• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.2
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• pp.119-130
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• 2010

Pulmonary toxicity of talc containing tremolite asbestos (TCT) has been studied in term sequential in Sprague-Dawely rats. UICC chrysotile(average diameter 0.03${\mu}m$, average length 2.93${\mu}m$) was applied as the positive control. TCT was analyzed for its physicochemical properties by transmission electron microscope equipped with energy dispersive X-ray spectrometer(TEM-EDS). The effects of 2mg TCT(talc average diameter 9.7${\pm}$8.4${\mu}m$; tremolite average diameter 1.6${\pm}$1.6${\mu}m$, average length 10.8${\pm}$7.0${\mu}m$) on pathological changes were evaluated after 1, 8 weeks instilled into rat lungs. 2mg Chrysotile continuously affected lung pathological changes. Inflammation and granuloma response broke out from 1 week after instilled with chrysotile and the pathological examination further showed increased legions of lung after 8 weeks. But TCT did not showed lung pathological changes. The biopersistence of TCT and chrysotile was evaluated by TEM- EDS. Whereas chrysotile continuously have retained to 8 weeks instilled into rat lungs, talc of TCT showed statistically significant decrease of diameter from 1 weeks and statistically significant change in Si atomic % compositions at 8 weeks instilled into rat lungs. Physicochemical properties of tremolite of TCT were not affected until 8 weeks instilled into rat lungs. This study showed that the durability of TCT in the lungs is much weaker than chrysotile.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.4-31
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• 2018

The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.538-541
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• 2009

Humans have a long history of asbestos use. There are reports from the Roman era, of asbestos victims among the slaves who worked in asbestos mines. The fact that asbestos can induce lung cancer and mesothelioma was verified epidemiologically in the 1960s. Asbestos related diseases are predominantly occupational in nature but can be caused by environmental exposure. Environmental mesothelioma is mainly associated with tremolite asbestos and this information comes from many countries including Turkey, Greece, Corsica, New Caledonia and Cyprus. In 1993, the first case of mesothelioma in Korea was reported in an asbestos textile worker. Recently, some asbestos disease victims who lived near an asbestos factory have their cases before the courts. A series of recent asbestos-related events in Korea, for example, the shocking revelation of asbestos containing talc in baby powders have caused the general public to become aware of the health risks of asbestos exposure. Asbestos related diseases are characterized by a long latency period, especially, mesothelioma which has no threshold of safety. Hence the best strategy for preventing asbestos related diseases is to decrease asbestos exposure levels to as low as possible.

• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.1-6
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• 1990

Clacic amphiboles along the tremolite (Tr)-tschermakite(Ts) joint were synthesized using a piston-cylinder appratus. At 750-85$0^{\circ}C$and 12-2 kb, amphibole+corundum coexist with zoisite($\pm$talc, chlorite, and Mg-staurolite), but with anorthite($\pm$cholorite, spinel, pyroxenes, and sapphirine) at lower P. At 90$0^{\circ}C$, amphibole+corundum+clinopyroxene($\pm$anorthite, forsterite, sapphirine, and garnet) are stable over the P range 12-18 kb. These amphibole-bearing assemblages are replaced at high P by clcinopyroxene+talc+chlorite+zoisite at 650-75$0^{\circ}C$, and at higher temperatures by garnet+clinopyroxene($\pm$zoisite, orthopyroxene, and Mg-staurolite). Synthetic amphiboles with Ts>~45 mol% contain as much as 0.15 excess cations per formula unit(pfu) based on 23 oxygens(anhydrous formula), whereas less tschermakitic ones are deficient in cation occupancy by up to 0.18 pfu. This trend is attributed to the 야/trioctahedral substitution in Ca-amphiboles. Compositions of synthetic amphiboles display systematic changes with P and T governed by coexisting mineral assemblages. The Ts content (=[8-Si-Na]/2) increases with increasing T( Ts/ T=~0.1 nik% K-1) in the range 750-85$0^{\circ}C$, but remains nearly constant at 850-90$0^{\circ}C$. Pressure dramatically affects the Ts content of Ca-amphiboles:it increases with P at 8-12 kb( Ts/ T=2-3 mol% K-1), but significantly decreases at 12-21 kb( Ts/ P=-2.5 mol% Kb-1). Hence, the most tschermakitic amphiboles, containing 60$\pm$5 mol % Ts, or 1.2$\pm$0.1 tetrahedral Al, occur at 12 kb and 850-90$0^{\circ}C$. Compositions of Ca-amphiboles defined by a simple reaction, 3 Tr+2 zoisite+7 corundum+H2O=5 Ts, are reversed and used to estimate thermodynamic parameters of tschermakite assuming ideal mixing of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$=566.9$\pm$13.7 J mol-1K, -1and H$^{\circ}$=-12518.36$\pm$15.17 kJ mol.-1

• Economic and Environmental Geology
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• v.51 no.4
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• pp.309-322
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• 2018

Naturally occurring asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. It is proved that inhalation of asbestos fibers can lead to increase risk of developing several diseases such as lung cancer and malignant mesothelioma. The parent rocks of asbestos have been mainly associated with (ultra)mafic and carbonate rock. The previous studies on NOA were mainly limited to (ultra)mafic rock-hosted asbestos, but studies on carbonate rock-hosted asbestos are relatively rare in S. Korea. Therefore, this study was aimed to examine mineralogical characteristics of carbonate rock-hosted NOA at three sites including Muju and Jangsu, Jeonbuk province and Asan, Chungnam province. Types of rocks at the three sites mainly consisted of Precambrian metasedimentary rocks, carbonate rock, and Cretaceous and Jurassic granites. Asbestos-containing carbonate rock samples were obtained for mineralogical characterization. XRD, PLM, EPMA, SEM and EDS analyses were used to characterize mineralogical characteristics of the carbonate rock-hosted NOA. From the carbonate rock, fibrous minerals were occurred acicular and columnar forms in the three sites. Fibrous minerals were composed of mainly tremolite and associated minerals included possibly asbestos containing materials (ACM) such as talc, vermiculite, and sepiolite. The length and aspect ratios of tremolite were similar to the standard asbestiform (length >$5{\mu}m$, length:width = 3:1). These results indicate that both non-asbestiform and asbestiform tremolite with acicular forms occurred in carbonate rocks at three sites. Geological and geochemical characteristics and mineral assemblages indicate tremolite and associated minerals might be formed by hydrothermal alternation and/or hydrothermal veins of carbonate rocks due to intrusion of acidic igneous rocks.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.122-147
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• 2017

The Jungsandong sites are distributed across quartz and mica schist formations in Precambrian, and weathering layers include large amounts of non-plastic minerals such as mica, quartz, felspar, amphibole, chlorite and so on, which form the ground of the site. Neolithic pottery from Jungsandong exhibits various brown colors, and black core is developed along the inner part for some samples, and sharp comb-pattern and hand pressure marks can be observed. Their non-plastic particles have various composition, size distribution, sorting and roundness, so they are classified into four types by their characteristic mineral compositions. I-type (feldspar pottery) is including feldspar as the pain component or mica and quartz. II-type (mica pottery) is the combination of chloritized mica, talc, tremolite and diopside. III-type (talc pottery) is with a very small amount of quartz and mica. IV-type (asbestos pottery) is containing tremolite and a very small amount of talc. The inner and outer colors of Jungsandong pottery are somewhat heterogeneous. I-type pottery group shows differences in red and yellow degree, depending on the content of feldspar, and is similar to III-type pottery. II-type is similar to IV-type, because its red degree is somewhat high. The soil of the site is higher in red and yellow degree than pottery from it. The magnetic susceptibility has very wide range of 0.088 to 7.360(${\times}10^{-3}$ SI unit), but is differentiated according to minerals, main components in each type. The ranges of bulk density and absorption ratio of pottery seem to be 1.6 to 1.7 and 13.1 to 26.0%, respectively. Each type of pottery shows distinct section difference, as porosity and absorption ratio increase in the order as follows: I-type (organic matter fixed sample) < III-type and IV-type < I-type < II-type (including IV-type of IJP-15). The reason is that differences in physical property occur according to kind and size of non-plastic particles. Although Jungsandong pottery consists of mixtures of various materials, the site pottery has a geological condition on which all mineral composition of Jungsandong pottery can be provided. There, it is thought that raw materials can be supplied from weathered zone of quartz and mica schist, around the site. However, different constituent minerals, size and rock fragments are shown, suggesting the possibility that there can be more raw material pits. Thus, it is estimated that there may be difference in clay and weathering degree.