Au début des années 1970, les travailleurs de l'amiante de Thetford Mines et d'Asbestos ont entrepris un combat pour assainir leurs milieux de travail et leurs villes, dans lesquelles les mines étaient imbriquées. À Thetford Mines, ils ont mené une longue grève de sept mois et demi qui a conduit à la mise sur pied du Comité d'étude sur la salubrité dans l'industrie de l'amiante, puis, avec l'élection du jeune Parti québécois, à la Loi sur la santé et la sécurité du travail qui introduisait les principes de l'élimination des dangers à la source et de la participation des travailleurs à son application. La crédibilité de leurs syndicats s'en trouvait renforcée. Mais bientôt la montée d'un mouvement international visant à bannir l'amiante et la crise économique du début des années 1980 allaient porter un dur coup à l'industrie et entrainer un déclin que rien ne pourrait arrêter. Les travailleurs miniers, qui s'étaient unis contre leurs employeurs et parfois contre l'État dans leur combat pour la santé, s'allièrent dès lors à leurs entreprises et aux pouvoirs publics pour promouvoir le minéral et tenter de préserver leurs emplois et la vitalité de leurs régions. Ils n'ont jamais envisagé l'arrêt de la production d'amiante car ils ont toujours considéré qu'il est possible d'en maitriser les risques et ils défendirent bec et ongles leur produit en arguant du caractère sécuritaire de ses utilisations modernes, malgré un consensus international grandissant à l'encontre de cette thèse. / The asbestos workers in the cities of Thetford Mines and Asbestos launched a campaign for better working conditions and healthier living conditions despite the entanglement of the mines in the heart of their cities, in the early 1970s. The unions in Thetford Mines together led a long, seven-and-a-half month strike, which culminated with the establishment of a committee on hygiene in the asbestos industry (Comité d’étude sur la salubrité dans l’industrie de l’amiante), and then, with the election of the young Parti Québécois, with a new occupational safety and health law which implemented the principles of eliminating dangers at their source, as well as that of worker participation in the endeavour. The asbestos unions had become credible political players. But the rise of an international movement to ban asbestos, along with the economic crisis of the early 1980s, dealt a crushing blow to the industry from which it would never recover. The miners, who had come together to take on their employers - and the government in some cases – to better their health, soon sided with industry and the public authorities to promote asbestos as a way to preserve their jobs and the life of their surrounding areas. They had never considered ceasing asbestos production because they believed the hazards could be controlled, and they persisted in their steadfast defense of the safety of the product even as an international consensus formed against this thesis.

Text in English with abstracts and keywords in English, Afrikaans, Sepedi and Sesotho / Soil and other geological materials found on the crust of the Earth are known to be rich in naturally occurring silicate minerals. Asbestos is one of the fibrous silicate minerals that was mined predominantly in some regions of Limpopo, Mpumalanga and Northern Cape provinces in South Africa. Despite the cessation of asbestos mining due to associated human health effects in 2002, there is still a concern about possible environmental exposure to asbestos fibres. A single asbestos fibre is made of millions of microscopic needle-like fibrils which break easily to produce inhalable size fractions that are reported to cause lung diseases. The main source of asbestos fibres in former mining areas is asbestos mine dumps and asbestos contaminated surface soil. Asbestos mine dumps in Limpopo Province are partially rehabilitated, while in Mpumalanga Province they are not rehabilitated and all these dumps are now under the care of government because the original owners have abandoned them. The settleable dust is the first indicator of airborne dust pollution and the rate of settleable dust rates was used to select the sites to be monitored. A pilot study was conducted to test the performance of the ASTMD1739:1998 and ASTM D 1739:1970 methods. The method was further modified and optimized to measure asbestos load in settleable dust samples. A total ten sites located around vulnerable human settlements that are in close proximity to the abandoned asbestos mine dumps were chosen in Mpumalanga and Limpopo Provinces respectively. Airborne, surface and trapped dust samples were collected once a month around human settlements that are in close proximity to the abandoned asbestos mine dumps from April 2016 to June 2017. Airborne dust samples were collected using the official settleable dust monitoring method, the general particulate matter E-sampler and the official asbestos Air-Con 2 sampler. Surface dust was collected outdoors around the settleable dust collection units using a brush and dust pan and was stored in labeled zipper bags made of plastic material. Trapped dust samples were collected using sticky tape both indoors and outdoors around the window panes, on surfaces of furniture and on windscreens of old cars and were stored in labeled closed containers. Surface soil samples were also screened with the hand held asbestos analyser before collection. The samples were extensively and carefully prepared and handled to avoid or minimize cross contamination using standard laboratory methods and were analysed using calibrated analytical instruments. An adapted method (ASTMD 1739:1970) was used to determine the presence of asbestos hazard in a form of mineral count. This method was also used for the identification of asbestos and other minerals in different dust samples using the XRD technique. Physical features of all minerals such as the shape, size and type were also determined as part of the characterization process using the SEM-EDS technique. The ASTMD1739:1998 method gave rise to higher retention of settleable dust, hence it was found to be more efficient. Unfortunately, this best performing method is not legislated or regulated by the government. This researcher concludes that the reasons could be due to the different shapes of the windshield designs (which means the different designs of windshields) at may make it difficult to standardize and control. However, this information gap provides an opportunity of a longer focused study of this method with the intention of finding a standardized windshield design that could be recommended for use in the country. Secondly, the units that had both water and algaecide gave rise to higher settleable Mpumalanga. Three exceedances of 600 mg/m2/day of residential limit regulated through National Dust Control Regulation no.28 of 2013 presented in decreasing order in Limpopo were 2724 mg/m2/day at Site E, 1638 mg/m2/day at Site D and 834 mg/m2/day at Site B in the same month of March 2017 . The XRF data of metal oxides, including these top three [Si(IV)O2, Fe2(III)O3 and Al2(III)O3], confirm the dominance of silicate minerals in surface dust samples from both provinces. The XRD mineralogy data from filtered settleable dust show the dominance of the amphibole asbestos particulates ranging from 18 to 56 % in Limpopo province and 2.0 to 3.0 % in Mpumalanga province. Low presence of serpentine minerals with the highest being 2.0 % and 7.0 % in Limpopo and Mpumalanga provinces respectively. About 8.0 to 43 % of amphibole asbestos minerals were measured on trapped dust in Limpopo together with zero detection of serpentine. No asbestos minerals were detected on trapped dust from Mpumalanga, despite the close proximity of the unrehabilitated asbestos mine dumps All airborne asbestos fibres that were captured on the filter substrates were a bove the limit value of 100 f/mL of air. The highest airborne asbestos fibre and concentration counts m easured were 40 fibres and 0, 00434 f /mL concentration in October 2017 at Site A. The second highest fibre count concentration was measured in June with 0,00287 f/mL at Site A in September 2017 and 0,01085 f/mL at the Site D in June 2017 monitoring sites. Again, the highest in June 2017 with 0,00125 f/mL for Site A for Limpopo Province. In Mpumalang a the lowest asbestos fibre concentration which are be low the OHSA no. 39 of 1993 and MDHS 39/ 4, 1995 0.1 f/mL and 100 f/mL However, from the safety perspective all asbestos fibres or minerals inhaled are a hazard to human health. The study established that the adapted asbestos mineral count method succeeded in identifying and quantifying the asbestos minerals that existed in the settleable dust samples from the study areas. These outcome s were successfully validated with the test undertaken using both the officially (Air Con 2 sampler) and unofficial (E sampler) recognized method of asbestos fibre count. The adapted mineral count method provides the research community with an alternative, cost effective and user friendly method of analysis. Also, the validation method s gave additional new information. Of a total of 120 of ex- posed filter papers used in the official asbestos fibre Air Con 2 sampler, 28 filters had positive presence of asbestos fibres, making it 23 collection efficiency And of the 100 exposed filt er papers used in for E samplers, only 8% collection efficiency was recorded. The results means that the official asbestos fibre Air Con 2 sampler has 23 more collection efficiency than the general particulate matter E sampler for air- borne asbestos monitoring. The impact of these results could also be that a general particulate matter high volume sampler c ould still be used for asbestos fibre monitoring in the absence of a specific and selective Air Con 2 sampler, as long as the user appreciates abo ut 23 collection deficiency. These findings go a long way in helping to make air quality research domain accessible. Since the ASTM D1739:1998 method has been found to perform better than the officially recognized method, this study recommends that the regulators of air quality in the country consider it. But, the method will first require some improvement and standardization particularly the different wind shield designs before it could be officially accepted as the method of collection and analyses for settleable dust. It is hoped that the air quality research community will take up the challenge. / Grond en ander geologiese materiale wat op die aardkors aangetref word, is bekend dat hulle ryk is in silikaatminerale wat natuurlik voorkom. Asbes is een van die veselagtige silikaatminerale wat hoofsaaklik in sommige streke van die Limpopo, Mpumalanga en Noord-Kaap Provinsies in Suid-Afrika ontgin is. Ondanks die staking van asbesmynbou in 2002 as gevolg van gepaardgaande gesondheidseffekte op mense, is daar steeds kommer oor moontlike blootstelling aan asbesvesels in die omgewing. 'n Enkele asbesvesel bestaan uit miljoene mikroskopiese naaldagtige vesels wat maklik breek om partikels van inasembare grootte te produseer wat volgens berigte longsiektes veroorsaak. Die belangrikste bron van asbesvesels in voormalige myngebiede is asbesmynhope en besmette asbesoppervlakgrond. Asbesmynhope in Limpopo Provinsie word gedeeltelik gerehabiliteer, terwyl hulle in Mpumalanga Provinsie nie gerehabiliteer word nie, en al hierdie mynhope is nou onder die regering se toesig omdat die oorspronklike eienaars die mynhope verlaat het. Die neerslagbare stof is die eerste aanduiding van stofbesoedeling in die lug en is gebruik om die terreine wat gemoniteermoet word, te kies. 'n Loodsstudie is uitgevoer om die prestasie van die ASTMD1739:1998 en ASTMD1739:1970 metodes te toets. In die loop van die studie is 'n amptelike ASTMD1739:1970 metode gebruik en toegepas vir die versameling van neerslagbare stofmonsters. In Mpumalanga en Limpopo Provinsies respektiewelik is daar altesaam tien (10) terreine gekies rondom kwesbare menslike nedersettings wat naby die verlate asbesmynhope geleë is. Stofmonsters in die lug, oppervlak en wat vasgevang is, is een keer per maand versamel vanaf April 2016 tot Junie 2017 rondom menslike nedersettings in die nabyheid van die verlate asbesmynhope. Stofmonsters in die lug is versamel volgens die amptelike neerslagbare stofmoniteringsmetode, die E monsternemer en die Air-Con 2 monsternemer. Oppervlakstof is buite met behulp van 'n kwas en stofpan rondom die neerslagbare stofopvangeenhede opgevang en is in gemerkte ritsakke van plastiekmateriaal geberg. Stofmonsters wat vasgevang is, is met behulp van kleeflint, binne en buite, om vensterruite, op meubeloppervlaktes en op voorruitte van ou motors versamel, en is in gemerkte geslote houers geberg. Oppervlakgrondmonsters is ook voor versameling met die draagbare asbesanaliseerder gefilter. Die monsters is breedvoerig en sorgvuldig voorberei en hanteer om kruisbesmetting tot ‘n minimum te beperk deur gebruik te maak van standard laboratoriummetodes en is ontleed met behulp van gekalibreerde analitiese instrumente. 'n Aangepaste metode is gebruik om die teenwoordigheid van asbesgevaar in 'n vorm van mineraaltelling te bepaal. Hierdie metode is ook gebruik vir die identifisering van asbes en ander minerale in verskillende stofmonsters met behulp van die XRD tegniek. Die fisiese kenmerke van alle minerale soos die vorm, grootte en tipe is ook bepaal as deel van die karakteriseringsproses met behulp van die SEM-EDS tegniek. Die ASTMD1739:1998 metode het gelei tot 'n hoër retensie van neerslagbare stof, en daarom is gevind dat dit doeltreffender is. Ongelukkig word hierdie metode wat die beste presteer nie deur die regering gewettig of gereguleer nie. Hierdie navorser kom tot die gevolgtrekking dat die redes kan wees as gevolg van die verskillende vorms van die voorruitontwerpe wat dit moeilik kan maak om dit te standaardiseer en te beheer. Hierdie inligtingsgaping bied egter 'n geleentheid tot 'n langer gefokusde studie van hierdie metode met die doel om 'n gestandaardiseerde voorruitontwerp te vind wat aanbeveel kan word vir gebruik in die land. Tweedens het die eenhede wat beide water en alge-suurwater gehad het, gelei tot 'n hoër neerslagbare stof in Mpumalanga Provinsie. Drie oorskrydings wat in dalende volgorde in Limpopo aangebied is, was 2724 mg/m2/dag op perseel E, 1638 mg/m2/dag op perseel D en 834 mg/m2/dag op perseel B in dieselfde maand van Maart 2017. Die XRF data van metaaloksiede, met inbegrip van hierdie top drie [Si(IV)O2, Fe2(III)O3 en Al2(III)O3], bevestig die oorheersing van silikaatminerale in oppervlakstofmonsters van beide provinsies. Die XRD mineralogiedata van gefiltreerde, neerslagbare stof toon die oorheersing van die amfibool asbesdeeltjies wat wissel tussen 18 en 56 % in Limpopo Provinsie en 2.0 en 3.0 % in Mpumalanga Provinsie. Daar is ‘n lae teenwoordigheid van serpentynminerale met die hoogste onderskeidelik 2.0 % en 7.0 % in die Limpopo en Mpumalanga Provinsies onderskeidelik. Ongeveer 8.0 tot 43 % van die amfibool asbesminerale is op vasgevangde stof in Limpopo gemeet, tesame met geen opsporing van serpentyn. Geen asbesminerale is opgespoor in die vasgevangde stof van Mpumalanga nie, ondanks die nabyheid van die ongerehabiliteerde asbesmynhope. Alle asbesvesels in die lug wat op die filtersubstrate vasgelê is, was bo die grenswaarde van 100 f/mL lug. Die hoogste asbesvesel en konsentrasietellings in die lug gemeet, was 40 vesels en 'n konsentrasie van 2.083 f/mL in Oktober op Terrein A. Die volgende hoogste veseltellingkonsentrasie is in Junie gemeet met 6.590 f/mL op die Terrein A en 5.272 f/mL op die Terrein D moniteringsterreine. In Mpumalanga was die hoogste asbesveselkonsentrasie 2.190 f/mL in Junie en 2.083 f/mL in November op Terrein D. Uit ‘n veiligheidsperspektief is alle asbesvesels of minerale wat ingeasem word egter 'n gevaar vir die mens se gesondheid. Die studie het vasgestel dat die aangepaste asbesmineraaltellingmetode daarin geslaag het om die asbesminerale wat in die neerslagbare stofmonsters uit die studiegebiede bestaan te identifiseer en te kwantifiseer. Hierdie uitkoms is suksesvol bekragtig met die toets wat onderneem is met behulp van die amptelik erkende metode vir die telling van asbesvesel. Die aangepaste mineraaltellingmetode bied aan die navorsingsgemeenskap 'n alternatiewe, koste-effektiewe en gebruikersvriendelike ontledingsmetode. Aangesien daar gevind is dat die ASTMD1739:1998 metode beter presteer as die amptelik erkende metode, beveel hierdie studie aan dat die reguleerders van luggehalte in die land dit oorweeg. Maar die metode sal eers verbetering en standaardisering verg, veral die verskillende windskermontwerpe voordat dit amptelik aanvaar kan word as die metode om neerslagbare stof te versamel en te ontleed. Daar word gehoop dat die gemeenskap wat luggehalte navors die uitdaging sal aanpak. / Mabu le dišomišwa tše dingwe tša bothutaswika tše di hwetšagalago bokagodimo ba Lefase di tsebja di e na le diminerale tše dintši tša tlhago tše di diragalago ka tlhago. Marela ke e ngwe ya diminerale tše di nago le dimela tše di ntši kudu tše di bego di epšwa kudu mafelong a mangwe a diphrofentshe "diphrofentsheng tša Limpopo, Mpumalanga le North Cape Afrika Borwa. Le ge go feditšwe go epšwa marela ka lebaka la ditlamorago tše amanago le maphelo a batho ka 2002, go na le pelaelo malebana le go utullwa ga malwetši a marela. Fibre ke ye ngwe ya marela ye e dirilwego ka maekrosekopiki tše dimilione tše di ka senyegago bonolo go tšweletša khemobonolo yeo e hlamago malwetši a mafahla. Sehlodikgolo sa malwetši a marela mafelong a mathomo ao go bego go le meepo ke sekoti sa marela le mabu a ka godimo ga marela. Dikoti tša meepo ya Marela Phrofentsheng ya Limpopo di mpšhafaditšwe ka tsela ye itšego, eupša Phrofentsheng ya Mpumalanga ga se tša mpšhafatšwa gomme mafelo a ka moka a laolwa ke mmušo gobane beng ba tšona ba di tlogetše. Lerole le ka rarollwago ke sešupopele sa tšhilafalo ya moya e dirwago ka moya gomme se be se šomišwa go kgetha mafelo ao a loketšwego go hlokomelwa. Go ile gwa dirwa tekolo ya go leka tšhomo ya mekgwa ya ASTMD1739: 1998 le ASTM D 1739: 1970. Ge re ntše re tšwela pele ka thuto, go šomišitšwe mokgwa wa semmušo wa ASTM D1739: 1970 gomme wa šomišwa lebakeng la go kgoboketša sampole ya lerole e ka rarollwago. Mafelo a lesome (10) a hweditšwe kgauswi le bodulo ba batho bjo bo lego kotsing ka dikoti tša meepo ya marela di ile tša kgethwa diphrofentsheng tša Mpumalanga le Limpopo ka go latelana. Disampole tša moya tša ka godimo ga lefase, godimo le tše di khutilego di ile tša kgoboketšwa ga tee kgweding kgauswi le bodulo ba batho tše di bego kgauswi kudu le dikoti tša meepo ya marela go tloga ka la 2016 Mopitlo go fihla ka Phupu 2017. Mehuta ya lerole ye sepetšwago ke moya e ile ya kgoboketšwa go šomišwa mokgwa wa semolao wa go tšweletša lerole, E-sampler le sampole ya Air-Con 2. Lerole la ka godimo le be le kgoboketšwa ka ntle go rarela dikarolo tša go kgoboketša lerole go šomišwa poratšhe le pane ya kota gomme le bolokelwa ka mekotleng e nago le zipper ye dirilwego ka polasetiki. Sampole ya lerole le le bego le gaeletšwe le ile la kgoboketšwa ka theipi ya go momela bokagareng le bokantle bja morumofasetere,mabotong a phahlo , le godimo ga galasebokapele dikoloing tša kgale gomme tša bolokwa ka gare ga didirišwa tšeo di makilwego. Disampolo tša mabu a ka godimo di be di hlahlobjwa gape ka mokgwa wa go kgwa ka letsogo ke mohlahlobi wa marela pele go kgoboketšwa. Disampole di be di lokišitšwe kudu ebile di dirilwe ka tlhoko go efoga tšhilafalo ka mekgwa ye tlwaelegilwego ya laporatori gomme ba e hlahloba ba šomiša didirišwa tša go hlahloba. Mokgwa o ikgethilego o šomišwa go hwetša bogona ba kotsi ya marela ka mokgwa wa palo ya diminerale. Mokgwa wo o be o šomišitšwe gape le go bošupong ba marela le diminerale tše dingwe ka gare ga disampole tše di fapanego tša lerole go šomišwa mokgwa wa XRD. Dibepegopono tša diminerale ka moka go swana le sebopego, bogolo le mohuta le tšona di be di tšewa e le karolo ya tshepetšo ya pharodipataka go bogolo le mohuta le tšona di be di tšewa e le karolo ya tshepetšo ya pharodipataka go šomišwa mokgwa wa SEM-EDS. Mokgwa wa ASTMD1739: 1998 o ile wa dira gore go bolokwe lerole le phagameng ka go fetolegago, ka gona go hweditšwe gore le šoma gabotse kudu. Ka bomadimabe, mokgwa wo o tšweletši kudu ge o ngwadišwa ke molao go mmušo. Monyakišiši wo o phetha ka gore mabaka e ka ba ka lebaka la dibopego tše di fapaneng tša meralo ya setsi sa moya se se ka dirago gore go be boima go tseba le go laola. Le ge go le bjalo, sekgoba se sa tshedimošo se fa monyetla wa go ithuta nepišo e telele ya maikemišetšo a go hwetša moralo o tiišitšwego wa moya o ka šišinywago gore o šomišwe ka nageng. Ya bobedi, diyuniti tše di bego di e na le meetsi le algaecide di ile tša tšweletša maemo a phagamego Mpumalanga Phrofentsheng. Ditekanyetšo tše tharo tše di tšweleditše ka tatelano ya taolo e fokotšegago e be e le 2724 mg/ m2/ letšatši go Site E, 1638 mg / m2/ letšatši go Site D le 834 mg/ m2/ letšatši go Site B kgweding ye tee ya Hlakola 2017 Dintlha tša XRF tša di-oxide tša tšhipi, go akaretša tše tše tharo tša godimo [Si (IV) O2, Fe2 (III) O3 le Al2 (III) O3], di tiiša boleng bo phagameng ba diminerale tša silrate mehuteng ya lerole ye e tšwago diphrofentsheng ka bobedi. Dintlha tša XRD tša mineralogy tše di tšwago leroleng le tšhilafatšong di ka tšewa di bontšha phelo ya marela ya amphibole go tloga go 18 go iša go 56% phrofentsheng ya Limpopo le 2.0 go iša go 3.0% phrofentsheng ya Mpumalanga. Bogonatlase ba diminerale tša serpentine tše phagameng ka go fetišiša e le 2.0% le 7.0% diphrofentsheng tša Limpopo le Mpumalanga ka go latelana. Go lekana 8.0 go iša go 43% ya diminerale tša marela tše lekantšwego di ile tša lekanywa leroleng le ageeletšwego ka Limpopo gammogo le go utullwa ga serpentine. Ga go na diminerale tša marela tše di hweditšwego leroleng le ageeletšwego le tšwago Mpumalanga, le ge e le kgauswi kgauswi le dikoti tša mope wa maraba wa marela se a mpšhafatšwago. Mehuta ka moka ya moya ya marela ye e bego e swerwe ka gare ga moya o bego o Mehuta ka moka ya moya ya marela ye e bego e swerwe ka gare ga moya o bego o le ka godimo wa boleng ba moya wa 100 f /mL. Mohuta o phagamego go fetišiša wa moya wa marela le dipalo tša mahlorišo a lekantšwego e be e le tše 40 le bogolo ba 2.083 f /mL ka Diphalane go Site A. Tekanyomahloriš e latelago ya fiber e lekantšwe Phupu ka 6.590 f /mL go Site A le 5.272 f /mL Site D mafelong a tlhahlobo. Nageng ya Mpumalanga, di-fibre tša marela tše phagamego ka go fetišiša e be e le 2.190 f / mL ka Phupu le 2.083 f /mL ka Dibatsela go Site D. Le ge go le bjalo, go latela ponego ya tšhireletšo, fibre ka moka tša marela goba diminerale tše di hengwago di kotsi maphelong a botho. Boithuto bo bo utullotše gore mokgwa wo lekantšwego wa marela o bontšhitšwegošupo o atlegile go kgetholla le go hlakola diminerale tša marela tše di bego di le gona ka gare ga disampolo tša lerole le tšwago mafelong a boithuto. Sephetho se se netefaditšwe katlego le tlhahlobo ye e dirilwego e šomišwago mokgwa wo amogetšwego ke molao wa marela fiber. Mokgwa o lekantšwego wa diminerale o thuša setšhaba sa dinyakišišo ka mokgwa o mongwe wa tlhahlobo ye e šongwago, gabotse e bile ye botho. Go tloga go mokgwa wa ASTM D1739: 1998 o hweditšwe o šoma gabotse go feta mokgwa wo amogetšwego ke molao, thuto ye e šupetša gore balaodi ba boleng ba moya nageng ba e nagane. Empa, mokgwa wo o tla hloka mpšhafatšo le maemo pele kudu meralo ye fapaneng ya thebe ya moya pele e ka amogelwa ke molao e le mokgwa wa go kgoboketša le go sekaseka lerole le le ka rarolwago. Re tshepa gore setšhaba sa dinyakišišo tša boleng ba moya se tla tšea bothata bo. / Mobu le lisebelisoa tse ling tsa jioloji tse fumanehang bokaholimo ba Lefatše li tsejoa li na le liminerale tse ngata tsa tlhaho tse etsahalang ka tlhaho. Asbestos ke e 'ngoe ea liminerale tse nang le silika e ngata e neng e chekoa haholo libakeng tse ling tsa liprofinse tsa "liprofinse tsa Limpopo, Mpumalanga le North Cape Afrika Boroa. Leha ho felisoa morafo oa asbestos ka lebaka la litlamorao tse amanang le bophelo bo botle ba batho ka 2002, ho ntse ho na le ts'oenyeho mabapi le ho pepesetsoa ha tikoloho likhoele tsa asbestos. Fiber e le 'ngoe ea asbestos e entsoe ka likhoele tse limilione tse kang nale tse tsoang habonolo ho hlahisa likaroloana tse sa bonoeng tse tlalehang libaka-mafuamatšo. Mohloli o ka sehloohong oa likhoele tsa asbestos libakeng tseo pele e neng e le tsa meepo ke lithako tsa asbestos le mobu o silafetseng oa asbestos. Likotlo tsa merafo ea Asbestos Profinseng ea Limpopo li nchafalitsoe ka tsela e itseng, athe Profinseng ea Mpumalanga ha e nchafatsoe 'me libaka tsena kaofela li laoloa ke mmuso hobane beng ba tsona ba ba lahlile. Lerōle le ka rarolloang ke letšoao la pele la tšilafalo ea moea e tsoang ka moea mme le ne le sebelisetsoa ho khetha libaka tseo li lokelang ho-shebelloa. Ho ile ha etsoa boithuto ba ho leka ts'ebetso ea mekhoa ea ASTMD1739: 1998 le ASTM D 1739: 1970. Ha re ntse re tsoela pele ka thuto, ho sebelisitsoe mokhoa oa semmuso oa ASTM D1739: 1970 'me oa sebelisoa bakeng sa ho bokella sampole ea lerōle e ka rarolloang. Sebaka sa libaka tse leshome (10) tse fumanehang haufi le bolulo ba batho ba tlokotsing tse haufi le libaka tse lahliloeng tsa meepo ea asbestos li ile tsa khethoa liprofinseng tsa Mpumalanga le Limpopo ka ho latellana. Lisampole tsa moea tse ka holim'a lefatše, holimo le tse patiloeng li ile tsa bokelloa hang ka khoeli ho potoloha libaka tsa bolulo tsa batho tse haufi haholo le libaka tse lahliloeng tsa moepo oa asbestos ho tloha ka Mmesa 2016 ho fihlela ka Phuptjane 2017. Mefuta ea lerōle e tsamaisoang ke moea e ile ea bokelloa ho sebelisoa mokhoa oa semolao oa ho hlahisa lerōle, E-sampler le sampole ea Air-Con 2. Lerōle le kaholimo le ne le bokelloa ka ntle ho potoloha likarolo tsa ho bokella lerōle le sebelisa brashi le pane ea patsi mme le bolokiloe ka mekotleng e nang le zipper e entsoeng ka thepa ea polasetiki. Mehlala ea lerōle e neng e tšoasehile e ile ea bokelloa ho sebelisoa theipi e khangoang ka tlung le kantle kahare ho lifensetere, ka holim'a thepa ea ka tlung le lifensetereng tsa likoloi tsa khale 'me li bolokiloe ka har'a lisebelisoa tse koetsoeng. Meetso ea mobu e kaholimo le eona e ile ea hlahlojoa ka letsoho le ts'oaroang ka asbestos pele ho pokello. Mehlala e ne e hlophisitsoe haholo ebile e entsoe ka hloko ho qoba ho silafatsa kapa ho fokotsa tšilafalo ea tšebeliso ea mekhoa e tloaelehileng ea laboratori mme e ile ea hlahlojoa ho sebelisoa lisebelisoa tsa tekanyetso. Mokhoa o ikhethileng o sebelisitsoe ho fumana ho ba teng ha kotsi ea asbestos ka mokhoa oa palo ea liminerale. Mokhoa ona o ne o boetse o sebelisoa bakeng sa ho khetholla asbestos le liminerale tse ling ka har'a disampole tse fapaneng tsa lerōle ho sebelisoa mokhoa oa XRD. Litšobotsi tsa 'mele tsa liminerale tsohle tse kang sebopeho, boholo le mofuta le tsona li ne li nkuoa e le karolo ea ts'ebetso ea sebopeho ho sebelisa mokhoa oa SEM-EDS. Mokhoa oa ASTMD1739: 1998 o ile oa etsa hore ho bolokoe lerōle le phahameng ka ho fetelletseng, ka hona ho fumanoe hore le sebetsa hantle haholo. Ka bomalimabe, mokhoa ona o atlehileng ka ho fetisisa ha o ngolisoe ke molao kapa 'muso. Mofuputsi enoa o phethela ka hore mabaka a ka ba teng ka lebaka la sebopeho se fapaneng sa meralo ea setsi sa moea se ka etsang hore ho be thata ho tseba le ho laola. Leha ho le joalo, lekhalo lena la tlhaiso-leseling le fana ka monyetla oa ho ithuta ho tsepameng molemong oa mokhoa ona ka sepheo sa ho fumana moralo o tiisitsoeng oa moea o ka khothalletsoang hore o sebelisoe ka har'a naha. Ya bobedi, diyuniti tse neng di na le metsi le algaecide li ile tsa hlahisa maemo a phahameng a ho tsetsahala Mpumalanga. Litekanyetso tse tharo tse fanoeng ka tatellano ea taolo e fokotsehang e ne e le 2724 mg/ m2/ letsatsi ho Site E, 1638 mg /m2/ letsatsi ho Site D le 834 mg / m2/letsatsi ho Site B ka khoeli e tšoanang ea Hlakubele 2017. Lintlha tsa XRF tsa li-oxide tsa tšepe, ho kenyelletsa tsena tse tharo tse holimo [Si (IV) O2, Fe2 (III) O3 le Al2 (III) O3], li tiisa boleng bo phahameng ba liminerale tsa silrate mefuteng ea lerōle e tsoang liprofinseng ka bobeli. Lintlha tsa XRD tsa mineralogy tse tsoang lerōleng le ts'ilafatsoang li ka nkuoa li bonts'a phello ea asbestos ea amphibole ho tloha ho 18 ho isa ho 56% profinseng ea Limpopo le 2.0 ho isa ho 3.0% profinseng ea Mpumalanga. Boteng bo tlase ba liminerale tsa linoha tse phahameng ka ho fetisisa e le 2.0% le 7.0% liprofinseng tsa Limpopo le Mpumalanga ka ho latellana. Hoo e ka lerōleng le ts'oaroang ho la Limpopo hammoho le ho sibolloa ha noha. Ha ho na liminerale tsa asbestos tse fumanoeng lerōleng le tsubelletsoeng le tsoang Mpumalanga, leha ho le haufi le marang-rang a litopo tsa asbestos tse sa ntlafatsoang. Mefuta eohle ea moea e kang asbestos e neng e hapiloe kahare ho moea o ne o le kaholimo ho boleng ba moea oa 100 f /mL. Mofuta o phahameng ka ho fetisisa oa moea oa asbestos le lipalo tsa mahloriso tse lekantsoeng e ne e le likhoele tse 40 le boholo ba 2.083 f /mL ka Mphalane ho Site A. Khakanyo e latelang ea fiber fiber e latelang e lekantsoe ka Pherekhong ka 6.590 f /mL ho Site A le 5.272 f /mL setsing D libaka tsa tlhahlobo. Naheng ea Mpumalanga, li-fiber tsa asbestos tse phahameng ka ho fetisisa e ne e le 2.190 f /mL ka Phuptjane le 2.083 f /mL ka Pulungoana ho Site D. Leha ho le joalo, ho latela pono ea ts'ireletso, likhoele tsohle tsa asbestos kapa liminerale tse kentsoeng li kotsi bophelong ba motho. Boithuto bo fumane hore mokhoa o lekantsoeng oa "asbestos" o ntlafalitsoeng o atlehile ho tseba le ho hlakisa liminerale tsa asbestos tse neng li le teng ka har'a mehlala ea lerōle e tsoang libakeng tsa boithuto. Sephetho sena se netefalitsoe ka katleho le tlhahlobo e entsoeng e sebelisang mokhoa o amohetsoeng ka molao oa asbestos fiber count. Mokhoa o lekantsoeng oa liminerale o thusa sechaba sa lipatlisiso ka mokhoa o mong oa tlhahlobo o sebetsang, o sebetsang hantle ebile o sebelisang botsoalle. Ho tloha ha mokhoa oa ASTM D1739: 1998 o fumanoe o sebetsa hantle ho feta mokhoa o amohetsoeng ka molao, thuto ena e khothaletsa hore batsamaisi ba boleng ba moea naheng ba e nahane. Empa, mokhoa ona o tla hloka ntlafatso le maemo pele haholo mealo e fapaneng ea thebe ea moea pele e ka amoheloa ka molao e le mokhoa oa ho bokella le ho sekaseka lerōle le ka rarolloang. Re tšepa hore sechaba sa lipatlisiso tsa boleng ba moea se tla nka bothata bona. / Environmental Science / Ph. D. (Environmental Sciences)

L’appréciation de la puissance cancérogène des fibres d’amiante chrysotile repose en grande partie sur des jugements subjectifs et incertains des experts et des analystes en raison des résultats hétérogènes et équivoques d’études épidémiologiques et toxicologiques sérieuses. L’approche probabiliste bayésienne en évaluation de risques peut formaliser l’impact des jugements subjectifs et de leurs incertitudes sur les estimations de risques, mais elle est encore peu utilisée en santé publique. Le présent travail examine la possibilité d’appliquer l’approche bayésienne dans une récente élicitation d’opinions d’experts pour estimer la toxicité du chrysotile, le degré de consensus et de divergence, ainsi que les niveaux d’incertitude des experts. Les estimations des experts concordaient assez bien sur la différence de toxicité entre chrysotile et amphiboles pour les mésothéliomes. Pour le cancer du poumon, les évaluations probabilistes étaient bien plus disparates. Dans ce cas, les jugements des experts semblaient influencés à différents degrés par des biais heuristiques, surtout les heuristiques d’affect et d’ancrage liés à la controverse du sujet et à l’hétérogénéité des données. Une méthodologie rigoureuse de préparation des experts à l’exercice d’élicitation aurait pu réduire l’impact des biais et des heuristiques sur le panel. / Characterizing the carcinogenic potency of chrysotile asbestos fibres relies a great deal on subjective and uncertain judgements by experts and analysts, given heterogeneous and equivocal results of important epidemiological and toxicological studies. The probabilistic Bayesian approach in risk assessments quantifies these subjective judgements and their uncertainties, along with their impact on risk estimations, but it is rarely used in the public health context. This report examines how the Bayesian approach could have been applied to a recent elicitation of experts’ opinions to estimate the toxicity of chrysotile asbestos, the degree of convergence and divergence, as well as the uncertainty levels of these experts. The experts’ estimations on the relative toxicity of chrysotile and amphibole asbestos were similar in the case of mesothelioma. However, in the case of lung cancer, the heterogeneity of the studies resulted in diverging and incompatible probabilistic evaluations. The experts’ judgements seemed influenced by heuristic biases, particularly the affect and anchor heuristics associated with a controversial topic and to heterogeneous data. If the elicitation process had been prepared following a rigorous methodology, these heuristics and biases could have been mitigated.

Cette thèse vise à comprendre comment les acteurs concernés par un drame collectif de grande ampleur, ici le scandale de l’amiante, tentent de se mettre d’accord quant à ce qui constitue une juste réparation des dommages engendrés. Le scandale de l’amiante a donné naissance à des innovations au niveau de l’indemnisation des victimes, avec la création d’un Fonds d’indemnisation (le Fiva), et la rénovation du dispositif de la « faute inexcusable de l’Employeur » devant les Tribunaux des Affaires Sanitaires et Sociales. Ces innovations ont questionné le système d’indemnisation traditionnel des Accidents du Travail et des Maladies Professionnelles, système consistant en une indemnisation forfaitaire reposant sur un système de gestion paritaire. Il s’agit alors de comprendre comment les dispositifs d’indemnisation qui font suite à un scandale sanitaire coexistent avec les dispositifs issus de l’État-Providence mis en place en 1946, et comment ces différents dispositifs permettent l’expression de différents types de citoyenneté. Afin de répondre à ces questions, la thèse s’attache à décrire les évaluations normatives portées par les acteurs sur les dispositifs d’indemnisation, ainsi que la manière dont ces évaluations se confrontent les unes aux autres. Fondée essentiellement sur des entretiens avec les acteurs concernés et sur des ethnographies d’associations locales, la thèse articule trois niveaux d’analyse :Les acteurs institutionnels qui ont participé à la création ou à la rénovation des dispositifs d’indemnisation des maladies de l’amiante (représentants syndicaux et associatifs, avocats, représentants patronaux, représentants des pouvoirs publics). La thèse montre comment les acteurs attribuent différentes finalités aux dispositifs d’indemnisations et évaluent différemment leurs principes de fonctionnement. Elle met en évidence une fracture importante entre représentants syndicaux et associatifs qu’elle tente d’expliquer.Les associations locales visent à aider les personnes à obtenir indemnisation. La thèse s’attache à décrire la diversité des modes de structuration et de fonctionnement de ces associations, qui émanent de communautés variées, et montre l’influence de cette diversité sur la manière dont elles viennent en aide aux victimes.Les parcours d’indemnisation des victimes elles-mêmes et des ayants droit sont ensuite analysés, en s’attachant à mettre l’accent sur la diversité des manières dont ceux-ci formulent ce qui leur arrive, expriment des reproches, et réclament réparation. La thèse met en évidence l’influence de la carrière des personnes et des associations locales sur leurs itinéraires. / In this dissertation I aim to understand how actors affected by a major collective drama, here the asbestos scandal, try to reach agreement on what constitutes a fair compensation of the harms that have been caused. The asbestos scandal has given birth to innovations in the way victims are compensated, through the creation of a Compensation Fund (the Fiva) and the renewal of the procedure of « Faute inexcusable de l’employeur ». These innovations have come to question the traditional compensation system for Work-Related Accidents and Illnesses, which consisted of a lump-sum compensation based on a system of joint management between representatives of trade-unions and employers. The objective is to understand how compensation mechanisms that are created following a public health scandal coexist with mechanisms grounded in the welfare state that were put into place back in 1946, and how these different mechanisms allow the expression of different types of citizenship. In order to respond to these questions, the dissertation describes the normative evaluations expressed by different actors on these compensation mechanisms, as well as the way in which these evaluations confront each other. The dissertation is based mainly on interviews with the involved actors and on ethnographies of local associations, and articulates three analytical levels:The institutional actors that have participated in the creation or renovation of compensation mechanisms of asbestos-related diseases (union and association representatives, lawyers, employer representatives, government agents). The dissertation shows how actors attribute different ends to the compensation mechanisms and evaluate their principles and functioning differently. The thesis brings to light an important divide between union representatives and associations, which it tries to explain. Local associations seek to aid persons in obtaining compensation. The dissertation describes the diversity in the structuration and mode of functioning of these associations, that emanate from different types of communities, and shows the influence of this diversity on the way in which these associations provide aid to victims. Finally, the compensation paths of victims themselves and beneficiaries are analyzed, accentuating the diversity of ways in which they name what is happening to them, in how they express blame, and in how they claim compensation. The dissertation brings to light the influence of persons’ careers and of local associations on the itineraries they pursue.

L’appréciation de la puissance cancérogène des fibres d’amiante chrysotile repose en grande partie sur des jugements subjectifs et incertains des experts et des analystes en raison des résultats hétérogènes et équivoques d’études épidémiologiques et toxicologiques sérieuses. L’approche probabiliste bayésienne en évaluation de risques peut formaliser l’impact des jugements subjectifs et de leurs incertitudes sur les estimations de risques, mais elle est encore peu utilisée en santé publique. Le présent travail examine la possibilité d’appliquer l’approche bayésienne dans une récente élicitation d’opinions d’experts pour estimer la toxicité du chrysotile, le degré de consensus et de divergence, ainsi que les niveaux d’incertitude des experts. Les estimations des experts concordaient assez bien sur la différence de toxicité entre chrysotile et amphiboles pour les mésothéliomes. Pour le cancer du poumon, les évaluations probabilistes étaient bien plus disparates. Dans ce cas, les jugements des experts semblaient influencés à différents degrés par des biais heuristiques, surtout les heuristiques d’affect et d’ancrage liés à la controverse du sujet et à l’hétérogénéité des données. Une méthodologie rigoureuse de préparation des experts à l’exercice d’élicitation aurait pu réduire l’impact des biais et des heuristiques sur le panel. / Characterizing the carcinogenic potency of chrysotile asbestos fibres relies a great deal on subjective and uncertain judgements by experts and analysts, given heterogeneous and equivocal results of important epidemiological and toxicological studies. The probabilistic Bayesian approach in risk assessments quantifies these subjective judgements and their uncertainties, along with their impact on risk estimations, but it is rarely used in the public health context. This report examines how the Bayesian approach could have been applied to a recent elicitation of experts’ opinions to estimate the toxicity of chrysotile asbestos, the degree of convergence and divergence, as well as the uncertainty levels of these experts. The experts’ estimations on the relative toxicity of chrysotile and amphibole asbestos were similar in the case of mesothelioma. However, in the case of lung cancer, the heterogeneity of the studies resulted in diverging and incompatible probabilistic evaluations. The experts’ judgements seemed influenced by heuristic biases, particularly the affect and anchor heuristics associated with a controversial topic and to heterogeneous data. If the elicitation process had been prepared following a rigorous methodology, these heuristics and biases could have been mitigated.

Abstract not available. / Thesis (M.Dev.Studies)-University of Natal, Durban, 2000.

Ce projet de recherche-création en cinéma porte sur l’histoire d’une ancienne ville minière. En 1971, un glissement de terrain provoqué par les excavations d’une exploitation minière emporte une partie de la ville d’Asbestos (et de son histoire) au fond du trou. Cet événement hautement symbolique est devenu le point d’ancrage d’une problématique sur la représentation de la mémoire collective au cinéma. En écartant une approche « archiviste » du cinéma documentaire (images et enregistrements du passé), j’ai cherché à faire voir ce qui avait disparu dans le paysage matériel d’Asbestos, mais qui subsistait pourtant dans la mémoire des citoyens. Trois grands axes ont structuré mon projet. 1) Peut-on faire voir le passé d’Asbestos avec des images de son paysage actuel? 2) Est-il possible que la parole vernaculaire soit le meilleur moyen de faire (re)vivre et de faire (re)voir les expériences d'une communauté? 3) Est-ce dans l’interaction entre les images du présent et la parole des témoins de l’histoire que l’on peut révéler un passé disparu? / This film research-creation project focuses on the history of a former mining town. In 1971, a landslide triggered by the excavations of the adjacent mine swept part of the town of Asbestos – and its history – to the bottom of the pit. This symbolic incident serves as the basis for an exploration of how best to represent collective memory in film. In eschewing the archival approach of documentary cinema (using images and audio recordings from the past), I have tried to show what has disappeared from the town’s physical landscape yet is still very present in the memory of its inhabitants. My project is underpinned by three main questions: 1) Can Asbestos’s past be evoked through images of its current landscape? 2) Could capturing the spoken words of its inhabitants be the best way to bring a community’s experiences back to life and share them with others? 3) Can a bygone past be revealed through the interplay of present images and vernacular accounts of recent or distant history?

No description available.

Malignt mesoteliom är en ovanlig och aggressiv cancerform. Den är vanligast i pleura och kallas då pleuralt mesoteliom. Vanligaste orsaken till utveckling av pleuralt mesoteliom är exponering för asbest. Insjuknande patienter har dålig prognos och begränsade behandlingsmöjligheter. Röntgen kan i ett första stadie ge diagnos av sjukdomen. Oftast behövs också en biopsi tas för fastställande av diagnos. Även provtagning av pleuravätskan kan ge värdefull diagnostisk information. Immunhistokemi är en viktig tilläggsanalys för diagnos med biopsier och cellblock. Immunhistokemi innebär färgning med antikroppar. För pleuralt mesoteliom kan exempelvis antikropparna PD-L1 och calretinin användas för diagnostisering. I denna studie färgades 10 parade pleurabiopsier och cellblock från pleuravätska från patienter med malignt mesoteliom. Antikropparna PD-L1 och calretinin användes. Syftet var att utvärdera uttrycket av PD-L1 och calretinin. Alla infärgade glas undersöktes i ljusmikroskop. För PD-L1 ansågs enbart membranfärgning som positivt infärgad och för calretinin ansågs cytoplasmatisk och/eller kärnfärgning som positiv. Procentuellt antal positiva tumörceller undersöktes vid två cutoff värden, ≥1 % och ≥10 %. Procentuellt antal <1 % vid cutoff ≥1 % och procentuellt antal <10 % vid cutoff ≥10 % ansågs negativt. Detta gällde för båda antikropparna. Antal positiva och negativa biopsier samt cellblock och konkordansen redovisades. Overall percentage agreement (OPA), Cohen’s kappa (κ) och konfidensintervall (CI) beräknades också. Resultatet visade på lägre antal positiva färgningar för cellblocken jämfört med biopsierna för båda antikropparna. För konkordansen visades att den vara lika för PD-L1 och calretinin vid cutoff ≥1 % men högre för PD-L1 än för calretinin vid cutoff ≥10 %. / Malignant mesothelioma is a rare and aggressive cancer. It is most common in the pleura, called pleural mesothelioma. The most common reason for developing pleural mesothelioma is exposure to asbestosis. Patients that get sick have a poor prognosis and limited treatment options. X-ray can in a first stadium give diagnose of the disease. A biopsy is often necessary to confirm the diagnosis. Even sampling of pleural fluid can give valuable diagnostic information. Immunohistochemistry is a common additional analysis for diagnosis with biopsy and cell block. Immunohistochemistry implies staining with antibodies. For example, for pleural mesothelioma the antibodies PD-L1 and calretinin can be used for diagnosis. In this study 10 paired pleural biopsies and cell blocks from pleural fluid from patients with malign mesothelioma were immunostained. The study aimed to evaluate expression of PD-L1 and calretinin. All the stained glasses were evaluated by a light microscope. For PD-L1, only membranous staining was considered positive and for calretinin cytoplasmic and/or nuclear staining was considered positive. Percentage number of positive tumor cells were evaluated at two cutoff values, ≥1 % and ≥10 %. Percentage number <1 % at cutoff ≥1 % and percentage number <10 % at cutoff ≥10 % were considered negative. The same criteria were applied for both antibodies. The number of positive and negative biopsies as well as cell blocks and the concordance were reported. Overall percentage agreement (OPA), Cohen’s kappa (κ) and confidence interval (CI) was also calculated. Result showed lower number of positive staining for the cell blocks than for the biopsies for both antibodies. The concordance was shown to be equal for PD-L1 and calretinin at cutoff ≥1 % but higher for PD-L1 than for calretinin at cutoff ≥10 %.

Les maladies pulmonaires tel que l’amiantose ou le mésotheliome proviennent de l‘interaction entre les fibres d’amiantes et les cellules humaines. L’hétérogénéité morphologique et chimique des fibres nous oblige à disposer de moyens analytique capable d’analyser l’interaction organique – inorganique. Nos travaux ont pour but de développer une méthodologie d'imagerie infrarouge couplé avec le rayonnement synchrotron. Grâce à cette technique, nous pourrons analyser les effets des fibres d'amiantes sur une cellule unique. La méthodologie a été testée sur des cellules cultivées directement sur des substrats transparents à l'infrarouge. Les expériences réalisées ont été étendu à l'imagerie Raman in vitro de cellule individuelle vivante en interaction avec différents types de fibres afin de mieux évaluer l'effet pathogène de celle ci sur les cellules pulmonaire. / Lung disease as asbestosis and mesothelioma come from the interaction between asbestos fibers and human cells. The morphological and chemical heterogeneity of these fibers leads us to use analytical techniques capable of analyzing the organic/inorganic interaction. Our work aims the development of FTIR method couple with the synchrotron radiation. Thanks to that technique, we could analyse the effects of the asbestos fibers on a lung human cell. These technique has been developped on cultured cells directly on IR transparent substrates. The experimentation have been developped to in vitro RAMAN imaging of individual living cell in interaction with different types of fibers. The goal was a better understanding of the pathological effect of the asbestos fibers on the human lung cells.