• Safety and Health at Work
• /
• v.8 no.1
• /
• pp.105-115
• /
• 2017

Background: The goal of this study is to develop a general population job-exposure matrix (GPJEM) on asbestos to estimate occupational asbestos exposure levels in the Republic of Korea. Methods: Three Korean domestic quantitative exposure datasets collected from 1984 to 2008 were used to build the GPJEM. Exposure groups in collected data were reclassified based on the current Korean Standard Industrial Classification ($9^{th}$ edition) and the Korean Standard Classification of Occupations code ($6^{th}$ edition) that is in accordance to international standards. All of the exposure levels were expressed by weighted arithmetic mean (WAM) and minimum and maximum concentrations. Results: Based on the established GPJEM, the 112 exposure groups could be reclassified into 86 industries and 74 occupations. In the 1980s, the highest exposure levels were estimated in "knitting and weaving machine operators" with a WAM concentration of 7.48 fibers/mL (f/mL); in the 1990s, "plastic products production machine operators" with 5.12 f/mL, and in the 2000s "detergents production machine operators" handling talc containing asbestos with 2.45 f/mL. Of the 112 exposure groups, 44 groups had higher WAM concentrations than the Korean occupational exposure limit of 0.1 f/mL. Conclusion: The newly constructed GPJEM which is generated from actual domestic quantitative exposure data could be useful in evaluating historical exposure levels to asbestos and could contribute to improved prediction of asbestos-related diseases among Koreans.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.9
• /
• pp.613-623
• /
• 2013

This study is purposed to evaluate the airborne asbestos concentrations in life environment surroundings in Seoul. In study, we investigated airborne asbestos concentrations in thirteen subway stations, four monitoring networks and each vicinity roadside, six stream surroundings, four tunnels quarterly and we also investigated relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks and time-based airborne asbestos concentration variability for two typical monitoring networks, two subway stations transferred and used by lots of people through Phase Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM). The airborne asbestos concentrations by PCM for 4 objects of study were less than the detection limit (7 fiber/$mm^2$) in 111 (50%) out of 223 samples. The highest concentration was 0.0130 f/cc. But additional TEM analysis result for samples exceeding the guideline value for indoor air quality (0.01 f/cc) proposed by the Ministry of Environment (Korea), no asbestos was detected. Similarly TEM analysis result for 124 samples, no asbestos was detected. The average airborne asbestos concentrations by PCM in subway stations, monitoring networks, streams and tunnels were $0.0041{\pm}0.0027$ f/cc, $0.0015{\pm}0.0011$ f/cc, $0.0024{\pm}0.0012$ f/cc and $0.0016{\pm}0.0020$ f/cc. All objects of study were satisfied with the guideline value for indoor air quality. The relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks was generally positive correlation (r = 0.660). The higher ambient temperature was and the more transient population was, the airborne asbestos concentrations by time for two subway stations were increased. While the airborne asbestos concentrations for two monitoring networks showed no variation pattern according to time.

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

• Journal of the Mineralogical Society of Korea
• /
• v.24 no.2
• /
• pp.119-131
• /
• 2011

The asbestos contents in some representative building materials were analyzed using JIS (Japanese Industrial Standard) X-ray diffraction (XRD) method. The changes in mineral composition during analysis process and problems in JIS method were also examined. XRD analysis of some representative domestic building materials used for roof, wall, ceiling, and floor indicates that slate have the highest asbestos content having 6.87~6.93% of chrysotile. Other building materials analyzed in this study also have 1.35~3.98% of chrysotile contents. The XRD analysis results of asbestos contents in some domestic building materials are presented in this study. This method is very effective for the asbestos content evaluation of building materials according to newly modified asbestos content regulation (Law of Industrial Safety and Health, 2007-26) that limits asbestos content less than 0.1% by Ministry of Employment and Labor. Small amount of tremolite as well as chrysotile were also observed in some samples. With consideration of crystal shape, contents and geological occurrence, it is considered that tremolite is an associated mineral of chrysotile and is not intentionally added. Complemental analyses with optical microscope and SEM/EDS are also necessary because XRD method cannot distinguish asbestiform from non-asbestiform. The XRD method applied in this study is very effective in the asbestos content analysis of building materials, specially building materials showing high asbestos concentration in residues due to the high loss rate with ashing and acid dissolution procedure.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.6
• /
• pp.434-441
• /
• 2014

This study is purposed to measure airborne asbestos concentrations at demolition sites and surrounding areas of asbestos containing buildings in Seoul and examine whether the measurement results correspond with allowable exhaust standard for asbestos of the Asbestos Safety Control Act. The airborne asbestos concentrations for 37 sites were below the detection limit ($7fiber/mm^2$) in 101 (35%) out of 288 samples. The whole average airborne asbestos concentration in 37 sites was $0.003{\pm}0.002f/cc$(max 0.0013 f/cc) and almost the whole airborne asbestos concentrations were satisfied with allowable exhaust standard for asbestos, 0.01 f/cc, of the Asbestos Safety Control Act. So possibility of asbestos exposure is not yet a major concern at current levels for sites demolished of asbestos containing buildings in Seoul. Looking at each sampling point, the average airborne asbestos concentrations in boundary line of site, entrance of sanitation, around the workplace (in), around the workplace (out), negative pressure units, storage area for waste, outlet for waste and residential area of residents were respectively $0.002{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.005{\pm}0.004f/cc$, $0.005{\pm}0.003f/cc$ and $0.003{\pm}0.002f/cc$. As a result, all sampling points of study were satisfied with allowable exhaust standard for asbestos, 0.01 f/cc, of the Asbestos Safety Control Act.

• Journal of the Mineralogical Society of Korea
• /
• v.28 no.2
• /
• pp.165-171
• /
• 2015

Dust samples collected from air in metropolitan areas of Busan and Ulsan were analyzed by phase contrast microscopy, phase contrast dispersion microscopy and SEM. Asbestos concentration in dust samples was lower than detection limit. Many fibrous materials were observed in dust samples, but most of them were organic fibers. Inorganic fibers such as rock fiber, ceramic fiber and gypsum were contained in the samples and non-fibrous minerals such as quartz, calcite and feldspar were also occasionally observed. Domestic law requires that asbestos in air dust is mainly analyzed by phase contrast microscopy. From this study, however, precise analysis of asbestos was almost impossible by this method only. As indicated in JIS method of Japan, therefore, count and identification of asbestos were more efficient by dispersion staining method after removing organic materials in samples by low temperature incinerator.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.3 no.1
• /
• pp.100-109
• /
• 1993

This study was performed to evaluate the asbestos exposure levels and variations in textile, brake lining manufacturing and slate manufacturing industries. For this study, fifteen plants of brake lining manufacturing industry, 7 plants of textile industry, and 2 plants of slate manufacturing industry were selected and surveyed. Geometric means (GMs) of airborne asbestos concentrations in textile, brake lining manufacturing, and slate manufacturing industries were 1.42 f/cc(0.07-6.1O f/cc), 0.19 f/cc(<0.01-2.67 f/cc) and 0.08 f/cc(0.02-0.67 f/cc), respectively. In textile industry overall GMs of airborne asbestos concentrations in plants with less than 50 workers and in plants with more than 50 workers were 1.60 f/cc and 0.3 f/cc, respectively. Therefore, the size of plant showed some difference in the airborne asbestos concentrations. Three out of 7(42.9%) exceed the Korean standard, 2 f/cc, and every plant exceed the USA standard, 0.2 f/cc of the OSHA-Permissible Exposure Level(OSHA-PEL). Especially, one plant showed the highest average concentration of 2.87 f/cc. In brake lining manufacturing industry, the plants with less than 50 workers showed 0.22 f/cc. The plants with more than 50 workers showed 0.18 f/cc. All plants showed the exposure level below the Korean standard. Five of 15 (33.3%) were above the OSHA-PEL. One plant showed the highest average concentraton of 0.84 f/cc. In slate manufacturing industry, the average exposure level was 0.08 f/cc, and all of the plants were below the Korean standard and the OSHA-PEL.

• Toxicological Research
• /
• v.27 no.3
• /
• pp.137-141
• /
• 2011

This study was conducted to assess the exposure risk through inhalation to baby powder for babies and adults under simulated conditions. Baby powder was applied to a baby doll and the amount of baby powder consumed per application was estimated. The airborne exposure to baby powder during application was then evaluated by sampling the airborne baby powder near the breathing zones of both the baby doll and the person applying the powder (the applicator). The average amount of baby powder consumed was 100 mg/application, and the average exposure concentration of airborne baby powder for the applicator and baby doll was 0.00527 mg/$m^3$ (range 0.00157~0.01579 mg/$m^3$) and 0.02207 mg/$m^3$ (range 0.00780~0.04173 mg/$m^3$), respectively. When compared with the Occupational Exposure Limit of 2 mg/$m^3$ set by the Korean Ministry of Labor and the Threshold Limit Value (TLV) of 2 mg/$m^3$ set by the ACGIH (American Conference of Governmental Industrial Hygienists), the exposure concentrations were much lower. Next, the exposure to asbestos-containing baby powder was estimated and the exposure risk was assessed based on the lung asbestos contents in normal humans. As a result, the estimated lung asbestos content resulting from exposure to asbestos-containing baby powder was found to be much lower than that of a normal Korean with no asbestos-related occupational history.

• Analytical Science and Technology
• /
• v.27 no.3
• /
• pp.153-160
• /
• 2014

While variety of cases of studies about asbestos analysis methods are released internationally, the results of Asbestos Containing Materials (ACM) according to differences in the method of the analysis is becoming an issue. In this study, homogeneity ensured ACM samples were analyzed by visual estimation method and point counting method, and the result cound be used not only to improve the reliability on asbestos analysis of the institutions and analysts but also to obtain the basic data of Polarizing Light Microscope (PLM) analysis by comparing and evaluating. Asbestos analysis were divided into qualitative and quantitative analysis method. The quantitative analysis was performed by visual estimation method and point counting method (total 400 points) of EPA 600-R-93-116 method by using PLM. Firstly, The following was the result of homogeneity of the samples by ANOVA (Analysis of variance) and the results were satisfied. The results of qualitative analysis showed that the samples were chrysotile and amosite, and about the results of quantitative analysis, asbestos concentration determined by point counting method tend to be lower than concentrations determined by visual estimation method and also, pont counting method was a little more complicated and time-consuming.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.6 no.2
• /
• pp.165-175
• /
• 1996

Fourteen(14) large commercial buildings located in Seoul with friable sprayed-on surface insulation material on ceiling were investigated for fiber types in bulk material and for airborne fiber concentrations in buildings by transmission electron microscopy (TEM) in order to compare the results with those by polarized light microscopy (PLM) and phase contrast microscopy (PCM). The results were as follows: 1. Chrysotile asbestos was found in one bulk sample out of total 14 bulk samples collected. Glass fiber and mineral wool were the two major constituents of the bulk samples. 2. The Na-Mg-Si-Ca-Fe-Al ratios of the EDX spectra which were normalized with the Si peak were 0-1.0-10-8.3-4.0-4.0 in mineral wool and 0-5-10-21-0-0 in chrysotile asbestos, respectively. 3. Airborne fiber concentrations were log-normalcy distributed and the geometric mean (geometric standard deviation) fiber concentrations by TEM in the underground parking lots and inside buildings were 0.0048 f/cc(1.93) and 0.0040 f/cc(2.27), respectively with no statistical difference. In the outdoor ambient air, statistically significantly lower concentration of 0.0018 f/cc(2.04) was measured. 4. The TEM/PCM ratios of airborne fiber concentrations ranged 0.5 - 2.0 for 80 % of airborne samples analyzed, end the regression equation between TEM and PCM was PCM=-0.2724+1.1355(TEM) with the coefficient of determination $R^2=0.52$. The results of this study confirmed that the sprayed-on surface insulation material found in some commercial buildings may possibly be contaminated with asbestos fiber. Since statistically significant relationship of fiber concentrations measured by PCM and TEM inside buildings and ambient air was found, previous results by PCM in ambient air could be used to estimate the ambient fiber concentrations in knowing the ratio of TEM/PCM.