• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.119-127
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• 2012

Objectives: The aim of this study is to identify concentration characteristics of indoor and outdoor airborne total fiber particles and asbestos in Gyeongnam Provinces. Methods: This study investigated concentration characteristics of indoor fiber particles from 748 schools and 38 public facilities as well as outdoor particles from 11 sites through PCM (phase contrast microscope). SEM/EDX (scanning electron microscope/energy dispersive using X-ray analysis) was used to obtain physicochemical information of asbestos fiber particles. The study identified asbestos rate in the 15 samples from indoor and outdoor airborne total fiber particles. Results: 1. The average indoor airborne concentrations of total fiber particles were $0.0011{\pm}0007$ f/cc in schools and $0.0015{\pm}0007$ f/cc in public facilities by PCM. Over 90% of the fiber particles were identified as single fibers. 2. The average outdoor airborne concentrations of total fiber particles were $0.0007{\pm}0002$ f/cc, and they were lower than those of indoor airborne concentrations. 3. The results showed that the form of asbestiform was diverse as skein of thread like form and long needle, which was relatively narrower than that of glass fiber and rock wool. 4. The results of SEM/EDX analysis of 15 areas where total fiber particle was relatively high showed that the form was rather similar to that of asbestos, but chemical composition was proven to be non-asbestos. Conclusions: The concentration of indoor and outdoor airborne total fiber particles of Gyeongnam Provinces satisfied the IAQ (Indoor air quality) level of 0.01 f/cc and asbestos was not found in most of the samples by SEM/EDX.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.2
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• pp.144-153
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• 1991

This study was conducted to evaluate worker exposure to airborne asbestos fibers by industry, and to evaluate polarized-light microscopy for determining airborne asbestos fibers. A total of 11 plants including asbestos textile, brake-lining manufacturing, slate manufacturing, and automobile maintenance shops were investigated. Rsults of the study are summarized as follows. 1. Worker exposure levels to airborne asbestos fibers were the highest in asbestos textile industry, followed by brake-lining manufacturing, slate manufacturing, and automobile maintenance shops, in order. In asbestos textile industry, large variation of asbestos levels was found by plants. The worst plant indicated airborne fiber concentrations in excess of 10 fibers/cc, however, the best plant showed concentrations within 0.50 fibers/cc. 2. Characterization of airborne fibers by industry indicated that fibers from asbestos textile industry were the longest with the largest aspect ratio. Fibers from automobile maintenance shops were the shortest with the smallest aspect ratio. Based on characteristics of fibers and the highest levels of concentrations, it is concluded that workers in the asbestos textile industry are exposed to the highest risk of producing asbestosis, lung cancer, and mesothelioma. 3. Result s obtained using polarized-light microscopy were $43.7{\pm}12.3%$ of the results obtained using phase contrast microscopy. This may be resulted from the worse resolution of polarized-light microscopy than that of phase contrast microscopy. Based on the results, it is recommended that polarized-light microscopy be used for mainly bulk sample analyses and further study be performed to improve the method for determining airborne samples. However, polarized-light microscopy can be used for determining thick fibers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.123-136
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• 2013

Objectives: This paper was prepapred to report airborne asbestos fiber concentrations in asbestos textile, brake-lining, commutator, and building materials manufacturing industries, and some other asbestos related industries in Korea from 1994 to 2006. Methods: Airborne asbestos data that have been sampled and analyzed in the above industries during 1994-2006 were collected. These data were reviewed to scrutinize the qualified data based on the records such as sampling and analyzed method and quality control procedures. All asbestos data were generated using the National Institute for Occupational Safety & Health (NIOSH) Method 7400. Results: Average concentration of asbestos fiber was 2.14 fibers/cc(0.02-15.6 fibers/cc) in the asbestos textile industry, 0.26 fibers/cc(0.01-1.01 fibers/cc) in the building-materials industry, 0.15 fibers/cc(0.01-0.93 fibers/cc) in the brake-lining manufacturing industry, and 0.14 fibers/cc(0.03-1.36 fibers/cc) in the commutator producing industry. For these industries, the percentage of samples of which asbestos fiber concentrations above the limit of exposure(0.1 fibers/cc) was 97.6% in the asbestos textile industry, 62.3% in the building-materials industry, 53.5% in the brake-lining manufacturing industry, and 34.3% in the commutator producing industry. Asbestos fiber concentration was below the limit of exposure in the gasket producing, petrochemistry, musical instrument producing industries, and the brake-lining exchange operations. Conclusions: Airborne asbestos fiber level in the asbestos textile, brake-lining producing, commutator and building-material producing industries was above the limit of exposure, but in the gasket producing, petrochemistry, musical instrument producing industries and the brake-lining exchange operations were below the limit of exposure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.35-40
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• 2013

Objectives: Asbestos contents of crushed serpentine rocks and airborne fiber concentrations of workers were determined at two serpentine quarries and a steel mill. Methods: Bulk samples of uncrushed and crushed serpentine rocks were collected and analyzed by PLM and TEM. Airborne asbestos samples were collected from the breathing zone of workers and the vicinity of working area and analyzed by PCM and TEM. Results: Chrysotile was identified with antigorite, lizardite and non-asbestiform actinolite in bulk samples. The arithmetic means of chrysotile contents in crushed serpentines were 0.11, 0.01, 0.42%(W/W) by quarry A, quarry B and a steel mill, respectively. The asbestos concentrations of all personal samples were less than 0.1 f/cc which is the permissible exposure limit of workers in Korea. The arithmetic means of airborne asbestos concentrations were 0.017 f/cc and 0.009 f/cc in personal samples collected from two serpentine quarries. The asbestos concentrations of all personal samples collected from a steel mill were less than LODs by PCM analysis but asbestos was detected in area samples by TEM. By the job tasks of serpentine quarries, crusher/separator operation generated the highest exposure to airborne asbestos. Conclusions: Although chrysotile contents in crushed serpentines of quarries were less the permissible level, the highest exposure of workers in serpentine quarries reached up to 76% of the permissible level of airborne asbestos. There were also possibilities of occupational exposure to airborne asbestos in a steel mill. The present exposure study should encourage further survey and occupational control of quarries producing serpentine or other types of asbestos-bearing rocks.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.139-145
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• 2011

Objectives: This investigation is purposed to evaluate the airborne asbestos concentrations in the public buildings having asbestos containing materials(ACMs) in Seoul. Methods: The Seoul Metropolitan Government carried out an asbestos survey to the city-owned public buildings to identify the level of risk exposure, classified into low, moderate and high risk. To evaluate the airborne concentration of asbestos, 11 sampling sites in ten buildings based on the survey were selected. The air samples from the eleven sites were analyzed by Phase Contrast Microscopy(PCM) and Transmission Electron Microscopy (TEM), and compared the analytical results from the both. Results: 1. The airborne fiber concentrations by PCM were less than the detection limit($7f/mm^2$) in 9(82%) out of 11 sampling sites. The highest concentration was 0.0043 f/cc, but it was below the guideline value for indoor air quality(0.01 f/cc), proposed by the Ministry of Environment, Korea. 2. In two sampling sites, having moderate risk level, the chrysotile was identified and showed it's concentrations of 0.0102 s/cc and 0.0058 s/cc, less than $5{\mu}m$ lengths. 3. The ACMs identified in the two sampling sites were a packing material(65% of chrysotile) in mechanical area and a thermal system insulation(5% of chrysotile) in a boiler room. Having more possibility of asbestos emission in the mechanical area, it would be required to set up and carry out the asbestos management plan. Conclusions: Based on the result of this study, the airborne asbestos concentrations in the public buildings with ACMs were generally lower than the guideline value for indoor air quality. There are widespread concerns about the possible health risk resulting from the presence of airborne asbestos fibers in the public buildings. Most of the previous studies about airborne asbestos analysis in Korea were performed based on PCM method that asbestos and non-asbestos fibers are counted together. In the public and commercial buildings, having ACMs, it is suggested that the asbestos be analyzed by TEM method to identify asbestos due to concerns about asbestos exposure to workers and unspecified people.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.219-224
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• 2016

Objectives: Lung cancer occurred with worker working in an urban bus garage. A survey was conducted to investigate whether lung cancer had causal relationship with work. Exposure to asbestos and diesel engine exhaust were suspected. Methods: Airborne asbestos was sampled on membrane filter and analyzed using phase-contrast microscopy. Airborne diesel exhaust was sampled using quartz filter and analyzed with thermal-optical analyzer. Polynuclear aromatic hydrocarbons was sampled using PTFE filter and XAD-2 tube and analyzed with gas chromatography-mass selective detector. Results: Airborne asbestos concentration was under 0.01 fiber/cc. Worker who warmed up an engine of urban bus for 2 hours was exposed to elemental carbon concentration, $15.5{\mu}g/m^3$. Only naphtalene among polynuclear aromatic hydrocarbons was detected. Conclusions: It was difficult to conclude about worker exposure to asbestos because working hour related asbestos was too short. In reviewing papers, the exposure to asbestos over 0.01 fiber/cc during exchange brake lining was found. It was identified that worker's occupational exposure to diesel exhaust based on elemental carbon was higher than the other occupational exposure to diesel exhaust.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.8-15
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• 2009

This study was examined to find out asbestos exposure level the factors which affected the level at asbestos abatement sites. We visited a total of thirteen building demolition sites(3 apartments, 3 schools, 4 stores, and 3 houses) were visited to collect samples and related data from August to November, 2006. The results of this study were as follows 1. The results of an analysis of bulk samples to identify types of asbestos at the asbestos abatement sites showed that the kinds of the asbestos detected were chrysotile by 50.0%, were tremolite by 2.6%, and were the contents of chrysotile by 3 to 20%. 2. The geometric mean concentration of asbestos was 0.007 f/cc(range 0.001-0.34 f/cc) and its geometric standard deviation was 5.83. Of the samples, however, 12 exceeded the Korean Occupational Exposure Limit(0.1f/cc). 3. Of the materials, textile material had the highest concentration with geometric mean of 0.016 f/cc. When asbestos-containing materials were removed using T type tools, the geometric mean concentration of asbestos was 0.061 f/cc. The level by this method was much higher than by other removal methods. In analysis by the type of building, the geometric mean concentration of asbestos in stores was 0.042 f/cc and was higher than in other buildings. 4. The Poisson regression analysis was applied to find out the factors that affect the airborne asbestos concentration. As a result of the analysis, removal using a T type tool was the most important factor affecting the asbestos concentration(p<0.01). In conclusion, the airborne asbestos concentration(geometric mean) in asbestos abatement sites was 0.007 f/cc(0.001~0.34 f/cc), and 12(14.6%) of all samples were over the 0.1 f/cc. These results showed that asbestos abatement workers have been exposed to the high level of airborne asbestos because they have not been keeping asbestos removal rule. In accordance with increases of the number of building demolition sites, the better government regulation on asbestos abatement methods should be made and be performed well at building demolition sites.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.72-81
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• 2015

Objectives: The aim of this study was to investigate the exposure and risk assessment of residents near asbestos mines in Korea. Methods: To assess asbestos types and airborne concentrations, air monitoring was performed in the neighborhoods of Kwangcheon (KC) and Sinsuk (SS) mines, which were leading South Korean mines in the past. In addition, activity-based-sampling (ABS) of residents' particular activities were conducted in order to estimate the Excess Lifetime Cancer Risks (ELCRs) for the residents. Conclusions: The average concentration of airborne asbestos in KC was 0.0014 f/cc and 0.0015 f/cc by PCM and TEM, respectively. In SS it was equal at 0.0012 f/cc by PCM and TEM. No statistically significant difference was found in the average concentration of airborne asbestos between the two mines. The average asbestos concentration of ABS was 0.0048 f/cc (PCM) and 0.0042 f/cc (TEM) in KC, while it was 0.0137 f/cc (PCM) and 0.0125 f/cc (TEM) in SS. It was found that the average asbestos concentration of ABS in SS was statistically significantly higher than that of KC (p<0.01). The results of ELCRs by scenario in KC showed that the scenarios of bicycle, car, weed control, weed whacking, child playing in the dirt, and physical training fell within $1{\times}0^{-6}-1{\times}10^{-4}$, which is the acceptable range of ELCR. The scenarios of motorcycle, walker, digging, and field sweeping, however, exceeded the acceptable range. In SS, only the scenario of car fell within the acceptable range, while all of the other scenarios exceeded the acceptable range.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.113-121
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• 2014

Objectives: This study is intended to seek credible and efficient measurements on airborne asbestos concentrations that allow immediate action by establishing complementary data through comparative analysis with existing PCM and KF-100 method real-time monitoring equipment in working areas in Seoul where asbestos-containing buildings are being demolished, including living environment surroundings. Materials: We measured airborne asbestos concentrations using PCM and KF-100 at research institutes, monitoring networks, subway stations and demolition sites of asbestos-containing buildings. Through this measurement data and KF-100 performance testing, we drew a conversion factor and applied it via KF-100. Finally we verified the relationship between PCM and KF-100 with statistical methods. Results: The airborne asbestos concentrations by PCM for the objects of study were less than the detection limit(7 fiber/$mm^2$) in three (20%) out of 15 samples. The highest concentration was 0.009 f/cc. The airborne asbestos concentrations by PCM in laboratories, monitoring networks, subway stations and demolition sites of asbestos-containing buildings were respectively $0.002{\pm}0.000$ f/cc, $0.004{\pm}0.001$ f/cc, $0.009{\pm}0.001$ f/cc, and $0.002{\pm}0.000$ f/cc. As a result of KF-100 performance testson rooftops, the conversion factor was 0.1958. Applying the conversion factor to KF-100 for laboratories, the airborne asbestos concentrations ratio of the two ways was nearly 1:1.5($R^2$=0.8852). Also,the airborne asbestos concentration ratio of the two ways was nearly 1:1($R^2$=0.9071) for monitoring networks, subway stations, and demolition sites of asbestos-containing buildings. As a result of independent sample t-tests, there was no distinction between airborne asbestos concentrations monitored in the two ways. Conclusions: In working areas where asbestos-containing buildings are being demolished, including living environment surroundings, quickly and accurately monitoring airborne asbestos scattered in the air around the working area is highly important. For this, we believea mutual interface of existing PCM and a real-time monitoring equipment method is possible.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.157-167
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• 1994

This study was conducted to analyze the relationship between the types of fiber and its content and the levels of airborne fiber concentrations at eight parking lots where sprayed insulation material was found on the walls and ceilings. Also this study was designed to find the relationship between the levels of airborne fiber concentrations and such variables as air current, humidity, total exhaust volume, surface condition of insulation material and building age. The results obtained were as follows : 1. No significant correlation was found between the levels of airborne tiber concentration and the building age, air current, humidity, total exhaust volume, space and the number of traffics. 2. A significant correlation was found between the levels of airborne fiber concentration and the MMMF content of the insulation material(r=0.7594). However, no significant correlation was found between the levels of airborne fiber concentration and total fiber content of insulation material. 3. The differences of the airborne fiber concentrations among Cateogory 1, 2 and 3 classified by the degrees of surface insulation material maintenance were very significant. 4. Two bulk samples contained 30% crodicolite and 1% anthophylite. The MMMFs, in all parking lots, included mineral wool, cellulose fiber, trace cellulose fiber, trace tiber glass and vermiculite. 5. The mean value and the range of airborne fiber concentrations at 8 parking lots were $0.0239{\pm}0.0095f/cc$ and 0.0054-0.0447 f/cc, respectively. The fiber concentrations of 35 out of 38 samples(92%) were over 0.01 f/cc which is the Environment Administration's recommended asbestos level for the underground space. This study suggests that most of building insulation materials used in Korea, contain MMMF and sometimes asbestos. Currently, MMMF pollution levels may exceed the Environment Administration's recommended level for underground space. It has been found that airborne fiber concentrations increased significantly with MMMF content and with the maintenance condition of surface material. Therefore, it is recommended that a proper management technique should be developed and immediately implemented since the conditions of surface material will be gradually deteriorated due to building age and usage. Since health hazards of the MMMF, similar to those of asbestos, are being gradually acknowledged, a proper management technique which is applicable to control total airborne fiber concentrations, both asbestos and MMMF, be developed and an acceptable indoor air standard be promulgated as early as possible.