The application of the modified crude settleable dust approach as a viable asbestos mineral test method

Abstract

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.