclear Information System (INIS)

Macdonald, C.R.; Laverock, M.J.

1998-01-01

Protection of the environment from radionuclide releases requires knowledge of the normal background levels of radiation exposure in the exposed biotic community and an estimate of the detriment caused by additional exposure. This study modeled the background exposure and dose to the lungs of small burrowing mammals from 222 Rn in artificial burrows in radon-rich soils at a site in southeastern Manitoba. E-PERM chambers used to measure 222 Rn in soil showed good reproducibility of measurement, with an average coefficient of variance (CV) of about 10%. Geometric mean (GM) 222 Rn concentrations at nine randomly selected sites ranged from 5,490 Bq/m 3 (GSD = 1.57, n = 7) to 41,000 Bq/m 3 (GSD = 1.02, n = 5). Long-term monitoring of 222 Rn concentrations in artificial burrows showed large variation within and between burrows and did not show consistent variation with season, orientation of the burrow opening, or levels of 226 Ra in the soil. Annual GM concentrations in individual burrows ranged from 7,480 Bq/m 3 (GSD = 1.60) to 18,930 Bq/m 3 (GSD = 1.81) in burrows several meters apart. A grand GM of 9,990 Bq/m 3 (GSD = 1.81, n = 214) was measured over the site for the year. An exposure model was constructed for five small mammal species based on their respiration rates and the number of hours spent in the burrow, active or hibernating, exposed to soil gas 222 Rn, and the time spent out of the burrow exposed to atmospheric 222 Rn. A background dose of 0.9 mGy/a from atmospheric 222 Rn (40 Bq/m 3 ) was estimated for a large-bodied (80 kg), nonburrowing animal living on the soil surface. The highest exposures (mJ/a) in burrowing mammals occurred in those species with the highest respiration rates. Hibernation accounted for a small fraction of total annual exposure ( 22R n concentrations from the field studies and an equilibrium factor (F) of 0.5, doses to lung ranged from 90 mGy/a in the badger to 700 mGy/a in the pocket gopher. These doses closely correspond to those

The problems of individual monitoring for internal exposure of monazite storage facility workers

International Nuclear Information System (INIS)

Ekidin, A.; Kirdin, I.; Yarmoshenko, I.; Zhukovsky, M.

2006-01-01

traditionally two situations of internal inhalation exposure by alpha emitting nuclides are considered in radiological protection: occupational exposure due to inhalation of plutonium aerosols; inhalation exposure by 222 Rn daughters in working places and in home. for these situations the problems of radioactive aerosols intake, nuclide dynamics in human body, internal dosimetry, nuclide excretion, monitoring of internal exposure have been investigated in details especially for plutonium inhalation exposure. The results of these studies are presented in details in ICRP Publications and UNSCEAR reports. However there is very specific case in which the special analysis of internal inhalation exposure is need. it is the working places with anomalous, extremely high concentration of thoron ( 220 Rn) daughters. The problems of internal radiation exposure of workers in such working place are the main topic of this publication. (authors)

Measurements of indoor 222RN activity in dwellings and workplaces of Curitiba (Brazil)

International Nuclear Information System (INIS)

Corrêa, Janine N.; Paschuk, Sergei A.; Del Claro, Flávia; Kappke, Jaqueline; Perna, Allan F.N.; Schelin, Hugo R.; Denyak, Valeriy

2014-01-01

The present work describes the results of systematic measurements of radon ( 222 Rn) in residential environments and workplaces in the Metropolitan Region of Curitiba (Paraná State, Brazil) during the period 2004–2012. For radon in air activity measurements, polycarbonate Track Etch Detectors CR-39, mounted in diffusion chambers protected by borosilicate glass fiber filters, were used. After being exposed in air, the CR-39 detectors were submitted to a chemical etching in a 6.25 M NaOH solution at 70 °C for 14 h. The alpha particle tracks were identified and manually counted with an optical microscope, and with the results of previously performed calibrations, the indoor activity concentration of 222 Rn was calculated. The calibration of CR-39 and the alpha particle tracks chemical development procedures were performed in collaboration the National Institute of Radiological Sciences (NIRS, Japan). The major part of indoor 222 Rn concentration in residences was found to be below 100 Bq/m 3 . In the case of working places, all measurements of 222 Rn concentrations were below 100 Bq/m 3 . These values are considered within the limits set by international regulatory agencies, such as the US EPA and ICRP, which adopt up to 148 and 300 Bq/m 3 as upper values for the reference levels for radon gas activity in dwellings, respectively. The latest value of 300 Bq/m 3 for radon activity in air is proposed by ICRP considering the upper value for the individual dose reference level for radon exposure of 10 mSv/yr. - Highlights: • Radon activity in air of dwellings was measured. • Radon activity in air of workplaces was measured. • Obtained experimental results are compared with International Norms and Regulations

Determination of Rn concentration in groundwater

International Nuclear Information System (INIS)

Takada, Shigeru; Handa, Madoka; Okano, Yasuhiro; Saito, Masaaki; Suzuki, Takashi

1984-01-01

The method of prediction of earthquakes by the change of concentration of Rn in groundwater was developed by U.S.S.R. and People's Republic of China, and was not known clearly. Since 1975, the research works on this subject were commenced by University of Tokyo, Geological Survey of Agency of Industrial Science and Technology and Tokyo Metropolitan Isotopic Research Center. Along with the development of an automatic continuous measuring apparatus with high reliability, the systems for the measurement of the Rn concentration in groundwater were established. At the time of the earthquake off Izu-Oshima on January 14, 1978, clear precursor was found in an artesian flowing well in Nakaizu 0f Izu Peninsula, and the unusual phenomena which seemed be the precursor of an earthquake were recognized in other districts of Izu and Tokai. On August 8, 1983, an earthquake of magnitude 6 occurred in the boundary region of Yamanashi and Kanagawa Prefectures. Preceding the earthquake, the unusual change of the concentration of Rn was recognized at several observation wells in Tokyo, and the unusual change was observed after the earthquake also. The possibility that the unusual change of the Rn concentration in groundwater is the precursor of earthquakes is high, and this phenomenon is expected to make contribution for the prediction of earthquakes, though there remain many problems to be solved. Further works are scheduled to establish the practical method of predicting earthquakes. (Isimitsu, A.)

Preliminary experiences with 222Rn gas in Arizona homes

International Nuclear Information System (INIS)

Kearfott, K.J.

1989-01-01

Results of a survey of 222Rn gas using four-day charcoal canister tests in 759 Arizona homes are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several homes having elevated indoor 222Rn air concentrations. Approximately 18% of the homes tested exceeded 150 Bq m-3 (4 pCi L-1), with 7% exceeding 300 Bq m-3 (8 pCi L-1). Several Arizona cities had larger fractions of homes exceeding 150 Bq m-3 (4 pCi L-1), such as Carefree and Cave Creek (23%), Paradise Valley (30%), Payson (33%), and Prescott (31%). The Granite Dells and Groom Creek areas of Prescott had in excess of 40-60% of the houses tested exceeding 150 Bq m-3 (4 pCi L-1). Elevated 222Rn concentrations were measured for a variety of home types having different construction materials. Private well water was identified as a potentially significant source of 222Rn gas in Prescott homes, with water from one well testing over 3.5 MBq m-3 (94,000 pCi L-1). A 222Rn concentration in air exceeding 410,000 Bq m-3 (11,000 pCi L-1) was measured using a four-day charcoal canister test in a house in Prescott which had a well opening into a living space. Additional measurements in this 150-m3 dwelling revealed a strikingly heterogeneous 222Rn concentration. The excessive 222Rn level in the dwelling was reduced to less than 190 Bq m-3 (5.2 pCi L-1) by sealing the well head with caulking and providing passive ventilation through a pipe

Locating karst depressed columns by means of Rn measurement on the surface

International Nuclear Information System (INIS)

Tang Daimao; Liu Hongfu; Duan Hongjie; Duan Lindi; Sui Haichen

1999-01-01

The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. The author discussed the surface Rn concentration's abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration's abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns

Levels of Rn and its daughters in houses in the northern part of China

International Nuclear Information System (INIS)

Zhang Yulin; Wang Gongpeng; Yu Shui; Wang Yuping; Li Weina.

1993-01-01

In this paper we described the levels of Rn and Rn daughters and their diurnal variation in spring and autumn in 18 typical houses in Harbin, Changchun and Jinxi. The results showed that there was no difference in levels of Rn and Rn daughters inside and outside the new and old houses in spring. The Rn concentration was 7.4∼12.5 Bq m -3 . The level of Rn daughters was 1.0-1.3 mWL. Both of them generally increased in winter and the Rn concentration was 15.1-95.1 Bq m -3 . The potential energy of Rn daughters was 4.6-21.3 mWL. The potential energy of Rn daughters in new houses were 20 and 10 times those in spring in Changchun and Harbin respectively and Rn concentrations were 10 and 4 times those in spring respectively. Rn concentrations in a few houses exceeded 200 Bq m -3 . It was lower from 12:00 to 20:00 and slightly higher from 20:00 to the next morning, and the high concentration peak can be found at morning from 4:00 to 6:00 after 24 hours continuous observation. The results was in agreement with those reported in UNSCEAR 1982 Report

Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

Science.gov (United States)

Fijałkowska-Lichwa, L.; Przylibski, T. A.

2011-04-01

considered solution for the ventilation system not only does not prevent radioactive exposure of the staff, but can even increase it. The authors have also observed comparable characteristics of the annual patterns of 222Rn activity concentration changes in underground spaces and residential buildings situated in the same or similar climatic zones.

Human Exposure Assessment for Air Pollution.

Science.gov (United States)

Han, Bin; Hu, Li-Wen; Bai, Zhipeng

2017-01-01

Assessment of human exposure to air pollution is a fundamental part of the more general process of health risk assessment. The measurement methods for exposure assessment now include personal exposure monitoring, indoor-outdoor sampling, mobile monitoring, and exposure assessment modeling (such as proximity models, interpolation model, air dispersion models, and land-use regression (LUR) models). Among these methods, personal exposure measurement is considered to be the most accurate method of pollutant exposure assessment until now, since it can better quantify observed differences and better reflect exposure among smaller groups of people at ground level. And since the great differences of geographical environment, source distribution, pollution characteristics, economic conditions, and living habits, there is a wide range of differences between indoor, outdoor, and individual air pollution exposure in different regions of China. In general, the indoor particles in most Chinese families comprise infiltrated outdoor particles, particles generated indoors, and a few secondary organic aerosol particles, and in most cases, outdoor particle pollution concentrations are a major contributor to indoor concentrations in China. Furthermore, since the time, energy, and expense are limited, it is difficult to measure the concentration of pollutants for each individual. In recent years, obtaining the concentration of air pollutants by using a variety of exposure assessment models is becoming a main method which could solve the problem of the increasing number of individuals in epidemiology studies.

222Rn studies and mapping in the city of Curitiba - Brazil

International Nuclear Information System (INIS)

Correa, Janine Nicolosi; Fior, Loriane; Paschuk, Sergei A.; Schelin, Hugo R.; Pecequilo, Brigitte R. S.; Paula Melo, Vicente de

2008-01-01

This work describes radon monitoring performed in cooperation between the Laboratory of Ionizing Radiations of the Federal University of Technology - Parana (UTFPR), the Institute of Nuclear and Energetic Researches (IPEN) and the Institute of Radiation Protection and Dosimetry (IRD), from the Brazilian Nuclear Energy Commission (CNEN), during the last two years. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60 cm 2 , was built using ceramic and concrete blocks. This construction was performed within a protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set to 15 days considering previous calibration performed at IRD, where a efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of the alpha tracks was achieved by electrochemical etching. The track identification and counting were done using a code based on the MATLAB Image Processing Toolbox. The cell chambers were built following four main steps: 1) assembling the walls using the blocks and mortar; 2) plaster installation; 3) wall surface finishing using lime; 4) wall surface insulation by paint. By comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it was concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by a factor of approximately 2.5. The construction materials were submitted to the instant measurements of radon concentration using a ALPHA GUARD Professional detector. The samples of the construction materials were stored inside an acrylic container (sealed up

The influence of the nature of soil and plant and pollution on the 238U, 232Th, 222Rn and 220Rn concentrations in various natural honey samples using nuclear track detectors: impact on the adult consumers

International Nuclear Information System (INIS)

Misdaq, M.A.; Mortassim, A.

2009-01-01

238 U and 232 Th concentrations as well as 222 Rn and 220 Rn α-activities per unit volume were measured in various natural honey samples collected from different regions in Morocco using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). These radionuclides were also measured in soils, plant flowers and nectar solutions corresponding to the honey samples studied. In addition, these radionuclides were measured in different imported honey samples. The measured 238 U, 232 Th, 222 Rn and 220 Rn concentrations ranged from (1.5 ± 0.1) mBq kg -1 to (10.6 ± 0.6) mBq kg -1 , (1.1 ± 0.1) mBq kg -1 to (4.2 ± 0.2) mBq kg -1 , (1.5 ± 0.1) Bq kg -1 to (10.6 ± 0.6) Bq kg -1 and (1.1 ± 0.1) Bq kg -1 to (4.2 ± 0.2) Bq kg -1 for the honey samples studied, respectively. Annual 238 U, 232 Th and 222 Rn intakes by Moroccan adults from the consumption of honey were assessed. The influence of the nature of soil and plant on the 238 U and 232 Th contents of the studied honey samples was investigated. These measurements were completed by an investigation of the 238 U and 232 Th transfer between soils and plant flowers and that between plant flowers and honey, and also by the investigation of the influence of pollution due to different material dusts on 238 U, 232 Th and 222 Rn in the honey samples studied. Committed equivalent doses due to the annual intake of 238 U, 232 Th and 222 Rn were evaluated in the organs of adult members of the Moroccan rural population from the ingestion of the honey samples. The maximum total committed effective dose due to 238 U, 232 Th and 222 Rn from the ingestion of natural honey by the Moroccan rural population was found to be equal to 0.64 μSνy -1 . (author)

Use of 222Rn-resistant techniques in new home construction

International Nuclear Information System (INIS)

Watson, J.E. Jr.; Cote, R.A.

1999-01-01

The objective of this project was to assess the status of the use of 222 Rn-resistant construction techniques in new home construction in the eight Zone 1 counties of North Carolina. Zone 1 counties have an average predicted indoor 222 Rn screening potential greater than 148 Bq m -3 (4 pCi L -1 ). To facilitate a response from builders, a brief survey form was designed and printed on the back of a self-addressed, postage-paid postcard. This survey form was mailed to 460 home builders in the Zone 1 counties. The response rate was 17%, which can be compared to the 4.9% response rate obtained in a national survey conducted by the National Association of Home Builders Research Center. In their survey, 62% of the responding builders reported that they had built some or many homes in 1996 using construction techniques to reduce the entry of radon into homes, but only 10% of the builders reported using these techniques for many homes. The National Association of Home Builders survey determined that, nationally, 30% of homes built in Zone 1 counties had 222 Rn venting features. There is the potential for bias in the results of their survey (as well as in the results of the National Association of Home Builders survey) since the response rates were low

Relationship between 222Rn concentration in soil water and degree of saturation

International Nuclear Information System (INIS)

Hamada, Hiromasa; Komae, Takami

1996-01-01

The object of the researches an analyzing downward flow to groundwater using 222 Rn concentration in water as an indicator has been saturated flow. However, when groundwater table is low, downward flow from surface is unsaturated flow. In this paper, the authors represented the relationship between 222 Rn concentration in soil water and degree of saturation, and measured the vertical distributions of 222 Rn concentrations in groundwater and 222 Rn concentration in water table in the fields. As the results, it was found that 222 Rn concentrations in the vicinity of groundwater table decreased by unsaturated downward flow. Moreover, from the variation of 222 Rn concentrations in groundwater table, it was possible to show the occurrence of the unsaturated downward flow by paddy fields irrigation, i.e., the downward flow of the soil water pushed out by irrigation water, the unsaturated percolation in the irrigation period, and the redistribution of the soil water after the release of ponding water. The degree of saturation in downward flow was calculated to be about 50% from 222 Rn concentrations in the irrigation period and in the non-irrigation period. It was deduced that the value was within reasonable range considering the difference of the hydraulic conductivities between of the upper layer and of the lower layer. These results proved that the relationship between 222 Rn concentrations in soil water and degree of saturation represented by the authors was reasonable and that the analytical method using 222 Rn concentrations in groundwater table as an indicator was useful 10 analyze the actual stale of unsaturated downward flow. (author)

Regularity of random attractors for fractional stochastic reaction-diffusion equations on Rn

Science.gov (United States)

Gu, Anhui; Li, Dingshi; Wang, Bixiang; Yang, Han

2018-06-01

We investigate the regularity of random attractors for the non-autonomous non-local fractional stochastic reaction-diffusion equations in Hs (Rn) with s ∈ (0 , 1). We prove the existence and uniqueness of the tempered random attractor that is compact in Hs (Rn) and attracts all tempered random subsets of L2 (Rn) with respect to the norm of Hs (Rn). The main difficulty is to show the pullback asymptotic compactness of solutions in Hs (Rn) due to the noncompactness of Sobolev embeddings on unbounded domains and the almost sure nondifferentiability of the sample paths of the Wiener process. We establish such compactness by the ideas of uniform tail-estimates and the spectral decomposition of solutions in bounded domains.

Use of 222Rn for estimation of greenhouse gases emissions at Russian territory

Science.gov (United States)

Berezina, E. V.; Elansky, N. F.

2009-04-01

It is well known that 222Rn is widely used as a tracer for studying different atmospheric processes including estimations of greenhouse gases emissions. Calculation of 222Rn fluxes from the soil into the atmosphere allows quantitative estimation of greenhouse gases emissions having the soil origin or sources of which are located near the surface. For accurate estimation of 222Rn fluxes detailed investigations of spatial and temporal variations of its concentrations are necessary. 222Rn concentrations data in the atmospheric surface layer over continental Russia from Moscow to Vladivostok obtained during the six TROICA (Transcontinental Observations Into the Chemistry of the Atmosphere) expeditions of the mobile laboratory along the Trans-Siberian railroad are analyzed. Spatial distribution, diurnal and seasonal variations of surface 222Rn concentrations along the Trans-Siberian railroad are investigated. According to the obtained data surface 222Rn concentration values above continental Russia vary from 0.5 to 75 Bq/m3 depending on meteorological conditions and geological features of the territory with the average value being 8.42 ± 0.10 Bq/m3. The average 222Rn concentration is maximum in the autumn expedition and minimum in the spring one. The factors mostly influencing 222Rn concentration variations are studied: surface temperature inversions, geological features of the territory, precipitations. 222Rn accumulation features in the atmospheric surface layer during night temperature inversions are analyzed. It was noted that during night temperature inversions the surface 222Rn concentration is 7 - 8 times more than the one during the nights without temperature inversions. Since atmospheric stratification determines accumulation and diurnal variations of many atmospheric pollutants as well as greenhouse gases its features are analyzed in detail. Surface temperature inversions were mainly observed from 18:00-19:00 to 06:00-07:00 in the warm season and from 16

Intercomparison of Rn-222 determination from groundwater

DEFF Research Database (Denmark)

Vesterbacka, P.; Pettersson, H.; Hanste, U.-M.

2010-01-01

An intercomparison exercise on Rn-222 determination in groundwater was organized between eight Nordic laboratories. The individual laboratory results were in most cases within 20% of the median value and within reported uncertainties. Considering the particular difficulties in preparing, transpor......An intercomparison exercise on Rn-222 determination in groundwater was organized between eight Nordic laboratories. The individual laboratory results were in most cases within 20% of the median value and within reported uncertainties. Considering the particular difficulties in preparing...

Professional Values of RN-to-BSN Students in an Online Program.

Science.gov (United States)

Koomey, Cynthia L; Osteen, Kathryn; Gray, Jennifer

2015-01-01

Professional values are an important component of nursing education. This cross-sectional study assessed the professional values of 222 students in an online RN-to-BSN program. Higher scores were related to items reflecting direct patient care and accountability for nursing practice. Items focusing on nursing theory, cost of care, and professional nursing organization revealed lower scores.

Study on a charcoal-based monitor for Rn-220 in air

International Nuclear Information System (INIS)

Yu Yiqiao; Solomon, S.B.

1993-01-01

Activated charcoal has been used in both passive monitors (Cohen, Pondy et al. 1987) and active monitors (Solomon and Gan, 1989) for the measurements of 222 Rn in air. Cooled, charcoal-impregnated filters, viewed in-situ by a solid state alpha detector, have been used for 220 Rn-in-breath studies. In general, γ ray counting of 220 Rn samples collected on activated charcoal has not been used. This paper describes the development and calibration of a charcoal based monitor designed to measure 220 Rn levels down to a lower limit of 10 Bq m -3 over sampling periods of 4 to 15 h. The activity of 212 Pb (10.6 h) produced from 220 Rn (55.6 s) collected in an activated charcoal-based sampler is 1/700 the total 220 Rn activity. A typical Hp-Ge detector has a MDL for a two-hours count of approximately 0.1 Bq of 212 Pb for the 239 keV γ-ray. For a MDL of 10 Bq·m -3 of 220 Rn in air, a volume of at least 7 m 3 must be sampled, assuming no breakthrough. The present charcoal-based 220 Rn monitor is designed to maximize the path length through the activated charcoal while sufficient cross-sectional area is retained to allow flow rates up to 0.03 m 3 ·kg -1 is packed into a specially designed aluminum container. The container is modeled on a Marinelli beaker to maximize the counting efficiency, while the sample flow through the chambers of the monitor is optimized to maintain radial symmetry. experiments demonstrated that 94% of 220 Rn was adsorbed by the charcoal in the monitor under a flow rate of 0.03 m 3 ·min -1 at 25 degree C and 85%. RH in 15 h. The monitor is designed to fit over a 70 mm diameter Hp-Ge detector. Preliminary measurements of 220 Rn in two buildings and a cave, using the active monitors and 'grabing' samples under a flow rate of 0.03 m 3 ·min -1 and a period of 4 h, indicated concentrations of between 18.6 and 142.0 Bq·m 3

Internal exposure from building materials exhaling (222)Rn and (220)Rn as compared to external exposure due to their natural radioactivity content.

Science.gov (United States)

Ujić, Predrag; Celiković, Igor; Kandić, Aleksandar; Vukanac, Ivana; Durasević, Mirjana; Dragosavac, Dusan; Zunić, Zora S

2010-01-01

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of (226)Ra, (232)Th and (40)K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.

Integrative genomic analysis of interleukin-36RN and its prognostic value in cancer.

Science.gov (United States)

Lv, Zhilei; Fan, Jinshuo; Zhang, Xiuxiu; Huang, Qi; Han, Jieli; Wu, Feng; Hu, Guorong; Guo, Mengfei; Jin, Yang

2016-02-01

Interleukin (IL)-36RN, previously known as IL1-F5 and IL-1δ, shares a 360-kb region of chromosome 2q13 with members of IL-1 systems. IL-36RN encodes an anti-inflammatory cytokine, IL-36 receptor antagonist (IL-36Ra). In spite of IL-36Ra showing the highest homology to IL-1 receptor (IL-1R) antagonist, it differs from the latter in aspects including its binding to IL-lRrp2 but not to IL-1R1. IL-36RN is mainly expressed in epithelial cells and has important roles in inflammatory diseases. In the present study, IL-36RN was identified in the genomes of 27 species, including human, chimpanzee, mouse, horse and dolphin. Human IL-36RN was mainly expressed in the eye, head and neck, fetal heart, lung, testis, cervix and placenta; furthermore, it was highly expressed in bladder and parathyroid tumors. Furthermore, a total of 30 single nucleotide polymorphisms causing missense mutations were determined, which are considered to be the causes of various diseases, such as generalized pustular psoriasis. In addition, the link between IL-36RN and the prognosis of certain cancer types was revealed through meta-analysis. Tumor-associated transcriptional factors c-Fos, activator protein-1, c-Jun and nuclear factor κB were found to bind to the upstream region in the IL-36RN gene. This may indicate that IL-36RN is involved in tumorigenesis and tumor progression through the regulation of tumor-associated transcriptional factors. The present study identified IL-36RN in various species and investigated the associations between IL-36RN and cancer prognosis, which would determine whether IL-36RN drove the evolution of the various species with regard to tumorigenesis.

Occupational exposure assessment and radiation dose estimation of vegetable-plant farmers to 222Rn in greenhouses of Shouguang county, China

International Nuclear Information System (INIS)

Wanwei Li; Weifang Medical University, Weifang, Shandong; Xiaohong Li; Fei Wang; Yongyong Xu

2016-01-01

This study aims to: assess exposure levels of radon and explore seasonal variations of radon concentrations in greenhouses in Shouguang county. Estimate annual radon radiation dose level for vegetable-plant farmers working in greenhouses. During detection period, the annual mean radon concentration was approximately 286 Bq m -3 . The annual radon radiation dose of farmers is 3.3 mSv a -1 . Both obvious seasonal variations in average radon concentrations and radon radiation dose in greenhouses are observed. Both levels are much higher in winter and spring than in summer and autumn. (author)

Absolute measurement of the activity of 222Rn using a proportional counter

International Nuclear Information System (INIS)

Busch, Ingo; Greupner, Heinz; Keyser, Uwe

2002-01-01

A measuring set-up comprising a proportional counter of calculable 222 Rn efficiency and quantifiable active volume (δ V 222 Rn efficiency is determined by computer simulation of the measured α-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222 Rn is obtained, which is independent of the unit of activity of 226 Ra

An Exposure Assessment of Polybrominated Diphenyl Ethers ...

Science.gov (United States)

EPA announced the availability of the final report, An Exposure Assessment of Polybrominated Diphenyl Ethers. This report provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure. This final report addresses the exposure assessment needs identified in the OPBDE Workgroup project plan. It provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure.

Spectroscopy of 211Rn approaching the valence limit

International Nuclear Information System (INIS)

Davidson, P.M.; Dracoulis, G.D.; Byrne, A.P.; Kibedi, T.; Fabricus, B.; Baxter, A.M.; Stuchbery, A.E.; Poletti, A.R.; Schiffer, K.J.

1993-01-01

High-spin states in 211 Rn were populated using the reaction 198 Pt( 18 O, 5n) at 96 MeV. Their decay was studied using γ-ray and electron spectroscopy. The known level scheme is extended up to a spin of greater than 69/2 and many non-yrast states are added. Semi-empirical shell-model calculations and the properties of related states in 210 Rn and 212 Rn are used to assign configurations to some of the non-yrast states. The properties of the high-spin states observed are compared to the predictions of the multi-particle octupole-coupling model and the semi-empirical shell model. The maximum reasonable spin available from the valence particles and holes in 77/2 and states are observed to near this limit. (orig.)

Ole Bjørn Kraft 1893-1980

DEFF Research Database (Denmark)

Skov, Christian Houlberg

2010-01-01

Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister.......Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister....

Development of an aerosol chamber for calibration of 220Rn progeny detectors

Science.gov (United States)

Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji

2014-09-01

This paper describes an aerosol chamber system that can be used for calibrations and performance experiments of passive 220Rn progeny detectors. For the purpose of this study, an aerosol generation system using carnauba wax as the aerosol material was mounted into the 220Rn chamber. We used the chamber to measure characteristics of the equilibrium factor (F) of 220Rn and unattached fraction (fp) of 220Rn progeny, which are important parameters for dose estimation. The first experiment showed that continuous and stable generation of the unattached and aerosol-attached 220Rn progeny concentrations was obtained. We observed that the spatial distributions in the chamber of the vertical profiles of the unattached and aerosol-attached 220Rn progeny concentrations were homogeneous, as were the particle number concentration and count median diameter. The values of F and fp and their characteristics observed in this study were in the same range as the values reported from indoor measurements. We found that the characteristics of F and fp were dependent on the aerosol conditions (particle diameter and particle number concentration).

222Rn and 220Rn concentrations measured in various natural honey samples by using nuclear track detectors and resulting radiation doses to the members of the rural populations in Morocco

International Nuclear Information System (INIS)

Misdaq, M. A.; Mortassim, A.

2008-01-01

Radon ( 222 Rn) and thoron ( 220 Rn) concentrations were measured in sixteen natural honey material samples collected from different regions in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The concentrations of these radionuclides were also measured in nectar solutions corresponding to the studied honey samples. The measured concentrations of 222 Rn and 220 Rn in honey samples ranged from (2.3 ± 0.2) to (8.1 ± 0.6) Bq.l -1 and (1.8 ± 0.1) to (3.9 ± 0.3) Bq.l -1 , respectively. Committed equivalent doses due to annual intakes of 222 Rn were evaluated in the human gastrointestinal tract compartments of adult members of the Moroccan populations from the ingestion of studied honey samples. The influence of the target tissue mass and activities due to 222 Rn on the annual committed equivalent doses in the compartments of the human gastrointestinal tract was investigated. (authors)

Factors affecting radon removal from Rn-222 enriched water

International Nuclear Information System (INIS)

Abulfaraj, W.H.; Mamoon, A.

1994-01-01

Continued use of potable well water that has elevated levels of Rn-222 is harmful to human health. activated carbon, aeration and heating can remove radon from treated water. Water artificially enriched with Rn-222 using a pitchblende source was studied in a laboratory scale model under controlled conditions. (author), 3 figs., 3 refs

A micromegas detector for {sup 222}Rn emanations measurements

Energy Technology Data Exchange (ETDEWEB)

García, J. A.; Garza, J. G.; Irastorza, I. G.; Mirallas, H. [Laboratorio de Física Nuclear y Altas Energías, Universidad de Zaragoza, Zaragoza (Spain)

2013-08-08

The {sup 222}Rn emanation has significant contribution in the overall background for rare event searches experiments. In order to measure this emanations a high sensitivity detector has been designed. The detection method is based on the electrostatic collection of the {sup 222}Rn daughters on a Micromegas detector. Using a chamber with a volume of 21.2 l for the collection of {sup 218}Po and {sup 214}Po progeny of {sup 222}Rn and a 12 × 12cm{sup 2} pixelized Micromegas for the α detection. The advantages of the Micromegas detectors are the low intrinsic radioactivity and the track reconstruction of the α’s, having excellent capabilities for event discrimination.

Til julefrokost med Bjørn & Okay

DEFF Research Database (Denmark)

Smith-Sivertsen, Henrik

2012-01-01

I denne artikel vises med udgangspunkt i en beskrivelse af et specifikt arrangement med det danske danseorkester Bjørn & Okay, hvordan man optræder inden for denne særlige musiktradition. Bjørn & Okays performative udgangspunkt er, at de, trods en status som landskendt orkester med mange hits, i ...... the audience and constantly telling them what to do. At the same time he and the other musicians actively bond with the audience, both onstage and offstage, which helps building the spirit of community, which is the clear goal of the musical performance....

Rn 222 in the Black Sea waters

International Nuclear Information System (INIS)

Arbuzova, A.P.; Batrakov, G.F.; Eremeev, V.N.; Zemlyanoj, A.D.; Ivanova, T.M.

1988-01-01

Results of Rn 222 concentration measurements in the Black Sea waters obtained in the summer of 1986 during the expedition of the Akademik Vernadskij research ship are presented. It is ascertained that the intensity of vertical turbulent exchange produces the main effect on Rn 222 distribution in the sea surface waters. The vertical distribution in a 200 m layer is characterized by the growth of concentration with depth, which is caused by the presence of Ra 226 increased concentration region, that coincides with the boundary layer between oxygen and hydrogen sulfide

Spectroscopy of 211Rn approaching the valence limit

International Nuclear Information System (INIS)

Davidson, P.M.; Dracoulis, G.D.; Kibedi, T.; Fabricius, B.; Baxter, A.M.; Stuchbery, A.E.; Poletti, A.R.; Schiffer, K.J.

1993-02-01

High spin states in 211 Rn were populated using the reaction 198 Pt( 18 O,5n) at 96 MeV. The decay was studied using γ-ray and electron spectroscopy. The known level scheme is extended up to a spin of greater than 69/2 and many non-yrast states are added. Semi-empirical shell model calculations and the properties of related states in 210 Rn and 212 Rn are used to assign configurations to some of the non-yrast states. The properties of the high spin states observed are compared to the predictions of the Multi-Particle Octupole Coupling model and the semi-empirical shell model. The maximum reasonable spin available from the valence particles and holes is 77/2 and states are observed to near this limit. 12 refs., 4 tabs., 8 figs

Development of an integrated sampler based on direct 222Rn/220Rn progeny sensors in flow-mode for estimating unattached/attached progeny concentration

International Nuclear Information System (INIS)

Mishra, Rosaline; Sapra, B.K.; Mayya, Y.S.

2009-01-01

A flow-mode integrated sampler consisting of a wire-mesh and filter-paper array along with passive solid state nuclear track detectors has been developed for estimating unattached and attached fraction of 222 Rn/ 220 Rn progeny concentration. The essential element of this sampler is the direct 222 Rn/ 220 Rn progeny sensor (DRPS/DTPS), which is an absorber-mounted-LR115 type nuclear track detector that selectively registers the alpha particles emitted from the progeny deposited on its surface. During sampling at a specified flow-rate, the unattached progeny is captured on the wire-mesh; while the attached progeny gets transmitted and is captured on the filter-paper. The alpha particles emitted by the deposited progeny atoms are registered on the sensors placed at a specified distance facing the wire-mesh and the filter-paper, respectively. The various steps involved in the development of this flow-mode direct progeny sampler such as the optimization of the sampling rate and the distance between the sensor and the deposition substrate are discussed. The sensitivity factor of the DTPS-loaded sampler for 220 Rn progeny deposited on the wire-mesh and filter-paper is found to be 23.77 ± 0.64 (track cm -2 h -1 ) (Bq m -3 ) -1 and 22.30 ± 0.18 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively; while that of DRPS-loaded sampler for 222 Rn progeny deposition, is 3.03 ± 0.14 (track cm -2 h -1 ) (Bq m -3 ) -1 and 2.08 ± 0.07 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively. The highlight of this flow-mode sampler is its high sensitivity and that it utilizes the passive technique for estimating the unattached and attached progeny concentration, thus doing away with the alpha counting procedures.

From Vulnerability to Dignity: The RN Declaration of Self-Esteem.

Science.gov (United States)

Janzen, Katherine J; Mitchell, Maureen; Renton, Lesley J; Currie, Genevieve; Nordstrom, Pamela M

2015-11-04

Registered nurses (RNs) experience vulnerability from a variety of sources in today's healthcare organizations. While RN vulnerability can be associated with positive outcomes with patients and clients, vulnerability can also be dangerous to RNs as they struggle with outside forces that many feel they have no control over. The study aims to maintain and enhance the dignity of RNs and provide a beacon to RNs who may have become wounded in the healthcare setting and/or their own profession. The study was conducted in a conference entitled "Advancing Nursing Practice Through Change, Innovation and Creativity" held at a midsized university in western Canada. The participants were 115 administrators, members of RN regulatory bodies, nursing faculty, nurse educators, and staff nurses. An activity entitled "Wild Thinking" gave participants an opportunity to reflect upon the conference and their personal experiences of change, innovation, and creativity they wished to see within the workplace. All responses were collected at the end of the activity, transcribed verbatim, and analyzed for themes. Arising from 16 themes, the RN Declaration of Self-Esteem was created. The RN Declaration of Self-Esteem may be helpful in promoting empowerment at the individual RN level as well as in the collective professional level. © 2015 Wiley Periodicals, Inc.

Factors controlling temporal variability of near-ground atmospheric 222Rn concentration over central Europe

Science.gov (United States)

Zimnoch, M.; Wach, P.; Chmura, L.; Gorczyca, Z.; Rozanski, K.; Godlowska, J.; Mazur, J.; Kozak, K.; Jeričević, A.

2014-09-01

Concentration of radon (222Rn) in the near-ground atmosphere has been measured quasi-continuously from January 2005 to December 2009 at two continental sites in Europe: Heidelberg (south-west Germany) and Krakow (southern Poland). The atmosphere was sampled at ca. 30 and 20 m above the local ground. Both stations were equipped with identical instruments. Regular observations of 222Rn were supplemented by measurements of surface fluxes of this gas in the Krakow urban area, using two different approaches. The measured concentrations of 222Rn varied at both sites in a wide range, from less than 2.0 Bq m-3 to approximately 40 Bq m-3 in Krakow and 35 Bq m-3 in Heidelberg. The mean 222Rn content in Krakow, when averaged over the entire observation period, was 30% higher than in Heidelberg (5.86 ± 0.09 and 4.50 ± 0.07 Bq m-3, respectively). Distinct seasonality of 222Rn signal is visible in the obtained time series of 222Rn concentration, with higher values recorded generally during late summer and autumn. The surface 222Rn fluxes measured in Krakow also revealed a distinct seasonality, with broad maximum observed during summer and early autumn and minimum during the winter. When averaged over a 5-year observation period, the night-time surface 222Rn flux was equal to 46.8 ± 2.4 Bq m-2 h-1. Although the atmospheric 222Rn levels at Heidelberg and Krakow appeared to be controlled primarily by local factors, it was possible to evaluate the "continental effect" in atmospheric 222Rn content between both sites, related to gradual build-up of 222Rn concentration in the air masses travelling between Heidelberg and Krakow. The mean value of this build-up was equal to 0.78 ± 0.12 Bq m-3. The measured minimum 222Rn concentrations at both sites and the difference between them was interpreted in the framework of a simple box model coupled with HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) analysis of air mass trajectories. The best fit of experimental data was

Exploring Global Exposure Factors Resources for Use in Consumer Exposure Assessments

Science.gov (United States)

Zaleski, Rosemary T.; Egeghy, Peter P.; Hakkinen, Pertti J.

2016-01-01

This publication serves as a global comprehensive resource for readers seeking exposure factor data and information relevant to consumer exposure assessment. It describes the types of information that may be found in various official surveys and online and published resources. The relevant exposure factors cover a broad range, including general exposure factor data found in published compendia and databases and resources about specific exposure factors, such as human activity patterns and housing information. Also included are resources on exposure factors related to specific types of consumer products and the associated patterns of use, such as for a type of personal care product or a type of children’s toy. Further, a section on using exposure factors for designing representative exposure scenarios is included, along with a look into the future for databases and other exposure science developments relevant for consumer exposure assessment. PMID:27455300

Asbestos Exposure Assessment Database

Science.gov (United States)

Arcot, Divya K.

2010-01-01

Exposure to particular hazardous materials in a work environment is dangerous to the employees who work directly with or around the materials as well as those who come in contact with them indirectly. In order to maintain a national standard for safe working environments and protect worker health, the Occupational Safety and Health Administration (OSHA) has set forth numerous precautionary regulations. NASA has been proactive in adhering to these regulations by implementing standards which are often stricter than regulation limits and administering frequent health risk assessments. The primary objective of this project is to create the infrastructure for an Asbestos Exposure Assessment Database specific to NASA Johnson Space Center (JSC) which will compile all of the exposure assessment data into a well-organized, navigable format. The data includes Sample Types, Samples Durations, Crafts of those from whom samples were collected, Job Performance Requirements (JPR) numbers, Phased Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) results and qualifiers, Personal Protective Equipment (PPE), and names of industrial hygienists who performed the monitoring. This database will allow NASA to provide OSHA with specific information demonstrating that JSC s work procedures are protective enough to minimize the risk of future disease from the exposures. The data has been collected by the NASA contractors Computer Sciences Corporation (CSC) and Wyle Laboratories. The personal exposure samples were collected from devices worn by laborers working at JSC and by building occupants located in asbestos-containing buildings.

Rn-222 release to the environment: comparison between different granite sources

International Nuclear Information System (INIS)

Mamoon, M.; Kamal, S.M.

2005-01-01

In this work three different types of granites were studied, namely: pure granite, alkali granite and altered (hydrated) alkali granite. General radioactivity of the granites was studied along with the potential for 222 Rn emanation. The study indicated that altered alkali granite releases, relatively, the highest 222 Rn emanation to the surrounding air while alkali granite emits the more intense gamma radiation of the three granites. Hence, altered alkali granite can be used as a laboratory source for 222 Rn.

Assessment pozzolanicity waste red ceramics produced in Valley Assu / RN

International Nuclear Information System (INIS)

Palhares, Rodolfo de Azevedo; Pereira, Arthur Ruan da Silva; Cabral, Kleber Cavalcanti; Nobrega, Andreza Kelly Costa

2016-01-01

It is known that both the cement industry as a ceramist contribute much to the generation of environmental impacts. Be the Co2 in the atmosphere, as well as the generation of excessive waste, reaching 20%. The objective of this study is to analyze the potential pozollanic of waste from the red ceramic industries Valley Assu / RN, in order that this material can be incorporated as alternative raw material in the manufacture of ecological and similar brick, replacing partially in its composition Portland cement. Thus contributing to reducing the environmental impact produced by both the ceramics industry, such as cement. To evaluate the efficiency of pozollanic material, it was made sample preparation and then the physico-chemical characterization. After performing tests, it was noticed that the material has the minimum requirements established in standard to be considered as pozollanic material. (author)

Reducing RN Vacancy Rate: A Nursing Recruitment Office Process Improvement Project.

Science.gov (United States)

Hisgen, Stephanie A; Page, Nancy E; Thornlow, Deirdre K; Merwin, Elizabeth I

2018-06-01

The aim of this study was to reduce the RN vacancy rate at an academic medical center by improving the hiring process in the Nursing Recruitment Office. Inability to fill RN positions can lead to higher vacancy rates and negatively impact staff and patient satisfaction, quality outcomes, and the organization's bottom line. The Model for Improvement was used to design and implement a process improvement project to improve the hiring process from time of interview through the position being filled. Number of days to interview and check references decreased significantly, but no change in overall time to hire and time to fill positions was noted. RN vacancy rate also decreased significantly. Nurse manager satisfaction with the hiring process increased significantly. Redesigning the recruitment process supported operational efficiencies of the organization related to RN recruitment.

Børn på YouTube – nydelse og nørderi

DEFF Research Database (Denmark)

Johansen, Stine Liv

2017-01-01

Mange børn og unge bruger dagligt adskillige timer på videodelingsplatformen YouTube. Her kan de dyrke deres individuelle interesser, deres ’guilty pleasures’ og følge med i youtuberes dagligliv. For mange børn og unge er muligheden for selv at producere indhold ligeledes en relevant del af...... attraktionen ved YouTube. På baggrund af en igangværende, kvalitativ undersøgelse præsenteres i denne artikel en række relevante perspektiver ved børn og unges brug af YouTube. Et væsentligt aspekt er, at voksne sjældent involverer sig i børn og unges brug af YouTube. Men hvis man ønsker at tage aktivt del...... børn og unges (digitale) dannelsesprocesser kan det godt betale sig at holde øje med, hvad de laver på YouTube – og forsøge at forstå, hvad de får ud af det....

Exposure Assessment Tools by Chemical Classes - Nanomaterials

Science.gov (United States)

EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

Exposure Assessment Tools by Tiers and Types - Deterministic and Probabilistic Assessments

Science.gov (United States)

EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

Determinants of Dermal Exposure Relevant for Exposure Modelling in Regulatory Risk Assessment

NARCIS (Netherlands)

Marquart, J.; Brouwer, D.H.; Gijsbers, J.H.J.; Links, I.H.M.; Warren, N.; Hemmen, J.J. van

2003-01-01

Risk assessment of chemicals requires assessment of the exposure levels of workers. In the absence of adequate specific measured data, models are often used to estimate exposure levels. For dermal exposure only a few models exist, which are not validated externally. In the scope of a large European

Comparative Probabilistic Assessment of Occupational Pesticide Exposures Based on Regulatory Assessments

Science.gov (United States)

Pouzou, Jane G.; Cullen, Alison C.; Yost, Michael G.; Kissel, John C.; Fenske, Richard A.

2018-01-01

Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions, including more vulnerable or sensitive subgroups. Incorporation of these analyses into current regulatory methods for occupational pesticide exposure is enabled by the exposure data sets and associated data currently used in the risk assessment approach of the Environmental Protection Agency (EPA). Monte Carlo simulations were performed on exposure measurements from the Agricultural Handler Exposure Database and the Pesticide Handler Exposure Database along with data from the Exposure Factors Handbook and other sources to calculate exposure rates for three different neurotoxic compounds (azinphos methyl, acetamiprid, emamectin benzoate) across four pesticide-handling scenarios. Probabilistic estimates of doses were compared with the no observable effect levels used in the EPA occupational risk assessments. Some percentage of workers were predicted to exceed the level of concern for all three compounds: 54% for azinphos methyl, 5% for acetamiprid, and 20% for emamectin benzoate. This finding has implications for pesticide risk assessment and offers an alternative procedure that may be more protective of those at the extremes of exposure than the current approach. PMID:29105804

Comparative Probabilistic Assessment of Occupational Pesticide Exposures Based on Regulatory Assessments.

Science.gov (United States)

Pouzou, Jane G; Cullen, Alison C; Yost, Michael G; Kissel, John C; Fenske, Richard A

2017-11-06

Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions, including more vulnerable or sensitive subgroups. Incorporation of these analyses into current regulatory methods for occupational pesticide exposure is enabled by the exposure data sets and associated data currently used in the risk assessment approach of the Environmental Protection Agency (EPA). Monte Carlo simulations were performed on exposure measurements from the Agricultural Handler Exposure Database and the Pesticide Handler Exposure Database along with data from the Exposure Factors Handbook and other sources to calculate exposure rates for three different neurotoxic compounds (azinphos methyl, acetamiprid, emamectin benzoate) across four pesticide-handling scenarios. Probabilistic estimates of doses were compared with the no observable effect levels used in the EPA occupational risk assessments. Some percentage of workers were predicted to exceed the level of concern for all three compounds: 54% for azinphos methyl, 5% for acetamiprid, and 20% for emamectin benzoate. This finding has implications for pesticide risk assessment and offers an alternative procedure that may be more protective of those at the extremes of exposure than the current approach. © 2017 Society for Risk Analysis.

Matérn-based nonstationary cross-covariance models for global processes

KAUST Repository

Jun, Mikyoung

2014-01-01

-covariance models, based on the Matérn covariance model class, that are suitable for describing prominent nonstationary characteristics of the global processes. In particular, we seek nonstationary versions of Matérn covariance models whose smoothness parameters

Perfect simulation and moment properties for the Matérn type III process

DEFF Research Database (Denmark)

Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

2010-01-01

In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the m......In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound...

Assessment of natural radiation exposure and radon exhalation rates from the soil of Islamabad District of Pakistan

International Nuclear Information System (INIS)

Mujahid, S.A.

2007-01-01

Complete text of publication follows. The earth's crust is a main source of natural radionuclides in soils and rocks. The specific levels of background gamma radiation depend upon the geological composition of each lithologically separated area, and the content of the rock from which the soils originate the radioactive elements of 226Rn, 232Th and 40K. These naturally occurring radionuclides of terrestrial origin in soil can be a source of external radiation exposure through the gamma ray emission whereas internal exposure occurs through the inhalation of radon gas. The measurements of natural radioactivity and the assessment of radiological hazards in the soil samples of Islamabad district of Pakistan have been carried out using High Purity Germanium (HPGe) detector. The radon exhalation rates from these samples have also been estimated employing the 'closed-can' technique of passive dosimeters. The measured activities of 226Ra, 232Th and 40K were found in the range 14 - 30, 18 - 40 and 301 - 655 Bq.kg-1. The annual effective dose was calculated in the range 0.15 - 0.31 mSv. The values of external and internal hazard indices were less than 1. The radon exhalation rates these areas were found in the range 200 - 345 mBq.m-2h-1.

Challenges and Perspectives of Nanoparticle Exposure Assessment

OpenAIRE

Lee, Ji Hyun; Moon, Min Chaul; Lee, Joon Yeob; Yu, Il Je

2010-01-01

Nanoparticle exposure assessment presents a unique challenge in the field of occupational and environmental health. With the commercialization of nanotechnology, exposure usually starts from the workplace and then spreads to environment and consumer exposure. This report discusses the current trends of nanoparticle exposure assessment, including the definition of nanotechnology relevant terms, essential physicochemical properties for nanomaterial characterization, current international activi...

Design of real-time monitoring and control system of 222Rn/220Rn sampling for radon chamber

International Nuclear Information System (INIS)

Wu Rongyan; Zhao Xiuliang; Zhang Meiqin; Yu Hong

2008-01-01

This paper describes the design of 222 Rn/ 220 Rn sampling monitoring and control system based on single-chip microcomputer of series Intel51. The hardware design involves the choosing and usage of sensors-chips, A/D conversion-chip, USB interface-chip, keyboard-chip, digital display-chip, photoelectric coupling isolation-chips and drive circuit-chips of the direct current pump. Software design is composed by software of Personal Computer (PC) and software of Single Chip Microcomputer (SCM). The data acquisition and conversion and the flux control of direct current pump are realized by using soft of Visual Basic and assemble language. The program flow charts are given. Furthermore, we improved the stability of the direct current pump by means of PID Control Algorithms. (authors)

Assessing population exposures to motor vehicle exhaust.

Science.gov (United States)

Van Atten, Chris; Brauer, Michael; Funk, Tami; Gilbert, Nicolas L; Graham, Lisa; Kaden, Debra; Miller, Paul J; Bracho, Leonora Rojas; Wheeler, Amanda; White, Ronald H

2005-01-01

The need is growing for a better assessment of population exposures to motor vehicle exhaust in proximity to major roads and highways. This need is driven in part by emerging scientific evidence of adverse health effects from such exposures and policy requirements for a more targeted assessment of localized public health impacts related to road expansions and increasing commercial transportation. The momentum for improved methods in measuring local exposures is also growing in the scientific community, as well as for discerning which constituents of the vehicle exhaust mixture may exert greater public health risks for those who are exposed to a disproportionate share of roadway pollution. To help elucidate the current state-of-the-science in exposure assessments along major roadways and to help inform decision makers of research needs and trends, we provide an overview of the emerging policy requirements, along with a conceptual framework for assessing exposure to motor-vehicle exhaust that can help inform policy decisions. The framework includes the pathway from the emission of a single vehicle, traffic emissions from multiple vehicles, atmospheric transformation of emissions and interaction with topographic and meteorologic features, and contact with humans resulting in exposure that can result in adverse health impacts. We describe the individual elements within the conceptual framework for exposure assessment and discuss the strengths and weaknesses of various approaches that have been used to assess public exposures to motor vehicle exhaust.

Eksklusion og inklusion af minoritetsdanske børn i dagtilbud

DEFF Research Database (Denmark)

Tireli, Üzeyir

2014-01-01

Med udgangspunkt i minoritetsdanske børn som case, beskæftiger artiklen sig med inklusions- og eksklusionsprocesserne i dagtilbud. Den diskursive konstruktion af "os" og "dem" synes at være en af hovedårsagerne til eksklusion af disse børn. Forfatteren kommer med bud på og ideer til hvordan disse...

Valence configurations in 214Rn

International Nuclear Information System (INIS)

Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Bark, R.A.; Poletti, A.R.

1987-01-01

Excited states of 214 Rn, up to spins of ≅ 24 ℎ have been studied using γ-ray and electron spectroscopy following the 208 Pb( 9 Be,3n) 214 Rn reaction. The level scheme (which differs substantially from earlier work) is compared with the results of a semi-empirical shell model calculation. The availability of high-spin orbitals for the four valence protons and two valence neutrons, and the effect of the attractive proton-neutron interaction, leads to the prediction of high-spin states at an unusually low excitation energy. Experimentally, the high level density leads to difficulties in the level scheme assignments at high spin. Nevertheless, configuration assignments, supported by transition strengths deduced from the measured lifetimes (in the nanosecond region) are suggested for the main yrast states. The decay properties also suggest that configuration mixing is important. The possibility of a gradual transition to octupole deformation, implied by the decay properties of the 11 - and 10 + yrast states is also discussed. (orig.)

Radon exposure in uranium mining industry vs. exposure in tourist caves

International Nuclear Information System (INIS)

Quindos Poncela, L.; Fernandez Navarro, P.; Sainz Fernandez, C.; Gomez Arozamena, J.; Bordonoba Perez, M.

2004-01-01

There is a fairly general consensus among health physicists and radiation professionals that exposure to radon progeny is the largest and most variable contribution to the population's exposure to natural sources of radiation. However, this exposure is the subject of continuing debate concerning the validity of risk assessment and recommendations on how to act in radon-prone areas. The purpose of this contribution is to situate the radon issue in Spain in two very different settings. The first is a uranium mining industry located in Saelices el Chico (Salamanca), which is under strict control of the Spanish Nuclear Safety Council (CSN). We have measured radon concentrations in different workplaces in this mine over a five-year period. The second setting comprises four tourist caves, three of which are located in the province of Cantabria and the fourth on the Canary Island of Lanzarote. These caves are not subject to any administrative control of radiation exposure. Measured air 222 Rn concentrations were used to estimate annual effective doses due to radon inhalation in the two settings, and dose values were found to be from 2 to 10 times lower in the uranium mine than in the tourist caves. These results were analysed in the context of the new European Basic Safety Standards Directive (EU-BSS, 1996). (authors)

Investigations into the long-distance atmospheric transport in Central Europe using Rn-222

International Nuclear Information System (INIS)

Volpp, H.J.

1984-01-01

An measuring network was used to determine the atmospheric Rn-222 content in Central Europe (Northern and Southern Germany, Poland). Rn-222 is to serve as tracer for the long-distance atmospheric transport in central Europe. For several areas, an average Rn-222 flux density was found. The radon source 'continent' and the soil as radon source have been taken into account. (DG) [de

The activity concentrations of 222Rn and corresponding health risk in groundwater samples from basement and sandstone aquifer; the correlation to physicochemical parameters

International Nuclear Information System (INIS)

Abdurabu, Wedad Ali; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Heryansyah, Arien

2016-01-01

This study aims to evaluate the activity concentrations of 222 Rn and to assess the corresponding health risk in groundwater samples obtained in Juban District, Ad Dali’ Governorate, Yemen. The measurements were performed by RAD 7 radon detector manufactured by DURRIDGE COMPANY Inc. The activity concentrations of 222 Rn ranged from 1.0±0.2 Bq l −1 to 896.0±0.8 Bq l −1 . 57% of the groundwater samples were above the US Environmental Protection Agency (USEPA) recommended value for Rn in water. Induced coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of uranium in groundwater samples. The measured concentration of U ranged from 0.33±0.01 μg l −1 to 24.6±0.6 μg l −1 . The results were comparable to internationally recommended values. The highest concentration of U and 222 Rn were found to be in the basement aquifer, while the lowest concentrations of both radionuclides were in the sandstone aquifer. High concentrations of Rn are found along fault zones. The relationship between the activity concentration of 222 Rn, concentration of U and physicochemical parameters were investigated. The results showed a very strong relationship between activity concentrations of 222 Rn with concentrations of U and the salinity of water. - Highlights: • The highest concentration of U and 222 Rn was found to be in the basement aquifer. • A 57% of the groundwater samples were above the USEPA recommended value. • Mean annual effective dose for ingestion was 24 times the world average. • Mean annual effective dose for inhalation was 23 times the world. • Strong relationship between 222 Rn with concentration of U in the basement aquifer.

Health risk assessment of exposure to ionizing radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu

2011-01-01

Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

Embryo-fetal transfer of bevacizumab (Avastin) in the rat over the course of gestation and the impact of neonatal Fc receptor (FcRn) binding.

Science.gov (United States)

Thorn, Mitchell; Piche-Nicholas, Nicole; Stedman, Donald; Davenport, Scott W; Zhang, Ning; Collinge, Mark; Bowman, Christopher J

2012-10-01

There is concern about embryo-fetal exposure to antibody-based biopharmaceuticals based on the increase of such therapies being prescribed to women of childbearing potential. Therefore, there is a desire to better characterize embryo-fetal exposure of these molecules. The pregnant rat is a standard model for evaluating the potential consequences of exposure but placental transfer of antibody-based biopharmaceuticals is not well understood in this model. The relative embryo-fetal distribution of an antibody-based biopharmaceutical was evaluated in the rat. Bevacizumab (Avastin) was chosen as a tool antibody since it does not have significant target binding in the rat that might influence embryo-fetal biodistribution. Avastin was labeled with a fluorescent dye, characterized, and injected into pregnant rats at different gestation ages. Labeled Avastin in fetal tissues was visualized ex vivo using an IVIS 200 (Caliper, A PerkinElmer Company, Alameda, CA). Avastin localized to the fetus as early as 24-hr post intravenous injection of the dam, and was taken up by the fetus in a dose-dependent manner. Avastin was detectable in the developing embryo as early as gestation day 13 and continued to be transferred until the end of gestation. Fetal transfer of Avastins mutated in the portion of the antibody that binds the neonatal Fc receptor (FcRn) was tested in late gestation and was found to correlate with affinities of the mutant Avastin antibody to FcRn. The novel application of this imaging technology was used to characterize the onset and duration of Avastin maternal-fetal transfer in rats and the importance of FcRn binding. © 2012 Wiley Periodicals, Inc.

Multiplication on Rn -A ...

Indian Academy of Sciences (India)

topology can be used to prove the results in the first article. While the discussion ... {O}) x (JRn \\ {O}) ~ JRn \\ {O} with an element e E ]Rn \\ {O} such that m(e, ... in 1966, using sophisticated methods from topology. To state this ... If G is a finite group then G is a ... (Topology on Sn is of course the induced topology from. JRn+1.) ...

Eighty percent by 2020: the present and future of RN-to-BSN education.

Science.gov (United States)

McEwen, Melanie; Pullis, Bridgette R; White, Mary Joe; Krawtz, Susan

2013-10-01

More than 600 RN-to-BSN programs currently exist in the United States, and the numbers of programs and students are growing rapidly. This unprecedented growth is a result of several factors, including the Institute of Medicine's recommendation that 80% of RNs be BSN prepared by 2020. This survey was undertaken to explore key ideas and issues related to RN-to-BSN education to gather information on how RN-to-BSN programs are changing and to uncover concerns posited by program directors. The survey indicated that lack of standardization has resulted in significant variability in expectations and requirements among RN-to-BSN programs. Further, numerous questions need to be answered and concerns addressed to develop strategies to maintain growth, improve access, and remove barriers without sacrificing quality. Findings can be used to ensure that RN-to-BSN education prepares graduates for the future health care system and that the outcome is not just a piece of paper. Copyright 2013, SLACK Incorporated.

Measurement of Rn-222 concentration in underground water in Osaka stratum group in Sennan area

International Nuclear Information System (INIS)

Fukui, Masami; Katsurayama, Kosuke

1977-01-01

The Rn-222 concentration in underground water is reported as follows, which is the result obtained when the ground inspection was carried out in the Research Reactor Institute of Kyoto University located at Kumatori area in Osaka stratum group. Underground water, at different depth, well water and rain water were taken, and the contained Rn-222 was extracted with toluene to measure by liquid scintillation technique. Rn-222 concentration in rain water was 3.5 - 8.0 pCi/l, while the concentration in well water was 130 - 250 pCi/l, and that in underground water was 240 - 313 pCi/l. The seasonal change, geographical difference and variation according to depth of Rn-222 concentration were examined. Rn-222 behavior in soil should be investigated more in detail in reference to Rn-222 dispersion, transport and equilibrium problems in soil-water system in the future. (Kobatake, H.)

Indsats for forældre til børn med ADHD

DEFF Research Database (Denmark)

Neubert, Katja

2012-01-01

Et nyt review, udarbejdet af forskergruppen omkring Morris Zwi, undersøger om interventionsprogrammer til forældre til børn med ADHD er effektive, når det gælder reducering af børnenes ADHD-relaterede adfærd og associerede problemer som eksempelvis indlæringsproblemer. Reviewet peger på, at en...... indsats til forældre til børn med ADHD kan have en gavnlig effekt på børnenes adfærd. Interventionen kan også være med til at sænke stressniveauet hos forældre til disse børn, og forbedre forældrenes selvtillid....

Optimizing measurement sensitivity to facilitate monitoring environmental levels of Rn-daughter concentrations

International Nuclear Information System (INIS)

Keefe, D.J.; McDowell, W.P.; Groer, P.G.; Witek, R.T.

1977-01-01

In the measurement of environmental levels of radioactivity, the primary problem is the accumulation of a statistically meaningful number of counts within a reasonable period of time. In the case of measurements of airborne 222 Rn-daughter concentrations, the problem is further complicated by the particularly short half-life, 3.05 minutes, of RaA (Po 218 ). Since the Rn-daughters, (RaA, RaB [Pb 214 ] and RaC [Bi 214 ]) are of interest, the equations interrelating these Rn-daughter concentrations were derived from the laws of radioactive-series decay. These equations, although straightforward, are cumbersome to solve. To facilitate the efficient use of these equations, a computer program has been written which permits the calculation of Rn-daughter concentrations or expected counts for a given set of measurement parameters (flow rate and detector efficiencies). A subroutine then calculates the optimum pumping and counting times required to provide the number of counts necessary for acceptable statistics at environmental levels of 222 Rn-daughter concentrations. This subroutine contains a set of parameters, flow rate and efficiencies, that are fixed using realistic restrictions. The use of these optimized pumping and counting times results in maximum measurement sensitivity under realistic constraints

RN students need to tell their stories.

Science.gov (United States)

Blecke, J; Flatt, M M

1993-04-01

Finally, what is it about RN students' experiences in the transition process in nursing education that makes their stories need to be told? Actually this question is asked from both the side of the RN students who are the learners and need to tell the stories, and the side of the educator/advisor who needs to have the stories told. In short, the answer to both is that these stories reveal very graphically and meaningfully what is happening in the learning and professional development processes and, simultaneously, they facilitate the progression of those processes. The RN students seem to have an innate sense about what telling their stories will do for them in relation to their learning and professional development processes. They require very little encouragement to prompt their story telling. For the educators/advisors, no other strategy is as adaptable and achieves as much in relation to facilitating the learning and development processes. For both parties, the graphic revelations in stories paint a picture of how past, present, and future blend together to form a meaningful, coherent view of a position in the world. According to Antonovsky's (1979) work on stress and coping, such a view is necessary if stress is to be resisted and health maintained.(ABSTRACT TRUNCATED AT 400 WORDS)

Opportunities for using spatial property assessment data in air pollution exposure assessments

Directory of Open Access Journals (Sweden)

Keller C Peter

2005-10-01

Full Text Available Abstract Background Many epidemiological studies examining the relationships between adverse health outcomes and exposure to air pollutants use ambient air pollution measurements as a proxy for personal exposure levels. When pollution levels vary at neighbourhood levels, using ambient pollution data from sparsely located fixed monitors may inadequately capture the spatial variation in ambient pollution. A major constraint to moving toward exposure assessments and epidemiological studies of air pollution at a neighbourhood level is the lack of readily available data at appropriate spatial resolutions. Spatial property assessment data are widely available in North America and may provide an opportunity for developing neighbourhood level air pollution exposure assessments. Results This paper provides a detailed description of spatial property assessment data available in the Pacific Northwest of Canada and the United States, and provides examples of potential applications of spatial property assessment data for improving air pollution exposure assessment at the neighbourhood scale, including: (1 creating variables for use in land use regression modelling of neighbourhood levels of ambient air pollution; (2 enhancing wood smoke exposure estimates by mapping fireplace locations; and (3 using data available on individual building characteristics to produce a regional air pollution infiltration model. Conclusion Spatial property assessment data are an extremely detailed data source at a fine spatial resolution, and therefore a source of information that could improve the quality and spatial resolution of current air pollution exposure assessments.

Forskning i musikterapi - børn med en Autisme Spektrum Forstyrrelse

DEFF Research Database (Denmark)

Holck, Ulla

2011-01-01

Der er forskningsmæssig evidens for, at musikterapi med børn med en autisme spektrum forstyrrelse (ASF) har en signifikant effekt. Cochrane reviews påviser, at musikterapi fremmer verbal og navnlig nonverbal kommunikation hos børn med ASF. En RCT-undersøgelse viser endvidere en signifikant effekt...

Natural 222Rn and 220Rn indicate the impact of the Water–Sediment Regulation Scheme (WSRS) on submarine groundwater discharge in the Yellow River estuary, China

International Nuclear Information System (INIS)

Xu, Bochao; Xia, Dong; Burnett, William C.; Dimova, Natasha T.; Wang, Houjie; Zhang, Longjun; Gao, Maosheng; Jiang, Xueyan; Yu, Zhigang

2014-01-01

Highlights: • 220 Rn and 222 Rn were combined to locate intensive SGD sites. • Influence of WSRS to SGD was found for the first time. • SGD was a dominant nutrient pathway in the Yellow River estuary. - Abstract: Submarine groundwater discharge (SGD) in estuaries brings important influences to coastal ecosystems. In this study, we observed significant SGD in the Yellow River estuary, including a fresh component, during the Water–Sediment Regulation Scheme (WSRS) period. We used the 222 Rn and 220 Rn isotope pair to locate sites of significant SGD within the study area. Three apparent SGD locations were found during a non-WSRS period, one of which became much more pronounced, according to the remarkably elevated radon levels, during the WSRS. Increased river discharge (from 245 m 3 s −1 to 3560 m 3 s −1 ) and the elevated river water level (from 11 m to 13 m) during the WSRS led to a higher hydraulic head, enhancing groundwater discharge in the estuary. Our results suggest that high river discharge (>3000 m 3 s −1 ) might be necessary for elevated fresh submarine groundwater discharging (FSGD). Vertical profiles of salinity, DO and turbidity anomalies along the benthic boundary layer also indicated significant FSGD in the estuary during the WSRS. Nutrient concentrations had positive correlations with 222 Rn during a 24-h observation, which indicates that SGD is a dominant nutrient pathway in this area

Results of Long-term Measurement of 222Rn Volume Activity in Soil Air

International Nuclear Information System (INIS)

Holy, K.; Matos, M.; Boem, R.; Stanys, T.; Hola, O.; Polaskova, A.

1999-01-01

Radon in the soil air was continuously monitored for four years. The measured volume activities differ one from another even three times. On the basis of the measured data the annual and average daily courses of the 222 Rn volume activity were studied for individual months. In annual courses the winter and also summer maxima of the 222 Rn volume activity were found out. The study of the average daily courses revealed that the oscillation of the 222 Rn volume activity about its average value during a day is only a few percent. For dry summer months a linear relation was found out between the changes of the 222 Rn volume activity and the changes of the atmospheric pressure in their average daily courses (Authors)

Measurement of 222Rn flux, 222Rn emanation and 226Ra concentration from injection well pipe scale

International Nuclear Information System (INIS)

Rood, A.S.; Kendrick, D.T.

1996-01-01

The presence of Naturally Occurring Radioactive Material (NORM) has been recognized since the early 1930s in petroleum reservoirs and in oil and gas production and processing facilities. NORM was typically observed in barite scale that accumulated on the interior of oil production tubing and in storage tank and heater-treater separation sludge. Recent concern has been expressed over the health impacts from the uncontrolled release of NORM to the public. There are several potential exposure pathways to humans from oil-field NORM. Among these is inhalation of radon gas and its daughter products. For this exposure pathway to be of any significance, radon must first be released from the NORM matrix and diffuse in free air. The radon emanation fraction refers to the fraction of radon atoms produced by the decay of radium, that migrate from the bulk material as free gaseous atoms. The purpose of this investigation was to characterize the radon release rates from NORM-scale contaminated production tubing being stored above ground, characterize the radon emanation fraction of the bulk scale material when removed from the tubing, and characterize the radium concentrations of the scale. Accurate characterization of 222 Rn emanation fractions from pipe scale may dictate the type of disposal options available for this waste. Characterization of radon release from stored pipes will assist in determining if controls are needed for workers or members of the public downwind from the source. Due to the sensitive nature of this data, the location of this facility is not disclosed

Vold mod børn

DEFF Research Database (Denmark)

Christensen, Else; Agerlund Sloth Larsen, Dorthe

er der gennemført en interviewundersøgelse, hvor i alt 14 sagsbehandlere fra fire forskellige store kommuner er interviewet om deres erfaringer fra sager med (mistanke om) fysisk vold mod børn, om hvordan sådanne sager sædvanligvis starter i socialforvaltningen, om undersøgelsesforløbet, om...

Seasonal variation of 222Rn in seawater samples from Ubatuba embayments, SP, Brazil, for the assessment of submarine groundwater discharge

International Nuclear Information System (INIS)

Lopes, Patricia da Costa

2005-01-01

We describe here an application of excess 222 Rn to estimate SGD in a series of small embayments of Ubatuba, Sao Paulo State, Brazil, covering latitudes between 23 deg 26'S and 23 deg 46'S and longitudes between 45 deg 02'W e 45 deg 11'W. Excess 222 Rn inventories obtained in 24 vertical profiles established from March/03 to July/05 varied from 345 ±±24 to 18,700 ± 4,900 dpm/m 2 . The highest inventories of excess 222 Rn were observed both in Flamengo and Fortaleza embayments, during summer campaigns (rainy season). The estimated total fluxes required to support inventories measured varied from 62 ± 4 to 3,385 +- 880 dpm/m 2 d. Considering these results, the SGD advective rates necessary to balance the fluxes calculated in Ubatuba embayments ranged from 0.1 x 10 -1 to 1.9 cm/d. Taking into account all SGD fluxes obtained, the percentual variability was 89% (seasonal variation in 3 years period, n = 24 measurements). Although, if we consider each year of study separately, the respective percentual variabilities estimated are 72% in 2003 (n = 10 measurements), 127% in 2004 (n = 6 measurements) and 97% in 2005 (n = 8 measurements). (author)

The neonatal Fc receptor, FcRn, as a target for drug delivery and therapy.

Science.gov (United States)

Sockolosky, Jonathan T; Szoka, Francis C

2015-08-30

Immunoglobulin G (IgG)-based drugs are arguably the most successful class of protein therapeutics due in part to their remarkably long blood circulation. This arises from IgG interaction with the neonatal Fc receptor, FcRn. FcRn is the central regulator of IgG and albumin homeostasis throughout life and is increasingly being recognized as an important player in autoimmune disease, mucosal immunity, and tumor immune surveillance. Various engineering approaches that hijack or disrupt the FcRn-mediated transport pathway have been devised to develop long-lasting and non-invasive protein therapeutics, protein subunit vaccines, and therapeutics for treatment of autoimmune and infectious disease. In this review, we highlight the diverse biological functions of FcRn, emerging therapeutic opportunities, as well as the associated challenges of targeting FcRn for drug delivery and disease therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Exposure to radon and mortality standard in a coal miner cohort in Brazil

International Nuclear Information System (INIS)

Veiga, Lene Holanda Sadler; Amaral, Eliana; Koifman, Sergio

2002-01-01

High levels of radon and his products have been found at a underground coal mine, at the Southern Brazil, in operation since 1945. The 222 Rn concentration levels measured were 7000 Bq/m 3 and 0.7 WL for the radon sons (7.7 WLM/year), which are values considered higher than the limits for intervention in a working environments (500 to 1500 Bq/m3 of 222 Rn) and the occupational exposure limit (4.0 WLM/year). Due to the unique opportunity found in these miner group, it was decided to construct a cohort with miners from that mining (underground and surface) viewing the evaluation of the possible effects to the health decurrens from that exposure

Performance improvements on passive activated charcoal 222Rn samplers

International Nuclear Information System (INIS)

Wei Suxia

1996-01-01

Improvements have been made on passive activated charcoal 222 Rn samplers with sintered metal filters. Based on the samplers of good adaptability to temperature and humidity developed before, better charcoal was selected to further improve their performance in radon absorption ability and moisture-resistance. And charcoal quantity in samplers was strictly controlled. The integration time constant of the improved samplers was about 4.3 days. As the sampler was combined with gamma spectrometer to measure radon concentration, the calibration factor was 0.518 min -1 ·Bq -1 ·m 3 for samplers of 7 days exposure time, and the minimum detectable concentration 0.28 Bq·m -3 if counting time for both background and sample is 1000 minutes. The improved samplers are suited to accurately determine the indoor and outdoor average radon concentration under conditions of great variation in temperature and humidity

Radon level in China and elevated indoor exposure in carbon brick and cave dwellings

International Nuclear Information System (INIS)

Wang Zuoyuan

1992-01-01

A nation wide survey of Chinese houses was conducted to determine the average annual effective dose to Chinese population from exposure to radon and its daughter products. The indoor and outdoor concentrations of radon and its daughters were measured using scintillation flask, two filter and carbon canister methods, as well as modified Tsivoglou methods for Rn daughters. Average Rn concentrations are 26.2Bqm -3 and 13.5Bqm -3 for indoor and outdoor environment, respectively. Potential alpha energy concentration, indoor is 744 x 10 -10 Jm -3 , outdoor is 511 x 10 -10 Jm -3 . Equilibrium Factor of Rn daughters are 0.49 (indoor) and 0.61 (outdoor). Occupancy Factor is 0.77 and 0.23. Using appropriate conversion factors, the annual average effective dose to Chinese population is 0.967 mSv. And also, the indoor Rn concentration and gamma dose rate were surveyed in two rural Provinces: Gansu and Jianxi. The fact was found that lung cancer mortality of population lived in high Rn level dwellings is higher than in control groups. An epidemiological retrospective case-control study is recommended in houses with high Rn level. (author)

222Rn levels in Kingsville, Texas, and vicinity near an in situ uranium mine

International Nuclear Information System (INIS)

McGehee, T.L.; Martino, M.R.; Harr, T.L.; Samudio, A.

1994-01-01

An investigation of the 222 Rn levels in ground water, soils, and indoor air has disclosed two 222 Rn ground-water anomalies in the Kingsville, Texas, area from uranium-enriched sandstones of the Evangeline aquifer. Indoor air 222 Rn levels were measured in summer 1991 (from undetectable to 3.2 pCi/l) and winter 1991-1992 (0.01 to 3.98 pCi/l) to determine seasonal extremes and risk to the public. Soil 222 Rn concentration maps ranging from undetectable to 75.4 pCi/l correlate to the low levels found in homes. Results of this study are based on analyses of 218 water samples, 52 in situ soil samples, and 104 indoor air samples. Water samples were injected into a scintillation mix (EPA/EERF-Manual-78-1) and analyzed by liquid scintillation techniques. Indoor air and soil samples were collected using passive charcoal canisters and analyzed by gamma-ray detection techniques (EPA 520/5-87-005). One ground-water 222 Rn anomaly lies near the permitted boundary of a large uranium deposit that is being mined. Private wells near the ore body yielded, 1,023 to 23,256 pCi/l at the well head. A second anomaly is located 2.5 mi (4 km) north of the uranium ore body near Naval Air Station, Kingsville. Private water wells in this area yielded 442 to 1,950 pCi/l 222 Rn at the well head. The radon anomalies are related to subsurface mineralization, which is one of the known natural geologic hazards of this area. Indoor air 222 Rn levels are well below the U.S. Environmental Protection Agency (US/EPA) action limit of 4 pCi/l. However, the high levels of 222 RN in ground water should be mitigated before entry into the home environment. High 222 Rn levels in ground water were reduced to background levels in household waters by use of a pre-introduction large-capacity holding tank

Dry soil diurnal quasi-periodic oscillations in soil 222Rn concentrations

International Nuclear Information System (INIS)

Tommasone Pascale, F.; De Francesco, S.; Carbone, P.; Cuoco, E.; Tedesco, D.

2014-01-01

222 Rn concentrations have been monitored during the dry season in August 2009 and August 2010, in a reworked alluvial-pyroclastic soil of the Pietramelara Plain, in Southern Italy, with the aim of determining the role of atmospheric factors in producing the quasi-periodic oscillations in soil 222 Rn concentrations reported in the literature. In this study we present the results of a detailed analysis and matching of soil 222 Rn concentrations, meteorological and solar parameters where the observed oscillations feature a characteristic behavior with second order build-up and depletion limbs, separated by a daily maximum and minimum. All these features are clearly shown to be tied to sunrise and sunset timings and environmental radiative flux regimes. Furthermore, a significant, and previously unreported, second order correlation (r 2  = 0.73) between daily maximum hourly global radiation and the daily range of soil 222 Rn concentrations has been detected, allowing estimates of the amplitude of these oscillations to be made from estimated or measured solar radiation data. The correlation has been found to be valid even in the presence of persistent patchy daytime cloudiness. In this case a daytime prolongation of the night-time build up stage and an attenuation or even suppression of daytime depletion is observed (a previously unreported effect). Neither soil cracking, nor precipitation, both suggested in some studies as causative factors for these oscillations, during the dry season appear to be necessary in explaining their occurrence. We also report the results of an artificial shading experiment, conducted in August 2009, that further support this conclusion. As soil 222 Rn concentrations during the dry season show a characteristic daily cycle, radon monitoring in soils under these conditions necessarily has to be gauged to the timings of the daily maximum and minimum, as well as to the eventual occurrence of cloudiness and to its related effects, in order to

Extreme levels of 222Rn and U in a private water supply

International Nuclear Information System (INIS)

Lowry, J.D.; Hoxie, D.C.; Moreau, E.

1987-01-01

In 1985, the Maine Department of Human Services discovered a private water supply in Leeds, ME, that contains over 40,700 BqL -1 (1.1 x 10 +6 pCil -1 ) of 222 Rn on average, and ranges between 13,300 and 59,200 Bql -1 . The well water also contains a gross alpha concentration of approximately 10.0 BqL -1 (270 pCiL -1 ), of which more than 95 percent is U (403 ugL -1 ). The ratio of 234 U to 238 U averages 1.17, which compares closely to the sea water at 1.14. The Ra content comprises less than 2 percent of the gross alpha. The levels of 222 Rn and U are considered to be extremely high, with the 222 Rn being the highest known level the authors are aware of for a drinking water supply. This area of Maine has geologic features characteristic of those shown by others to have a high potential for elevated levels of 222 Rn and other radioisotopes. The purpose of this paper is to update the information presented previously about this site, in particular to the ramifications on treatment alternatives associated with the presence of both 222 Rn and U in a water supply

Postmortem Changes in Pork Muscle Protein Phosphorylation in Relation to the RN Genotype

DEFF Research Database (Denmark)

Lametsch, René; Larsen, Martin Røssel; Essén-Gustavsson, Birgitta

2011-01-01

Postmortem changes in pork muscle protein phosphorylation in relation to the RN(-) genotype were investigated using one-dimensional gel electrophoresis and a phosphor specific staining. The phosphorylation levels of several protein bands were found to be affected by the RN(-) genotype and to change...... of phosphorylation of these key enzymes during the postmortem metabolism. The results illustrate that the protein phosphorylation level of the muscle proteins could be interpreted as a global metabolic fingerprint containing information about the activity status of the enzymes in the postmortem metabolism....... during postmortem development. Glycogen phosphorylase, phosphofructokinase, and pyruvate kinase were found in protein bands affected by the RN(-) genotype, and the phosphorylation profile indicates that part of the increased rate and extended pH decline of the RN(-) genotype could be a consequence...

Determinants of dermal exposure relevant for exposure modelling in regulatory risk assessment.

Science.gov (United States)

Marquart, J; Brouwer, D H; Gijsbers, J H J; Links, I H M; Warren, N; van Hemmen, J J

2003-11-01

Risk assessment of chemicals requires assessment of the exposure levels of workers. In the absence of adequate specific measured data, models are often used to estimate exposure levels. For dermal exposure only a few models exist, which are not validated externally. In the scope of a large European research programme, an analysis of potential dermal exposure determinants was made based on the available studies and models and on the expert judgement of the authors of this publication. Only a few potential determinants appear to have been studied in depth. Several studies have included clusters of determinants into vaguely defined parameters, such as 'task' or 'cleaning and maintenance of clothing'. Other studies include several highly correlated parameters, such as 'amount of product handled', 'duration of task' and 'area treated', and separation of these parameters to study their individual influence is not possible. However, based on the available information, a number of determinants could clearly be defined as proven or highly plausible determinants of dermal exposure in one or more exposure situation. This information was combined with expert judgement on the scientific plausibility of the influence of parameters that have not been extensively studied and on the possibilities to gather relevant information during a risk assessment process. The result of this effort is a list of determinants relevant for dermal exposure models in the scope of regulatory risk assessment. The determinants have been divided into the major categories 'substance and product characteristics', 'task done by the worker', 'process technique and equipment', 'exposure control measures', 'worker characteristics and habits' and 'area and situation'. To account for the complex nature of the dermal exposure processes, a further subdivision was made into the three major processes 'direct contact', 'surface contact' and 'deposition'.

Probabilistic mercury multimedia exposure assessment in small children and risk assessment.

Science.gov (United States)

Morisset, Typhaine; Ramirez-Martinez, Alejandra; Wesolek, Nathalie; Roudot, Alain-Claude

2013-09-01

Emissions of mercury in the environment have been decreasing for several years. However, mercury species are still found in different media (food, water, air and breast-milk). Due to mercury toxicity and typical behaviour in children, we have conducted a mercury exposure assessment in French babies, and small children aged 0 to 36months. Consumption and mercury concentration data were chosen for the exposure assessment. The Monte Carlo technique has been used to calculate the weekly exposure dose in order to integrate inter-individual variability and parameter uncertainty. Exposure values have been compared to toxicological reference values for health risk assessment. Inorganic mercury median exposure levels ranged from 0.160 to 1.649μg/kg of body weight per week (95th percentile (P95): 0.298-2.027µg/kg bw/week); elemental mercury median exposure level in children was 0.11ng/kg bw/week (P95: 28ng/kg bw/week); and methylmercury median exposure level ranged from 0.247 to 0.273µg/kg bw/week (P95: 0.425-0.463µg/kg bw/week). Only elemental mercury by inhalation route (indoor air) and methylmercury by ingestion (fish and breast-milk) seem to lead to a health risk in small children. These results confirm the importance of assessing total mercury concentration in media like breast-milk, indoor air and dust and methylmercury level in food, other than fish and seafood. In this way, informed monitoring plan and risk assessment in an at-risk sub-population can be set. © 2013 Elsevier Ltd. All rights reserved.

{sup 222} Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley; Determinacion de {sup 222} Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

Energy Technology Data Exchange (ETDEWEB)

Hernandez A, A

1998-10-01

Concentration levels of {sup 222} Rn and {sup 226} Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The {sup 222} Rn source is the decay of {sup 226} Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. {sup 222} Rn concentration was determined by the liquid scintillation technique, {sup 226} Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for {sup 226} Rn, the average {sup 222} Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and

Characterization of 222Rn entry into a basement structure surrounded by low permeability soil

International Nuclear Information System (INIS)

Ward, D.C.

1992-01-01

An experimental facility has been developed to monitor the entry rate and concentration of 222 Rn in two basement type structures surrounded by soil having a permeability on the order of 1- -12 m 2 . A data acquisition system recorded environmental conditions outside and inside the structures, including basement air exchange rates, every 15 min. Indoor 222 Rn concentrations ranged from 400 to 1400 Bq m -3 . The observed 222 Rn entry rate is highly variable and has two primary components; a constant input rate caused by diffusion of 222 Rn through the concrete walls and floor, and a variable rate that depends upon indoor-soil pressure differentials of only a few pascals. Pressure differentials are dependent upon wind speed and wind direction. Stack effect was not significant. During a two week period, with relatively calm winds, diffusion through the concrete walls and floor plus the floor-wall joint accounted for more than 80% of the total 222 Rn entry

Assessment of occupational radiation exposure in underground artisanal gold mines in Tongo, Upper East Region of Ghana

International Nuclear Information System (INIS)

Doyi, I.; Oppon, O.C.; Glover, E.T.; Gbeddy, G.; Kokroko, W.

2013-01-01

Assessments of radon and gamma radiation levels were carried out in underground artisanal gold mines in Tongo. This is one of the numerous artisanal gold mining communities in Ghana. Solid State Nuclear Track Detectors (SSNTDs) were used to estimate the mean 222 Rn concentration and dose rates during the Harmattan season (November 2010 to February 2011). The values for the 222 Rn concentration at each monitoring site ranged from 14 ± 4 Bq m −3 to 270 ± 9 Bq m −3 , with a mean value of 98 Bq m −3 . These measurements are well below the lower action level of 500 Bq m −3 recommended by ICRP for workplaces. The activity concentrations of 40 K, 232 Th and 238 U were determined using gamma-ray spectroscopy method. The effective dose estimates of 0.11 ± 0.02 mSv y −1 to 0.68 ± 0.04 mSv y −1 were below the allowable limit of 20 mSv per annum for occupational exposure control recommended by the ICRP. The total annual effective dose varied from 0.22 ± 0.04 mSv y −1 to 1.92 ± 0.08 mSv y −1 . -- Highlights: • Mean radon concentration ranged from 14 ± 4 Bq m −3 to 270 ± 9 Bq m −3 . • Annual effective dose of radionuclides from 0.11 ± 0.02 to 0.69 ± 0.04 mSv y −1 . • 238 U, 232 Th and 40 K contributed 5–20%, 39–78% and 17–49% of effective dose. • Max total annual effective dose of 1.9 ± 0.08 mSv y −1 below 20 mSv y −1 set by ICRP 60

222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

International Nuclear Information System (INIS)

Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

2015-01-01

A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

[Aquatic Ecological Index based on freshwater (ICE(RN-MAE)) for the Rio Negro watershed, Colombia].

Science.gov (United States)

Forero, Laura Cristina; Longo, Magnolia; John Jairo, Ramirez; Guillermo, Chalar

2014-04-01

Aquatic Ecological Index based on freshwater (ICE(RN-MAE)) for the Rio Negro watershed, Colombia. Available indices to assess the ecological status of rivers in Colombia are mostly based on subjective hypotheses about macroinvertebrate tolerance to pollution, which have important limitations. Here we present the application of a method to establish an index of ecological quality for lotic systems in Colombia. The index, based on macroinvertebrate abundance and physicochemical variables, was developed as an alternative to the BMWP-Col index. The method consists on determining an environmental gradient from correlations between physicochemical variables and abundance. The scores obtained in each sampling point are used in a standardized correlation for a model of weighted averages (WA). In the WA model abundances are also weighted to estimate the optimum and tolerance values of each taxon; using this information we estimated the index of ecological quality based also on macroinvertebrate (ICE(RN-MAE)) abundance in each sampling site. Subsequently, we classified all sites using the index and concentrations of total phosphorus (TP) in a cluster analysis. Using TP and ICE(RN-MAE), mean, maximum, minimum and standard deviation, we defined threshold values corresponding to three categories of ecological status: good, fair and critical.

Radon transport modelling: User's guide to RnMod3d

DEFF Research Database (Denmark)

Andersen, Claus Erik

2000-01-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It canalso be used for flux calculations of radon...... decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning ofradon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may...... be anisotropic. This guide includes benchmark tests based on simpleproblems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality....

Quantitative research on critical thinking and predicting nursing students' NCLEX-RN performance.

Science.gov (United States)

Romeo, Elizabeth M

2010-07-01

The concept of critical thinking has been influential in several disciplines. Both education and nursing in general have been attempting to define, teach, and measure this concept for decades. Nurse educators realize that critical thinking is the cornerstone of the objectives and goals for nursing students. The purpose of this article is to review and analyze quantitative research findings relevant to the measurement of critical thinking abilities and skills in undergraduate nursing students and the usefulness of critical thinking as a predictor of National Council Licensure Examination-Registered Nurse (NCLEX-RN) performance. The specific issues that this integrative review examined include assessment and analysis of the theoretical and operational definitions of critical thinking, theoretical frameworks used to guide the studies, instruments used to evaluate critical thinking skills and abilities, and the role of critical thinking as a predictor of NCLEX-RN outcomes. A list of key assumptions related to critical thinking was formulated. The limitations and gaps in the literature were identified, as well as the types of future research needed in this arena. Copyright 2010, SLACK Incorporated.

Human exposure assessment to environmental chemicals using biomonitoring.

Science.gov (United States)

Calafat, Antonia M; Ye, Xiaoyun; Silva, Manori J; Kuklenyik, Zsuzsanna; Needham, Larry L

2006-02-01

In modern societies, humans may be exposed to a wide spectrum of environmental chemicals. Although the health significance of this exposure for many chemicals is unknown, studies to investigate the prevalence of exposure are warranted because of the chemicals' potential harmful health effects, as often indicated in animal studies. Three tools have been used to assess exposure: exposure history/questionnaire information, environmental monitoring, and biomonitoring (i.e. measuring concentrations of the chemicals, their metabolites, or their adducts in human specimens). We present an overview on the use of biomonitoring in exposure assessment using phthalates, bisphenol A and other environmental phenols, and perfluorinated chemicals as examples. We discuss some factors relevant for interpreting and understanding biomonitoring data, including selection of both biomarkers of exposure and human matrices, and toxicokinetic information. The use of biomonitoring in human risk assessment is not discussed.

Adult student satisfaction in an accelerated RN-to-BSN program: a follow-up study.

Science.gov (United States)

Boylston, Mary T; Jackson, Christina

2008-01-01

This mixed-method study revealed accelerated RN-to-BSN (bachelor of science in nursing) students' levels of satisfaction with a wide range of college services in a small university. Building on seminal research on the topic [Boylston, M. T., Peters, M. A., & Lacey, M. (2004). Adult student satisfaction in traditional and accelerated RN-to-BSN programs. Journal of Professional Nursing, 20, 23-32.], the Noel-Levitz Adult Student Priorities Survey (ASPS) and qualitative interview data revealed primary factors involved in nontraditional (adult) accelerated RN-to-BSN student satisfaction. The ASPS assesses both satisfaction with and importance of the following factors: academic advising effectiveness, academic services, admissions and financial aid effectiveness, campus climate, instructional effectiveness, registration effectiveness, safety and security, and service excellence. Of these factors, participants considered instructional effectiveness and academic advising effectiveness as most important and concomitantly gave high satisfaction ratings to each. In contrast, convenience of the bookstore, counseling services, vending machines, and computer laboratories were given low importance ratings. The participants cited convenience as a strong marketing factor. Loss of financial aid or family crisis was given as a reason for withdrawal and, for most students, would be the only reason for not completing the BSN program. Outcomes of this investigation may guide faculty, staff, and administrators in proactively creating an educational environment in which a nontraditional student can succeed.

Børn, unge og sociale netværkssider. Hvad ved vi?

DEFF Research Database (Denmark)

Larsen, Malene Charlotte

2012-01-01

været. Herefter skal vi se på, hvordan børn og unge selv begrunder deres brug af sociale netværkssider, og hvilke motiver der ligger bag deres mange timer foran skærmen. Dernæst sætter kapitlet fokus på børn og unges venskaber på sociale netværkssider, hvad der karakteriserer et venskab i dag, og...

Sårbare børn og unge i tandplejeregi i Danmark

DEFF Research Database (Denmark)

Uldum, Birgitte; Christensen, Hanne Nødgaard; Haubek, Dorte

2016-01-01

Hvorledes identificeres sårbare børn og unge i tandplejeregi i Danmark? I denne artikel sættes fokus på danske sårbare børn og unge i tandplejeregi og på udviklingen I Danmark siden 2009. En dansk spørgeskemaundersøgelse om tandplejens erfaring fra 2008 omtales kort. Der lægges vægt på det odonto...

Soil gas 222Rn and volcanic activity at El Hierro (Canary Islands) before and after the 2011 submarine eruption

Science.gov (United States)

Padilla, G.; Hernández, P. A.; Padrón, E.; Barrancos, J.; Melián, G.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Calvo, D.; Hernández, I.; Pereza, M. D.; Pérez, N. M.

2012-04-01

El Hierro (278 km2) is the southwesternmost island of the Canarian archipelago. From June 19, 2011 to January 2012, more than 11,950 seismic events have been detected by the seismic network of IGN. On 10 October 2011 the earthquake swarm changed its behaviour and produced a harmonic tremor due to magma movement, indicating that a submarine eruption located at 2 km south of La Restinga had started which is still in progress. Since 2003, the ITER Environmental Research Division now integrated in the Instituto Volcanológico de Canarias, INVOLCAN, has regularly performed soil gas surveys at El Hierro as a geochemical tool for volcanic surveillance. Among the investigated gases, soil gas radon (222Rn) and thoron (220Rn) have played a special attention. Both gases are characterized to ascend towards the surface mainly through cracks or faults via diffusion or advection, mechanisms dependent of both soil porosity and permeability, which in turn vary as a function of the stress/strain changes at depth. Years before the starts of the volcanic-seismic crisis on July 17, 2011, a volcanic multidisciplinary surveillance program was implemented at El Hierro including discrete and continuous measurements of 222Rn and 220Rn. Two soil gas 222Rn surveys had been carried out at El Hierro in 2003 and 2011, and four continuous geochemical monitoring stations for 222Rn and 220Rn measurements had been installed (HIE02, HIE03, HIE04 and HIE08). Soil gas 222Rn surveys were carried out at the surface environment of El Hierro after selecting 600 sampling observation sites (about 40 cm depth). Geochemical stations measure 222Rn and 220Rn activities by pumping the gas from a PVC pipe inserted 1m in the ground and thermally isolated. The results of the 2003 and 2011 soil gas 222Rn surveys show clearly a relatively higher observed 222Rn activities in the surface environment on 2011 than those observed on 2003 when no anomalous seismicity were taking place beneath El Hierro. The observed

Comparing NET and ERI standardized exam scores between baccalaureate graduates who pass or fail the NCLEX-RN.

Science.gov (United States)

Bondmass, Mary D; Moonie, Sheniz; Kowalski, Susan

2008-01-01

In the United States, nursing programs are commonly evaluated by their graduates success on the National Council Licensure Examination for Registered Nurses (NCLEX-RN). The purpose of this paper is to describe a change in NCLEX-RN success rates following the addition of standardized exams throughout our program's curriculum, and to compare these exam scores between graduates who pass NCLEX-RN and those who do not. Our results indicate an 8.5% change (p pass rate from our previous 5-year mean pass rate, and significant differences in standardized test scores for those who pass the NCLEX-RN compared to those who do not (p pass NCLEX-RN than not.

Extraction and purification of {sup 227}Ac and development of solid {sup 219}Rn source

Energy Technology Data Exchange (ETDEWEB)

Tang, Quan; Qiu, Shoukang; Xiao, Detao; Zhou, Yaohui; An, Xiaogang [University of South China, Hengyang (China). Radon Key Laboratory of Hunan Province/School of Nuclear Science and Technology

2014-04-01

The method of {sup 227}Ac extraction and purification from high-grade uranium ore and the test results of solid {sup 219}Rn source made from {sup 227}Ac are reported in this paper. With five years of follow-up monitoring, radiochemical purity of {sup 227}Ac and the emanation power of solid {sup 219}Rn source has been checked by emanation method and γ-spectrometry, the results showed that {sup 228}Th, {sup 231}Pa and {sup 226}Ra have been effectively removed and the emanation power of {sup 219}Rn source is about 80%. The long-term test results also showed that the {sup 219}Rn emanation rate remains stable in a wide air humidity range (40% ∝ 90%). Though the {sup 219}Rn source has not been accurately calibrated yet, it has been applied in the research for delay coincidence measurement of {sup 223}Ra. (orig.)

Björn Andersson – et liv for elevene, lærerne og naturfagene Björn Andersson – a life for students, teachers and science

Directory of Open Access Journals (Sweden)

Svein Sjøberg

2013-11-01

Full Text Available This article is written in memory of Professor Björn Andersson (1939-2013, the pioneer in the emerging field of science education research in Sweden. In 1976 he was the first to present a PhD in the field of science education in the Nordic countries, and later he became the first to hold a chair in this field in Sweden. The article lifts his PhD (Andersson, 1976 as an example for how a PhD should be written and argues that it should be re-read today. The theses has a clear purpose and research agenda, a well-argued theoretical foundation, a solid anchoring to classroom context, sound choices of methods, excellent analysis of empirical data, both qualitative and qualitative, and a clear presentation of findings and implications. In the decades that followed, Björn was the key person to build the field of science education research in Sweden. This article presents just a few aspects of his wide scope of interests and activities as they have unfolded on the national as well as on the international scene. Björn brought international perspectives to Sweden, and he also represented Sweden abroad. Now, nearly 40 years after Björn graduated, the field of science education in Sweden and the other Nordic countries is well established and flourishing. Björn combined a series of qualities and can serve as a model for new generations: a concern for the learner, teachers and their classroom activities, and a care for coworkers. He provides an example of how to combine an academic activity with a devotion to improve the quality of teaching and learning.

Indoor 222Rn measurements in the region of Beijing, People's Republic of China

International Nuclear Information System (INIS)

Ren, T.S.; Lin, L.Q.; Chen, Z.P.; Li, G.Y.; Chen, A.M.

1987-01-01

Passive integrating activated C detectors were used to study the regional distribution and temporal variation of 222 Rn in indoor air in dwellings in the Beijing region. Measurements were made in 537 dwellings, which were either detached houses or multi-family apartments. The city-wide study was completed in 1985. The distributions are approximately log-normal with 90% of the dwellings having 222 Rn levels less than 60 Bq m-3. The weighted average 222 Rn concentration has been found to be 22.4 Bq m-3. Averages for detached houses and multi-family dwellings are 25.9 and 15.2 Bq m-3, respectively. Assuming an equilibrium factor of 0.5 and an occupancy factor of 0.8, the average equilibrium equivalent concentration of 222 Rn progeny is 11.2 Bq m-3 and the annual average effective dose equivalent is 1.1 mSv

Ra-226 and Rn-222 in saline water compartments of the Aral Sea region

International Nuclear Information System (INIS)

Schettler, Georg; Oberhänsli, Hedi; Hahne, Knut

2015-01-01

Highlights: • 222 Rn and 226 Ra concentrations in different water compartments of the Aral Sea region. • 226 Ra-analysis based on 222 Rn-ingrowth versus MS-analysis after solid-phase extraction. • 226 Ra in different groundwater types of the Aral Sea Basin. • 222 Rn distribution in the Aral Sea, western basin. - Abstract: The Aral Sea has been shrinking since 1963 due to extensive irrigation and the corresponding decline in the river water inflow. Understanding of the current hydrological situation demands an improved understanding of the surface water/groundwater dynamics in the region. 222 Rn and 226 Ra measurements can be used to trace groundwater discharge into surface waters. Data of these radiometric parameters were not previously available for the study region. We determined 222 Rn activities after liquid phase extraction using Liquid Scintillation Counting (LSC) with peak-length discrimination and analyzed 226 Ra concentrations in different water compartments of the Amu Darya Delta (surface waters, unconfined groundwater, artesian water, and water profiles from the closed Large Aral Sea (western basin). The water samples comprise a salinity range between 1 and 263 g/l. The seasonal dynamics of solid/water interaction under an arid climate regime force the hydrochemical evolution of the unconfined groundwater in the Amu Darya Delta to high-salinity Na(Mg)Cl(SO 4 ) water types. The dissolved radium concentrations in the waters were mostly very low due to mineral over-saturation, extensive co-precipitation of radium and adsorption of radium on coexisting solid substrates. The analysis of very low 226 Ra concentrations (<10 ppq) at remote study sites is a challenge. We used the water samples to test and improve different analytical methods. In particular, we modified a procedure developed for the α-spectrometric determination of 226 Ra after solid phase extraction of radium using 3M Empore™ High Performance Extraction Disks (Purkl, 2002) for the

The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements.

Science.gov (United States)

Johnston, Peter N; Hult, Mikael; Gasparro, Joël; Martínez-Canet, María-José; Vasselli, Roberto; McKenzie, Raymond J; Solomon, Steven B; Lambrichts, Ivo

2005-01-01

It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product (210)Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of (210)Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of (210)Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground gamma-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of (210)Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of (210)Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the (210)Pb is associated with the hydroxyapatite.

The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements

International Nuclear Information System (INIS)

Johnston, Peter N.; Hult, Mikael; Gasparro, Jogl; Martinez-Canet, Maria-Jose; Vasselli, Roberto; McKenzie, Raymond J.; Solomon, Steven B.; Lambrichts, Ivo

2005-01-01

It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product 210 Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of 210 Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of 210 Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground γ-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of 210 Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of 210 Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the 210 Pb is associated with the hydroxyapatite

Retrospective Occupational Exposure Assessment in Community-Based Studies Made Easier

International Nuclear Information System (INIS)

Fritschi, L.; Girschik, J.; Friesen, M.C.; Glass, D.; Monash, G.B.; Sadkowsky, T.

2010-01-01

Occ DEAS Assessing occupational exposure in retrospective community-based case-control studies is difficult as measured exposure data are very seldom available. The expert assessment method is considered the most accurate way to attribute exposure but it is a time consuming and expensive process and may be seen as subjective, non reproducible, and non transparent. In this paper, we describe these problems and outline our solutions as ope rationalized in a web-based software application (Occ DEAS). The novel aspects of Occ DEAS are combining all steps in the assessment into one software package; enmeshing the process of assessment into the development of questionnaires; selecting the exposure(s) of interest; specifying rules for exposure assignment; allowing manual or automatic assessments; ensuring that circumstances in which exposure is possible for an individual are highlighted for review; providing reports to ensure consistency of assessment. Development of this application has the potential to make high-quality occupational assessment more efficient and accessible for epidemiological studies

Assessment of predictive dermal exposure to chemicals in the work environment

Directory of Open Access Journals (Sweden)

Agnieszka Jankowska

2017-08-01

Full Text Available Assessment of dermal exposure to chemicals in the work environment is problematic, mainly as a result of the lack of measurement data on occupational exposure to chemicals. Due to common prevalence of occupational skin exposure and its health consequences it is necessary to look for efficient solutions allowing for reliable exposure assessment. The aim of the study is to present predictive models used to assess non-measured dermal exposure, as well as to acquaint Polish users with the principles of the selected model functioning. This paper presents examples of models to assist the employer in the the assessment of occupational exposure associated with the skin contact with chemicals, developed in European Union (EU countries, as well as in countries outside the EU. Based on the literature data dermal exposure models EASE (Estimation and Assessment of Substance Exposure, COSHH Essentials (Control of Substances Hazardous to Health Regulations, DREAM (Dermal Exposure Assessment Method, Stoffenmanager , ECETOC TRA (European Centre for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment, MEASE (Metal’s EASE, PHED (Pesticide Handlers Exposure Database, DERM (Dermal Exposure Ranking Method and RISKOFDERM (Risk Assessment of Occupational Dermal Exposure to Chemicals were briefly described. Moreover the characteristics of RISKOFDERM, guidelines for its use, information on input and output data were further detailed. Problem of full work shift dermal exposure assessment is described. An example of exposure assessment using RISKOFDERM and effectiveness evaluation to date were also presented. When no measurements are available, RISKOFDERM allows dermal exposure assessment and thus can improve the risk assessment quality and effectiveness of dermal risk management. Med Pr 2017;68(4:557–569

Martin Pärn Kunstihoone salongis

Index Scriptorium Estoniae

1999-01-01

15. 03 Martin Pärna mööbligrupi "Martin" presentatsioon. 1998. a. pälvis M. Pärn Euroopa disainipreemia Best in the Best Rote Punkt, mida jagab Design Zentrum Nordrhein Westfalen. 1999. a. parim on M. Pärna Martela OY-le projekteeritud klapplaud. Aasta Design Team - Philipsi disaini meeskond. Äramärgitud tooted on näitusel Nordrhein Westfaleni Design Zentrumis

222 Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley

International Nuclear Information System (INIS)

Hernandez A, A.

1998-01-01

Concentration levels of 222 Rn and 226 Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The 222 Rn source is the decay of 226 Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. 222 Rn concentration was determined by the liquid scintillation technique, 226 Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for 226 Rn, the average 222 Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and fertilizers and detritus. Most of the studied water

Measurements of octupole collectivity in Rn and Ra nuclei using Coulomb excitation

CERN Multimedia

We propose to exploit the unique capability of HIE-ISOLDE to provide post-accelerated $^{221,222}$Rn and $^{222,226,228}$Ra ion beams for the study of octupole collectivity in these nuclei. We will measure E3 transition moments in $^{222}$Rn and $^{222,226,228}$Ra in order to fully map out the variation in E3 strength in the octupole mass region with Z$\\thicksim$88 and N$\\thicksim$134. This will validate model calculations that predict different behaviour as a function of N. We will also locate the position of the parity doublet partner of the ground state in $^{221}$Rn, in order to test the suitability of odd-A radon isotopes for EDM searches.

RN Job Satisfaction and Retention After an Interprofessional Team Intervention.

Science.gov (United States)

Baik, Dawon; Zierler, Brenda

2018-04-01

Despite continuing interest in interprofessional teamwork to improve nurse outcomes and quality of care, there is little research that focuses on nurse job satisfaction and retention after an interprofessional team intervention. This study explored registered nurse (RN) job satisfaction and retention after a purposeful interprofessional team training and structured interprofessional bedside rounds were implemented. As part of a larger study, in this comparative cross-sectional study, pre- and post-intervention data on RN job satisfaction and turnover rate were collected and analyzed. It was found that RNs had significantly higher job satisfaction after the interprofessional team intervention. The 6-month period turnover rate in the post-intervention period was slightly lower than the 6-month period turnover rate in pre-intervention period; however, the rate was too low to provide statistical evidence. Ongoing coaching and supportive work environments to improve RN outcomes should be considered to enhance quality of care and patient safety in healthcare.

Mineral water 222 Rn activity decrease due to consumption habits

International Nuclear Information System (INIS)

Cipriani, Moacir; Taddei, Maria Helena Tirollo; Silva, Nivaldo Carlos da

2001-01-01

Mineral waters from the Pocos de Caldas Plateau springs, an elevated region with high natural radioactivity, in the State of Minas Gerais, Brazil, have significant 222 Rn concentration on site. The highest concentration in the waters are from: Fonte Villela - Aguas da Prata (∼ 1000 Bql -1 ); Fonte Grande Hotel - Pocinhos do Rio Verde (∼ 400 Brq -1 ) and Fonte CNEN Lab - Pocos de Caldas (∼ 290 Bql -1 ). These waters are used by the population as drinking water and due to consumption habits, can lead to internal doses above accepted limits for the public. This work deals with the decrease of 222 Rn activity in mineral waters fro two different popular consumption habits, and with the adult effective dose equivalent reduction due to water consumption habits. It has been found that the estimated dose based on the biokinetic Crawford-Brown model, can be one fourth of dose based on 222 Rn activity on site. (author)

Determination of 222Rn in water by absorption in polydimethylsiloxane mixed with activated carbon and gamma-ray spectrometry: An example application in the radon budget of Paterno submerged sinkhole (Central Italy)

International Nuclear Information System (INIS)

Voltaggio, M.; Spadoni, M.

2013-01-01

Highlights: ► Polydimethylsiloxane and Activated Carbon were used as passive gas accumulator. ► Water-impermeable properties of PDMS combine with adsorptive properties of AC. ► PDMS–AC accumulators can be used to study 222 Rn in water. ► Measured 222 Rn specific activity in PDMS–AC matches the theoretical results. ► We used PDMS–AC in the radon budget of a submerged sinkhole. - Abstract: Passive gas accumulators made of polydimethylsiloxane (PDMS) mixed with activated C (AC) were studied to measure their efficiency for sampling Rn in water. In this composite the water-impermeable properties of PDMS act synergistically with adsorptive properties of AC, even when the accumulators are immersed in water for many days. A series of tests where cylindrical shaped PDMS–AC disks were exposed to different 222 Rn-enriched waters showed that measured 222 Rn specific activity matches the theoretical results coming from the equation that describes the process of internal diffusion integrated with the Rn decay term. The linear relationship between 222 Rn in water and the accumulation process in PDMS–AC, the influence of temperature and the different sensitivity of the composite and its components were also studied and discussed. The high Rn volumetric enrichment factor in PDMS–AC disks respect to water resulted in about 206: 1, so lowering detection limits for 222 Rn in water to 20 Bq m −3 when the total activity of Rn progeny in disks is measured by high resolution gamma-ray spectrometry. The use of PDMS–AC accumulators was tested at the Paterno submerged sinkhole, in central Italy. This study allowed the production of a detailed synchronous vertical profile of the Rn content in the middle of the lake and to define the Rn balance by assessing the discharge rate of submerged springs and the average residence time of the lake water

Determination of Rn-222 in drinking water. An important parameter for the natural radioactivity exposure assessment; Bestimmung von {sup 222}Rn in Trinkwasser. Ein wichtiger Parameter fuer die Erfassung der natuerlich bedingten Strahlenbelastung

Energy Technology Data Exchange (ETDEWEB)

Zoiy, Myroslav [Forschungszentrum Juelich GmbH (Germany)

2017-08-01

The natural radiation exposure includes external exposure due to terrestric and cosmic radiation and internal exposure due to respiration and food - incorporation. Incorporated radionuclides are partially absorbed in the vascular and lymphatic systems and partially excreted after a certain biological half-time through kidneys and intestines, and partially the lungs. The radiation exposure is defined as effective annual dose in Sievert. In Germany the medium natural exposure is 2.1 mSv per year.

Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

2017-06-15

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

Wishful Thinking? Inside the Black Box of Exposure Assessment.

Science.gov (United States)

Money, Annemarie; Robinson, Christine; Agius, Raymond; de Vocht, Frank

2016-05-01

Decision-making processes used by experts when undertaking occupational exposure assessment are relatively unknown, but it is often assumed that there is a common underlying method that experts employ. However, differences in training and experience of assessors make it unlikely that one general method for expert assessment would exist. Therefore, there are concerns about formalizing, validating, and comparing expert estimates within and between studies that are difficult, if not impossible, to characterize. Heuristics on the other hand (the processes involved in decision making) have been extensively studied. Heuristics are deployed by everyone as short-cuts to make the often complex process of decision-making simpler, quicker, and less burdensome. Experts' assessments are often subject to various simplifying heuristics as a way to reach a decision in the absence of sufficient data. Therefore, investigating the underlying heuristics or decision-making processes involved may help to shed light on the 'black box' of exposure assessment. A mixed method study was conducted utilizing both a web-based exposure assessment exercise incorporating quantitative and semiqualitative elements of data collection, and qualitative semi-structured interviews with exposure assessors. Qualitative data were analyzed using thematic analysis. Twenty-five experts completed the web-based exposure assessment exercise and 8 of these 25 were randomly selected to participate in the follow-up interview. Familiar key themes relating to the exposure assessment exercise emerged; 'intensity'; 'probability'; 'agent'; 'process'; and 'duration' of exposure. However, an important aspect of the detailed follow-up interviews revealed a lack of structure and order with which participants described their decision making. Participants mostly described some form of an iterative process, heavily relying on the anchoring and adjustment heuristic, which differed between experts. In spite of having undertaken

Construction of natural radiation exposure study network - overview and current status

International Nuclear Information System (INIS)

Tokonami, Shinji

2010-01-01

A new project entitled 'Construction of natural radiation exposure study network' was adopted in the Program of Promotion of International Joint Research under the Special Coordination Funds for Promoting Science and Technology operated by the Ministry of Education, Culture, Sports, Science and Technology of Japan. Eight institutions were involved in this project and the project will continue until March, 2012. The aims of the project are to assess the dose for natural radiation exposures using state-of- the-art measurement techniques in four Asian countries (China, India, Korea and Thailand) and their outcomes will be distributed worldwide. Throughout the project, conventional measurement techniques will be improved and be optimized. More scientific data and results will be obtained as well. In particular, the following advanced technologies for inhalation exposures will be introduced: (1) Discriminative measurements of radon ( 222 Rn) and thoron ( 220 Rn) gases, (2) Evaluation of thoron decay products concentration, (3) Simple but effective particle size distribution measurements. In China, we are conducting a case-control study of radon and lung cancer in Gansu, China. This Gansu area was investigated in the past for the case-control study. New data are being accumulated. In India, we focused on Orissa in order to carry out radiation measurements in this project. In parallel, Kerala is currently involved as the comparative study area. In Korea, we are now measuring radon and thoron in radon/thoron prone areas. These results will give us new information for further understanding of exposure due to radon and thoron. In Thailand, we are carrying out comprehensively radiation measurements in NORM industries. Not only these surveys but also quality assurance of radon measurements are being addressed in Japan. We have managed an international intercomparison exercise of passive radon detectors at NIRS. This study presents an overview of the project and current status

Determining chance coincidence, survival factor and decay factor in 220Rn delayed coincidence measurement

International Nuclear Information System (INIS)

Huang Derong; Yan Yongjun; Zhou Jianliang; Qiu Shoukang

2013-01-01

The method and calculation formulas to determine the chance coincidence in the 220 Rn coincidence measurement are introduced in this paper. The poisson distribution is introduced to correct the chance coincidence. The relative deviation of the true coincidence between the method and the Giffin's is within 5% after the correction of the cohance coincidence. The measurement of 220 Rn is done by comparative measurement with RAD7. The results shows that 220 Rn can be measured by the method with a relative deviation of 14%. Mean while, for the 220 Rn flow regime is difficult to meet the condition of calculation formulas, a solution to solve the survival factor and decay factor is proposed and the error come from the useage of theoretical calculation formula is avoided. (authors)

222Rn in private well water in the vicinity of uranium mines over ten years

International Nuclear Information System (INIS)

Yunoki, Eiji; Kataoka, Toshio; Michihiro, Kenshu; Sugiyama, Hirokazu; Shimizu, Mitsuo; Mori, Tadashige

1994-01-01

There are many small uranium mines of the sedimentary type in Kamisaibara, Okayama Prefecture, Japan. As inhabitants in Kamisaibara consume water from privately-dug wells, it is important to investigate distributions of 222 Rn in privately-dug well water in the vicinity of the mines. The determination of 222 Rn in well water was carried out from April 1980 to October 1990. Though small in area (16 km 2 ), each well water has its own characteristic activity concentrations of 222 Rn. The activity concentrations of 222 Rn are almost constant for each specific well over a long period (about 10 years). In general, the correlation coefficients for several sampling points are small. As Akawase and Tennoh are situated in the same rock type, the correlation coefficient is the highest value in this area. The estimated dose equivalent for the human stomach is approximately 0.4-54 μSv/year. The type of distribution of 222 Rn in privately-dug well water is log normal. (author)

Skolestøtte til børn i familiepleje – delrapport I

DEFF Research Database (Denmark)

Eiberg, Misja; Andersen, Luna Kragh; Scavenius Sonne-Schmidt, Christoffer

I denne rapport beskrives resultaterne af et randomiseret kontrolleret forsøg med to skolestøttende indsatser til familieplejeanbragte børn i den danske folkeskole i alderen 6-14 år. Gennem afprøvningen af de to indsatser har forskningsprojektet ”Skolestøtte til børn i familiepleje” undersøgt, hv...

Predictors of Success and Failure for ADN Students on the NCLEX-RN

Science.gov (United States)

Benefiel, Diane

2011-01-01

The purpose of this study was to: 1) analyze the relationship of preprogram and nursing program variables on National Council Licensure Examination for Registered Nurses (NCLEX-RN) success and failure, and 2) develop a model to predict success and failure on the NCLEX-RN. The convenience sample was comprised of 245 spring, summer, and fall midterm…

Perspectives for integrating human and environmental exposure assessments.

Science.gov (United States)

Ciffroy, P; Péry, A R R; Roth, N

2016-10-15

Integrated Risk Assessment (IRA) has been defined by the EU FP7 HEROIC Coordination action as "the mutual exploitation of Environmental Risk Assessment for Human Health Risk Assessment and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process" (Wilks et al., 2015). Since exposure assessment and hazard characterization are the pillars of risk assessment, integrating Environmental Exposure assessment (EEA) and Human Exposure assessment (HEA) is a major component of an IRA framework. EEA and HEA typically pursue different targets, protection goals and timeframe. However, human and wildlife species also share the same environment and they similarly inhale air and ingest water and food through often similar overlapping pathways of exposure. Fate models used in EEA and HEA to predict the chemicals distribution among physical and biological media are essentially based on common properties of chemicals, and internal concentration estimations are largely based on inter-species (i.e. biota-to-human) extrapolations. Also, both EEA and HEA are challenged by increasing scientific complexity and resources constraints. Altogether, these points create the need for a better exploitation of all currently existing data, experimental approaches and modeling tools and it is assumed that a more integrated approach of both EEA and HEA may be part of the solution. Based on the outcome of an Expert Workshop on Extrapolations in Integrated Exposure Assessment organized by the HEROIC project in January 2014, this paper identifies perspectives and recommendations to better harmonize and extrapolate exposure assessment data, models and methods between Human Health and Environmental Risk Assessments to support the further development and promotion of the concept of IRA. Ultimately, these recommendations may feed into guidance showing when and how to apply IRA in the regulatory decision

Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China.

Science.gov (United States)

Zhou, Xiaocheng; Chen, Zhi; Cui, Yueju

2016-10-01

The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should

Exposure Assessment Tools by Lifestages and Populations - General Population

Science.gov (United States)

EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

The fundamentals of integrating service in a post-licensure RN to BSN program.

Science.gov (United States)

Washington-Brown, Linda; Ritchie, Arlene

2014-01-01

Integrating service in a post-licensure registered nurse to bachelor of science in nursing (RN to BSN) program provides licensed registered nurse (RN) students the opportunity to learn, develop, and experience different cultures while serving the community and populations in need (McKinnon & Fitzpatrick, 2012). Service to the community, integrated with academic learning can be applied in a wide variety of settings, including schools, universities, and community faith-based organizations. Academic service-learning (ASL) can involve a group of students, a classroom, or an entire school. In the RN to BSN program, the authors use a student-directed service learning approach that integrates service-learning throughout the curriculum. RN students are introduced to service-learning at program orientation prior to the start of classes and receive reinforcement and active engagement throughout the curriculum. The students and volunteer agencies receive and give benefits from the services provided and the life lessons gained through mentorship, education, and hands-on experiences.

Safety assessments for potential exposures

International Nuclear Information System (INIS)

Dunn, D.I.

2012-04-01

Safety Assessment of potential exposures have been carried out in major practices, namely: industrial radiography, gamma irradiators and electron accelerators used in industry and research, and radiotherapy. This paper focuses on reviewing safety assessment methodologies and using developed software to analyse radiological accidents, also review, and discuss these past accidents.The primary objective of the assessment is to assess the adequacy of planned or existing measures for protection and safety and to identify any additional measures that should be put in place. As such, both routine use of the source and the probability and magnitude of potential exposures arising from accidents or incidents should be considered. Where the assessment indicates that there is a realistic possibility of an accident affecting workers or members of the public or having consequences for the environment, the registrant or licensee should prepare a suitable emergency plan. A safety assessment for normal operation addresses all the conditions under which the radiation source operates as expected, including all phases of the lifetime of the source. Due account needs to be taken of the different factors and conditions that will apply during non-operational phases, such as installation, commissioning and maintenance. (author)

The neonatal Fc receptor (FcRn) binds independently to both sites of the IgG homodimer with identical affinity.

Science.gov (United States)

Abdiche, Yasmina Noubia; Yeung, Yik Andy; Chaparro-Riggers, Javier; Barman, Ishita; Strop, Pavel; Chin, Sherman Michael; Pham, Amber; Bolton, Gary; McDonough, Dan; Lindquist, Kevin; Pons, Jaume; Rajpal, Arvind

2015-01-01

The neonatal Fc receptor (FcRn) is expressed by cells of epithelial, endothelial and myeloid lineages and performs multiple roles in adaptive immunity. Characterizing the FcRn/IgG interaction is fundamental to designing therapeutic antibodies because IgGs with moderately increased binding affinities for FcRn exhibit superior serum half-lives and efficacy. It has been hypothesized that 2 FcRn molecules bind an IgG homodimer with disparate affinities, yet their affinity constants are inconsistent across the literature. Using surface plasmon resonance biosensor assays that eliminated confounding experimental artifacts, we present data supporting an alternate hypothesis: 2 FcRn molecules saturate an IgG homodimer with identical affinities at independent sites, consistent with the symmetrical arrangement of the FcRn/Fc complex observed in the crystal structure published by Burmeister et al. in 1994. We find that human FcRn binds human IgG1 with an equilibrium dissociation constant (KD) of 760 ± 60 nM (N = 14) at 25°C and pH 5.8, and shows less than 25% variation across the other human subtypes. Human IgG1 binds cynomolgus monkey FcRn with a 2-fold higher affinity than human FcRn, and binds both mouse and rat FcRn with a 10-fold higher affinity than human FcRn. FcRn/IgG interactions from multiple species show less than a 2-fold weaker affinity at 37°C than at 25°C and appear independent of an IgG's variable region. Our in vivo data in mouse and rat models demonstrate that both affinity and avidity influence an IgG's serum half-life, which should be considered when choosing animals, especially transgenic systems, as surrogates.

Estimating the relation between groundwater and river water by measuring the concentration of Rn-222

Energy Technology Data Exchange (ETDEWEB)

Yoneda, Minoru; Morisawa, Shinsuke [Kyoto Univ. (Japan). Faculty of Engineering

1997-02-01

This study aimed to estimate the relationship between groundwater in shallow layer and river water by determining the concentrations of {sup 222}Rn and nitric nitrogen along with water temperature. The region around ca. 20 km along river A in a certain basin was chosen as a test area. The Rn concentration of groundwater was determined by Rn extracting with toluene and counting in liquid scintillation counter, whereas for river water, it was determined by activated charcoal passive collector method developed by the authors, by which the amount of Rn adsorbed on activated charcoal was estimated by Ge-solid state detector. In addition, water temperature and nitric nitrogen concentration were measured at various points in the test area. Thus, a distribution map of the three parameters was made on the basis of the data obtained in December, 1989. Since Rn concentration is generally higher in ground water than river water and the water temperature in December is higher in the former, it seems likely that the concentrations of Rn and nitric nitrogen would become higher in the area where ground water soaks into river water. Thus, the directions of ground water flow at the respective sites along river A were estimated from the data regarding the properties of ground water. (M.N.)

Dynamics of Rn transport from the cellar to the living area in an unheated house

International Nuclear Information System (INIS)

Furrer, D.; Crameri, R.; Burkart, W.

1991-01-01

Environmental parameters such as temperature and wind, occupant activities, and house-specific parameters such as subsoil geology, leakiness of the substructure to soil gas, and air exchange rate are the main factors influencing Rn entry into a building and its subsequent indoor behavior. Experiments performed in an unheated, uninhabited house showed a reproducible diurnal fluctuation of the indoor concentration of Rn decay products. Strong, long-term correlations between temperature differences indoor-outdoor (indoor temperature minus outdoor temperature) and pressure differences outdoor-indoor (outdoor pressure minus indoor pressure) were found. At positive temperature differences inside-outside, an average airflow velocity of about 0.05 m s-1 between ground floor and first floor was detected. This air movement was able to vertically transport Rn at a rate of approximately 11 kBq h-1 in a volume of air of about 5.5 m3 through a cross-sectional area of only 0.03 m2. For this specific house, stack effects were identified as the main driving force for Rn migration from the cellular to higher floors. The diurnal fluctuation of Rn progeny concentrations in the living area can be explained by temporal variations in the amount of Rn-rich air transported vertically from the cellar into the building as a consequence of stack effects

Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

Directory of Open Access Journals (Sweden)

Miraç KAMIŞLIOĞLU

2014-12-01

Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

Design and operation of an automated beta-particle counting system for the measurement of 220Rn (and 222Rn) progeny

International Nuclear Information System (INIS)

Bigu, J.

1992-01-01

A fully automated system of the continuous (active) type has been designed for the unattended quantification of 222 Rn progeny and 220 Rn progeny in calibration and test facilities, as well as working and living environments. The system uses a β-particle detector and associated electronic circuitry, in conjunction with an in-house microprocessor-based processing interface card and a personal computer, operated by specially developed in-house software. The system represents a significant improvement over systems using α-particle detectors because of its enhanced flexibility of design and virtual elimination of plate-out effects in the sampling head, and of self-absorption phenomena in the sampling filter. The β-particle system was tested and calibrated in a Radon and Thoron Test Facility of the walk-in type under a variety of experimental conditions. (author)

Human IgG lacking effector functions demonstrate lower FcRn-binding and reduced transplacental transport.

Science.gov (United States)

Stapleton, Nigel M; Armstrong-Fisher, Sylvia S; Andersen, Jan Terje; van der Schoot, C Ellen; Porter, Charlene; Page, Kenneth R; Falconer, Donald; de Haas, Masja; Williamson, Lorna M; Clark, Michael R; Vidarsson, Gestur; Armour, Kathryn L

2018-03-01

We have previously generated human IgG1 antibodies that were engineered for reduced binding to the classical Fcγ receptors (FcγRI-III) and C1q, thereby eliminating their destructive effector functions (constant region G1Δnab). In their potential use as blocking agents, favorable binding to the neonatal Fc receptor (FcRn) is important to preserve the long half-life typical of IgG. An ability to cross the placenta, which is also mediated, at least in part, by FcRn is desirable in some indications, such as feto-maternal alloimmune disorders. Here, we show that G1Δnab mutants retain pH-dependent binding to human FcRn but that the amino acid alterations reduce the affinity of the IgG1:FcRn interaction by 2.0-fold and 1.6-fold for the two antibodies investigated. The transport of the modified G1Δnab mutants across monolayers of human cell lines expressing FcRn was approximately 75% of the wild-type, except that no difference was observed with human umbilical vein endothelial cells. G1Δnab mutation also reduced transport in an ex vivo placenta model. In conclusion, we demonstrate that, although the G1Δnab mutations are away from the FcRn-binding site, they have long-distance effects, modulating FcRn binding and transcellular transport. Our findings have implications for the design of therapeutic human IgG with tailored effector functions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Radium-226 body burden in U miners by measurement of Rn in exhaled breath.

Science.gov (United States)

Srivastava, G K; Raghavayya, M; Kotrappa, P; Somasundaram, S

1986-02-01

Uranium miners were made to inhale Rn-free medical O2 and exhale through a 5.2-1 A1 chamber before reporting to work. The chamber was sealed and isolated from the sampling circuit. An electrostatic plate collected the freshly formed Rn-decay products. The subsequent programmed alpha counting of the plate yielded a Rn concentration in the exhaled breath. Assuming that the exhaled breath represents a certain fraction of the Rn produced inside the body, the body burden of 226Ra was calculated. Standardisation of this procedure and the data collected on 310 miners are discussed. The procedure is simple and applicable for routine measurements. The miner needs to be in the laboratory for only 10 min. The system is also portable for field application. For routine use, the minimum detectable concentration is 3.87 Bq X m-3 which corresponds to a body burden of 0.26 kBq in a typical miner, if one assumes the Rn release fraction from the body as 84%. The system offers a more convenient and sensitive alternative to whole-body counting of workers for 226Ra.

A Concise Synthesis of Three Branches Derived from Polysaccharide RN1 and Anti-Pancreatic Cancer Activity Study

Directory of Open Access Journals (Sweden)

Deqin Cai

2017-10-01

Full Text Available RN1, a polysaccharide from flowers of Panax pseudo-ginsieng Wall. Var. notoginseng (Burkill Hoo & Tseng, is a potential multi-targeting drug candidate for pancreatic cancer treatment. However, the active targeting domain of RN1 is still unknown. Herein, three RN1 derived branches were synthesized via [3+2] or [2+2] strategies, efficiently. Two pentasaccharides, 18 and 27, showed similar inhibition effect on pancreatic cancer BxPC-3 cells to that of RN1 at same concentration. Interestingly, tetrasaccharide 21 potently inhibited gemcitabineresistant cell line Panc-1 at high concentration. These suggest that the branches of RN1 might be the active targeting domain and tetrasaccharide 21 might be a potential leading compound for pancreatic cancer with gemcitabine resistance.

Mapping of 222Rn and 4He in soil gas over a karstic limestone-granite boundary: correlation of high indoor 222Rn with zones of enhanced permeability

International Nuclear Information System (INIS)

O'Connor, P.J.; Gallagher, V.; Van den Boom, G.

1992-01-01

Recent indoor radon reconnaissance surveys in Ireland have identified buildings with high radon concentrations (up to 1700 Bq.m -3 ) overlying Carboniferous karstic limestone sequences in the western part of the country. A detailed investigation of indoor 222 Rn and soil gas 222 Rn and 4 He concentrations has been carried out over a karstic limestone-uraniferous granite boundary in County Galway. High indoor 222 Rn concentrations occur in dwellings over both lithologies. Radon migratory routes in bedrock and overburden appear to be controlled by zones of enhanced permeability, e.g. fractures, faults, etc. which are defined by linear arrays of elevated 4 He soil gas values. While the ultimate source of radon remains conjectural, the greatly enhanced permeability of karstified limestone is thought to be of fundamental importance in providing a means of rapid radon transport into overlying soils and buildings. (author)

Influence of IL-1RN intron 2 variable number of tandem repeats (VNTR) polymorphism on bipolar disorder.

Science.gov (United States)

Rafiei, A; Hosseini, S H; Taheri, M; Hosseni-khah, Z; Hajilooi, M; Mazaheri, Z

2013-01-01

Several lines of evidence point to the role of neurobiological mechanisms and genetic background in bipolar disorder (BD). The interleukin-1 receptor antagonist (IL-1Ra) is the principal regulator of IL-1α and IL-1β bioactivities. This study aimed to investigate the potential role of the variable number of tandem repeats (VNTR) polymorphisms of the IL-1Ra gene (IL1RN) in conferring susceptibility to BD. In total, 217 patients meeting DSM-IV-TR criteria for BD and 212 controls were recruited for the study. Genotyping of IL1RN was determined by polymerase chain reaction amplification of VNTR of 86 base pairs in intron 2 of IL1RN. The genotype distribution of IL1RN polymorphism was significantly different between BD patients and controls. The IL1RN*1/2 genotype was more prevalent in BD patients than in controls (44.2 vs. 30.2%, p = 0.003). Multiple logistic regression analysis demonstrated that IL1RN*1/2 heterozygotes had a significantly higher risk for BD (OR 1.83 and 95% CI 1.22-2.74, p = 0.003). Further stratification of the BD patients into IL1RN*2 allele carrier and noncarrier subgroups revealed a strong association between IL1RN*2 carriage and prolongation of the disease (p = 0.02). These findings suggest a positive association between VNTR polymorphism in IL1RN and BD. Additional studies, particularly with a prospective approach, are necessary to clarify the precise role of the VNTR polymorphism on the disease in different ethnic populations. Copyright © 2013 S. Karger AG, Basel.

Development of standard methods for activity measurement of natural radionuclides in waterworks as basis for dose and risk assessment—First results of an Austrian study

International Nuclear Information System (INIS)

Stietka, M.; Baumgartner, A.; Seidel, C.; Maringer, F.J.

2013-01-01

A comprehensive study with the aim to evaluate the risks due to radiation exposure for workers in water supply is conducted in 21 Austrian waterworks. The development of standard methods for the assessment of occupational exposure of water work staff is a part of this study. Preliminary results of this study show a wide range of Rn-222 activity concentration in waterworks with values from (28±10) Bq/m 3 to (38,000±4000) Bq/m 3 . Also seasonal variations of the Rn-222 activity concentration could be observed. - Highlights: • In this study operational exposure of water work staff was evaluated. • The Rn-222 concentration in indoor air in waterworks was measured for 1 year. • Results show a wide range of Rn-222 activity concentration in waterworks. • Seasonal variations of the Rn-222 activity concentration could be observed

The Transition Experiences of Graduates of a Synchronous Online LPN to RN Program

Science.gov (United States)

Hoag, Debra K.

2016-01-01

This qualitative case study included a review of the nursing shortage, nursing education, contemporary learners, the LPN and RN, the future of nursing education, online education, and transitions experiences. These topics defined this study by providing the underpinnings to understand the LPN to RN journey. According to the American Association of…

Distribution Log Normal of 222 Rn in the state of Zacatecas, Mexico

International Nuclear Information System (INIS)

Garcia, M.L.; Mireles, F.; Quirino, L.; Davila, I.; Rios, C.; Pinedo, J.L.

2006-01-01

In this work the evaluation of the concentration of 222 Rn in air for Zacatecas is shown. The Solid State Nuclear Track Detectors were used as the technique for the realization of the measurements in large scale with cellulose nitrate LR-115, type 2, in open chambers of 222 Rn. The measurements were carried out during three months in different times of the year. In the results it is presented the log normal distribution, arithmetic mean and geometric media for the concentration at indoor and outdoor of residence constructions, the concentration at indoor of occupational constructions and in the 57 municipal heads of the state of Zacatecas. The statistics of the values in the concentration showed variation according to the time of the year, obtaining high quantities in winter seasons for both cases. The distribution of the concentration of 222 Rn is presented in the state map for each one of the municipalities, representing the measurement places in the entire state of Zacatecas. Finally the places where the values in the concentration of 222 Rn in air are near to the one limit settled down by the EPA of 148 Bq/m 3 are presented. (Author)

Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

International Nuclear Information System (INIS)

Kearfott, Kimberlee J; Noon, Evan P; Rafique, Muhammad

2015-01-01

Previous studies measured the effects of 222 Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222 Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222 Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222 Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222 Rn gas, which was in the order of 0.5 nSv Bq −1  m 3  d −1 . (paper)

Levan-type fructooligosaccharide production using Bacillus licheniformis RN-01 levansucrase Y246S immobilized on chitosan beads

Directory of Open Access Journals (Sweden)

Surawut Sangmanee

2016-06-01

Full Text Available Bacillus licheniformis RN-01 levansucrase Y246S (LsRN-Y246S was immobilized by covalently linking onto chitosan, Sepabead EC-EP, and Sepabead EC-HFA, beads. The stability of immobilized LsRN-Y246S was found to be the highest with chitosan beads, retaining more than 70% activity after 13 weeks storage at 4 oC, and 68% activity after 12 hours incubation at 40°C. LsRN-Y246S immobilized on chitosan beads withstands sucrose concentrations up to 70% (w/v, retaining over 85% of its activity, significantly better than LsRN-Y246S immobilized on others supporting matrices. LsRN-Y246S immobilized on chitosan showed a 2.4 fold increase in activity in the presence of Mn2+, and gave slight protection against deactivation by of Cu2+, Zn2+, Fe3+, SDS and EDTA. A maximum of 8.36 g and an average of 7.35 g LFOS yield at least up to DP 11 can be produced from 25 g of sucrose, during five production cycles. We have demonstrated that LFOS can be effectively produced by chitosan immobilized LsRN-Y246S and purified.

Activated charcoal adsorber bed as a 222Rn hold up system for application in uranium mining industries

International Nuclear Information System (INIS)

Sudeep Kumara, K.; Karunakara, N.; Sahoo, B.K.; Gaware, J.J.; Sapra, B.K.; Mayya, Y.S.

2018-01-01

222 Rn, produced due to the decay of 226 Ra, can accumulate to high concentrations, and if adequate ventilation is not provided the workers may inhale the 222 Rn laden air, which would result in elevated inhalation dose in Uranium mining and milling operations. Similarly, in thorium mining and processing plants, the 220 Rn generated during monazite processing and thorium handling facility is of concern. In a previous publication it has been shown that adsorption in a flow-through charcoal bed offers an excellent method of alleviating the release of 220 Rn into occupational and public domain. In this paper we examine the utility of TMS as a 222 Rn hold up/delay system by evaluating its performance parameters such as breakthrough time (τ) and adsorption coefficient (K) at different flow rates

Evaluation of radiation exposure from a consumer product. A pillow

International Nuclear Information System (INIS)

Furuta, Etsuko; Aburai, Tamaru

1999-01-01

Radiation exposure from a pillow was analyzed. According to an advertisement of the pillow, this radioactive consumer product contains enough amounts of radioactive materials to induce radiation hormesis effects. The pillow consists of the filling chips made from kneading mineral ores and the polynosic linings contains natural radioactive ores. A γ-ray analysis of the pillow using pure Ge-MCA reveals that there exist radioactivities of thorium and uranium series mixtures in it at concentration of 0.58% by the weight. The observations of a chip surface by a scanning electron microscope show that the shapes of two sides are different each other. There are lots of sharp protuberances on the outside of the chip. To determine the direct external exposures from the pillow, film badges were placed on the pillow for 210 h and 2555 h. The dose equivalents of 210 h exposure was under 0.1 mSv which is a detection limit of a γ-ray by the film badges. However, that of 2555 h exposure was over 0.1 mSv less than 0.15 mSv. Quantities of internal exposures from inhalation of the vaporized Rn were measured by a Lucas Cell. It was 79 Bq/m 3 . There is no necessity for anxious about being broken in health inhaling the Rn-gass. (author)

IL-1RN VNTR polymorphism as a susceptibility marker for nasopharyngeal carcinoma in Portugal.

Science.gov (United States)

Sousa, Hugo; Breda, Eduardo; Santos, Alexandra M; Catarino, Raquel; Pinto, Daniela; Canedo, Paulo; Machado, José Carlos; Medeiros, Rui

2013-08-01

Nasopharyngeal carcinoma (NPC) is a rare malignancy in Western countries that is widely associated with the infection by Epstein-Barr virus (EBV). Several studies have showed that a common allele (allele 2) of the 86-bp variable number of tandem repeats (VNTR) polymorphism within intron 2 of the interleukin 1 receptor antagonist (IL-1RN) gene is associated with several disorders, including viral-associated cancers. We have developed a hospital-based case-control study to characterise the role of the IL-1RN 86-bp VNTR polymorphism in the development of NPC with 112 patients with the disease and 433 healthy individuals from the northern region of Portugal. IL-1RN genotypes were combined according to the number of repeats: allele 2 (A2), the short allele that corresponds to two repeats, and L, the long allele that corresponds to three or more repeats. Our study revealed that 31.2% of NPC patients were IL-1RN A2*A2, compared with 9.7% observed in the control group. The statistical analysis revealed that IL-1RN*A2 homozygosity for the A2 allele was associated with a fourfold increased risk for NPC development (pVNTR in NPC development in Portugal. Our study indicates IL-1RN*A2 homozygosity as a significant risk marker in our population and that it should be further investigated for the potential role in the definition of a susceptibility profile for NPC onset. Copyright © 2013 Elsevier Ltd. All rights reserved.

Progress in human exposure assessment for biocidal products

NARCIS (Netherlands)

Hemmen, J.J. van

2004-01-01

An important shortcoming in our present knowledge required for risk assessment of biocidal products is the assessment of human exposure. This knowledge gap has been filled in a preliminary fashion with the TNsG on human exposure to biocidal products (available from the ECB website). Explicit User

Assessment of chemical exposures: calculation methods for environmental professionals

National Research Council Canada - National Science Library

Daugherty, Jack E

1997-01-01

... on by scientists, businessmen, and policymakers. Assessment of Chemical Exposures: Calculation Methods for Environmental Professionals addresses the expanding scope of exposure assessments in both the workplace and environment...

Risk assessment and management of radiofrequency radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Dabala, Dana [Railways Medical Clinic Cluj-Napoca, Occupational Medicine Department, 16-20 Bilascu Gheorghe St., 400015 Cluj-Napoca (Romania); Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath St., 400293 Cluj-Napoca (Romania)

2013-11-13

Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management.

Risk assessment and management of radiofrequency radiation exposure

International Nuclear Information System (INIS)

Dabala, Dana; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia

2013-01-01

Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management

A sub-nationwide survey of outdoor and indoor 222Rn concentrations in China by passive method

International Nuclear Information System (INIS)

Jin Yihe; Ikebe, Y.; Iida, T.

1996-01-01

From Nov. 1988 to Mar. 1993, cooperated by China and Japan, a survey of outdoor and indoor 222 Rn concentrations in 10 cities which were highly populated in China was carried out by means of passive method. the annual mean of outdoor 222 Rn concentration in 10 cities was 8.8 Bq·m -3 . The highest of 13.5 Bq·m -3 was in Wuhan, the lowest of 3.3 Bq·m -3 was in Chongming Island of Shanghai; and there were no significant differences among the different years in the same areas. During the northwest wind seasons, about 50% of outdoor 222 Rn concentration in Taiwan was contributed by the airflow from the mainland. Typical apartment houses and offices built of brick and concrete were also surveyed for indoor 222 Rn concentration. The annual mean of indoor 222 Rn concentration in the 10 cities was 19.5 Bq·m - 3. The highest of 33.9 Bq·m -3 was observed in Guiyang, the lowest of 9.0 Bq·m -3 was observed in Chongming Island of Shanghai. The outdoor and indoor 222 Rn concentrations showed a clear seasonal pattern with the minimum in summer and the maximum in winter. And they also showed a clear geographic distribution tendency; they were higher in inland than in seashores, and higher in the south than in the north. The ratios of indoor to outdoor 222 Rn concentrations were from 1.1 to 4.6. The annual effective dose equivalents resulting from outdoor and indoor 222 Rn concentrations amounted to about 0.64 mSv·a -1 . The highest was in Guiyang, and the lowest was in Nantong, being 1.12 and 0.39 mSv·a -1 , respectively

Human exposure to bisphenol A by biomonitoring: Methods, results and assessment of environmental exposures

International Nuclear Information System (INIS)

Dekant, Wolfgang; Voelkel, Wolfgang

2008-01-01

Human exposure to bisphenol A is controversially discussed. This review critically assesses methods for biomonitoring of bisphenol A exposures and reported concentrations of bisphenol A in blood and urine of non-occupationally ('environmentally') exposed humans. From the many methods published to assess bisphenol A concentrations in biological media, mass spectrometry-based methods are considered most appropriate due to high sensitivity, selectivity and precision. In human blood, based on the known toxicokinetics of bisphenol A in humans, the expected very low concentrations of bisphenol A due to rapid biotransformation and the very rapid excretion result in severe limitations in the use of reported blood levels of bisphenol A for exposure assessment. Due to the rapid and complete excretion of orally administered bisphenol A, urine samples are considered as the appropriate body fluid for bisphenol A exposure assessment. In urine samples from several cohorts, bisphenol A (as glucuronide) was present in average concentrations in the range of 1-3 μg/L suggesting that daily human exposure to bisphenol A is below 6 μg per person (< 0.1 μg/kg bw/day) for the majority of the population

Are stepparents always evil? Parental death, remarriage, and child survival in demographically saturated Krummhörn (1720-1859) and expanding Québec (1670-1750).

Science.gov (United States)

Willführ, Kai P; Gagnon, Alain

2013-01-01

Parental death precipitates a cascade of events leading to more or less detrimental exposures, from the sudden and dramatic interruption of parental care to cohabitation with stepparents and siblings in a recomposed family. This article compares the effect of early parental loss on child survival in the past in the Krummhörn region of East Frisia (Germany) and among the French Canadian settlers of the Saint Lawrence Valley (Québec, Canada). The Krummhörn region was characterized by a saturated habitat, while the opportunities for establishing a new family were virtually unlimited for the French Canadian settlers. Early parental loss had quite different consequences in these dissimilar environments. Event history analyses with time-varying specification of family structure are used on a sample of 7,077 boys and 6,906 girls born between 1720 and 1859 in the Krummhörn region and 31,490 boys and 33,109 girls whose parents married between 1670 and 1750 in Québec. Results indicate that in both populations, parental loss is associated with increased infant and child mortality. Maternal loss has a universal and consistent effect for both sexes, while the impact of paternal loss is less easy to establish and interpret. On the other hand, the effect of the remarriage of the surviving spouse is population-specific: the mother's remarriage has no effect in Krummhörn, while it is beneficial in Québec. In contrast, the father's remarriage in Krummhörn dramatically reduces the survival chances of the children born from his former marriage, while such an effect is not seen for Québec. These population-specific effects appear to be driven by the availability of resources and call into question the universality of the "Cinderella" effect.

Configurations and level structure of 219Rn

International Nuclear Information System (INIS)

Sheline, R.K.; Liang, C.F.; Paris, P.

1998-01-01

The level structure of 219 Rn has been studied using the alpha decay of 223 Ra and coincident gamma rays. While only modest changes are required in the level structure, and only above 342.8 keV, severe changes are required throughout the level scheme in the spin assigments. These changes allow the assignment of two sets of anomalous bands with K=5/2 ± and K=3/2 ± . The K=5/2 ± bands have configurations intermediate between the reflection asymmetric configuration and the g 9/2 shell model configuration, while the K=3/2 ± bands have configurations intermediate between the mixed reflection asymmetric configuration and the i 11/2 shell model configuration. Comparison of the systematics of 219 Rn with neighboring isotones, isobars, and isotopes shows clearly the collapse of the quadrupole-octupole-type configurations into the less degenerate shell model configurations. copyright 1998 The American Physical Society

Measurements of 222Rn and 226Ra Levels in environmental samples by using liquid scintillation counter

International Nuclear Information System (INIS)

Moustafa, A.S.

2004-01-01

The advantageous of liquid scintillation counting technique for 6 Ra determination compared with other methods are the high counting efficiency and the easier sample preparation, with no need for sample pre-concentration. In this work, liquid scintillation counting system was used to measure 222 Rn and 226 Ra levels in environmental samples. The liquid scintillation cocktail was prepared in the laboratory and was found efficient for measuring 222 Rn. Soil, sediment and TENORM samples were dried, grind, sieved and added to hydrochloric acid, in a standard scintillation vial, preloaded with the liquid scintillation cocktail. By measuring 222 Rn levels in the prepared vials, at different intervals of time after preparation, 222 Rn and 226 Ra levels were determined

Exposures to radon in homes in Adana

International Nuclear Information System (INIS)

Yegingil, Z.

1990-01-01

Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. The use of solid state nuclear tracks detectors (SSNTD) is one of the most convenient techniques to assess the average radiation levels of alpha activities in the environment. By using CR-39 and LR-115 detectors long term alpha activities have been investigated to be noticeable the concentrations of natural radionuclides and Rn-222 exhalation rate under different environmental conditions in Adana. The radon distributions have been measured in soils an in single houses and apartment buildings in various floors in the summer and winter time. The seasonal variation of the radon concentration measured by CR-39 and LR-115 displayed a correlation. (author). 25 refs, 2 tabs

High-spin isomer in 211Rn, and the shape of the yrast line

International Nuclear Information System (INIS)

Dracoulis, G.D.; Fahlander, C.; Poletti, A.R.

1981-08-01

High spin yrast states in 211 Rn have been identified. A 61/2 - , 380 ns isomer found at 8856 keV is characterised as a core-excited configuration. The average shape of the yrast line shows a smooth behaviour with spin, in contrast to its neighbour 212 Rn. This difference is attributed to the presence of the neutron hole

Pædagoger og Perkere – etniske minoritetsbørn i det sociale system

DEFF Research Database (Denmark)

Vitus, Kathrine

: hvad gør mødet med en socialpædagogisk institution ved og for etniske minoritetsbørn? Hvilke praksisser, manøvremuligheder og handlerum har pædagoger? Hvorfor er mødet mellem danske velfærdsinstitutioner, deres professionelle og etniske minoritetsbørn, unge og deres familier tilsyneladende så svært? I...

Some remarks on exact methods for WL and 222Rn-daughter determination

International Nuclear Information System (INIS)

Groer, P.G.

1977-01-01

For an exact determination of the three 222 Rn-daughter concentrations (RaA, B and C) which properly weighted yield the Working Level, three equations relating observed counts (α or β) to these unknown concentrations have to be solved. The half-lives in the 222 Rn decay series, the type of decay and the counting errors, limit the suitable set of equations. Some aspects of two such exact methods are discussed

Læringsmodstand hos børn

DEFF Research Database (Denmark)

Broström, Stig

2017-01-01

I dette kapitel beskrives dimensioner ved børns læring og med særligt fokus på Illeris’ begreb læringsmodstand. Det tages udgangspunkt i den kulturhistoriske skoles læringsteori med reference til bl.a. Vygotsky og Leontjev. Børn i såvel dagtilbud som skolen vil løbende vise modstand mod læring. D...

An application of 222Rn alpha particle's tracks to uranium exploration

International Nuclear Information System (INIS)

Aguilar H, F.

1981-01-01

The uranium exploration method is based on the register of 222 Rn alpha particles; 222 Rn gas is generated in the chain 238 U desintegration. The detection of alpha particles was performed with cellulose nitrate films (NTC), located in a grid at the region in study. The alpha particles produce latent tracks in the NTC films; these tracks may be enlarged by chemical etching and are observed with an ordinary optic microscope, ninety seven NTC films were used, these were distributed in an area of approximately seventeen square kilometers, located in the municipalities of Granados and Huasabas in Sonora Mexico, the detectors remain in the ground for a thirty days mean period. The results obtained show an area with high 222 Rn concentration, this can be related with an underground uranium ore deposit. The more important conclusion is that the results obtained in this work can be used as preliminary results for other prospection methods in this particular area. (author)

Biodecolorization of Reactive Yellow-2 by Serratia sp. RN34 Isolated from Textile Wastewater.

Science.gov (United States)

Najme, Rabia; Hussain, Sabir; Maqbool, Zahid; Imran, Muhammad; Mahmood, Faisal; Manzoor, Hamid; Yasmeen, Tahira; Shehzad, Tanvir

2015-12-01

Remediation of colored textile wastewaters is a matter of interest. In this study, 49 bacteria were isolated from the textile wastewater and tested for their ability to decolorize reactive yellow-2 (RY2) dye. The most efficient isolate, RN34, was identified through amplification, sequencing, and phylogenetic analysis of its 16S rDNA and was designated as Serratia sp. RN34. This bacterium was also found capable of decolorizing other related reactive azo-dyes, including reactive black-5, reactive red-120, and reactive orange-16 but at varying rates. The optimum pH for decolorization of RY2 by the strain RN34 was 7.5 using yeast extract as cosubstrate under static incubation at 30 °C. The strain RN34 also showed potential to decolorize RY2 in the presence of considerable amounts of hexavalent chromium and sodium chloride. A phytotoxicity study demonstrated relatively reduced toxicity of RY2 decolorized products on Vigna radiata plant as compared to the uninoculated RY2 solution.

Calibration of a degassing-emanation line for 222Rn determination in seawater samples

International Nuclear Information System (INIS)

Farias, Luciana Aparecida

2002-01-01

The purpose of this study is to calibrate a degassing-emanation line and to determine 222 Rn and 226 Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring 226 Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of 222 Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of 222 Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of 222 Rn in excess increases with depth, as expected. (author)

Estimates concentrations in bottled 222Rn of the dose due to mineral waters in Iran

International Nuclear Information System (INIS)

Assadi, M. R.; Esmaealnejad, M.; Rahmatinejad, Z.

2006-01-01

Radon is a radionuclide that has the main role in exposure. Radon in water causes exposure in whole body but the largest dose being received by the stomach, as EPA (Environmental Protection Agency) estimates that radon in drinking water causes about 168 cancer deaths per year: 89 p ercent f rom lung cancer caused by breathing released to the indoor air from water and 11 p ercent f rom stomach cancer caused by consuming water containing radon. Now days the consumption of bottled mineral waters has become very popular. As is known, some kinds of mineral waters contain naturally occurring radionuclides in higher concentration than the usual drinking (tap) water. Surveys and reports on radon in most surface waters is low compared with radon level in groundwater and mineral water. In our work, the concentration of Rn(222) was determined in some bottled mineral waters available in Iran , and in next step the dose contribution ; due to ingestion ; for 1 l d -1 bottled mineral water consumption.

Update of the BIPM.RI(II)-K1.Rn-222 comparison of activity measurements for the radionuclide {sup 222}Rn to include the LNE-LNHB, France

Energy Technology Data Exchange (ETDEWEB)

Michotte, C.; Ratel, G. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Cassette, P. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Laboratoire national de metrologie et d' essais -Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex (France)

2012-02-15

In 2007, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 222}Rn to the International Reference System (SIR) for comparison. The value of the activity submitted was about 90 kBq. This key comparison result joins that of Switzerland and Germany in the key comparison database that now contains three results, identifier BIPM.RI(II)-K1.Rn-222. Consequently, the KCRV has been updated and the degrees of equivalence with the KCRV have been evaluated. (authors)

Exposure scenario libraries as a tool for exposure assessment

International Nuclear Information System (INIS)

Jiménez, Araceli Sánchez; Rashid, Shahzad; Van Tongeren, Martie; Brouwer, Derk; Fransman, Wouter; Fito, Carlos; Boulougouris, George

2015-01-01

The development of nanotechnology has reached a point where it is being widely applied, and numerous nanomaterials and nano-enabled products are handled across a broad range of industrial sectors. Exposure extends beyond occupational settings as products containing nanomaterials are used by different consumer groups.Despite the knowledge on their toxic effects is growing there is still not OEL for most NMS and therefore the precautionary approach is still used where levels are kept as low as possible Therefore there is a need to assess workers and consumers exposure. (paper)

Calibration of a degassing-emanation line for 222Rn determination in seawater samples; Calibracao de uma linha de emanacao para determinacao de {sup 222}Rn em amostras de agua do mar

Energy Technology Data Exchange (ETDEWEB)

Farias, Luciana Aparecida

2002-07-01

The purpose of this study is to calibrate a degassing-emanation line and to determine {sup 222}Rn and {sup 226}Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring {sup 226}Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of {sup 222}Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of {sup 222}Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of {sup 222}Rn in excess increases with depth, as expected. (author)

Using 222Rn as a tracer of geodynamical processes in underground environments

International Nuclear Information System (INIS)

Valladares, D.L.; Silva, A.A.R. da; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Lacerda, T.; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Anjos, R.M.; Rizzotto, M.; Velasco, H.; Rosas, J.P. de; Tognelli, G.

2014-01-01

Radon levels in two old mines in San Luis, Argentina, were measured and analyzed, with the aim to assess the potential use of this radioactive noble gas as a tracer of geological processes in underground environments. La Carolina gold mine and Los Cóndores tungsten mine are today used as tourism mines. CR-39 nuclear track detectors were used for this purpose. Measurements were performed during both winter and summer seasons. The findings show that in these environments, significant radon concentrations are subject to large seasonal fluctuations, due to the strong dependence on natural ventilation with the outside temperature variations. For both mines, higher concentration values of 222 Rn were observed in summer than in winter; with an extreme ratio of 2.5 times between summer and winter seasons for Los Cóndores mine. The pattern of radon transport inside La Carolina mine revealed, contrary to what was believed, that this mine behaves as a system with two entrances located at different levels. However, this feature can only be observed in the winter season, when there is a marked difference between the inside and outside temperatures of the mine. In the case of Los Cóndores mine, the radon concentration pattern distribution is principally established by air current due to chimney-effect in summer and winter seasons. In both cases, the analyses of radon pattern distribution appear as a good method to trace air currents, and then localize unknown ducts, fissures or secondary tunnels in subterranean environments. - Highlights: • 222 Rn levels in two old mines in San Luis, Argentina • CR-39 nuclear track detectors were used for this purpose • higher concentration values of 222 Rn were observed in summer than in winter • radon pattern distribution appear as a good method to trace air currents • it localizes unknown ducts, fissures or secondary tunnels in subterranean environments

Tutoring for Success: Empowering Graduate Nurses After Failure on the NCLEX-RN.

Science.gov (United States)

Lutter, Stacy L; Thompson, Cheryl W; Condon, Marian C

2017-12-01

Failure on the National Council Licensure Examination for Registered Nurses (NCLEX-RN) is a devastating experience. Most research related to NCLEX-RN is focused on predicting and preventing failure. Despite these efforts, more than 20,000 nursing school graduates experience failure on the NCLEX-RN each year, and there is a paucity of literature regarding remediation after failure. The aim of this article is to describe an individualized tutoring approach centered on establishing a trusting relationship and incorporating two core strategies for remediation: the nugget method, and a six-step strategy for question analysis. This individualized tutoring method has been used by three nursing faculty with a 95% success rate on an NCLEX retake attempt. Further research is needed to identify the elements of this tutoring method that influence success. [J Nurs Educ. 2017;56(12):758-761.]. Copyright 2017, SLACK Incorporated.

Spectroscopy of 212Rn

International Nuclear Information System (INIS)

Stuchbery, A.E.; Dracoulis, G.D.; Byrne, A.P.; Poletti, A.R.

1988-01-01

Excited states of 212 Rn have been studied using γ-ray and electron spectroscopy following the reactions 208 Pb( 9 Be, 5n) and 204 Hg( 13 C,5n). With the exception of the energy of the yrast 8 + → 6 + transition, the previously proposed level scheme has been verified. New transitions have been placed in the level scheme and new lifetime and g-factor results obtained. The level scheme and electromagnetic properties of selected isomeric states are compared with the results of shell model and semi-empirical shell-model calculations, including coupling to octupole vibrations. (orig.)

Spectroscopy of 212Rn

International Nuclear Information System (INIS)

Stuchbery, A.E.; Dracoulis, G.D.; Byrne, A.P.; Poletti, A.R.

1988-06-01

Excited states of 212 Rn have been studied using γ-ray and electron spectroscopy following the reactions 208 Pb ( 9 Be,5n) and 204 Hg( 13 C,5n). With the exception of the energy of the yrast 8 + → 6 + transition, the previously proposed level scheme has been verified. New transitions have been placed in the level scheme and new lifetime and g-factor results obtained. The level scheme and electromagnetic properties of selected isomeric states are compared with the results of shell model and semi-empirical shell-model calculations, including coupling to octupole vibrations

Average daily and annual courses of 222Rn concentration in some natural medium

International Nuclear Information System (INIS)

Holy, K.; Bohm, R.; Polaskova, A.; Stelina, J.; Sykora, I.; Hola, O.

1996-01-01

Simultaneous measurements of the 222 Rn concentration in the outdoor atmosphere of Bratislava and in the soil air over one year period have been made. Daily and seasonal variations of the 222 Rn concentration in both media were found. Some attributes of these variations as well as methods of measurements are presented in this work. (author). 17 refs., 6 figs

The Beckman-Quarles theorem for continuous mappings from R^n to C^n

OpenAIRE

Tyszka, Apoloniusz

2002-01-01

Let \\phi((x_1,...,x_n),(y_1,...,y_n))=(x_1-y_1)^2+...+(x_n-y_n)^2. We say that f:R^n -> C^n preserves distance d>=0 if for each x,y \\in R^n \\phi(x,y)=d^2 implies \\phi(f(x),f(y))=d^2. We prove that if x,y \\in R^n (n>=3) and |x-y|=(\\sqrt{2+2/n})^k \\cdot (2/n)^l (k,l are non-negative integers) then there exists a finite set {x,y} \\subseteq S(x,y) \\subseteq R^n such that each unit-distance preserving mapping from S(x,y) to C^n preserves the distance between x and y. It implies that each continuou...

The distribution of {sup 210}Pb in human bone and its impact on methods for the retrospective estimation of {sup 222}Rn exposure from in vivo measurements

Energy Technology Data Exchange (ETDEWEB)

Johnston, Peter N. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Hult, Mikael [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)]. E-mail: mikael.hult@cec.eu.int; Gasparro, Jogl [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Martinez-Canet, Maria-Jose [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Vasselli, Roberto [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); McKenzie, Raymond J. [Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Solomon, Steven B. [Australian Radiation Protection and Nuclear Safety Agency, Lower Plenty Road, Yallambie 3085 (Australia); Lambrichts, Ivo [Department of Histology, Limburg University Centrum (LUC), Diepenbeek (Belgium)

2005-07-01

It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product {sup 210}Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of {sup 210}Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of {sup 210}Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground {gamma}-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of {sup 210}Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of {sup 210}Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the {sup 210}Pb is associated with the hydroxyapatite.

Development of a preclinical 211Rn/211At generator system for targeted alpha therapy research with 211At.

Science.gov (United States)

Crawford, Jason R; Yang, Hua; Kunz, Peter; Wilbur, D Scott; Schaffer, Paul; Ruth, Thomas J

2017-05-01

The availability of 211 At for targeted alpha therapy research can be increased by the 211 Rn/ 211 At generator system, whereby 211 At is produced by 211 Rn electron capture decay. This study demonstrated the feasibility of using generator-produced 211 At to label monoclonal antibody (BC8, anti-human CD45) for preclinical use, following isolation from the 207 Po contamination also produced by these generators (by 211 Rn α-decay). 211 Rn was produced by 211 Fr electron capture decay following mass separated ion beam implantation and chemically isolated in liquid alkane hydrocarbon (dodecane). 211 At produced by the resulting 211 Rn source was extracted in strong base (2N NaOH) and purified by granular Te columns. BC8-B10 (antibody conjugated with closo-decaborate(2-)) was labeled with generator-produced 211 At and purified by PD-10 columns. Aqueous solutions extracted from the generator were found to contain 211 At and 207 Po, isolated from 211 Rn. High radionuclidic purity was obtained for 211 At eluted from Te columns, from which BC8-B10 monoclonal antibody was successfully labeled. If not removed, 207 Po was found to significantly contaminate the final 211 At-BC8-B10 product. High yield efficiencies (decay-corrected, n=3) were achieved for 211 At extraction from the generator (86%±7%), Te column purification (70%±10%), and antibody labeling (76%±2%). The experimental 211 Rn/ 211 At generator was shown to be well-suited for preclinical 211 At-based research. We believe that these experiments have furthered the knowledge-base for expanding accessibility to 211 At using the 211 Rn/ 211 At generator system. As established by this work, the 211 Rn/ 211 At generator has the capability of facilitating preclinical evaluations of 211 At-based therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

E-perm radon monitors for determining waterborne concentrations of dissolved in radon 222Rn

International Nuclear Information System (INIS)

Jester, W.A.; Kotrappa, P.

1989-01-01

This paper describes a simple and relatively inexpensive method in which E-Perm radon monitors are used to determine the concentration of dissolved 222 Rn in drinking water. This procedure takes advantage of E-Perm's ability to accurately measure the integral radon exposure under conditions of high humidity. The method was evaluated against the liquid scintillation procedure recommended by the U.S. Environmental Protection Agency (EPA) and was found to give excellent agreement. An E-perm is an electret ion chamber that consists of a small chamber constructed from a conducting plastic and having an electret at its base and a filtered air inlet at the top. The technique described in this paper takes advantages of E-Perm's insensitivity to high humidity

ASSESSING HUMAN EXPOSURE TO GRASS POLLEN IN DENMARK

DEFF Research Database (Denmark)

Peel, Robert George; Hertel, Ole; Herbert, Rob

Objectives: Exposure to pollen is typically assessed using data collected at fixed roof-top monitoring stations, which give a general picture of airborne pollen concentrations over a wide region. Actual exposure levels can be obtained through personal exposure monitoring. This is typically done u...

[Occupational exposure to nanoparticles. Assessment of workplace exposure].

Science.gov (United States)

Bujak-Pietrek, Stella

2010-01-01

Nanotechnology is currently one of the most popular branch of science. It is a technology that enables designing, manufacturing and application of materials and structures of very small dimensions, and its products are applied in almost every field of life. Nanoparticles are the structures having one or more dimensions of the order of 100 nm or less. They are used in precise mechanics, electronics, optics, medicine, pharmacy, cosmetics and many other spheres. Due to their very small size, nanostructures have completely different and specific properties, unknown for the bulk of materials. Fast-growing nanotechnology provides a wide spectrum of applications, but it also brings about new and unknown danger to human health. Nanotechnology is the branch that has developed rather recently, and much information about health risk and its influence on the environment is beyond our knowledge. Nanoparticles, released in many technological processes, as well as manufactured nanoparticles can induce occupational hazards to workers. The lack of regulations and standards, compulsory in the manufacture and use ofnanoparticles is a fundamental problem faced in the evaluation of exposure. Another problem is the choice of proper measurement equipment for surveying of very small particles - their number, mass and surface area in the workpost air. In this article, the possibility and scope of exposure assessment is discussed and a brief specification of available instrumentation for counting and assessing the parameters essential for classifying the exposure to nanoparticles is presented.

Variability and uncertainty in Swedish exposure factors for use in quantitative exposure assessments.

Science.gov (United States)

Filipsson, Monika; Öberg, Tomas; Bergbäck, Bo

2011-01-01

Information of exposure factors used in quantitative risk assessments has previously been compiled and reported for U.S. and European populations. However, due to the advancement of science and knowledge, these reports are in continuous need of updating with new data. Equally important is the change over time of many exposure factors related to both physiological characteristics and human behavior. Body weight, skin surface, time use, and dietary habits are some of the most obvious examples covered here. A wealth of data is available from literature not primarily gathered for the purpose of risk assessment. Here we review a number of key exposure factors and compare these factors between northern Europe--here represented by Sweden--and the United States. Many previous compilations of exposure factor data focus on interindividual variability and variability between sexes and age groups, while uncertainty is mainly dealt with in a qualitative way. In this article variability is assessed along with uncertainty. As estimates of central tendency and interindividual variability, mean, standard deviation, skewness, kurtosis, and multiple percentiles were calculated, while uncertainty was characterized using 95% confidence intervals for these parameters. The presented statistics are appropriate for use in deterministic analyses using point estimates for each input parameter as well as in probabilistic assessments. © 2010 Society for Risk Analysis.

Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

International Nuclear Information System (INIS)

Dhondt, Stijn; Beckx, Carolien; Degraeuwe, Bart; Lefebvre, Wouter; Kochan, Bruno; Bellemans, Tom; Int Panis, Luc; Macharis, Cathy; Putman, Koen

2012-01-01

In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO 2 and O 3 using only home addresses were compared with models that integrate all time-activity patterns—including time in commute—for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO 2 using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: ► Exposure to ambient air pollution was assessed integrating population mobility. ► This dynamic exposure was integrated into a health impact assessment. ► Differences between the dynamic and residential exposure were quantified. ► Modest differences in health impact were found at a regional level. ► At municipal level larger differences were found, influenced by gender and age.

Study of epidemiological risk of lung cancer in Mexico due indoor radon exposure

Science.gov (United States)

Ángeles, A.; Espinosa, G.

2014-07-01

In this work the lifetime relative risks (LRR) of lung cancer due to exposure to indoor 222Rn on the Mexican population is calculated. Cigarette smoking is the number one risk factor for lung cancer (LC), because that, to calculate the number of cases of LC due to exposure to 222Rn is necessary considers the number of cases of LC for smoking cigarette. The lung cancer mortality rates published by the "Secretaría de Salud" (SSA), the mexican population data published by the "Consejo Nacional de Población" (CONAPO), smoking data in the mexican population, published by the "Comisión Nacional Contra las Adicciones" (CONADIC), the "Organización Panamericana de la Salud" (OPS) and indoor 222Rn concentrations in Mexico published in several recent studies are used. To calculate the lifetime relative risks (LRR) for different segments of the Mexican population, firstly the Excess Relative Risk (ERR) is calculated using the method developed by the BEIR VI committee and subsequently modified by the USEPA and published in the report "EPA Assessment of Risks from Radon in Homes". The excess relative risks were then used to calculate the corresponding lifetime relative risks, again using the method developed by the BEIR VI committee. The lifetime relative risks for Mexican male and female eversmokers and Mexican male and female never-smokers were calculated for radon concentrations spanning the range found in recent studies of indoor radon concentrations in Mexico. The lifetime relative risks of lung cancer induced by lifetime exposure to the mexican average indoor radon concentration were estimated to be 1.44 and 1.40 for never-smokers mexican females and males respectively, and 1.19 and 1.17 for ever-smokers Mexican females and males respectively. The Mexican population LRR values obtained in relation to the USA and Canada LRR published values in ever-smokers for both gender are similar with differences less than 4%, in case of never-smokers in relation with Canada

Kan adoption hjælpe de glemte børn?

DEFF Research Database (Denmark)

Christoffersen, Mogens

2008-01-01

Er adoption bedre end opvækst på en moderne døgninstitution eller hos en plejefamilie? I et velfærdssamfund som det danske med lang tradition for fokus på, hvordan det går de anbragte børn, er dette et centralt spørgsmål.......Er adoption bedre end opvækst på en moderne døgninstitution eller hos en plejefamilie? I et velfærdssamfund som det danske med lang tradition for fokus på, hvordan det går de anbragte børn, er dette et centralt spørgsmål....

Updated estimates of HAL n and RN- effects on pork quality: fresh and processed loin and ham.

Science.gov (United States)

Cherel, P; Glénisson, J; Figwer, P; Pires, J; Damon, M; Franck, M; Le Roy, P

2010-12-01

A 1000-pig F2 intercross QTL detection experimental population was generated using two commercial sire lines. Independent carriers of HAL n and RN- mutations (10% and 14%, respectively) were included in this population as control genotypes. The effects of HAL n and RN- heterozygous genotypes on fresh and transformed loins and hams were estimated using a mixed model methodology. The results document the unfavorable effects of both mutations on meat quality. Smaller effects of HAL Nn genotype compared to HAL nn or RN-rn+ genotypes were estimated. Interestingly, effects of HAL Nn genotype on meat pH and loin color could be insignificant at 24-h postmortem, but translate into higher water losses on storage and cooking, and result in tougher cooked loin. Using the same methodology, significant effects of the PRKAG3 (RN) I199 allele on ultimate pH values but not on glycolytic potential were observed. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Measurements of 222Rn and its daughters and estimation of internal doses to workers in underground buildings

International Nuclear Information System (INIS)

Cao Jianping; Lu Zhizhao; Li Yuanshan

1993-03-01

The results of concentration measuring of 222 Ru and its daughters and estimation of internal doses to workers in the underground buildings at Nanjing city are presented. The double filtering membrane method and Thomas method were used in the monitoring of 222 Rn and its daughters, and the dose conversion factor was taken from the latest UNSCEAR report. Concentration distributions of 222 Rn and its daughters were approximately log-normal. The geometric means for 222 Rn was 40.5 Bq · m -3 and for its daughters was 1.4 x 10 -7 J · m -3 . The equilibrium factor was 0.63. The radioactive equilibrium ratio between short-lived 222 Rn daughters was 1:0.57:0.49. The estimation value of annual effective dose equivalent from 222 Rn daughters to workers working at underground sites was 1.3 mSv, which was 86% higher than that of those working on ground sites

Radiation exposure of the public as a result of the present operations of Ranger Uranium Mines Pty Ltd

Energy Technology Data Exchange (ETDEWEB)

Koperski, J

1986-04-01

Ranger Uranium Mines monitors ambient levels of ionising radiation in accordance with the Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores 1980. The radionuclides of interest are: U-238, Th-230, Ra-226, Pb-210, Po-210 and Rn-222 daughters (RnD). The aerial pathway appears to be the critical pathway for transfer of radioactive contaminants to the local population. The average annual effective dose equivalent rate to a member of the critical group from inhalation of long-lived radioactive dust is 0.22 +- 0.10 mSv/y, about 22 times below the limit of 5 mSv/y. No experimental evidence was found for any overall increase of exposure of the public due to consumption of bush food items collected in the vicinity of the Ranger site. The average exposure of the critical group member to RnD is likely to be 2.1 +- 3.1 mWLM/y, or 200 times below the annual limit of 0.4 WLM.

Advanced REACH tool: A Bayesian model for occupational exposure assessment

NARCIS (Netherlands)

McNally, K.; Warren, N.; Fransman, W.; Entink, R.K.; Schinkel, J.; Van Tongeren, M.; Cherrie, J.W.; Kromhout, H.; Schneider, T.; Tielemans, E.

2014-01-01

This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate

Assessing the risks from exposure to radon in dwellings

International Nuclear Information System (INIS)

Walsh, P.J.; Lowder, W.M.

1983-07-01

The factors used to assess the radiation dose and health risks from human exposure to radon in dwellings are critically reviewed in this summary. Sources of indoor radon and determinants of air concentrations and exposure levels are given as well as the uncertainties that exist in their formulation. Methods of assessing health effects from inhalation of radon and its progeny are discussed with emphasis on dosimetry of radon daughters and formulation of risk per dose values. Finally, methods of assessing risks for general population exposures to indoor radon concentrations are treated

Exposure assessment strategies for non-routine work operations (NORWO)

International Nuclear Information System (INIS)

Lew, V.; Cohen, J.; Chiusano, S.; McGann, C.; McLouth, L.

1993-09-01

The DOE Office of Health and Office of Safety and Health Oversight are collaborating to address special problems related to assessment of worker exposures associated with nonroutine work operations (NORWO), such as hazardous waste operations. Both off ices have formed a single working group of industrial hygiene specialists from the DOE, fts contractors, and other interested organizations which held its first meeting July 1993. The DOE Canter of Excellence for Exposure Assessment, maintained at Lawrence Livermore National Laboratory, is assisting in developing reasonable policies and guidance on exposure assessment strategies for NORWO. The DOE EA Center will research this subject to assist the DOE in formulating guidance documents for conduct of EA for NORWO that are consistent with the DOE draft EAS technical standard. This report presents an outline for a section on NORWO intended for inclusion in the DOE technical guidance documents for EAS and Hazardous Waste Operations Emergency Response (HAZWOPER) currently under development by the DOE Industrial Hygiene Division (EH-412), and EM-23. Also presented is a review of the July 21--23 meeting and a proposed workplan for developing NORWO exposure assessment procedures. Appendices include: (A) David Weitzman's memo on NORWO, (B) Draft annotated outline of the technical standard for the Assessment of Employee Exposure to Hazardous Chemical Agents, (C) ORC proposed EAS standard, (D) program for the October 31--November 3, 1993 ACGIH Conference on Occupational Exposure Databases, (E) agenda for the July 15, 1993 DOE meeting on NORWO, (F) viewgraphs used in formal presentations at this meeting, (G) Hanford Exposure Assessment Program Plan, and (H) a list of attendees and invitees to the July DOE -- NORWO meeting

Gas exchange in the Pee Dee River based on 222Rn evasion

International Nuclear Information System (INIS)

Moore, W.S.; Elsinger, R.J.

1983-01-01

Excess 222 Rn concentrations decrease downstream in the fresh water section of the Pee Dee River. Ground water is the primary source of the excess 222 Rn to the River. Using the radon concentration gradients determined during four sampling periods, gas exchange rates based on the stagnant film model are calculated. Stagnant film thicknesses range from 19 μm to 48 μm and mass transfer coefficients range from 2.1 m/d to 4.1 m/d

ON A PROLONGATION CONSTRUCTION FOR LOCAL NON-DIVERGENT VECTOR FIELDS ON Rn

Directory of Open Access Journals (Sweden)

A. M. Lukatsky

2015-01-01

Full Text Available The problem of a prolongation of non-divergent vector field, defined in a vicinity of zero in Rn t, to a finite non-divergent vector field on Rn is considered. Explicit formulas for the elements of the simple Lie algebra of non-divergent vector from the well-known Cartan series are obtained. This construction allows to move from the Euler equations for the ideal incompressible fluid to the Euler equations on finite-dimensional Lie groups.

210Pb in bone in vivo - a biodosimeter for assessing uranium miner radon progeny exposure

International Nuclear Information System (INIS)

Guilmette, R.A.; Snipes, M.B.; Hoover, M.D.; Leggett, R.W.; Laurer, G.R.; Lambert, W.E.; Coons, T.A.; Gilliland, F.D.

2002-01-01

A joint analysis of the results of 11 epidemiological studies of lung cancer among uranium miners has shown a significant level of variability in the relative risk per unit of exposure - in the range of a factor of 30 (Lubin et al., 1994). A significant fraction of the uncertainty associated with these risk coefficients may be due to differences in the methods and quality of data used in calculating cumulative exposures, in WLM, for the various miner populations. We hypothesize that in vivo measurement of 210 Pb, a long-lived radon decay product that is retained in bone, will provide an improved measure of Rn progeny exposures received by individual miners during their mining careers. To accomplish such in vivo measurements, the lovelace in vivo bioassay facility (LIVBF) was modified to obtain an optimized counting geometry for measuring 210 Pb in the skull. Six 12.7 cm diameter phoswich detectors were positioned about the head of a reclining subject (one in the posterior, and one in the anterior position, and four about the mid-sagittal plane), and photon emission from the skull was measured using anticoincidence multichannel analysis electronics. We analyzed the in vivo data from about 90 former uranium miners from the grants mining district, and compared the recorded WLM exposures for each uranium miner (data from the UNM epidemiological data base) with a WLM exposure calculated using a model developed specifically for this study. This model couples a Pb biokinetic model with the ICRP publication 66 respiratory tract dosimetry model. The analyses show that the independent measurements of exposure are statistically correlated, but with a large degree of variability occurring among individual values, and that a major source of uncertainty in mining exposure estimation is the uncertainty involved in accounting for non-mining sources of 210 Pb. (orig.)

Exposure monitoring and risk assessment of biphenyl in the workplace.

Science.gov (United States)

Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

2015-05-13

This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m³, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10⁻⁴ (central tendency exposure) and 0.56 × 10⁻⁴ (reasonable maximum exposure), which is below the acceptable risk value of 1.0 × 10⁻⁴. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

Directory of Open Access Journals (Sweden)

Hyeon-Yeong Kim

2015-05-01

Full Text Available This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure and 0.56 × 10−4 (reasonable maximum exposure, which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

Exposure assessment of process-related contaminants in food by biomarker monitoring.

Science.gov (United States)

Rietjens, Ivonne M C M; Dussort, P; Günther, Helmut; Hanlon, Paul; Honda, Hiroshi; Mally, Angela; O'Hagan, Sue; Scholz, Gabriele; Seidel, Albrecht; Swenberg, James; Teeguarden, Justin; Eisenbrand, Gerhard

2018-01-01

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario's and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.

222Rn concentration in the outdoor atmosphere and its relation to the atmospheric stability

International Nuclear Information System (INIS)

Holy, K.; Boehm, R.; Bosa, I.; Polaskova, A.; Hola, O.

1998-01-01

The radon in the outdoor atmosphere has been monitored continuously since 1991. On the basis of the measured data mainly the average daily and the average annual courses of the 222 Rn concentrations have been studied. The annual courses of 222 Rn concentration are similar for all years. They present the annual variations. The average course of the 222 Rn concentration calculated on the basis of all continual measurements in the years 1991-1997 reaches the maximum value in October and the minimum value in April. The average daily courses of the 222 Rn concentration for the individual months of the year. The average daily courses have a form of waves with a maximum in the morning hours and with a minimum in the afternoon. The maximal amplitudes of daily waves have been reached in the summer months, from June till August. The amplitudes of daily waves are very small at the end of an autumn and during the winter months. The analysis of the daily waves and annual courses of 222 Rn showed that the amplitudes of the daily waves are in proportion to the global solar radiation irradiating the Earth's surface. The day duration influence on the phase of the daily wave and the wind velocity influence mainly on the level of the radon concentration. For the study of the relation of the radon concentration in the outdoor atmosphere to the stability the data of the atmosphere were obtained and they were correlated with the radon concentration. The results indicate that the 222 Rn concentrations int he outdoor atmosphere could be used for determination of the vertical atmospheric stability and these ones could reflect the atmospheric stability more completely than the different classifications based on the knowledge pertinent to the meteorological parameters. (authors)

Dynamical Symmetry Breaking in RN Quantum Gravity

Directory of Open Access Journals (Sweden)

A. T. Kotvytskiy

2011-01-01

Full Text Available We show that in the RN gravitation model, there is no dynamical symmetry breaking effect in the formalism of the Schwinger-Dyson equation (in flat background space-time. A general formula for the second variation of the gravitational action is obtained from the quantum corrections hμν (in arbitrary background metrics.

Direct determination of 222Rn gas using the electret to remove daughters at formation

International Nuclear Information System (INIS)

Harley, N.H.

1981-01-01

Five compact, portable, continuous 222 Rn monitors have been constructed inhouse. Printed data can be obtained from intervals ranging from 10 minutes to 990 minutes. One hour count interval provides a lower limit of detection of 0.03 pCi 222 Rn/l -1 which is sufficient for measurement of any environmental level encountered. Calibration of the units was accomplished in the EML radon calibration room and the typical calibration factor is 165 counts per hour per pCi 222 Rn/l. The units are now being field tested. Two indoor/outdoor pairs are located in a single family dwelling and in a high rise apartment. One unit is being used for special studies

Non-ionizing electromagnetic exposure assessment and dosimetry

International Nuclear Information System (INIS)

Paulsson, L.E.

1992-11-01

A comprehensive literature survey of advancements in the area 'human exposure assessment and dosimetry' for the years 1988-1992 has been performed by the author and published elsewhere. In the present report that material has been complemented with a historical background and a thorough description of the physical principles behind the methods and techniques. The report covers strategies, principles, methods, limitations and future developments for the area of human exposure assessment and dosimetry of electromagnetic fields form extremely low frequencies up to and including microwaves

Geodesics in (Rn, d1

Directory of Open Access Journals (Sweden)

Mehmet KILIÇ

2016-09-01

Full Text Available The notion of geodesic, which may be regarded as an extension of the line segment in Euclidean geometry to the space we study in, has an important place in many branches of geometry, such as Riemannian geometry, Metric geometry, to name but a few. In this article, the concept of geodesic in a metric space will be introduced, then geodesics in the space (Rn, d1 will be characterized. Furthermore, some examples will be presented to demonstrate the effectiveness of the main result.

DREAM: a method for semi-quantitative dermal exposure assessment

NARCIS (Netherlands)

Wendel de Joode, B. van; Brouwer, D.H.; Kromhout, H.; Hemmen, J.J. van

2003-01-01

This paper describes a new method (DREAM) for structured, semi-quantitative dermal exposure assessment for chemical or biological agents that can be used in occupational hygiene or epidemiology. It is anticipated that DREAM could serve as an initial assessment of dermal exposure, amongst others,

Estimate of 50-year dose commitment to various organs and tissues of the body from inhalation of 222Rn free of its daughters

International Nuclear Information System (INIS)

Bernard, S.R.; Ford, M.R.; Snyder, W.S.

1976-01-01

Some topics discussed are as follows: retention of 222 Rn in fat, bone, heart, muscle, skin, testes, and urinary bladder; retention equations for Rn; decay scheme for Rn and 226 Ra; metabolic models for Po, Pb, and Bi; dose estimates to target organs for 222 Rn and its daughters that are not inhaled but produced from decay of 222 Rn; and estimation of MPC for bone marrow, gonads, and total body

Spilleregler i musikterapi med børn

DEFF Research Database (Denmark)

Holck, Ulla

2005-01-01

Artiklen gennemgår udvalgte eksempler på anvendelse af spilleregler i musikterapi med børneklientgrupper. Efter en kort introduktion af Priestleys syn på analytisk musikterapi med børn, præsenteres læseren således for en række caseeksempler fra faglitteraturen, der giver indblik i udformning og a...

Vold mod førskolebørn

DEFF Research Database (Denmark)

Oldrup, Helene; Lindstrøm, Maia; Korzen, Sara

Denne rapport handler om praksis og barrierer for opsporing af og underretning om vold mod førskolebørn. Rapporten er baseret på 22 kvalitative interviews med fagfolk inden for dagpasning, sundhedsvæsen og det sociale system. Undersøgelsen viser bl.a., at en del af fagfolkene ofte tøver med at un...

Expected indoor 222Rn levels in counties with very high and very low lung cancer rates

International Nuclear Information System (INIS)

Cohen, B.L.

1989-01-01

Counties in the US with high lung cancer rates should have higher average 222 Rn levels than counties with low lung cancer rates, assuming the average 222 Rn level in a county is not correlated with other factors that cause lung cancer. The magnitude of this effect was calculated, using the absolute risk model, the relative risk model, and an intermediate model, for females who died in 1950-1969. The results were similar for all three models. We concluded that, ignoring migration, the average Rn level in the highest lung cancer counties should be about three times higher than in the lowest lung cancer counties according to the theory. Preliminary data are presented indicating that the situation is quite the opposite: The average Rn level in the highest lung cancer counties was only about one-half that in the lowest lung cancer counties

Recent developments in carcinogenic risk assessment

International Nuclear Information System (INIS)

Krewski, D.; Murdoch, D.; Withey, J.R.

1989-01-01

In this paper, recent developments in the quantitative assessment of carcinogenic risks based on toxicological and epidemiological data are reviewed. In particular, model-free approaches to low-dose risk assessment which involve only the assumption of low-dose linearity are considered. Measures of carcinogenic potency which avoid the need to extrapolate to low doses are also described. The allometric bases for converting risk estimates between species are then discussed. Pharmacokinetic models for determining the dose delivered to the target tissue are examined, and the implications of using such models in extrapolating between doses, of exposure, and species are examined. The application of these concepts in chemical and radiation carcinogenesis is illustrated by means of brief case studies of methylene chloride and Rn. Biologically motivated cancer models based on the initiation-promotion-progression theory of carcinogenesis are discussed and compared with the classical multistage model. The estimation of risks with time-dependent exposure patterns is considered, and conditions under which the use of a time-weighted average dose is appropriate are identified. Finally, the estimation of carcinogenic risks posed by exposure to complex mixtures is explored. 92 references

Exposure assessment of tetrafluoroethylene and ammonium perfluorooctanoate 1951-2002.

Science.gov (United States)

Sleeuwenhoek, Anne; Cherrie, John W

2012-03-01

To develop a method to reconstruct exposure to tetrafluoroethylene (TFE) and ammonium perfluorooctanoate (APFO) in plants producing polytetrafluoroethylene (PTFE) in the absence of suitable objective measurements. These data were used to inform an epidemiological study being carried out to investigate possible risks in workers employed in the manufacture of PTFE and to study trends in exposure over time. For each plant, detailed descriptions of all occupational titles, including tasks and changes over time, were obtained during semi-structured interviews with key plant personnel. A semi-quantitative assessment method was used to assess inhalation exposure to TFE and inhalation plus dermal exposure to APFO. Temporal trends in exposure to TFE and APFO were investigated. In each plant the highest exposures for both TFE and APFO occurred in the polymerisation area. Due to the introduction of control measures, increasing process automation and other improvements, exposures generally decreased over time. In the polymerisation area, the annual decline in exposure to TFE varied by plant from 3.8 to 5.7% and for APFO from 2.2 to 5.5%. A simple method for assessing exposure was developed which used detailed process information and job descriptions to estimate average annual TFE and APFO exposure on an arbitrary semi-quantitative scale. These semi-quantitative estimates are sufficient to identify relative differences in exposure for the epidemiological study and should good data become available, they could be used to provide quantitative estimates for all plants across the whole period of operation. This journal is © The Royal Society of Chemistry 2012

Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

Energy Technology Data Exchange (ETDEWEB)

Dhondt, Stijn, E-mail: stijn.dhondt@vub.ac.be [Department of Medical Sociology and Health Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090, Brussels (Belgium); Beckx, Carolien, E-mail: Carolien.Beckx@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Degraeuwe, Bart, E-mail: Bart.Degraeuwe@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Lefebvre, Wouter, E-mail: Wouter.Lefebvre@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Kochan, Bruno, E-mail: Bruno.Kochan@uhasselt.be [Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Bellemans, Tom, E-mail: Tom.Bellemans@uhasselt.be [Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Int Panis, Luc, E-mail: Luc.intpanis@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Macharis, Cathy, E-mail: cjmachar@vub.ac.be [Department MOSI-Transport and Logistics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels (Belgium); Putman, Koen, E-mail: kputman@vub.ac.be [Department of Medical Sociology and Health Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090, Brussels (Belgium); Interuniversity Centre for Health Economics Research (I-CHER), Vrije Universiteit Brussel, Brussels (Belgium)

2012-09-15

In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO{sub 2} and O{sub 3} using only home addresses were compared with models that integrate all time-activity patterns-including time in commute-for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO{sub 2} using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: Black-Right-Pointing-Pointer Exposure to ambient air pollution was assessed integrating population mobility. Black-Right-Pointing-Pointer This dynamic exposure was integrated into a health impact assessment. Black-Right-Pointing-Pointer Differences between the dynamic and residential exposure were quantified. Black-Right-Pointing-Pointer Modest differences in health impact were found at a regional level. Black

Assessment of risk of potential exposures on facilities industries

International Nuclear Information System (INIS)

Leocadio, Joao Carlos

2007-03-01

This work develops a model to evaluate potential exposures on open facilities of industrial radiography in Brazil. This model will decisively contribute to optimize operational, radiological protection and safety procedures, to prevent radiation accidents and to reduce human errors in industrial radiography. The probabilistic safety assessment (PSA) methodology was very useful to assess potential exposures. The open facilities of industrial radiography were identified as the scenario to be analyzed in what concerns the evaluation of potential exposures, due to their high accidents indices. The results of the assessment of potential exposures confirm that the industrial radiography in Brazil is a high-risk practice as classified by the IAEA. The risk of potential exposure was estimated to be 40,5 x 10 -2 per year in Brazil, having as main consequences injuries to the workers' hands and arms. In the world scene, the consequences are worst, leading to fatalities of people, thus emphasizing the high risk of industrial radiography. (author)

Integration of Probabilistic Exposure Assessment and Probabilistic Hazard Characterization

NARCIS (Netherlands)

Voet, van der H.; Slob, W.

2007-01-01

A method is proposed for integrated probabilistic risk assessment where exposure assessment and hazard characterization are both included in a probabilistic way. The aim is to specify the probability that a random individual from a defined (sub)population will have an exposure high enough to cause a

Evolution of the concept of reduction the exposure levels to natural radiation and the new international standards in protection of radon

International Nuclear Information System (INIS)

Pavlovic, R.; Pavlovic, S.

1995-01-01

The new scientific information in last decade have caused significant changes in radiation protection standards. The subject of reduction the exposure to natural radiation is now regulated in more details. Some new aspects in protection against Rn exposure at home and work are discussed. (author)

Quantifying human exposure to air pollution - moving from static monitoring to spatio-temporally resolved personal exposure assessment

DEFF Research Database (Denmark)

Steinle, Susanne; Reis, Stefan; Sabel, Clive E

2013-01-01

exposure studies to accurately assess human health risks. ? We discuss potential and shortcomings of methods and tools with a focus on how their development influences study design. ? We propose a novel conceptual model for integrated health impact assessment of human exposure to air pollutants. ? We......Quantifying human exposure to air pollutants is a challenging task. Ambient concentrations of air pollutants at potentially harmful levels are ubiquitous in urban areas and subject to high spatial and temporal variability. At the same time, every individual has unique activity-patterns. Exposure...... results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population...

Pla(y)cefully – når børn finder sted gennemt transformationer af institutionelle konstruktioner

DEFF Research Database (Denmark)

Nørgård, Rikke Toft; Toft, Herdis

2014-01-01

, designere, kunstnere, pædagoger og forældre understøtte, at børn finder sted som mennesker i verden? Et svar kunne være, at vi, snarere end at indplacere børn i ’satte’ institutionelle kontekster, lader børn ’sætte’ deres eget sted, fx ved at lade dem ’pla(y)cefully’ transformere, hvad et gulv i en...... børnehave kan være, lade dem opdage, opfinde, opbygge og omskabe det. Lade børn eksperimentere og konstruere sig frem til egne pla(y)ces. Gennem en transdisciplinær tilgang kombinerer dette paper indsigter og resultater fra to særskilte forskningsprojekter omkring børn i børnehaver. Det ene projekt har...... gennem leg med artefakter, redskaber og teknologier i krydsfeltet mellem interaktionsdesign, human-centered design, digitale teknologier og konstruktionisme. Gennem den transdisciplinære tilgang til pla(y)ces og pla(y)cefullness og på bagrund af centrale emergerende kategorier i de to feltarbejder...

Measurements of ²²²Rn, ²²⁰Rn, and CO₂ Emissions in Natural CO₂ Fields in Wyoming: MVA Techniques for Determining Gas Transport and Caprock Integrity

Energy Technology Data Exchange (ETDEWEB)

Kaszuba, John [Univ. of Wyoming, Laramie, WY (United States); Sims, Kenneth [Univ. of Wyoming, Laramie, WY (United States)

2014-09-30

An integrated field-laboratory program evaluated the use of radon and CO₂ flux measurements to constrain source and timescale of CO₂ fluxes in environments proximate to CO₂ storage reservoirs. By understanding the type and depth of the gas source, the integrity of a CO₂ storage reservoir can be assessed and monitored. The concept is based on correlations of radon and CO₂ fluxes observed in volcanic systems. This fundamental research is designed to advance the science of Monitoring, Verification, and Accounting (MVA) and to address the Carbon Storage Program goal of developing and validating technologies to ensure 99 percent storage performance. Graduate and undergraduate students conducted the research under the guidance of the Principal Investigators; in doing so they were provided with training opportunities in skills required for implementing and deploying CCS technologies. Although a final method or “tool” was not developed, significant progress was made. The field program identified issues with measuring radon in environments rich in CO₂. Laboratory experiments determined a correction factor to apply to radon measurements made in CO₂-bearing environments. The field program also identified issues with radon and CO₂-flux measurements in soil gases at a natural CO₂ analog. A systematic survey of radon and CO₂ flux in soil gases at the LaBarge CO₂ Field in Southwest Wyoming indicates that measurements of ²²²Rn (radon), ²²⁰Rn (thoron), and CO₂ flux may not be a robust method for monitoring the integrity of a CO₂ storage reservoir. The field program was also not able to correlate radon and CO₂ flux in the CO₂-charged springs of the Thermopolis hydrothermal system. However, this part of the program helped to motivate the aforementioned laboratory experiments that determined

Sünteetiline lähenemine on edu pant / Tamara Luuk, Olga Pärn, Priit Pärn ; intervjueerinud Reet Varblane

Index Scriptorium Estoniae

Luuk, Tamara, 1952-

2011-01-01

Brügges kuni jaanuari lõpuni 2011 eksponeeritud belgia kunstniku Luc Tuymansi kureeritud näitusest "Madalaima tasandi reaalsus. Visioon Kesk-Euroopast" ("The Reality of the Lowest Rank. A Vision of Central Europe"). Osalema oli kutsutud 43 kunstnikku üle maailma. Priit Pärn Eestist esines söejoonistuste ja filmilõikudega näitusel ning eraldi filmiprogrammiga

Variable number of tandem repeat polymorphisms of the interleukin-1 receptor antagonist gene IL-1RN: a novel association with the athlete status

Directory of Open Access Journals (Sweden)

Ryckman Kelli K

2010-02-01

Full Text Available Abstract Background The interleukin-1 (IL-1 family of cytokines is involved in the inflammatory and repair reactions of skeletal muscle during and after exercise. Specifically, plasma levels of the IL-1 receptor antagonist (IL-1ra increase dramatically after intense exercise, and accumulating evidence points to an effect of genetic polymorphisms on athletic phenotypes. Therefore, the IL-1 family cytokine genes are plausible candidate genes for athleticism. We explored whether IL-1 polymorphisms are associated with athlete status in European subjects. Methods Genomic DNA was obtained from 205 (53 professional and 152 competitive non-professional Italian athletes and 458 non-athlete controls. Two diallelic polymorphisms in the IL-1β gene (IL-1B at -511 and +3954 positions, and a variable number tandem repeats (VNTR in intron 2 of the IL-1ra gene (IL-1RN were assessed. Results We found a 2-fold higher frequency of the IL-1RN 1/2 genotype in athletes compared to non-athlete controls (OR = 1.93, 95% CI = 1.37-2.74, 41.0% vs. 26.4%, and a lower frequency of the 1/1 genotype (OR = 0.55, 95% CI = 0.40-0.77, 43.9% vs. 58.5%. Frequency of the IL-1RN 2/2 genotype did not differ between groups. No significant differences between athletes and controls were found for either -511 or +3954 IL-1B polymorphisms. However, the haplotype (-511C-(+3954T-(VNTR2 was 3-fold more frequent in athletes than in non-athletes (OR = 3.02, 95% CI = 1.16-7.87. Interestingly, the IL-1RN 1/2 genotype was more frequent in professional than in non-professional athletes (OR = 1.92, 95% CI = 1.02-3.61, 52.8% vs. 36.8%. Conclusions Our study found that variants at the IL-1ra gene associate with athletic status. This confirms the crucial role that cytokine IL-1ra plays in human physical exercise. The VNTR IL-1RN polymorphism may have implications for muscle health, performance, and/or recovery capacities. Further studies are needed to assess these specific issues. As VNTR IL-1RN

The Multivariate Müntz-Szasz Problem in Weighted Banach Space on Rn

Directory of Open Access Journals (Sweden)

Xiangdong Yang

2014-01-01

Full Text Available The purpose of this paper is to give an extension of Müntz-Szasz theorems to multivariable weighted Banach space. Denote by {λk=(λk1,λk2,...,λkn}k=1∞ a sequence of real numbers in R+n. The completeness of monomials {tλk} in Cα is investigated, where Cα is the weighted Banach spaces which consist of complex continuous functions f defined on Rn with f(t exp(-α(t vanishing at infinity in the uniform norm.

Cea-Expo: A facility exposure matrix to assess passed exposure to chemical carcinogens and radionuclides of nuclear workers

International Nuclear Information System (INIS)

Telle-Lamberton, M.; Bouville, P.; Bergot, D.; Gagneau, M.; Marot, S.; Telle-Lamberton, M.; Giraud, J.M.; Gelas, J.M.

2005-01-01

A 'Facility-Exposure Matrix' (FEM) is proposed to assess exposure to chemical carcinogens and radionuclides in a cohort of nuclear workers. Exposures are to be attributed in the following way: a worker reports to an administrative unit and/or is monitored for exposure to ionising radiation in a specific workplace. These units are connected with a list of facilities for which exposure is assessed through a group of experts. The entire process of the FEM applied in one of the nuclear centres included in the study shows that the FEM is feasible: exposure durations as well as groups of correlated exposures are presented but have to be considered as possible rather than positive exposures. Considering the number of facilities to assess (330), ways to simplify the method are proposed: (i) the list of exposures will be restricted to 18 chemical products retained from an extensive bibliography study; (ii) for each of the following classes of facilities: nuclear reactors, fuel fabrication, high-activity laboratories and radiation chemistry, accelerators and irradiators, waste treatment, biology, reprocessing, fusion, occupational exposure will be deduced from the information already gathered by the initial method. Besides taking into account confusion factors in the low doses epidemiological study of nuclear workers, the matrix should help in the assessment of internal contamination and chemical exposures in the nuclear industry. (author)

Pärnävaaran koiraurheilukeskuksen markkinatutkimus

OpenAIRE

Primetta, Jaana

2017-01-01

Opinnäytetyön aiheena oli Pärnävaaran koiraurheilukeskuksen markkinatutkimus, jonka tavoitteena oli saada tietoa pohjoiskarjalaisten koiraharrastajien aktiivisuudesta ja kiinnostuksesta käyttää maakunnan alueella sijaitsevia koiraharrastushalleja. Lisäksi haluttiin selvittää, mitkä tekijät vaikuttavat harrastajien päätöksiin harrastustilaa valittaessa ja mitä toiveita ja odotuksia harrastajilla on koiraharrastushalleja kohtaan. Opinnäytetyössä toteutettiin kaksi erillistä kvantitati...

Estimation of effective dose from Rn emanating from 'the minus ion' effect wallpaper

International Nuclear Information System (INIS)

Yoshizawa, Y.; Minowa, H.; Morita-Murase, Y.; Furuta, E.

2006-01-01

We have examined the wall papers which declared 'the minus ion' effect to estimate external and internal exposure dose from them. Results of gamma-ray spectrometry revealed that they contain 0.03 to 0.35 Bq·g -1 of Th-series nuclides, 208 Tl, 212 Pb, 212 Bi and 228 Ac, and U-series one, 214 Pb. Distributions of radioactive nuclides in the samples were measured using an imaging plate and a FLA-2000 (Fuji Photo Film). The radiation doses from the printed side of the wall papers were 5 to 15 times higher than that of the back side. The 222 Rn concentrations emanating from the wall papers in a sealed container of 50 liter were measured using the PICO-RAD radon detectors. One wall paper showed two to five times higher than the background value. (author)

Assessment of exposure dose to workers in virtual decommissioning environments

International Nuclear Information System (INIS)

Jeong, KwanSeong; Moon, JeiKwon; Choi, ByungSeon; Hyun, Dongjun; Lee, Jonghwan; Kim, Ikjune; Kim, GeunHo; Seo, JaeSeok

2014-01-01

This paper is intended to suggest the method analyze and assess the exposure dose to workers in virtual decommissioning environments. To simulate a lot of decommissioning scenarios, decommissioning environments were designed in virtual reality. To simulate and assess the exposure dose to workers, human model also was designed in virtual environments. These virtual decommissioning environments made it possible to real-time simulate and assess the exposure dose to workers. This work was to be able to simulate scenarios of decommissioning so that exposure dose to workers could be measured and assessed. To establish the plan of exposure dose to workers during decommissioning of nuclear facilities before decommissioning activities are accomplished, the method of simulation assessment was developed in virtual radiological environments. But this work was developed as a tool of simulation for single subject mode. Afterwards, the simulation environment for multi-subjects mode will be upgraded by simultaneous modules with networking environments. Then the much more practical method will be developed by changing number of workers and duration of time under any circumstances of decommissioning

Assessment of exposure dose to workers in virtual decommissioning environments

Energy Technology Data Exchange (ETDEWEB)

Jeong, KwanSeong; Moon, JeiKwon; Choi, ByungSeon; Hyun, Dongjun; Lee, Jonghwan; Kim, Ikjune; Kim, GeunHo; Seo, JaeSeok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

This paper is intended to suggest the method analyze and assess the exposure dose to workers in virtual decommissioning environments. To simulate a lot of decommissioning scenarios, decommissioning environments were designed in virtual reality. To simulate and assess the exposure dose to workers, human model also was designed in virtual environments. These virtual decommissioning environments made it possible to real-time simulate and assess the exposure dose to workers. This work was to be able to simulate scenarios of decommissioning so that exposure dose to workers could be measured and assessed. To establish the plan of exposure dose to workers during decommissioning of nuclear facilities before decommissioning activities are accomplished, the method of simulation assessment was developed in virtual radiological environments. But this work was developed as a tool of simulation for single subject mode. Afterwards, the simulation environment for multi-subjects mode will be upgraded by simultaneous modules with networking environments. Then the much more practical method will be developed by changing number of workers and duration of time under any circumstances of decommissioning.

Diskussioner om børneperspektiv og inddragelse af børn - er barnet på vej ud med badevandet?

DEFF Research Database (Denmark)

Warming, H.

2007-01-01

Artiklen omhandler den nye sociologiske barndomsforsknings fordring på børneperspektiv og inddragelse af børn. Indledningsvis gøres der rede for, hvordan der i den nye barndomsforskning er blevet argumenteret både erkendelsesteoretisk og etisk for børneperspektiv og inddragelse af børn i forsknin......Artiklen omhandler den nye sociologiske barndomsforsknings fordring på børneperspektiv og inddragelse af børn. Indledningsvis gøres der rede for, hvordan der i den nye barndomsforskning er blevet argumenteret både erkendelsesteoretisk og etisk for børneperspektiv og inddragelse af børn i...

Assessment pozzolanicity waste red ceramics produced in Valley Assu / RN; Avaliacao da atividade pozolanica dos residuos de ceramica vermelha produzidos no Vale do Assu / RN

Energy Technology Data Exchange (ETDEWEB)

Palhares, Rodolfo de Azevedo; Pereira, Arthur Ruan da Silva; Cabral, Kleber Cavalcanti; Nobrega, Andreza Kelly Costa, E-mail: rodolfo.palhares@hotmail.com, E-mail: arthurruan_rn@hotmail.com, E-mail: kleber.cabral@ufersa.edu.br, E-mail: akcn123@hotmail.com [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil). Departamento de Ciencias Exatas

2016-07-01

It is known that both the cement industry as a ceramist contribute much to the generation of environmental impacts. Be the Co2 in the atmosphere, as well as the generation of excessive waste, reaching 20%. The objective of this study is to analyze the potential pozollanic of waste from the red ceramic industries Valley Assu / RN, in order that this material can be incorporated as alternative raw material in the manufacture of ecological and similar brick, replacing partially in its composition Portland cement. Thus contributing to reducing the environmental impact produced by both the ceramics industry, such as cement. To evaluate the efficiency of pozollanic material, it was made sample preparation and then the physico-chemical characterization. After performing tests, it was noticed that the material has the minimum requirements established in standard to be considered as pozollanic material. (author)

The measurement of 222Rn in drinking water by low-level liquid scintillation counting

International Nuclear Information System (INIS)

Barnett, J.M.; McKlveen, J.W.

1992-01-01

Radon-222 (Rn) has universally been found in well water. Non-stagnant ground water is collected at the well head while the well is pumping. The water is adjusted to a slow, non-aerated, steady flow through a clear tube, and a 500 ml glass bottle is filled. The sample is tightly capped after a high meniscus has developed. In the laboratory, standard 22 ml glass vials are filled with 10 ml of a toluene based mineral oil LS cocktail. Then, two 5 ml sample aliquots are pipetted into the vial. Vials are capped tightly, shaken vigorously, and placed in the liquid scintillation (LS) counter. Secular equilibrium is established in approximately 4 hours, after which samples are counted for 100 minutes each. The counting efficiency for Rn and progeny ranges between 315 to 345 percent depending on the chosen spectral window. The average background is about 6 cpm. A total of 28 wells were tested for Rn in the Carefree-Cave Creek, Arizone, USA area. The area's geometric average Rn concentration was found to be 46.5 Bq*1 -1 . The associated estimated lung dose is 0.51 mSv*y -1 . (author) 8 refs.; 1 fig.; 1 tab

Exposure of workers to radon progeny in the Baradla cave at Aggtelek

International Nuclear Information System (INIS)

Dezsoe, Z.

2004-01-01

By measuring the radon concentration using active technique in all parts of the cave visited in a tour and furthermore by assessing also the time spent at these locations, it is possible to determine the radon level averaged over a tour. The time averaged radon concentration along the route of the cave investigated has been estimated to 970 Bq/m 3 in summer and 410 Bq/m 3 in winter. We concluded that in 62 % of the year cave climate shows warm season and only in 38 % cold season Rn-levels. On this basis the yearly mean radon concentration averaged over the tour comes to 750 Bq/m3. This figure, however, should not be used to estimate exposure because the number of visitors is substantially higher in summer than in winter, so that the tour guides work much more in summer (about 750 tours) than in winter (about 270 tours). Taking this into account, the yearly mean Rn concentration is to 820 Bq/m 3 . Since the dose is delivered by radon progeny and not radon itself, one has to also assess the equilibrium factor representative in the cave. The data available in the literature show that F is always larger than under normal ambient conditions. Published values are between 0.5 - 0.8. As part of this work, several radon progeny concentration measurements have also been made in the Baradla cave at different locations. The results confirm the occurrence of high F-values in caves. Furthermore, the equilibrium factor is increased by the presence of humans (visitors or cavers). In the Virgin Cave, F = 0.5 - 0.6, which increases steadily to about 0.8 due to the activity of man. In this work, F = 0.8 has been used for the dose assessment. Using the ICRP 65 dosimetry model, exposure was calculated to be 4.04 mJhm 3 , which corresponds to an effective dose of 5.8 mSv. (P.A.)

222Rn and 14CO2 concentrations in the surface layer of the atmosphere

International Nuclear Information System (INIS)

Holy, K.; Chudy, M.; Sivo, A.; Richtarikova, M.; Boehm, R.; Polaskova, A.; Vojtyla, P.; Bosa, I.; Hola, O.

2002-01-01

Long-term monitoring of the Δ 14 C in the atmospheric near-ground CO 2 has been realized in Bratislava and Zlkovce, situated near the nuclear power plant Jaslovske Bohunice. Until 1993, the monthly mean Δ 14 C values showed a high variability. The annual means of Δ 14 C were about 30 per mille higher at Zlkovce than in highly industrialised Bratislava. An important change in the behaviour of the 14 C data has occurred since 1993. The records from both stations show the similar course, mainly due to the fact that there do not occur deep winter minima in Bratislava. This behaviour corresponds to the lower values of the total fossil fuel CO 2 emissions in the years after 1993 when compared to the previous years. At present, both sets of data show that the 14 C concentration is about 10% above the natural level. Since 1987 also the 222 Rn concentration in the surface layer of the atmosphere has been measured in Bratislava. These measurements provided an extensive set of the 222 Rn data characteristic for the inland environment with high level of atmospheric pollution. The seasonal and daily variations of the 222 Rn concentration were observed. The investigation of the relation between the monthly mean diurnal courses of the 222 Rn concentration and the atmospheric stability proved a high correlation between them. The 222 Rn data were used to interpret the anomalous Δ 14 C values in the surface layer of the atmosphere. (author)

Probabilistic assessment of wildfire hazard and municipal watershed exposure

Science.gov (United States)

Joe Scott; Don Helmbrecht; Matthew P. Thompson; David E. Calkin; Kate Marcille

2012-01-01

The occurrence of wildfires within municipal watersheds can result in significant impacts to water quality and ultimately human health and safety. In this paper, we illustrate the application of geospatial analysis and burn probability modeling to assess the exposure of municipal watersheds to wildfire. Our assessment of wildfire exposure consists of two primary...

The assessment of the aircrew exposure

International Nuclear Information System (INIS)

Tommasino, L.

2002-01-01

In 1991 ICRP first included exposure of aircraft crew to cosmic radiation as occupational exposure. The European Dosimetry Group (EURADOS) established a working group in 1992 to address this issue. The report 'Exposure of Air Crew to Cosmic Radiation' was published in the European Commission's Radiation Protection series as report 85. The first section of the report assesses the existing data on radiation exposure, describes the radiation environment at civil aviation altitudes and summarizes the computational models that have been developed to describe the cosmic ray radiation field in the atmosphere. The second section describes the quantities used to assess the radiation doses. It is clear that conventional radiation protection dosimetry as applied on the ground is not quite applicable to the situation for air crews. A multinational European research project was launched to investigate the problem of cosmic rays and dosimetry at aviation altitudes. The major objective was to measure the flux and energy spectra of neutrons and charged particles over a wide energy interval at aviation altitudes and compare the results with those calculated with various computer codes. Within the project much progress was made in different areas, for instance the determination of the fundamental physical characteristics of the cosmic radiation field at aircraft altitudes, development of instrumentation, measurements of dose rates and route doses and application of routine radiation protection. Surveys of air crew exposure have been carried out with different advanced dosimetric systems and comparisons were made between passive and real-time detector systems

The Future of Exposure Assessment: Perspectives from the ...

Science.gov (United States)

The British Occupational Hygiene Society, in collaboration with the Institute of Occupational Medicine, the University of Manchester, the UK Health and Safety Executive, and the University of Aberdeen hosted the 7th International Conference on the Science of Exposure Assessment (X2012) on 2 July–5 July 2012 in Edinburgh, UK. The conference ended with a special session at which invited speakers from government, industry, independent research institutes, and academia were asked to reflect on the conference and discuss what may now constitute the important highlights or drivers of future exposure assessment research. This article summarizes these discussions with respect to current and future technical and methodological developments. For the exposure science community to continue to have an impact in protecting public health, additional efforts need to be made to improve partnerships and cross-disciplinary collaborations, although it is equally important to ensure that the traditional occupational exposure themes are still covered as these issues are becoming increasingly important in the developing world. To facilitate this the ‘X’ conferences should continue to retain a holistic approach to occupational and non-occupational exposures and should actively pursue collaborations with other disciplines and professional organizations to increase the presence of consumer and environmental exposure scientists. The National Exposure Research Laboratory′s (NERL′

Determination of 222Rn in water samples from wells and springs in Tokyo by a modified integral counting method

International Nuclear Information System (INIS)

Homma, Y.; Murase, Y.; Handa, K.; Murakami, I.

1997-01-01

222 Rn in 2L-water samples was extracted with 30 mL toluene, and 21 mL of the toluene solution was transferred into a liquid scintillation vial, in which PPO - 2,5-diphenyloxazole was placed in advance. The total activity of 222 Rn in the water sample was calculated based on the Ostwald's coefficient of solubilities of 222 Rn in toluene and water at the temperature of the sample water and the volume of water and toluene. About 40% of 222 Rn dissolved in 2L-water sample can be collected. After allowing to stand for 3.5 h, the equilibrium mixture of 222 Rn and its daughters was measured with an Aloka liquid scintillation spectrometer using a modified integral counting method which extrapolates the integral counting curve not to the zero pulse-height, but to the zero detection threshold, an average energy required to produce a measurable pulse, of the liquid scintillation spectrometer. The general method which agitates water sample (usually about 10 mL) with a liquid scintillation cocktail is practical when the activity of 222 Rn is high. By adding 10 mL of water sample, however, it is possible also to add variable amounts of quencher. In some cases water sample is preserved with nitric acid. The slope of the integral counting rate curve increases as quench level of the sample increases. Therefore, it is clear that the modified integral counting method gives more accurate 222 Rn concentrations for water samples of strong quench than the conventional integral counting method. 222 Rn sample of 0.2 Bq/L can be determined within an overall uncertainty of 3.1%

222Rn, 226Ra, and U in drinking water in Hungary

International Nuclear Information System (INIS)

Szerbin, P.; Koeteles, G.

2002-01-01

Among radionuclides ingested by drinking water the most important ones are radon, radium and uranium, causing radiation exposure of the lungs, bones, and gastro-intestinal organs, mainly kidneys. For this reason, as a part of the National Environmental Health Program to determine the main risk factors of the Hungarian population from environmental substances, 222 Rn, 226 Ra, and U concentrations were measured in domestic water supplies. Water samples were taken from all of the 19 Hungarian counties. Three cities were chosen from each county by the criteria of number of the population. Samples were taken from the communal drinking water supplies. Radon was determined by short lived daughter products using scintillation technique after water degassing into Lucas cells. Radium and uranium were determined after chemical separation, by Lucas scintillation method and by liquid scintillation technique. The obtained results were compared to the available literature data. Radioactivity levels were assessed for conformity with the Hungarian standards, WHO guidelines, and used for dose calculations. It was concluded that the radioactivity of the drinking water in Hungary is in the order of magnitude of the worldwide average. The measured radioactivity levels never exceeded the limits of the valid Hungarian standards for annual intake limits and were adequate to WHO guidelines. It was found that public doses from radon, radium, and uranium ingestion by drinking water were 12.7, 8.8, and 7.3 μSv y -1 , respectively. Summarizing the results of the survey it was concluded that comparing these doses to the public dose from other natural sources of radiation are negligibly small. (author)

Udvikling af dialogisk kompetence hos børn med CI

DEFF Research Database (Denmark)

Dammeyer, Jesper Herup; Carstensen, Susanne; Karlshøj, Bente

2011-01-01

Der er relativ god viden om børn med CI’s sproglige udvikling, hvad angår sproglyde og ord. Derimod er der i den internationale forskning kun beskrevet meget lidt om den del af den sproglige udvikling, som ligger ud over sætningsniveauet. Denne artikel beskriver nogle af de resultater, der er...... fremkommet ved et fire år langt følgestudie af tre førskolebørn med CI. Børnenes sproglige udvikling er observeret og analyseret i forhold til dialogiske kompetencer. Resultaterne peger på, at børnene udvikler gode talesproglige kompetencer i løbet af den fireårige periode, men at børnene har brug for støtte...

Measurement of Rn-222 concentrations in building materials used in jordan

Energy Technology Data Exchange (ETDEWEB)

Ismail, A M; Abumyrad, K M; Kullab, M K; Albataina, B A [Physics Dept., Yarmouk University, 219-10 Irbid, (Jordan)

1995-10-01

In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m{sup 3} to 267 Bq/m{sup 3} with an average of 189 Bq/m{sup 3}. These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs.

Measurement of Rn-222 concentrations in building materials used in jordan

International Nuclear Information System (INIS)

Ismail, A.M.; Abumyrad, K.M.; Kullab, M.K.; Albataina, B.A.

1995-01-01

In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m 3 to 267 Bq/m 3 with an average of 189 Bq/m 3 . These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs

A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying; Bowman, Kenneth P.; Genton, Marc G.; Tokay, Ali

2014-01-01

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

A Matérn model of the spatial covariance structure of point rain rates

KAUST Repository

Sun, Ying

2014-07-15

It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

Quantitative self-assessment of exposure to solvents among shoe repair men

NARCIS (Netherlands)

Hertsenberg, S.; Brouwer, D.; Lurvink, M.; Rubingh, C.; Rijnders, E.; Tielemans, E.

2007-01-01

Self-assessment of exposure (SAE) refers to any exposure assessment methodology wherein the worker takes an active role in establishing his or her exposure status. The objective of this study was to investigate the reliability and feasibility of SAE approaches among shoe repair workers collecting

Technical Overview of Ecological Risk Assessment - Analysis Phase: Exposure Characterization

Science.gov (United States)

Exposure Characterization is the second major component of the analysis phase of a risk assessment. For a pesticide risk assessment, the exposure characterization describes the potential or actual contact of a pesticide with a plant, animal, or media.

Spatial and Temporal Dynamics in Air Pollution Exposure Assessment

Science.gov (United States)

Dias, Daniela; Tchepel, Oxana

2018-01-01

Analyzing individual exposure in urban areas offers several challenges where both the individual’s activities and air pollution levels demonstrate a large degree of spatial and temporal dynamics. This review article discusses the concepts, key elements, current developments in assessing personal exposure to urban air pollution (seventy-two studies reviewed) and respective advantages and disadvantages. A new conceptual structure to organize personal exposure assessment methods is proposed according to two classification criteria: (i) spatial-temporal variations of individuals’ activities (point-fixed or trajectory based) and (ii) characterization of air quality (variable or uniform). This review suggests that the spatial and temporal variability of urban air pollution levels in combination with indoor exposures and individual’s time-activity patterns are key elements of personal exposure assessment. In the literature review, the majority of revised studies (44 studies) indicate that the trajectory based with variable air quality approach provides a promising framework for tackling the important question of inter- and intra-variability of individual exposure. However, future quantitative comparison between the different approaches should be performed, and the selection of the most appropriate approach for exposure quantification should take into account the purpose of the health study. This review provides a structured basis for the intercomparing of different methodologies and to make their advantages and limitations more transparent in addressing specific research objectives. PMID:29558426

Assessment of inhomogeneous ELF magnetic field exposures

International Nuclear Information System (INIS)

Leitgeb, N.; Cech, R.; Schroettner, J.

2008-01-01

In daily life as well as at workplaces, exposures to inhomogeneous magnetic fields become very frequent. This makes easily applicable compliance assessment methods increasingly important. Reference levels have been defined linking basic restrictions to levels of homogeneous fields at worst-case exposure conditions. If reference levels are met, compliance with basic restrictions can be assumed. If not, further investigations could still prove compliance. Because of the lower induction efficiency, inhomogeneous magnetic fields such as from electric appliances could be allowed exceeding reference levels. To easily assess inhomogeneous magnetic fields, a quick and flexible multi-step assessment procedure is proposed. On the basis of simulations with numerical, anatomical human models reference factors were calculated elevating reference levels to link hot-spot values measured at source surfaces to basic limits and allowing accounting for different source distance, size, orientation and position. Compliance rules are proposed minimising assessment efforts. (authors)

Unbiased stereological estimation of d-dimensional volume in Rn from an isotropic random slice through a fixed point

DEFF Research Database (Denmark)

Jensen, Eva B. Vedel; Kiêu, K

1994-01-01

Unbiased stereological estimators of d-dimensional volume in R(n) are derived, based on information from an isotropic random r-slice through a specified point. The content of the slice can be subsampled by means of a spatial grid. The estimators depend only on spatial distances. As a fundamental ...... lemma, an explicit formula for the probability that an isotropic random r-slice in R(n) through 0 hits a fixed point in R(n) is given....

Standardizing measurement, sampling and reporting for public exposure assessments

Energy Technology Data Exchange (ETDEWEB)

Rochedo, Elaine R.R. [Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear, Av. Salvador Allende s/No. CEP 22780-160 Rio de Janeiro, RJ (Brazil)], E-mail: elaine@ird.gov.br

2008-11-15

UNSCEAR assesses worldwide public exposure from natural and man-made sources of ionizing radiation based on information submitted to UNSCEAR by United Nations Member States and from peer reviewed scientific literature. These assessments are used as a basis for radiation protection programs of international and national regulatory and research organizations. Although UNSCEAR describes its assessment methodologies, the data are based on various monitoring approaches. In order to reduce uncertainties and improve confidence in public exposure assessments, it would be necessary to harmonize the methodologies used for sampling, measuring and reporting of environmental results.

Forord til den danske udgave af bogen rådgivning og terapi med børn

DEFF Research Database (Denmark)

Kragh-Müller, Grethe

2007-01-01

En bog om rådgivning og terapi med børn med en integrativ indfaldsvinkel. Der tages udgangspunkt i forskellige teorier og metoder.......En bog om rådgivning og terapi med børn med en integrativ indfaldsvinkel. Der tages udgangspunkt i forskellige teorier og metoder....

Musikterapi med kontakt- og kommunikationssvage børn

DEFF Research Database (Denmark)

Frederiksen, Britta Vinkler

2009-01-01

I artiklen beskrives, hvordan musikterapi er med til at støtte en målrettet udviklingsproces hos børn, med diagnoser som Asperger syndrom, autisme, opmærksomhedsforstyrrelser, ADHD o.lign. Musikkens kvaliteter beskrives og illustreres gennem vignetter fra terapiforløb, der alle er foregået i Klinik...

A structured observational method to assess dermal exposure to manufactured nanoparticles: DREAM as an initial assessment tool

NARCIS (Netherlands)

Duuren-Stuurman, B. van; Pelzer, J.; Moehlmann, C.; Berges, M.; Bard, D.; Wake, D.; Mark, D.; Jankowska, E.; Brouwer, D.

2010-01-01

Preliminary results of inventories of exposure scenarios for nanomaterials have indicated possible dermal exposure. Within the NANOSH project focused on occupational safety and health aspects of nanotechnology a shortened version of the observational DeRmal Exposure AssessMent (DREAM) method was

A restructuring of RN1 package for MIDAS computer code

International Nuclear Information System (INIS)

Park, S. H.; Kim, D. H.; Kim, K. R.

2003-01-01

RN1 package, which is one of two fission product-related packages in MELCOR, has been restructured for the MIDAS computer code. MIDAS is being developed as an integrated severe accident analysis code with a user-friendly graphical user interface and modernized data structure. To do this, data transferring methods of current MELCOR code are modified and adopted into the RN1 package. The data structure of the current MELCOR code using FORTRAN77 causes a difficult grasping of meaning of the variables as well as waste of memory. New features of FORTRAN90 make it possible to allocate the storage dynamically and to use the user-defined data type, which lead to an efficient memory treatment and an easy understanding of the code. Restructuring of the RN1 package addressed in this paper includes module development, subroutine modification, and treats MELGEN, which generates data file, as well as MELCOR, which is processing a calculation. The verification has been done by comparing the results of the modified code with those from the existing code. As the trends are similar to each other, it hints that the same approach could be extended to the entire code package. It is expected that code restructuring will accelerate the code domestication thanks to direct understanding of each variable and easy implementation of modified or newly developed models

A restructuring of RN2 package for MIDAS computer code

International Nuclear Information System (INIS)

Park, S. H.; Kim, D. H.

2003-01-01

RN2 package, which is one of two fission product-related package in MELCOR, has been restructured for the MIDAS computer code. MIDAS is being developed as an integrated severe accident analysis code with a user-friendly graphical user interface and data structure. To do this, data transferring methods of current MELCOR code are modified and adopted into the RN2 package. The data structure of the current MELCOR code using FORTRAN77 causes a difficult grasping of meaning of the variables as well as waste of memory. New features of FORTRAN90 make it possible to allocate the storage dynamically and to use the user-defined data type, which lead to an efficient memory treatment and an easy understanding of the code. Restructuring of the RN2 package addressed in this paper includes module development, subroutine modification, and treats MELGEN, which generates data file, as well as MELCOR, which is processing a calculation. The validation has been done by comparing the results of the modified code with those from the existing code. As the trends are the similar to each other, it hints that the same approach could be extended to the entire code package. It is expected that code restructuring will accelerate the code domestication thanks to direct understanding of each variable and easy implementation of modified or newly developed models

Task-based exposure assessment of nanoparticles in the workplace

International Nuclear Information System (INIS)

Ham, Seunghon; Yoon, Chungsik; Lee, Euiseung; Lee, Kiyoung; Park, Donguk; Chung, Eunkyo; Kim, Pilje; Lee, Byoungcheun

2012-01-01

Although task-based sampling is, theoretically, a plausible approach to the assessment of nanoparticle exposure, few studies using this type of sampling have been published. This study characterized and compared task-based nanoparticle exposure profiles for engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. Two ENMW and two welding workplaces were selected for exposure assessments. Real-time devices were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations, and off-line analysis was performed using an electron microscope. Workplace tasks were recorded by researchers to determine the concentration profiles associated with particular tasks/events. This study demonstrated that exposure profiles differ greatly in terms of concentrations and size distributions according to the task performed. The size distributions recorded during tasks were different from both those recorded during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the type of workplace but also the concentration metrics. The concentrations measured by surface area and the number concentrations measured by condensation particle counter, particulate matter 1.0, and TWA mass concentrations all showed a similar pattern, whereas the number concentrations measured by scanning mobility particle sizer indicated that the welding fume concentrations at one of the welding workplaces were unexpectedly higher than were those at workplaces that were engineering nanoparticles. This study suggests that a task-based exposure assessment can provide useful information regarding the exposure profiles of nanoparticles and can therefore be used as an exposure assessment tool.

Biodegradation kinetics for pesticide exposure assessment.

Science.gov (United States)

Wolt, J D; Nelson, H P; Cleveland, C B; van Wesenbeeck, I J

2001-01-01

Understanding pesticide risks requires characterizing pesticide exposure within the environment in a manner that can be broadly generalized across widely varied conditions of use. The coupled processes of sorption and soil degradation are especially important for understanding the potential environmental exposure of pesticides. The data obtained from degradation studies are inherently variable and, when limited in extent, lend uncertainty to exposure characterization and risk assessment. Pesticide decline in soils reflects dynamically coupled processes of sorption and degradation that add complexity to the treatment of soil biodegradation data from a kinetic perspective. Additional complexity arises from study design limitations that may not fully account for the decline in microbial activity of test systems, or that may be inadequate for considerations of all potential dissipation routes for a given pesticide. Accordingly, kinetic treatment of data must accommodate a variety of differing approaches starting with very simple assumptions as to reaction dynamics and extending to more involved treatments if warranted by the available experimental data. Selection of the appropriate kinetic model to describe pesticide degradation should rely on statistical evaluation of the data fit to ensure that the models used are not overparameterized. Recognizing the effects of experimental conditions and methods for kinetic treatment of degradation data is critical for making appropriate comparisons among pesticide biodegradation data sets. Assessment of variability in soil half-life among soils is uncertain because for many pesticides the data on soil degradation rate are limited to one or two soils. Reasonable upper-bound estimates of soil half-life are necessary in risk assessment so that estimated environmental concentrations can be developed from exposure models. Thus, an understanding of the variable and uncertain distribution of soil half-lives in the environment is

Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway

CERN Multimedia

Maximilien Brice

2003-01-01

Photos 01,02: Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway signing the guest book; standing, Dr Carlo Wyss Photo 03: Luncheon in honour of Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway, April 2003. Around the table, from left to right: State Secretary Haugstad (standing); Prof. Cecilia Jarlskog, Adviser to the Director-General for Member State Relations; Mr Morten Knutsen, CERN staff - Purchase; Mr Jens Vigen, CERN staff, Library and Norwegian Contact; Prof. Steinar Stapnes, Prof. Univ. of Oslo and Physicist in the ATLAS experiment (in profile), Dr Carlo Wyss, Director for Accelerators (standing), Dr Leif Westgaard, Senior Adviser, Research Council of Norway, CERN Delegate. Photo 04: Luncheon in honour of Mr Bjørn Haugstad, State Secretary, Ministry of Education and Research, Norway, April 2003. Around the table, from left to right: State Secretary Haugstad (standing); Mr Jens Vigen, CERN staff, Library and Norwegian Contact; Prof. Steinar ...

Addressing bystander exposure to agricultural pesticides in life cycle impact assessment

DEFF Research Database (Denmark)

Ryberg, Morten Walbech; Rosenbaum, Ralph K.; Mosqueron, Luc

2018-01-01

Residents living near agricultural fields may be exposed to pesticides drifting from the fields after application to different field crops. To address this currently missing exposure pathway in life cycle assessment (LCA), we developed a modeling framework for quantifying exposure of bystanders...... magnitude of individual bystanders can be substantially larger than the exposure of populations not living in the proximity to agricultural fields. Our framework for assessing bystander exposure to pesticide applications closes a relevant gap in the exposure assessment included in LCA for agricultural...... to pesticide spray drift from agricultural fields. Our framework consists of three parts addressing: (1) loss of pesticides from an agricultural field via spray drift; (2) environmental fate of pesticide in air outside of the treated field; and (3) exposure of bystanders to pesticides via inhalation...

Risk assessment of exposure to radon concentration in indoor atmosphere and drinking water of Shimoga city, Karnataka, India

International Nuclear Information System (INIS)

Rangaswamy, D.R.; Sannappa, J.; Srinivasa, E.

2016-01-01

The exposure of population to natural sources of radiation has become an important issue in terms of radiological protection. The major contribution of dose from natural radiation in normal background regions arises due to inhalation of alpha-emitting radon and thoron, and their progenies, which are ubiquitous in both indoor and outdoor environs. The aim of the present study is to measure indoor radon, thoron and their progeny levels in the dwellings of Shimoga city and radon concentration in drinking water and to estimate the annual effective dose. The indoor concentration of radon, thoron and their progeny was measured using Solid-State Nuclear Track Detectors (SSNTDs) based twin chamber dosimeter cups. The 222 Rn concentration in drinking water was estimated by the Emanometry technique

Model equations for Calculating Rn-gas Concentrations in Air of Uranium Exploratory Tunnels, Allouga, West-Central Sinai , Egypt

International Nuclear Information System (INIS)

Abdel-Monem, A.A.; Soliman, S.F.H.; Abd El-Kader, F.H.; El-Naggar, A.M.; Eissa, H.M.; Abd El-Hafez, A.A.

2001-01-01

Gabal Allouga area is located some 40 km due east from Abu Zenima town on the east coast of the Gulf of Suez, West-Central Sinai, Egypt. A network of exploratory tunnels totaling 670m in length and approximately 2x2 m in cross section, were excavated within a paleosol clayey bed. They host (Fe, Mn)-, Cu-, and U-mineralizations. Portions of the tunnels are naturally ventilated and others portions are non-ventilated and show ground water seepage through fractures. Model equations were developed for calculating the Rn-gas concentrations in the air of the tunnels under dry conditions where Rn-gas transport is mainly by air flow through porous media as well as for wet conditions where Rn-gas transport is mainly by ground water flow into the tunnels. Under dry conditions the model calculated Rn-gas concentrations(15.2-60.6 PCi/1) are consistent with measured values by active techniques (3.26-22.85 pCi/1) and by SSNTD techniques (19-69.1 pCi/1) when the Rn-emanation coefficient (alpha= 0.05-0.2), the emanating rock thickness (X=10 cm) and U-concentration averages 30 ppm. Under wet and non-ventilated conditions the model calculated Rn-gas concentrations (159-1248 pCi/1) are consistent with the measured values by active techniques (231-1348 pCi/1) and by SSNTD techniques (144-999pCi/1), when the Rn-emanation coefficient (alpha=0.1-0.25), the ground water flow (F=0.04-0.10 ml/s -1 cm -2 ) and U-concertrations (100-250ppm)

An approach for assessing human exposures to chemical mixtures in the environment

International Nuclear Information System (INIS)

Rice, Glenn; MacDonell, Margaret; Hertzberg, Richard C.; Teuschler, Linda; Picel, Kurt; Butler, Jim; Chang, Young-Soo; Hartmann, Heidi

2008-01-01

Humans are exposed daily to multiple chemicals, including incidental exposures to complex chemical mixtures released into the environment and to combinations of chemicals that already co-exist in the environment because of previous releases from various sources. Exposures to chemical mixtures can occur through multiple pathways and across multiple routes. In this paper, we propose an iterative approach for assessing exposures to environmental chemical mixtures; it is similar to single-chemical approaches. Our approach encompasses two elements of the Risk Assessment Paradigm: Problem Formulation and Exposure Assessment. Multiple phases of the assessment occur in each element of the paradigm. During Problem Formulation, analysts identify and characterize the source(s) of the chemical mixture, ensure that dose-response and exposure assessment measures are concordant, and develop a preliminary evaluation of the mixture's fate. During Exposure Assessment, analysts evaluate the fate of the chemicals comprising the mixture using appropriate models and measurement data, characterize the exposure scenario, and estimate human exposure to the mixture. We also describe the utility of grouping the chemicals to be analyzed based on both physical-chemical properties and an understanding of environmental fate. In the article, we also highlight the need for understanding of changes in the mixture composition in the environment due to differential transport, differential degradation, and differential partitioning to other media. The section describes the application of the method to various chemical mixtures, highlighting issues associated with assessing exposures to chemical mixtures in the environment

Assessment of Industrial Exposure to Magnetic Fields (invited paper)

International Nuclear Information System (INIS)

Chadwick, P.

1999-01-01

Magnetic field strengths produced by industrial processes can be very large, but they often exhibit a marked spatial variation. Whilst there may be the potential for exposures of workers to be high, actual exposure will be determined to a great extent by working practices. Possible metrics for epidemiological studies might be based on the temporal variability of exposure as well as maximum operator exposure or time-weighted average exposure and, whilst it might be possible to estimate these quantities from spot magnetic field strength measurements and observed working practices, this might be very difficult to achieve in practice. An alternative would be the use of a logging dosemeter: this paper describes some of the results of exposure assessments carried out in industrial environments with a modified EMDEX II magnetic field dosemeter. Magnetic fields in industrial environments often have waveforms which are not purely sinusoidal. Distortion can be introduced by the magnetic saturation of transformer and motor cores, by rectification, by poor matching between oscillator circuits and loads and when thyristors are used to control power. The resulting repetitive but non-sinusoidal magnetic field waveforms can be recorded and analysed; the spectral data may be incorporated into possible exposure metrics. It is also important to ensure that measurement instrumentation is responding appropriately in a non-sinusoidal field and this can only be done if the spectral content of the field is characterised fully. Some non-sinusoidal magnetic field waveforms cannot be expressed as a harmonic series. Specialist instrumentation and techniques are needed to assess exposure to such fields. Examples of approaches to the assessment of exposure to repetitive and non-repetitive magnetic fields are also discussed. (author)

Instruments to assess and measure personal and environmental radiofrequency-electromagnetic field exposures.

Science.gov (United States)

Bhatt, Chhavi Raj; Redmayne, Mary; Abramson, Michael J; Benke, Geza

2016-03-01

Radiofrequency-electromagnetic field (RF-EMF) exposure of human populations is increasing due to the widespread use of mobile phones and other telecommunication and broadcasting technologies. There are ongoing concerns about potential short- and long-term public health consequences from RF-EMF exposures. To elucidate the RF-EMF exposure-effect relationships, an objective evaluation of the exposures with robust assessment tools is necessary. This review discusses and compares currently available RF-EMF exposure assessment instruments, which can be used in human epidemiological studies. Quantitative assessment instruments are either mobile phone-based (apps/software-modified and hardware-modified) or exposimeters. Each of these tool has its usefulness and limitations. Our review suggests that assessment of RF-EMF exposures can be improved by using these tools compared to the proxy measures of exposure (e.g. questionnaires and billing records). This in turn, could be used to help increase knowledge about RF-EMF exposure induced health effects in human populations.

Instruments to assess and measure personal and environmental radiofrequency-electromagnetic field exposures

International Nuclear Information System (INIS)

Bhatt, Chhavi R.; Redmayne, Mary; Abramson, Michael J.; Benke, Geza

2016-01-01

Radiofrequency-electromagnetic field (RF-EMF) exposure of human populations is increasing due to the widespread use of mobile phones and other telecommunication and broadcasting technologies. There are ongoing concerns about potential short- and long-term public health consequences from RF-EMF exposures. To elucidate the RF-EMF exposure-effect relationships, an objective evaluation of the exposures with robust assessment tools is necessary. This review discusses and compares currently available RF-EMF exposure assessment instruments, which can be used in human epidemiological studies. Quantitative assessment instruments are either mobile phone-based (apps/software-modified and hardware-modified) or exposimeters. Each of these tool has its usefulness and limitations. Our review suggests that assessment of RF-EMF exposures can be improved by using these tools compared to the proxy measures of exposure (e.g. questionnaires and billing records). This in turn, could be used to help increase knowledge about RF-EMF exposure induced health effects in human populations.

Existing Default Values and Recommendations for Exposure Assessment - A Nordic Exposure Group Project 2011

DEFF Research Database (Denmark)

Höglund, Lena; Räisänen, Jouni; Hämäläinen, Anne-Maija

range of more or less well-documented values originating from many different sources. The purpose of this report is to give an overview and to evaluate exposure factors that are currently used by the authorities and industry in the exposure assessments for both adults (occupational and consumer exposure......) and children in relation to REACH. Another important purpose of the report is to contribute towards a further harmonisation of exposure factors by giving recommendations of most valid and representative defaults. These recommendations can be used besides REACH also in biocide's and plant protection product...

Development Of Protocols For Simultaneous Measurements Of Rn, Tn Using Nuclear Track Detectors And Trial Application In Mining Areas Of Vietnam

International Nuclear Information System (INIS)

Bui Dac Dung; Trinh Van Giap; Le Dinh Cuong; Tran Khanh Minh; Nguyen Huu Quyet; Nguyen Van Khanh; Tran Ngoc Toan

2013-01-01

Radioactive gases Radon (Rn) and Thoron (Tn) contribute of more than 50% of natural radiation dose. However, separate measurements of Rn and Tn have not been paid enough attention. An Intergovernmental Cooperation Project was conducted at the Institute for Nuclear Science and Technology with the help from Hungarian experts. The main tasks of the project were to finalize 02 protocols for simultaneous measurements of Rn and Tn using nuclear track detectors and to test these protocols in investigating the concentrations of Rn and Tn, calculating the natural dose due to Rn and Tn, and evaluating the increased radiation dose and radiation safety due to mining activities. Main results of the project include 02 protocols for simultaneous measurements of Rn and Tn and the test results in the mining areas. Rn and Tn concentrations inside the coal mining tunnels are in the average level of Vietnam and the world. Tn concentration inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant was found to be very high, up to 2931 Bq/m 3 . Based on annual effective dose calculation, workers inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant could receive an annual effective dose due to Rn and Tn of 4.890 mSv/year, and the increasing dose of 4.710 mSv/year is for higher than 1 mSv/year recommended by the IAEA. (author)

Retrospective internal radiation exposure assessment in occupational epidemiology

International Nuclear Information System (INIS)

Neton, J.W.; Flora, J.T.; Spitz, H.B.; Taulbee, T.D.

2000-01-01

Epidemiologic studies of workers at U.S. Department of Energy facilities are being conducted by the U.S. National Institute for Occupational Safety and Health to evaluate the health risk associated with exposure to sources of external and internal ionizing radiation. While exposure to external sources of radiation can be estimated from personal dosimeter data, reconstruction of exposure due to internally deposited radioactivity is more challenging because bioassay monitoring data is frequently less complete. Although comprehensive monitoring was provided for workers with the highest internal exposures, the majority of workers were monitored relatively infrequently. This monitoring was conducted to demonstrate compliance with regulations rather than to evaluate exposure for use in epidemiologic studies. Attributes of past internal monitoring programs that challenge accurate exposure assessment include: incomplete characterization of the workplace source term; a lack of timely measurements; insensitive and/or nonspecific bioassay measurements; and the presence of censored data. In spite of these limitations, many facilities have collected a large amount of worker and workplace monitoring information that can be used to evaluate internal exposure while minimizing worker misclassification. This paper describes a systematic approach for using the available worker and workplace monitoring data that can lead to either a qualitative or quantitative retrospective assessment of internal exposures. Various aspects of data analysis will be presented, including the evaluation of minimum detectable dose, the treatment of censored data, and the use of combinations of bioassay and workplace data to characterize exposures. Examples of these techniques applied to a cohort study involving chronic exposure scenarios to uranium are provided. A strategy for expressing exposure or dose in fundamental, unweighted units related to the quantity of radiation delivered to an organ will also

The European radon mapping project

International Nuclear Information System (INIS)

Bossew, P.; Tollefsen, T.; Gruber, V.; De Cort, M.

2013-01-01

There is almost unanimous agreement that indoor radon (Rn) represents a hazard to human health. Large-scale epidemiological studies gave evidence that Rn is the second-most important cause o flung cancer after smoking and that also relatively low Rn concentrations can be detrimental. This has increasingly led to attempts to limit Rn exposure through regulation, mainly building codes. The proposed Euratom Basic Safety Standards (BSS) require Member States to establish Rn action plans aimed at reducing Rn risk, and to set reference values for Imitating indoor Rn concentration. In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary lo (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project. which is planned eventually 10 comprise geographical assessments of ali sources of exposure to natural radiation. Started first, a map of indoor Rn is now in an advanced phase, but still incomplete as national Rn surveys are ongoing in a number of European countries. A European map of geogenic Rn, conceptually and technically more complicated, was started in 2008. The main difficulty encountered is heterogeneity of survey designs, measurement and evaluation methods and database semantics and structures. An important part or the work on the Atlas is therefore to harmonize data and methods. We present the current state of the Rn maps and discuss some of the methodological challenges. (author)

The European radon mapping project

Energy Technology Data Exchange (ETDEWEB)

Bossew, P., E-mail: pbossew@bfs.de [German Federal Office for Radiation Protection, Berlin (Germany); Tollefsen, T.; Gruber, V.; De Cort, M., E-mail: tore.tollefsen@jrc.ec.europa.eu, E-mail: valeria.gruber@gmail.com, E-mail: marc.de-cort@jrc.ec.europa.eu [Institute for Transuranium Elements, Ispra, VA (Italy). DG Joint Research Centre. European Commission

2013-07-01

There is almost unanimous agreement that indoor radon (Rn) represents a hazard to human health. Large-scale epidemiological studies gave evidence that Rn is the second-most important cause o flung cancer after smoking and that also relatively low Rn concentrations can be detrimental. This has increasingly led to attempts to limit Rn exposure through regulation, mainly building codes. The proposed Euratom Basic Safety Standards (BSS) require Member States to establish Rn action plans aimed at reducing Rn risk, and to set reference values for Imitating indoor Rn concentration. In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary lo (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project. which is planned eventually 10 comprise geographical assessments of ali sources of exposure to natural radiation. Started first, a map of indoor Rn is now in an advanced phase, but still incomplete as national Rn surveys are ongoing in a number of European countries. A European map of geogenic Rn, conceptually and technically more complicated, was started in 2008. The main difficulty encountered is heterogeneity of survey designs, measurement and evaluation methods and database semantics and structures. An important part or the work on the Atlas is therefore to harmonize data and methods. We present the current state of the Rn maps and discuss some of the methodological challenges. (author)

Human exposure assessment: Approaches for chemicals (REACH) and biocides (BPD)

NARCIS (Netherlands)

Hemmen, J.J. van; Gerritsen-Ebben, R.

2008-01-01

The approaches that are indicated in the various guidance documents for the assessment of human exposure for chemicals and biocides are summarised. This reflects the TNsG (Technical notes for Guidance) version 2: human exposure assessment for biocidal products (1) under the BPD (Biocidal Products

A 'delayed' counting method to determine indoor Rn-222 levels indirectly

CERN Document Server

Iannopollo, V; Trimarchi, M; Tripepi, M G; Vermiglio, G

2001-01-01

A new indirect and 'delayed' way is presented to determine indoor concentration of Rn-222 by best-fitting methods. If a rapid knowledge of Rn-222 levels is required and if a detection system is not available in situ, it is possible to obtain concentration of radioactive gas by determining of 'delayed' counts of Po-214. The 'delay' time consists of two or three hours. The method is based on the use of cellulose filters for particulate collection and on the analysis of samples by alpha spectroscopy. It is also possible to obtain concentrations of short-lived radon daughters Po-218, Pb-214, Bi-214, which are very important quantities in a medical framework.

Assessment of occupational exposure to radiofrequency fields and radiation

International Nuclear Information System (INIS)

Cooper, T. G.; Allen, S. G.; Blackwell, R. P.; Litchfield, I.; Mann, S. M.; Pope, J. M.; Van Tongeren, M. J. A.

2004-01-01

The use of personal monitors for the assessment of exposure to radiofrequency fields and radiation in potential future epidemiological studies of occupationally exposed populations has been investigated. Data loggers have been developed for use with a commercially available personal monitor and these allowed personal exposure records consisting of time-tagged measurements of electric and magnetic field strength to be accrued over extended periods of the working day. The instrumentation was worn by workers carrying out tasks representative of some of their typical daily activities at a variety of radio sites. The results indicated significant differences in the exposures of workers in various RF environments. A number of measures of exposure have been examined with a view to assessing possible exposure metrics for epidemiological studies. There was generally a good correlation between a given measure of electric field strength and the same measure of magnetic field strength. (authors)

Nurses' impact on quality of care: lessons from RN4CAST

Directory of Open Access Journals (Sweden)

Walter Sermeus

2015-12-01

Full Text Available Introduction: The RN4CAST - study (acronym for Nurse Forecasting in Europe was launched in 2009 and ended in 2011 under the European Union's Seventh Framework Programme. The aim of the RN4CAST-study was to study how features of work environments and qualifications of the nurse workforce impact nurse retention, burnout among nurses and patient outcomes. Methods: The study was conducted in twelve European countries and was conducting a cross-sectional survey in 500 hospitals in which more than 33,000 nurses and more than 11,000 patients were involved. These data were linked to patient outcome data from administrative databases. Results: The study showed that patient outcomes such as patient mortality and patient satisfaction is highly related to nurse staffing characteristics such as patient-to-nurse ratios, nurse qualification and nursing work environment. Also nurse outcomes such as burnout, intention-to-leave, job satisfaction are related to staffing adequacy and nursing work environment. Discussion and conclusion: The RN4CAST study generated a large evidence base of nurse workforce issues across European health systems which is quite unique in terms of the number and qualification of nursing staff, the quality of working environments, burnout rates, job satisfaction rates, intention-to-leave rates that can be used for policy making.

Categorization framework to aid exposure assessment of nanomaterials in consumer products

DEFF Research Database (Denmark)

Hansen, Steffen Foss; Michelson, Evan S.; Kamper, Anja

2008-01-01

Exposure assessment is crucial for risk assessment for nanomaterials. We propose a framework to aid exposure assessment in consumer products. We determined the location of the nanomaterials and the chemical identify of the 580 products listed in the inventory maintained by the Woodrow Wilson Inte...

Tracing submarine groundwater discharge in the NE Gulf of Mexico by 222Rn

International Nuclear Information System (INIS)

Young, J.E.; Burnett, W.C.; Chanton, J.P.; Cable, P.H.; Corbett, D.R.

1993-01-01

Inputs of freshwater and dissolved components to the ocean by submarine groundwater discharge (SGD) have been largely neglected as source functions for biogeochemical budgets. In order to locate and quantify groundwater inputs, a tracing technique has been developed using 222 Rn, a member of the natural 238 U decay-series. Because 222 Rn has a short half-life (t 1/2 = 3.84 days), is an inert gas, is relatively easy to measure at low concentrations, and has concentrations in groundwater several orders of magnitude greater than seawater, it should make an excellent tracer. Excess 222 Rn concentrations far above ''normal'' ocean values were found in the bottom waters of the northeastern Gulf of Mexico, which suggests this region has significant groundwater discharge. After measuring high water column inventories of excess 222 Rn in this region, an advection/diffusion model was applied to evaluate potential benthic sources of radon. The model is designed to account for sediment diffusion of radon and includes a groundwater term for advective flow into the overlying water. Flow rates and concentrations are adjusted in the model to balance the large difference in the measured water column inventories and the inventory predicted by sediment diffusion alone. The vertical diffusive/advective transport determines the shape of the concentration gradient and fluxes at the sediment-water interface are calculate based on these terms. The authors work shows that SGD could account for as much as 95% of the radon inventory in these offshore waters

IL1 receptor antagonist gene IL1-RN variable number of tandem repeats polymorphism and cancer risk: a literature review and meta-analysis.

Directory of Open Access Journals (Sweden)

Ying Zhang

Full Text Available IL1 receptor antagonist (IL1RA and IL1beta (IL1β, members of the pro-inflammatory cytokine interleukin-1 (IL1 family, play a potential role against infection and in the pathogenesis of cancers. The variable number of tandem repeats (VNTR polymorphism in the second intron of the IL1 receptor antagonist gene (IL1-RN and a polymorphism in exon 5 of IL1B (IL1B+3954C>T, rs1143634 have been suggested in predisposition to cancer risk. However, studies have shown inconsistent results. To validate any association, a meta-analysis was performed with 14,854 cases and 19,337 controls from 71 published case-control studies for IL1-RN VNTR and 33 eligible studies contained 7,847 cases and 8917 controls for IL1B +3954. Odds ratios (ORs with 95% confidence intervals (CIs were calculated from comparisons to assess the strength of the association. There was significant association between the IL1-RN VNTR polymorphism and the risk of cancer for any overall comparison. Furthermore, cancer type stratification analysis revealed that there were significantly increased risks of gastric cancer, bladder cancer and other cancer groups. Infection status analysis indicated that the H. pylori or HBV/HCV infection and IL1-RN VNTR genotypes were independent factors for developing gastric or hepatocellular cancers. In addition, a borderline significant association was observed between IL1B+3954 polymorphism and the increased cancer risk. Although some modest bias could not be eliminated, this meta-analysis suggested that the IL1-RN VNTR polymorphisms may contribute to genetic susceptibility to gastric cancer. More studies are needed to further evaluate the role of the IL1B+3954 polymorphism in the etiology of cancer.

Radiation measurements in Egyptian pyramids and tombs -- occupational exposure of workers and the public

Energy Technology Data Exchange (ETDEWEB)

Bigu, J; Hussein, Mohamed I; Hussein, A Z

2000-02-01

A radiation survey of seven archaeological sites within Egyptian pyramids and tombs has been conducted in the Saggara area. Measurements were made of radon ({sup 222}Rn) and its short-lived decay products (progeny), as well as thoron ({sup 220}Rn) progeny and {gamma}-radiation. The results of these measurements have been used to calculate the maximum annual effective dose (MAD) and other important occupational radiation exposure variables. It was found that for the limited time to which occupational workers and visitors were exposed, their respective MAD values were lower than that recommended by the regulatory agency (i.e., 20 mSv per year for occupational workers and 1 mSv in a year for the public). However, it is shown that if the exposure times for occupational workers were to increase to 'normal' working schedules their MAD would be exceeded at three archaeological sites. Implementation of improved ventilation practices is recommended in those sites to reduce the exposure to occupational workers were their working schedules to be significantly increased. It is also recommended that further monitoring be conducted in the future to verify these results.

Radiation measurements in Egyptian pyramids and tombs -- occupational exposure of workers and the public

International Nuclear Information System (INIS)

Bigu, J.; Hussein, Mohamed I.; Hussein, A.Z.

2000-01-01

A radiation survey of seven archaeological sites within Egyptian pyramids and tombs has been conducted in the Saggara area. Measurements were made of radon ( 222 Rn) and its short-lived decay products (progeny), as well as thoron ( 220 Rn) progeny and γ-radiation. The results of these measurements have been used to calculate the maximum annual effective dose (MAD) and other important occupational radiation exposure variables. It was found that for the limited time to which occupational workers and visitors were exposed, their respective MAD values were lower than that recommended by the regulatory agency (i.e., 20 mSv per year for occupational workers and 1 mSv in a year for the public). However, it is shown that if the exposure times for occupational workers were to increase to 'normal' working schedules their MAD would be exceeded at three archaeological sites. Implementation of improved ventilation practices is recommended in those sites to reduce the exposure to occupational workers were their working schedules to be significantly increased. It is also recommended that further monitoring be conducted in the future to verify these results

Occupational exposure assessment: Practices in Malaysian nuclear agency

Energy Technology Data Exchange (ETDEWEB)

Sarowi, S. Muhd, E-mail: suzie@nuclearmalaysia.gov.my; Ramli, S. A.; Kontol, K. Mohamad [Radiation Safety & Health Division, Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia); Rahman, N. A. H. Abd. [Faculty of Science & Mathematics, Sultan Idris of Education Universit, 35900, Tanjong Malim, Perak Darul Ridzuan (Malaysia)

2016-01-22

Malaysian Nuclear Agency (Nuclear Malaysia) is the leading agency in introducing and promoting the application of nuclear science technology in Malaysia. The agency provides major nuclear facilities purposely for research and commercialisation such as reactor, irradiation plants and radioisotope production laboratory. When dealing with ionizing radiation, there is an obligatory requirement to monitor and assess the radiation exposure to the workers. The personal dose of radiation workers were monitored monthly by assessing their Thermoluminescence Dosimeter (TLD) dose reading. This paper will discuss the current practice in managing, assessing, record keeping and reporting of the occupational exposure in Nuclear Malaysia including the Health Physic Group roles and challenges. The statistics on occupational radiation exposure of monitored workers working in different fields in Nuclear Malaysia from 2011 - 2013 will also be presented. The results show that the null hypothesis (H{sub 0}) was accepted which the means of every populations are all equal or not differ significantly. This hypothesis states that the dose exposure received by the radiation workers in Nuclear Malaysia is similar and there were no significant changes from 2011 to 2013. The radiation monitoring programme correlate with the requirement of our national law, the Atomic Energy Licensing Act 1984 (Act 304)

Occupational exposure assessment: Practices in Malaysian nuclear agency

Science.gov (United States)

Sarowi, S. Muhd; Ramli, S. A.; Kontol, K. Mohamad; Rahman, N. A. H. Abd.

2016-01-01

Malaysian Nuclear Agency (Nuclear Malaysia) is the leading agency in introducing and promoting the application of nuclear science technology in Malaysia. The agency provides major nuclear facilities purposely for research and commercialisation such as reactor, irradiation plants and radioisotope production laboratory. When dealing with ionizing radiation, there is an obligatory requirement to monitor and assess the radiation exposure to the workers. The personal dose of radiation workers were monitored monthly by assessing their Thermoluminescence Dosimeter (TLD) dose reading. This paper will discuss the current practice in managing, assessing, record keeping and reporting of the occupational exposure in Nuclear Malaysia including the Health Physic Group roles and challenges. The statistics on occupational radiation exposure of monitored workers working in different fields in Nuclear Malaysia from 2011 - 2013 will also be presented. The results show that the null hypothesis (H₀) was accepted which the means of every populations are all equal or not differ significantly. This hypothesis states that the dose exposure received by the radiation workers in Nuclear Malaysia is similar and there were no significant changes from 2011 to 2013. The radiation monitoring programme correlate with the requirement of our national law, the Atomic Energy Licensing Act 1984 (Act 304).

Occupational exposure assessment: Practices in Malaysian nuclear agency

International Nuclear Information System (INIS)

Sarowi, S. Muhd; Ramli, S. A.; Kontol, K. Mohamad; Rahman, N. A. H. Abd.

2016-01-01

Malaysian Nuclear Agency (Nuclear Malaysia) is the leading agency in introducing and promoting the application of nuclear science technology in Malaysia. The agency provides major nuclear facilities purposely for research and commercialisation such as reactor, irradiation plants and radioisotope production laboratory. When dealing with ionizing radiation, there is an obligatory requirement to monitor and assess the radiation exposure to the workers. The personal dose of radiation workers were monitored monthly by assessing their Thermoluminescence Dosimeter (TLD) dose reading. This paper will discuss the current practice in managing, assessing, record keeping and reporting of the occupational exposure in Nuclear Malaysia including the Health Physic Group roles and challenges. The statistics on occupational radiation exposure of monitored workers working in different fields in Nuclear Malaysia from 2011 - 2013 will also be presented. The results show that the null hypothesis (H 0 ) was accepted which the means of every populations are all equal or not differ significantly. This hypothesis states that the dose exposure received by the radiation workers in Nuclear Malaysia is similar and there were no significant changes from 2011 to 2013. The radiation monitoring programme correlate with the requirement of our national law, the Atomic Energy Licensing Act 1984 (Act 304)

Anvender vi det optimale dosisregime for phenoxymethylpenicillin til børn mellem 0-10 år ?

DEFF Research Database (Denmark)

Glerup, Mia; Rittig, Søren; Veirum, Jens Erik

2011-01-01

fået anlagt i.v. adgang. 20 børn skal indtage phenoxymethylpenicillin mikstur 25 mg/kg og 20 børn skal indtage 50 mg/kg. Blodprøver udtages 0-7 timer efter indtagelsen. Metode 2: Koncentrationen af penicillinet i blodprøverne bestemmes ved at måle hæmningszonen for Streptococcus Pyogenes på en...... agarplade påsat patientserum. Herefter sammenlignes med hæmningszonerne for Streptococcus Pyogenes på en anden agarplade påsat kendte penicillinkoncentrationer i intervallet 0,5-32 μg/ml (Standard disk diffusion bioassay). Resultater. To børn er færdigundersøgt. Begge havde maksimal koncentration 1 time...

Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

OpenAIRE

Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

2015-01-01

This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable ma...

Mapping radioactivity in groundwater to identify elevated exposure in remote and rural communities

Energy Technology Data Exchange (ETDEWEB)

Kleinschmidt, Ross, E-mail: ross_kleinschmidt@health.qld.gov.a [Queensland University of Technology, Faculty of Science and Technology, Discipline of Physics, 2 George Street, Brisbane, Queensland 4000 (Australia); Health Physics Unit, Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, Queensland 4108 (Australia); Black, Jeffrey [Health Physics Unit, Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, Queensland 4108 (Australia); Akber, Riaz [Queensland University of Technology, Faculty of Science and Technology, Discipline of Physics, 2 George Street, Brisbane, Queensland 4000 (Australia)

2011-03-15

A survey of radioactivity in groundwater (110 sites) was conducted as a precursor to providing a baseline of radiation exposure in rural and remote communities in Queensland, Australia, that may be impacted upon by exposure pathways associated with the supply, treatment, use and wastewater treatment of the resource. Radionuclides in groundwater, including {sup 238}U, {sup 226}Ra, {sup 222}Rn, {sup 228}Ra, {sup 224}Ra and {sup 40}K were measured and found to contain activity concentration levels of up to 0.71 BqL{sup -1}, 0.96 BqL{sup -1}, 108 BqL{sup -1}, 2.8 BqL{sup -1}, 0.11 BqL{sup -1} and 0.19 BqL{sup -1} respectively. Activity concentration results were classified by aquifer lithology, showing correlation between increased radium isotope concentration and basic volcanic host rock. The groundwater survey and mapping results were further assessed using an investigation assessment tool to identify seven remote or rural communities that may require additional radiation dose assessment beyond that attributed to ingestion of potable water. - Research highlights: {yields} We studied the concentration of naturally occurring radioactivity in groundwater in Queensland, Australia. {yields} Groundwater radioactivity concentrations were classified by aquifer type, location and magnitude. {yields} Radioactivity concentration in groundwater was used to develop a tool to determine the potential for elevated radiation exposure to rural and remote communities, based on a case study of a reference site. {yields} Of 110 groundwater bores tested, seven were assessed as requiring further community dose assessment.

INFLUENCE OF EXPOSURE ASSESSMENT METHOD IN AN EPIDEMIOLOGIC STUDY OF TRIHALOMETHANE EXPOSURE AND SPONTANEOUS ABORTION

Science.gov (United States)

Trihalomethanes are common contaminants of chlorinated drinking water. Studies of their health effects have been hampered by exposure misclassification, due in part to limitations inherent in using utility sampling records. We used two exposure assessment methods, one based on ut...

Association between Interleukin-1 Receptor Antagonist (IL1RN) Variable Number of Tandem Repeats (VNTR) Polymorphism and Pulmonary Tuberculosis.

Science.gov (United States)