• Economic and Environmental Geology
• /
• v.46 no.2
• /
• pp.165-178
• /
• 2013

This study is for the genetic differences of two closed asbestos mines from Jeongjeon and Ocheon areas in Boryoung, Chungnam. They are mined asbestos for past several decades. Host rocks are serpentinites for Jeongjeon mine and dolomites for Ocheon mine. Asbestos samples and their host rocks are collected from the field trips and examined with microscopes and FESEM, and analysed with XRD and EDX to confirm for the type and/or compositions of the minerals. The asbestos occur as layers, cracks and fractures assummed as a pathway of the hydrothermal water, but show different characteristics. The serpentinites from the Jeongjeon mine contain chrysotile, tremolite and actinolite asbestos. Non-asbestos minerals including tremolite and actinolite were also found. The chrysotiles occur as a cross fiber or slip fiber at veins and along cracks of several mm to cm thickness. Tremolite and actinolite asbestos occur along cracks and fractures of several cm to ten cm thickness. It suggests that the asbestos from Jeongjeon area were formed by the reactions between serpentinite and hydrothermal water. The dolomites of the Ocheon mine only contain tremolite and actinolite asbestos. The asbestos occur along layers, cracks and fractures, suggestive of asbestos from Ocheon area formed by the reactions between dolomite and hydrothermal waters influxed along layers, cracks and fractures. Overall results suggest that two asbestos mines showing different host rocks are located in a Boryoung area. They show a different type of asbestos minerals, reflecting variety of petrogeneses.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.21 no.2
• /
• pp.110-115
• /
• 2011

Objectives: The aim of this study is to survey for finding asbestos containing equipment at the laboratories using picture based questionnaire and polarized light microscopic analysis. Methods: This study was conducted from 2009 to 2010 at a university in Seoul. In 2009, picture based questionnaire was distributed to 100 laboratories during the regular laboratory air quality monitoring. In 2010, we emailed all professors of the same university who have laboratories to participate voluntarily this survey. For the laboratories consented to participate survey, picture based questionnaire was distributed and collected. Suspected asbestos containing material and apparatus were collected at the laboratories which replied they have suspected material and equipment. Collected samples were analyzed with polarized light microscope at the laboratory accredited by ministry of employment and labor in Korea. Results: Total of 18 out of 100 laboratories reported that they had suspected asbestos containing equipment in 2009. Twenty-three samples were collected and three samples (13%), one heating mantle and two pairs of insulation gloves, contained asbestos. Thirty four laboratories reported they had suspected asbestos containing material or equipment in 2010. Sixty samples were collected and four of them (6%), two pairs of insulation gloves, one packing rope in dry oven and, one pair of tongs, contained asbestos. All founded asbestos was chrysotile and the content of chrysotile was more than 90% for all equipment except heating mantle which has less than 1%. Conclusions: We confirmed that asbestos was still used at the laboratories though strict regulations on asbestos use in Korea. The method of picture based questionnaire invented in this study could be applied for asbestos survey to other research institute or university where there are many laboratories because of its simplicity and accessibility without huge man power, cost and time.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.2
• /
• pp.223-228
• /
• 2021

The final disposal method for asbestos building materials is to be landfilled at a designated waste landfill in accordance with the Waste Management Act. However, it is difficult to secure a domestic designated waste landfill site to landfill the entire amount of asbestos waste, which is expected to emit more than 400,000 ton/year by 2044. In this study, a detoxification treatment was performed on a ceiling tex with a density of 1.0 to 1.2g/cm³ containing 3 to 7% of chrysotile, and it was used as a reinforcing fiber for extruded panels. It was confirmed that asbestos components were detoxified through the reaction process using 30% oxalic acid and carbon dioxide, and it was recognized that these detoxifying properties were maintained even after extrusion molding. However, it was found that milling to a fiber size of less than 1mm for complete detoxification of asbestos resulted in a decrease in reinforcing performance. Therefore, in the case of using detoxified asbestos fibers in the extrusion molding process, it is considered desirable to add fibers with a length of 5mm or more to improve the reinforcing performance.

• Journal of the Mineralogical Society of Korea
• /
• v.32 no.1
• /
• pp.15-39
• /
• 2019

An ultramafic complex occurs as an isolated lenticular body in the Andong area. The Andong ultramafic complex comprises ultramafic and mafic rocks, but mainly peridotites. The complex extends for several kilometer to ENE direction, adjacent to the Andong fault line. This study is for petrochemistry of the peridotites within the ultramafic complex and characteristics of asbestos occurrences. The peridotites are igneous origin, ranging from lherzolite to wehrlites and are characterized by high Fo olivine ($Fo_{0.85-0.87}$), Mg clinopyroxene ($Mg_{87.5-93.5}$), and tremolitic to tschermakitic hornblende. Geochemically, these rocks show high magnesium number (mainly Mg = 85.3-87.38) and transitional element and low alkali element contents. The peridotites host asbestos, including chrysotile, tremolite and actinolite asbestos, but dominated by amphibole asbestos. The amphibole asbestos are found along small fault face, and cleavage and fracture showing several cm to ten cm in width as slip and oblique fibers, while the chryostiles occur at cleavage and vein showing several mm-cm in width as cross and slip fibers. They are confirmed by PLM, XRD and SEM results. Overall characteristics of peridotites from the Andong ultramafic complex and occurrences of the asbestos are similar to those of worldwide orogenic related Alpine type ultramafic rocks and serpentinized ultramafic bodies in Chungnam, Korea, respectively.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.4
• /
• pp.233-257
• /
• 2023

Asbestos minerals are found at rocks and soils of the Hongseong and Bibong serpentine mines, western part of Chungnam. The area consists of and metasediment, and Mesozoic igneous intrusives with minor age-known gneiss complexes and Mesozoic sediments. With detailed geological investigations, rock samples for the serpentinite and amphibolite areas are collected at sites containing asbestos. Representative asbestos and rock samples are analysed by PLM, XRD, SEM and EPMA. Serpentinites are found as steeply dipping faults with adjacent gneiss complex to the NNE direction. Repeated alteration, including serpenitization and talcification, is found at the emplacement direction for the serpentinite body. Amphibollites occur as intrusives and stratiforms within the Precambrian gneiss complex. Serpentinite and amphibolite (or amphibole schist) contain amphiboles either as asbestiform or non-asbestiform. Varying amounts of asbestos minerals, including chrysotile, tremolite asbestos and actinolite asbestos, are found within the serpentinites. The asbestos minerals are found near the cracks or fractures and along the bedding plane. They occur as cross fiber, slip fiber and mass fiber types. Varying amounts of amphibole asbestos minerals, such as tremolite and actinolite asbestos, are found within amphibolites and as a mass fiber type. Overall results suggest that rocks of the serpentine mines contain serpentine and amphibole type asbestos minerals originated from the hydrothermal alteration. Considering construction nearby the mines and environmental risks by the asbestos, additional land management plans are required.

• Toxicological Research
• /
• v.18 no.1
• /
• pp.43-46
• /
• 2002

A 61 Year-old female patient was hospitalized for lung cancer. Her Occupational history indicated that she had worked for an asbestos company for 9 years from 1976. The histopathology of the lung revealed malignant bronchioalveolar adenocarcima (stage III) in the lower-left lobe, and a lung sample was found to cantion an unusually high level of asbestos, 218.9$\times$$10^6$ asbestos fibers/g of dry lung tissue. The majority of asbestos fibers found was chrusotile. yet no asbestos body was detected. When compared with Korean male (0.3$\times$$10^6$ fibers/g of dry lung tissue) and female subjects (0.15$\times$$10^6$ fibers/g of dry lung tissue) with no known history of occupational asbestos exposure, the apparent cause of the lung cancer in the current patient was occupational exposure to asbestos.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.4
• /
• pp.303-313
• /
• 2006

Two kinds of sepiolite (sepiolite 1, sepiolite 2), a $500^{\circ}C$ heat treated sepiolite (sepiolite 500), and a $700^{\circ}C$ heat treated sepiolite (sepiolite 700) were analyzed for their physicochemical properties. After these sepiolites were instilled into rat lungs, the effects of these substances on lung function and biochemical changes were evaluated. In addition, the fibers in the lungs were counted and characterized after the lungs were treated for electron microscopical analysis. The lungs instilled with sepiolites increased their weight and tidal volume statistically significantly compared with the unexposed control. The numbers of lymphocytes and polymorphonuclear cells (PMN) in the bronchoalveolar lavage (BAL) fluid also increased compared with the control, indicating the sepiolite induced inflammation. The heat treated sepiolites, however, did not show any toxicological differences from the untreated sepiolites. Although sepiolite showed less change in fiber atomic % compositions ( sepiolite 500, Si 0.9%, p <0.01 ; sepiolite 700, Si 3.7%, p<0.05) than chrysotile (Si 9.7%, p<0.01), the durability of the fibers in the lungs could not be determined in this subchronic experiment.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.23 no.4
• /
• pp.333-340
• /
• 2013

Objectives: This study was designed to establish an accurate analytical method for asbestos in a biological sample for determining occupational asbestos-related diseases and relief of the health effects of environmental asbestos. Methods: Biological samples were obtained from lungs of rats following intratracheal instillation of asbestos(Chrysotile, anthophyllite) and were prepared according to digestion method(Wet digestion, high temperature ashing, low temperature ashing). The samples were then analyzed for asbestos fibers using a transmission electron microscope equipped with an energy dispersive X-ray spectrometer. Results: Low temperature plasma ashing removed more of the organic components and reduced fiber loss compared to the wet digestion method, making specimens so prepared more suitable for transmission electron microsocpy. Conclusions: The low temperature ashing technique is the most accurate method for analyzing asbestos in biological samples.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.3
• /
• pp.253-266
• /
• 2016

Objectives: This study is for characteristics of asbestos occurrence (NOA, naturally occurring asbestos) from the Gapyeong area and its host rocks, serpentinites. Methods: Representative samples are collected from the serpentinite bodies, following degrees of hydrothermal alteration and metamorphism, after about 2 year field trips. Mineralogical, morphological and optical characteristics of the asbestos and host rocks are confirmed by PLM, XRD EPMA and SEM results. Results: The serpentinites are dunites and harzburgites, and host asbestos, including chrysotile, tremolite and actinolite. The asbestos chrysotiles are found as veins ranging from several millimeters to several centimeters in thickness, while asbestos-tremolite and -actinolite occur along cracks and fractures ranging up to ten centimeters in thickness. The chryostiles occur mainly as cross and slip fibers, while the amphibole asbestos is found as vein, slip and oblique fibers. More tremolitic grains are colorless and commonly show elongated or fiber shapes, whereas the magnesio hornblende grains mainly show light green and occur as subhedral to euhedral diamond grains. Conclusions: Overall characteristics of serpentinites from the Gapyeong area are similar to worldwide orogenic-related Alpine type ultramafic rocks serpentinized and serpentinites in South Chungcheong-do Province, Korea, and occurrences of asbestos are similar to those of the ultramafic bodies in South Chungcheong-do Province.

• Toxicological Research
• /
• v.17 no.3
• /
• pp.163-165
• /
• 2001

A patient,58 years of age, with suspected 0/l pneumoconiosis since 1993, complained of a dry cough and exertioning dyspnea for 6 months. He had worked in an asbestos company for more than 20 years from 1974. He was subsequently diagnosed with an interstitial lung disease during an annual special health check-up for asbestos workers. h chest X-ray showed an interstitial lung disease and high-resolution computed tomography (HRCT) showed a round opaque asbestosis with chronic hypersensitivity pneumonitis. A pulmonary function test indicated that the patient had a mild restrictive lung disease with FEV1 1.67 litters and 82% FEVl/FVC. The bronchoalveloar larvage fluid included many asbestos bodies, indicating previous exposure to asbestos. Transmission electron microscopy (TEM) using an energy dispersive X-ray analyzer (EDX) revealed many asbestos bodies consisting of mainly crocidolite fibers (6,071$\times$$10^6$fibers/g of dry lung). The patient had an unusually high asbestos content of 6,112$\times$$10^6$ asbestos fibers/9 of dry lung.