ITER-like antenna capacitors voltage probes: Circuit/electromagnetic calculations and calibrations

The analyses illustrated in this manuscript have been performed in order to provide the required data for the amplitude-and-phase calibration of the D-dot voltage probes used in the ITER-like antenna at the Joint European Torus tokamak. Their equivalent electrical circuit has been extracted and analyzed, and it has been compared to the one of voltage probes installed in simple transmission lines. A radio-frequency calibration technique has been formulated and exact mathematical relations have been derived. This technique mixes in an elegant fashion data extracted from measurements and numerical calculations to retrieve the calibration factors. The latter have been compared to previous calibration data with excellent agreement proving the robustness of the proposed radio-frequency calibration technique. In particular, it has been stressed that it is crucial to take into account environmental parasitic effects. A low-frequency calibration technique has been in addition formulated and analyzed in depth. The equivalence between the radio-frequency and low-frequency techniques has been rigorously demonstrated. The radio-frequency calibration technique is preferable in the case of the ITER-like antenna due to uncertainties on the characteristics of the cables connected at the inputs of the voltage probes. A method to extract the effect of a mismatched data acquisition system has been derived for both calibration techniques. Finally it has been outlined that in the case of the ITER-like antenna voltage probes can be in addition used to monitor the currents at the inputs of the antenna.

Dioxin levels in fertilizers from Belgium: determination and evaluation of the potential impact on soil contamination

Dioxins are harmful persistent organic pollutants (POPs) to which humans are exposed mostly via the consumption of animal products. They can enter the food chain at any stage, including crop fertilization. Fertilizers belong to several categories: synthetic chemicals providing the essential elements (mostly N, P and K) that are required by the crops but also organic fertilizers or amendments, liming materials, etc. Ninety-seven samples of fertilizers were taken in Belgium during the year 2011 and analyzed after a soft extraction procedure for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) using GC-IDHRMS. Only small qualitative differences could be observed between the main fertilizer categories since the PCDD:PCDF:DL-PCB average ratio obtained with the results expressed in TEQ was often close to 30:30:40 (typically for sewage sludge) or 40:30:30 (typically for compost). The median dioxin levels determined were generally lower than recorded previously and were the highest for sewage sludge and compost (5.6 and 5.5 ng TEQ/kg dry weight (dw), respectively). The levels in other fertilizers were lower including manure for which the median value was only 0.2 ng TEQ/kg dw. Several fertilization scenarios relying on the use of those fertilizers were assessed taking into consideration the application conditions prevailing in Belgium. From this assessment it could be concluded that the contribution of fertilizers to the overall soil contamination will be low by comparison of other sources of contamination such as atmospheric depositions. At the field scale, intensive use of compost and sewage sludge will increase dramatically the dioxin inputs compared with other fertilization practices but this kind of emission to the soil will still be relatively low compared to the dioxin atmospheric depositions.

Development of the gas-puff imaging diagnostic in the TEXTOR tokamak

Gas puff imaging (GPI) [S. J. Zweben, D. P. Stotler et al., Phys. Plasmas 9, 1981 (2002); R. J. Maqueda, G. A. Wurden et al., Rev. Sci. Instrum. 74, 2020 (2003)] is a powerful diagnostic that permits a two-dimensional measurement of turbulence in the edge region of a fusion plasma and is based on the observation of the local emission of a neutral gas, actively puffed into the periphery of the plasma. The developed in-vessel GPI telescope observes the emission from the puffed gas along local (at the puff) magnetic field lines. The GPI telescope is specially designed to operate in severe TEXTOR conditions and can be treated as a prototype for the GPI systems on next generation machines. Also, the gas puff nozzle is designed to have a lower divergence of the gas flow than previous GPI diagnostics. The resulting images show poloidally and radially propagating structures, which are associated with plasma blobs. We demonstrate that the local gas puff does not disturb plasma properties. Our results indicate also that the neutral gas emission intensity is more sensitive to the electron density than the electron temperature. Here, we present implementation details of the GPI system on TEXTOR and discuss some design and diagnostic issues related to the development of GPI systems in general.

[Asbestosis still exists…]

A diagnosis of asbestosis, lung fibrosis due to asbestos exposure, was proposed in 2003 in a 64-year-old woman on the basis of the history, computed tomography appearances, lung function studies, and biometric data. This diagnosis was confirmed by the pathological examination of a lung lobe resected surgically for bronchial carcinoma in 2010. The diagnosis of asbestosis is now rarely made as a result of a substantial decrease in dust exposure over the past decades and mainly because of the interdiction of asbestos use in western countries. Currently, the most frequent thoracic manifestations of asbestos exposure are benign pleural lesions and mesothelioma. It has also become exceptional to have pathological confirmation of the diagnosis, obtained in this woman thanks to the surgical treatment of another complication of her occupational exposure.

Potential impact of fertilization practices on human dietary intake of dioxins in Belgium

Dioxins can enter the food chain at any stage, including crop fertilization. Therefore, we developed a simple method for estimating the introduction of dioxins in the food chain according to various fertilization practices. Using dioxin's contamination data taken from the literature, we estimated that fertilization accounts for approximately 20% of the dioxin inputs on agricultural soils at country scale. For the estimations at the field scale, 6 fertilization scenarios were considered: sludge, compost, digestate, manure, mineral fertilizers, and a common fertilization scenario that corresponds to an average situation in Belgium and combines mineral and organic fertilizers. According to our first estimations, mineral fertilizers, common fertilization practices or manure bring less than 1 ng TEQ/m² while atmospheric deposition or digestate bring between 1 and 3 ng TEQ/m² and sludge or compost bring more than 3 ng TEQ/m². The use of solid fertilizers could potentially increase the dioxin levels in the 30 cm agricultural soil layer by 0 to ~1.5% per year (up to ~9% for the 5 cm thick surface layer). For animals, the increase in dioxin ingestion linked to the fertilization practices is lower than 1% for most scenarios with the exception of the compost scenario. Increases in human dietary intake of dioxin are estimated to be lower than 1% for conventional rearing methods (i.e. grazing animals are reared outdoor while pigs and poultry are reared indoor). Spraying liquid fertilizers on meadows and fodder crops, even if very limited in practice, deserves much more attention because this application method could theoretically lead to higher dioxin's intake by livestock (from 6 to ~300%). Considering an average half-life of dioxins in soils of 13 years, it appears that the risks of accumulation in soils and in the food chain are negligible for the various fertilization scenarios.

[The missions of the Occupational Diseases Fund. Under-claim and recognition of occupational lung cancer, in particular those related to asbestos]

The missions of the Occupational Diseases Fund are defined in application of the law regarding the insurance against occupational diseases. The workers covered by this law are granted several rights, such as a financial compensation in case of temporary or permanent disability, a further compensation if they have to be taken away from the risk in the workplace, the reimbursement of health care costs related to the occupational disease, or the payment of an annuity to the widow(er) if death is its ultimate consequence. Among the compensable diseases, we shall focus on lung cancer, and especially the one related to asbestos exposure. This type of cancer is clearly under-registrated in Belgium as in most countries of the European Union, leading to an insufficient number of cases entitled to compensation by our institution. In this instance, the insurance against occupational diseases and all related social advantages are hugely under-exploited in our country. It is our duty to increase doctors' awareness of the problem and spread accurate information to reverse this trend and provide occupational cancer cases with a legitimate compensation, in particular those related to asbestos. A wider knowledge of the occupational history of cancer patients, thanks to occupational physicians, and a better use of mineralogical analyses on lung samples, would improve this situation inacceptable on any level : medical, social or even human.

Black pigments in the liver related to gold and titanium deposits. A report of four cases

Black pigments are rarely described in the liver. We report four patients with chronic cholestasis and black pigments described on liver histological examination. Energy-dispersive X-ray analysis identified these black pigments as gold particles in the first three patients and titanium particles in the fourth. The origin of the gold deposits was unknown in this first patient and related to gold salts therapy in the two others. Titanium deposits was associated with hepatic granulomas and related to total knee replacement.

Pneumoconiosis after sericite inhalation

BACKGROUND

Between 1997 and 1999 three sericite plant workers in Parana, Brazil, were diagnosed with pneumoconiosis.

AIMS

To investigate and describe the radiological, clinical, and pathological changes in miners and millers exposed to sericite dust with mineralogical characteristics of inhaled dust.

METHODS

The working premises were visited to examine the sericite processing and to classify the jobs according to make qualitative evaluation. Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. Forty four workers were examined by a standard questionnaire for respiratory symptoms, spirometry, and chest x ray. Material from an open lung biopsy was reviewed for histopathological and mineralogical analysis, together with sericite samples from the work site to compare the mineral characteristics in lung lesions and work area.

RESULTS

Respirable dust contained 4.5-10.0% crystalline silica. Particle size distribution showed a heavy burden of very fine particles (23-55%) with a mean diameter of <0.5 microm. Mean age of sericite miners was 41.0 (11.9) and mean number of years of exposure was 13.5 (10.1). In 52.3% of workers (23/44), chest radiographs presented a median category of 1/0 or above, and 18.2% (8/44) had a reduced FEV1. There was a significant association between exposure indices and x ray category. Histological studies of the lung biopsy showed lesions compatible with mixed dust fibrosis with no silicotic nodules. x Ray diffraction analysis of the lung dust residue and the bulk samples collected from work area showed similar mineralogical characteristics. Muscovite and kaolinite were the major mineral particle inclusions in the lung.

CONCLUSION

Exposure to fine sericite particles is associated with the development of functional and radiological changes in workers inducing mixed dust lesions, which are distinct histologically from silicosis.

Trends in asbestos body counts in bronchoalveolar lavage fluid over two decades

As in most western countries, the use of asbestos has decreased in Belgium since the mid 1970's. Successive regulations have lowered the permissible levels of exposure and prohibited the use of various asbestos products. In order to assess the impact of these prevention measures on the pulmonary fibre burden of asbestos-exposed patients, the bronchoalveolar lavage fluid (BALF) asbestos body (AB) analysis database of the authors' laboratory was reviewed for the period 1983-2000. A total of 4,772 cases were considered, of which 95% were males. AB concentration exceeded 1 AB x mL BALF(-1) in 36.1%. There was essentially no change in the mean concentration of AB over the period evaluated. However, the concentrations in individuals with very high levels decreased over time. This was associated with a shift in exposure categories from primary asbestos workers to those exposed during handling of asbestos-containing materials or to asbestos in place in buildings or industrial sites. This is consistent with epidemiological data indicating that the number of severe cases of asbestosis caused by very high cumulated doses decreases but that benign pleural diseases and mesothelioma remain the most frequent asbestos-related diseases. Past prevention measures are not expected to have a measurable influence on the incidence of mesothelioma in the near future.

[The pneumology department]

The department of pneumology of the Erasme hospital exists since 25 years. The basic clinical activities include pulmonary function testing (7,500 patients per year), endoscopy, including interventional endoscopy (1,500 patients per year), thoracic oncology, allergology, rehabilitation and aid to smoking cessation. The following expertise fields have been largely developed: lung transplantation, treatment of cystic fibrosis in collaboration with the children's hospital Reine Fabiola, occupational.

Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats

BACKGROUND AND AIMS

Environmental exposures to chrysotile and tremolite from the soil cause pleural plaques and mesothelioma in northeast Corsica. Goats grazing in the contaminated areas inhale asbestos fibres. We used this natural animal model to study whether these exposures actually result in increased fibre burdens in the lungs and parietal pleura.

METHODS

Ten goats from areas with asbestos outcrops and two from other areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy.

RESULTS

Both chrysotile and tremolite fibres were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 microm were 0.27 x 10(6) fibres/g dry lung tissue and 1.8 x 10(6) fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysotile fibres shorter than 5 microm were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5 microm in lung and parietal pleural samples, respectively.

CONCLUSIONS

Environmental exposure in northeast Corsica results in detectable chrysotile and tremolite fibre loads in the lung and parietal pleura of adult goats. Tremolite fibres of dimensions with a high carcinogenic potency are detected in the parietal pleura.

Pseudoasbestos bodies and fibers in bronchoalveolar lavage of refractory ceramic fiber users

Refractory ceramic fibers (RCF) are widely used to replace asbestos in applications requiring high heat resistance. Ferruginous bodies mimicking asbestos bodies (ABs) have been detected in the lungs of RCF production workers. This raises the question about their presence in other occupational groups and whether "typical ABs" still reflect past asbestos exposures in all settings. An AB counting by phase-contrast light microscopy and a screening test by analytical electron microscopy were systematically performed on all bronchoalveolar lavage fluids (BALF) submitted to our laboratory in 1992 through 1997 (n = 1,800). When RCF were detected in electron microscopy, the structures considered as "typical ABs" were marked under light microscopy and prepared for further chemical and structural analysis. Pseudo-ABs on RCF were detected in samples from nine subjects (0.5%). All of them had worked either as foundry workers, steel workers, or welders. In these subjects, alumino-silicate fibers compatible with RCF accounted for 42% of the core fibers analyzed, other nonasbestos fibers for 28%, and asbestos fibers for 30%. ABs thus remain a valid marker of asbestos retention but attention must be paid to a possible occurrence of pseudo-asbestos bodies on RCF and other nonasbestos fibers in end-users of refractory fibers.

The role of environmental and occupational exposures in Turkish immigrants with fibre-related disease

Environmental exposure to tremolite and erionite causes endemic diseases of the lung and pleura in Turkey. This study aimed to evaluate the impact of these exposures and further occupational exposures on fibre-related diseases in Turkish immigrants living in Belgium. The study included 51 males and 17 females that emigrated < 1-38 yrs ago. Most of them (n=46) had nonmalignant pleural lesions, one had asbestosis and one had mesothelioma. Environmental asbestos exposure was likely for the majority of patients (60%), but there were also reports of possible occupational asbestos (n = 14) and erionite (n = 2) exposure. Tremolite was the main fibre type in bronchoalveolar lavage fluid (BALF). Elevated concentrations of amosite or crocidolite were detected in only two patients. The delay elapsed since the end of the environmental exposure had no influence on the asbestos body or the tremolite fibre concentrations in the BALF of Turkish immigrants. Most fibre-related diseases in Turkish immigrants are probably due to environmental rather than occupational exposure. Precise information about geographical origin and occupation should be obtained when investigating these patients. Mineralogical analysis of bronchoalveolar lavage fluid gives valuable information on the type and intensity of exposure, especially in patients with both environmental and occupational exposure.

Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey

OBJECTIVES

The high incidence of malignant mesothelioma in some villages of Cappadocia (Turkey) is due to environmental exposure to erionite fibres. The aim was to evaluate the fibre burden in bronchoalveolar lavage fluid (BALF) from inhabitants of an erionite village and compare it with Turkish subjects with or without environmental exposure to tremolite asbestos.

METHODS

Ferruginous bodies (FBs) and fibres were measured and analyzed by light and transmission electron microscopy (TEM) in the BALF of 16 subjects originating from Tuzköy.

RESULTS

FBs were detected in the BALF of 12 subjects, with concentrations above 1 FB/ml in seven of them. Erionite was the central fibre of 95.7% of FBs. Erionite fibres were found in the BALF of all subjects, by TEM, and these fibres were low in Mg, K, and Ca compared with erionite from Tuzköy soil. The mean concentration of erionite fibres in BALF was similar to that of tremolite fibres in Turks with environmental exposure to tremolite. The proportion of fibres longer than 8 microm in BALF represented 35.6% for erionite compared with 14.0% for tremolite. The asbestos fibre concentrations in erionite villagers was not different from that in Turks without environmental exposure to tremolite.

CONCLUSION

Analysis of BALF gives information about fibre retention in populations environmentally exposed to erionite for whom data on fibre burden from lung tissue samples are scarce. This may apply to exposed Turks having emigrated to other countries.

Quasistationary high confinement discharges with trans-greenwald density on TEXTOR-94

Confinement quality as good as ELM-free H-mode at densities substantially above the Greenwald density limit ( &nmacr;(e,0)/n(GW) = 1.4) has been obtained in discharges with a radiative boundary under quasistationary conditions for 20 times the energy confinement time. This is achieved by optimizing the gas-fueling rate of RI-mode discharges which tailors their favorable energy confinement and leads to discharges with beta values just below the operational limit beta(n) = 2 of TEXTOR-94, thereby effectively avoiding confinement back transitions or disruptions. In addition, this high-density regime is favorable for helium removal and results in figures of merit tau(*)(p,He)/tau(E) approximately 10-15, relevant for a future fusion power reactor.

[Role of biometric analysis in the retrospective assessment of exposure to asbestos]

Despite intrinsic limitations due to differences in the bio-persistence of the various asbestos types, in the definition of control populations and in analytical techniques used by the laboratories, mineralogical analysis of biological samples is useful in the assessment of past exposure to asbestos. It provides additional information to occupational and environmental questionnaires, particularly when exposure to asbestos is doubtful, unknown or forgotten by a subject. Results should be interpreted taking into account clinical information. A positive result does not mean existence of asbestos-related disease. A negative result does not exclude previous significant asbestos exposure, clearly identified by an occupational questionnaire (particularly for exposure to chrysotile). Threshold values indicative of a high probability of previous asbestos exposure have been established for bronchoalveolar lavage fluid (BALF) samples and lung tissue samples. Quantification of asbestos bodies by light microscopy is easy to perform. Sensitivity and specificity of this analysis towards the total pulmonary asbestos fiber burden is good. Therefore this analysis should be performed first. Mineralogical analysis in BALF or lung tissue should be considered only when sampling is supported by diagnostic or therapeutic implications.

Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage

Environmental or domestic exposure to asbestos fibers originating from local soil is responsible for a high incidence of diseases in large rural areas of Turkey. Bronchoalveolar lavage fluids (BALF) were obtained for 65 Turkish subjects originating from these areas and for 42 Turkish controls. Asbestos bodies (ABs) and uncovered fibers (UFs) were quantified by phase contrast light microscopy. Total fiber burden was determined by transmission electron microscopy. The main asbestos types disclosed were tremolite and to a lesser extent chrysotile. AB and fiber concentrations were higher in environmentally exposed subjects (geometric mean [geometric standard deviation]: 5.20 [6.22] AB/ml, 444 [11.6] tremolite fibers/ml) than in control subjects (0.22 [1.45] AB/ml, 12.0 [15.4] tremolite fibers/ml) (p < 0.001). In subjects environmentally exposed in Turkey, AB burdens on tremolite were in the same range as those on commercial amphiboles in subjects occupationally exposed in Belgium. In Turkish subjects, values above either 1 AB/ml, 3 uncovered fiber/ml in light microscopy, or 300 fibers/ml in electron microscopy indicated usually an abnormal alveolar retention reflecting a significant cumulative exposure from environmental or domestic origin. These observations are probably valid for other areas in the world where diseases associated with environmental exposure to soil- derived asbestos fibers occur and for immigrants originating from these areas.

Guidelines for mineral fibre analyses in biological samples: report of the ERS Working Group. European Respiratory Society

Microscopic techniques for analysing asbestos fibres in lung tissue and bronchoalveolar lavage have provided major information in the understanding of asbestos-related diseases. These analyses are increasingly applied for clinical work and medicolegal problems. Differences in sampling, preparation and counting techniques, definitions of reference populations and expression of results have caused major difficulties in comparing results from different laboratories. Therefore it appeared necessary to set a goal to harmonize these analyses between the European laboratories active in this field. This article summarizes the work of a European Respiratory Society working group with participation from nine European laboratories. The five main issues touched upon are: 1) definitions of control populations and reference levels; 2) sampling, preparation and analytical techniques; 3) asbestos fibres in lung tissues in different pathologies; 4) asbestos bodies in lung tissue, bronchoalveolar lavage and sputum; and 5) basis for the interpretation of fibres and asbestos bodies in biological samples. These guidelines indicate the crucial importance of several factors for the interpretation of the results; namely, adequate sampling, comparable analytical procedures and expression of the results, the use of well-defined reference populations, and a comprehensive understanding of the factors affecting the fibre retention and the dose-responses associated with the different asbestos-related diseases.

Analysis of asbestos bodies in BAL from subjects with particular exposures

Four patients with asbestos-related diseases and with unusual exposures underwent bronchoalveolar lavage (BAL) for mineralogical analysis. Asbestos bodies (AB) were counted by light microscopy and analyzed by transmission electron microscopy and X-ray energy spectrometry. AB's were found in all cases, after a mean delay from the end of exposure of 27.7 years. Analysis of the core fibers indicated the type of alveolar asbestos burden and was compared with the previous exposures: Pleural plaques due to household exposure to amosite and crocidolite. Pleural plaques due to occult occupational exposure to crocidolite in a coal miner. Asbestosis due to environmental exposure to tremolite in Turkey. Asbestosis, pleural plaques, and peritoneal mesothelioma due to a short, intense exposure to crocidolite. AB counting in BAL and identification of the central fibers by analytical electron microscopy is a useful, non-invasive and reliable method to evaluate the alveolar retention of bio-persistent fibers and to relate them to specific exposures.

Atypical mycobacteriosis as a complication of talc pneumoconiosis

A 57 year old man, receiving compensation for talc pneumoconiosis since 1977, was admitted to hospital for the first time in 1987, with symptoms of weight loss, fever, dyspnoea and productive cough. A chest roentgenogram showed bilateral cavitation. Two years later, Mycobacterium xenopi was found in sputum cultures. Despite specific oral antibiotherapy, the patient's health deteriorated and he died in 1990. To the best of our knowledge, this is the first reported case of an association of talcosis with a M. xenopi pneumonia. The relative timing of the two diseases suggests that talc pneumoconiosis predisposed to the infection by M. xenopi.