Lic.-avh. (sammanfattning) Stockholm : Tekn. högsk., 2006. / Härtill 3 uppsatser.

L'exposition médicale diagnostique aux rayonnements ionisants représente environ 40% de l'exposition totale aux radiations en France. L'utilisation du scanner, beaucoup plus irradiant que l'imagerie conventionnelle, ne cesse de progresser, y compris chez les enfants, dont la radiosensibilité est supérieure à celle des adultes. Plusieurs études récentes sont en faveur d'une augmentation du risque de leucémie et de tumeur cérébrale après exposition au scanner dans l'enfance. Une cohorte nationale multicentrique a été mise en place à l'IRSN depuis 2009 incluant plus de 108 137 enfants soumis à un ou plusieurs scanners avant l'âge de 10 ans sur la période 2000-2010 dans 23 services de radiologie pédiatriques de CHU, répartis sur l'ensemble du territoire. L'estimation des doses reçues au niveau des principaux organes a été faite en fonction des protocoles utilisés. La grande variabilité des doses selon les services témoigne de la nécessité d'optimisation des protocoles. Près de 3% des enfants de la cohorte présentaient un facteur de prédisposition aux cancers étudiés. Le croisement de la cohorte avec le registre national des cancers pédiatriques a identifié 106 cas incidents de cancer, dont 22 tumeurs cérébrales et 17 leucémies. Chez les enfants sans facteur de prédisposition, un excès de risque positif mais non significatif était observé pour la leucémie et les tumeurs cérébrales en fonction de la dose, similaire à celui observé pour la population d'étude dans son ensemble. Chez les enfants avec un facteur de prédisposition au cancer, le risque diminuait, possiblement en lien avec une mortalité précoce augmentée entrainant un déficit de risque de cancer radio-induit à plus long terme. Le projet européen EPI-CT inclut 9 cohortes nationales, dont la cohorte française et regroupera plus d’un million d’enfants exposés au scanner. L’analyse conjointe de ces données permettra d’apporter prochainement des résultats complémentaires sur ce sujet. / Medical diagnostic exposure to ionizing radiation represents about 40% of the total annual radiation exposure in France. The CT scans, which represent only 5% of the total number of X-rays examinations, account for half of the total collective dose associated with medical diagnostic exposure. However, its use continues to grow, including in children, for whom the radio sensitivity is known to be greater than in adults. Several recent studies support an increased risk of leukemia and brain tumors after exposure to CT scan in childhood. A national multicenter cohort was set up at the IRSN since 2009 including 108 137 children subjected to at least one CT scans before the age of 10 during the 2000 to 2013 period in 23 French University hospital’s pediatric radiology departments. Children's exposure was assessed based on radiological protocols. It was observed high variability of doses according to the participant departments, reflecting the need for protocol optimization. Moreover, children with predisposing factor for studied cancers represented 3% of the study population, a percentage well above that observed in the general population. The linkage of the cohort with the National Register of pediatric cancers identified 106 incident cases of cancer in the cohort, 22 brain tumors and 17 leukemias. For children without predisposing factor, it was observed a non-significant excess risk of cancer according to the received dose, similar to that observed for the whole study population. For children with predisposing factor to cancer, the risk decreased without reaching significance, possibly linked to earlier non-cancer mortality in this group and then to a lower risk to develop later radiation induced cancer. The European project EPI-CT, which includes 9 national cohorts (including the French cohort), will include more than one million children and then will bring further results on this topic.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21826号 / 農博第2339号 / 新制||農||1067(附属図書館) / 学位論文||H31||N5198(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)准教授 髙橋 知之, 教授 北山 兼弘, 准教授 刑部 正博 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Diagnostic X-rays are the most important man-made source of radiation exposure for the general population, contributing about 14% of the total annual exposure worldwide from all sources. However, although diagnostic X-rays provide great benefits, it is generally accepted that their use involves some small risk of developing cancer. The risk to an individual is probably small because radiation doses are usually low, but the large number of people exposed annually means that even small individual risks could translate into a considerable number of cancer cases. The aim of this work was to reestimate this risk on the basis of the annual number of CT examinations undertaken in the Czech Republic and typical doses applied. But there wasn't possible to find necessary data for planned reckonings by return, because their archiving isn't obligatory. This study, therefore, only describes common incidence of ionising radiation with human organism and further, all inevitable mathematically-physical equations needed for realization of primary planned investigation, with all necessary datal inputs included. In findings of this work there are drafted and demonstrated procedures, how to obtain and cultivate needed data ,so it was possible to compare it with technical literature.

Bien que les technologies d’imagerie soient un acquis réel de la médecine moderne, leur introduction ne semble pas avoir été précédée d’une démarche réflexive suffisante qui aurait permis d’anticiper les multiples enjeux que rencontre la pratique radiologique actuelle. En effet, à force de se focaliser sur les acquis techniques et scientifiques, le cadre de radioprotection en place semble ne pas avoir suffisamment considéré l’apport essentiel que représente la connaissance des aspects sociaux, éthiques et humains que peuvent amener des domaines comme la bioéthique. Cette insuffisance fait en sorte que l’on se retrouve aujourd’hui face à des enjeux importants relatifs à la radioprotection du patient comme la surutilisation des examens radiologiques ou encore le manque d’information des acteurs du milieu face aux risques des rayonnements. Après un état des lieux des enjeux éthiques en radiologie diagnostique ayant un impact sur la radioprotection médicale des patients, un enjeu majeur de la pratique actuelle, qui est la justification inadéquate des prescriptions d’examens radiologiques, sera analysé selon une approche par principes. De cet exercice, visant à démontrer comment l’éthique peut concrètement contribuer à la radioprotection, découle l’impératif d’une vision nouvelle et globale permettant de proposer des pistes de solution aux controverses liées à l’utilisation actuelle de l’imagerie. Dans une perspective de santé des populations, il est important de contribuer à la diminution de la banalisation du recours au rayonnement ionisant dans la pratique médicale diagnostique en alliant bioéthique et radioprotection. Ce projet de recherche se veut être une étape limitée, mais nécessaire dans l’établissement de ce dialogue interdisciplinaire. / While imaging technologies represent a real achievement for modern medicine, their introduction seems not to have been preceded by a sufficiently reflective process that would have anticipated the multiple challenges arising in current radiological practice. In focusing on the technical and scientific achievements, the actual radiation protection framework fails to consider sufficiently the essential contribution brought by social, ethical and human dimensions of disciplines such as bioethics. This failure means that today we find ourselves faced with major issues related to patient radiation protection, such as overuse of radiological examinations or medical personnel’s lack of information about the risks of radiation. Following an overview of ethical issues in diagnostic radiology affecting medical radiation protection of patients, a major issue in current practice – i.e., the inadequate justification of radiological examination prescriptions – will be analyzed using a principle-based approach. From this exercise, which aims to demonstrate how ethics can contribute concretely to radiation protection, a need arises for a new and comprehensive vision leading to solutions for controversies related to the current use of medical imaging. In a population health perspective, it is important to contribute to the reduction of the trivialization of the use of ionizing radiation in diagnostic medical practice by combining both bioethics and radiation protection. This research project aims to be a modest but necessary first step in the establishment of such an interdisciplinary dialogue.

<p>U ovoj doktorskoj disertaciji predstavljena je radiolo&scaron;ka i strukturna karakterizacija građevinskih materijala koji se mogu naći u upotrebi u Srbiji. Izvr&scaron;ena je radiolo&scaron;ka karakterizaicija ukupno 348 uzoraka: granita,&nbsp; fosfogipsa,&nbsp; sirovina&nbsp; u&nbsp; keramičkoj&nbsp; industriji,&nbsp; keramičkih pločica,&nbsp; betona,&nbsp; opeke,&nbsp; maltera,&nbsp; siporeksa,&nbsp; crepa&nbsp; i&nbsp; drugih<br />građevinskih materijala op&scaron;te upotrebe.&nbsp; Radiolo&scaron;ka karakterizacija je&nbsp; sprovedena&nbsp; merenjem&nbsp; koncentracija&nbsp; aktivnosti 226 Ra,232 Th&nbsp; i 40 K metodom&nbsp; gama&nbsp; spektrometrije,&nbsp; kao&nbsp; i&nbsp; ekshalacije&nbsp; radona&nbsp; iz selektovanih&nbsp; građevinskih&nbsp; materijala&nbsp; kori&scaron;ćenjem&nbsp; aktivnih&nbsp; uređaja RAD7,&nbsp; RTM&nbsp; 1688-2,&nbsp; AlphaGUard&nbsp; i&nbsp; AlphaE.&nbsp; Kori&scaron;ćenjem&nbsp; Monte Karlo&nbsp; simulacija&nbsp; izvr&scaron;ena&nbsp; je&nbsp; procena&nbsp; jačina&nbsp; apsorbovanih&nbsp; doza<br />gama&nbsp; zračenja,&nbsp; uočena&nbsp; su&nbsp; odstupanja&nbsp; od&nbsp; teorijski&nbsp; procenjenih vrednosti&nbsp; i&nbsp; dati&nbsp; predlozi&nbsp; za&nbsp; korekciju.&nbsp; Izvr&scaron;ena&nbsp; je&nbsp; procena radijacionog&nbsp; rizika&nbsp; od&nbsp; kori&scaron;ćenja&nbsp; analiziranih&nbsp; građevinskih materijala&nbsp; u&nbsp; enterijeru,&nbsp; kao&nbsp; i&nbsp; za&nbsp; profesionalna&nbsp; lica&nbsp; pri&nbsp; radu&nbsp; sa sirovinskim&nbsp; materijalima.&nbsp; Ispitivane&nbsp; su&nbsp; mogućnosti&nbsp; upotrebe fosfogipsa&nbsp; kao&nbsp; NORM&nbsp; materijala&nbsp; u&nbsp; proizvodnji gips-karton&nbsp; ploča&nbsp; i opeke&nbsp; uz procenu radijacionog rizika od upotrebe.&nbsp; Napravljeno je 8 uzoraka&nbsp; opeke&nbsp; sa&nbsp; različitim&nbsp; udelog&nbsp; fosfogipsa&nbsp; i&nbsp; izvr&scaron;ena&nbsp; je<br />radiolo&scaron;ka&nbsp; i&nbsp; strukturna&nbsp; karakterizacija&nbsp; dobijenih&nbsp; materijala. Ispitivane&nbsp; su&nbsp; varijacije&nbsp; koeficijenata&nbsp; emanacije&nbsp; radona&nbsp; iz građevinskih materijala tokom vremena, kao i uticaj efekata curenja i povratne difuzije koji dovode do tih varijacija. Ispitivan je takođe i uticaj strukture materijala u smislu mineralo&scaron;kog i hemijskog satava i&nbsp; poroznosti&nbsp; na&nbsp; vrednosti&nbsp; koeficijenta&nbsp; emanacije&nbsp; radona. Meneralo&scaron;ka&nbsp; karakterizacija&nbsp; uzoraka&nbsp; izvr&scaron;ena&nbsp; je&nbsp; metodom rendgenske&nbsp; strukturne&nbsp; analize&nbsp; (XRD),&nbsp; a&nbsp; hemijska&nbsp; metodom rendgenske&nbsp; fluorescentne&nbsp; analize&nbsp; (XRF).&nbsp; Merenje&nbsp; ukupne&nbsp; efektivne poroznosti izvr&scaron;eno je metodama apsorpcije vode i metodom živine porozimetrije.&nbsp; Na&nbsp; osnovu&nbsp; dobijenih&nbsp; rezultata&nbsp; uspostavljene&nbsp; su značajne&nbsp; korelacije&nbsp; između&nbsp; pojedinih&nbsp; radiolo&scaron;kih&nbsp; i&nbsp; strukturnih parametara za analizirane uzorke građevinskih materijala.</p> / <p>In&nbsp; this&nbsp; doctoral&nbsp; dissertation,&nbsp; the&nbsp; results&nbsp; of&nbsp; the&nbsp; radiological&nbsp; and structural characterization of building materials used in Serbia were presented.&nbsp; Radiological&nbsp; characterization&nbsp; of&nbsp; a&nbsp; total&nbsp; of&nbsp; 348&nbsp; samples was performed, including granite, phosphogypsum, raw&nbsp; materials&nbsp; in the ceramic industry, ceramic tiles, concrete, brick, mortar, siporex, tiles,&nbsp; and&nbsp; other&nbsp; materials&nbsp; frequently&nbsp; used&nbsp; as&nbsp; building&nbsp; materials.Radiological characterization was performed by measuring activity concentrations&nbsp; of 226 Ra,232 Th,&nbsp; and 40 K&nbsp; by&nbsp; gamma&nbsp; spectrometry method, as well&nbsp; as radon exhalation from selected building materials using active devices RAD7, RTM 1688-2, AlphaGuard and AlphaE.Using&nbsp; Monte&nbsp; Carlo&nbsp; simulations,&nbsp; the&nbsp; absorbed&nbsp; gamma&nbsp; dose&nbsp; rates were&nbsp; estimated.&nbsp; Furthermore,&nbsp; the&nbsp; deviations&nbsp; from&nbsp; the&nbsp; theoretically estimated&nbsp; absorbed&nbsp; dose&nbsp; rates&nbsp; were&nbsp; observed,&nbsp; and&nbsp; suggestions&nbsp; for correction were given. An assessment of the radiation risk from the use&nbsp; of&nbsp; analyzed&nbsp; building&nbsp; materials&nbsp; in&nbsp; the&nbsp; interior,&nbsp; as&nbsp; well&nbsp; as&nbsp; for occupational&nbsp; workers&nbsp; working&nbsp; with&nbsp; raw&nbsp; materials&nbsp; was&nbsp; conducted.The possibilities of using phosphogypsum as a NORM material in the production&nbsp; of&nbsp; gypsum&nbsp; plasterboard&nbsp; and&nbsp; bricks&nbsp; were&nbsp; investigated, with&nbsp; an&nbsp; assessment&nbsp; of&nbsp; the&nbsp; radiation&nbsp; risk&nbsp; due&nbsp; to&nbsp; use&nbsp; of&nbsp; phosphogypsum as a component in the building materials. 8 samples of&nbsp; bricks&nbsp; with&nbsp; different&nbsp; proportions&nbsp; of&nbsp; phosphogypsum&nbsp; were&nbsp; made and&nbsp; radiological&nbsp; and&nbsp; structural&nbsp; characterization&nbsp; of&nbsp; the&nbsp; obtained materials was performed. Variations of radon emanation coefficients from building materials over time, as well as the influence of leakage and&nbsp; back&nbsp; diffusion&nbsp; effects&nbsp; leading&nbsp; to&nbsp; these&nbsp; variations,&nbsp; were investigated. The influence of the structure of the material in terms of mineral and chemical composition and porosity on the values of the radon&nbsp; emanation&nbsp; coefficient&nbsp; was&nbsp; also&nbsp; investigated.&nbsp; The mineralogical characterization of the samples was performed by the method&nbsp; of&nbsp; X-ray&nbsp; structural&nbsp; analysis&nbsp; (XRD),&nbsp; and&nbsp; the&nbsp; chemical characterization&nbsp; by&nbsp; the&nbsp; method&nbsp; of&nbsp; X-ray&nbsp; fluorescence&nbsp; analysis (XRF). The measurement of total effective porosity was performed by water absorption methods and mercury porosimetry method. Based on&nbsp; the&nbsp; obtained&nbsp; results,&nbsp; significant&nbsp; correlations&nbsp; were&nbsp; establishedbetween&nbsp; individual&nbsp; radiological&nbsp; and&nbsp; structural&nbsp; parameters&nbsp; for&nbsp; the analyzed samples of construction materials.</p>