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고형물 석면분석에 대한 국내 정도관리 프로그램에서 나타난 분석 오류의 특성
권지운 ( Ji Woon Kwon ),정은교 ( Eun Kyo Chung ),이인섭 ( In Seop Lee ),강성규 ( Seong Kyu Kang ),김현욱 ( Hyun Wook Kim ) 한국산업위생학회 2011 한국산업보건학회지 Vol.21 No.4
This study was conducted to identify the characteristics of analytical errors shown in the Korean quality control program on bulk asbestos analyses using polarized light microscopy (PLM). 179 participating laboratories were required to analyze 4 samples respectively and asked to classify each test sample as asbestos-containing (positive) or non- asbestos-containing (negative). For positive samples, participants were also asked to identify the type and semiquantitate the contents of asbestos present. The test results showed 21 (4%) false negative errors among 562 samples, 9 (6%) false positive errors among 154 samples and 53 (9%) asbestos identification errors among 562 samples. Most of false negative and positive errors were observed in a few types of samples. Higher frequencies of asbestos identification errors were shown in samples containing two or more types of asbestos and samples containing anthophyllite, tremolite or actinolite asbestos. For semiquantitative analyses, the ratios of mean to nominal weight contents were 2.1 for chrysotile and 2.9 for amphiboles. A tendency of over-estimation was observed in semiquantitative analyses using the visual estimation technique and higher in case of analyzing samples containing amphiboles than chrysotile. Coefficients of variation (CVs) of semiquantitative analytical results were 0.44~0.83 and 0.5~1.14 for samples containing chrysotile and amphibole asbestos, respectively.
사문석 채석장과 제철소 내 사문석 취급 근로자의 공기 중 석면 노출 평가
권지운 ( Ji Woon Kwon ),서회경 ( Hoe Kyeong Seo ),김갑배 ( Kab Bae Kim ),정은교 ( Eun Kyo Chung ) 한국산업위생학회 2013 한국산업보건학회지 Vol.23 No.1
OObbjjeeccttiivveess: Asbestos contents of crushed serpentine rocks and airborne fiber concentrations of workers were determined at two serpentine quarries and a steel mill. MMeetthhooddss: 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. RReessuullttss: 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. CCoonncclluussiioonnss: 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.
최성원 ( Sung Won Choi ),권지운 ( Ji Woon Kwon ),백정은 ( Jung Eun Baek ),장광명 ( Kwang Myong Jang ),김대종 ( Dae Jong Kim ),김현욱 ( Hyun Wook Kim ) 한국산업보건학회 2014 한국산업보건학회지 Vol.24 No.4
Objectives: This study identified the general characteristics of asbestos inspection/analysis laboratories in Korea and confirmed the actual situations in terms of technical aspects from these characteristics. In addition, given the background of the current problem, it offers preliminary data for determining future plans for improvement. Methods: A questionnaire was developed and distributed to the asbestos inspection/analysis laboratories that used the ISO/IEC 17025 for asbestos sampling and testing by UKAS(United Kingdom Accreditation Service) and the Korea Laboratory Accreditation Scheme(KOLAS). A total of 202 institutions in Korea were selected for the study and 145(71.8%) questionnaires were returned. Results: The number of personnel of the surveyed institutions averaged 4.2±2 and 79.3% operated with less than five persons. In terms of education, the capital and other densely populated areas showed a high level of education(p<0.05). The level of education and facilities were determined by the magnitude of the institution(p<0.05). Institutions managed by highly educated directors were well-stocked with education and facilities(p<0.05). Institutions which had directors with considerable experiences received high scores overall and in particular higher scores in terms of education and facilities(p<0.05). At the level of the bottom five percent, the factor of education was 40.4% while the factor of measurement 49%, the factor of analysis 59%, the factor of facilities 61%, and the factor of survey 81%, respectively. Conclusions: To improve the quality of the institutions, in the short term, the problems identified in this study can be used to revise the related regulations. In the long term, a grading system of survey institutions needs to be established through the introduction of an accreditation system. However, the ongoing support of a government agency is required, including holding seminars and open education, suggesting guidelines for operation of asbestos inspection/analysis labs, and other means.
박승현 ( Seung Hyun Park ),정은교 ( Eun Kyo Chung ),권지운 ( Ji Woon Kwon ),김갑배 ( Kab Bae Kim ),정광재 ( Kwang Jae Chung ),이광용 ( Gwang Yong Yi ),신정아 ( Jung Ah Shin ),이인섭 ( In Seop Lee ),강성규 ( Seong Kyu Kang ) 한국산업위생학회 2011 한국산업보건학회지 Vol.21 No.3
Objectives: The purpose of this study was to investigate the status of asbestos-containing materials (ACMs) used on ships and to consider measures for preventing worker exposure to asbestos fibers. Methods: A total of 17 ships including 16 ships under repair and a ship under construction at shipyards in Korea were investigated. Bulk samples were collected from suspected ACMs on engine exhaust pipes, boiler steam pipes, generator exhaust pipes, and etc. in ships in order to identify the presence of ACMs. Types and contents of asbestos were determined using polarized light microscopy (PLM). Results: ACMs were found from 14 ships out of 17 ships investigated. Only chrysotile asbestos was found from all samples. ACMs were mainly found from samples collected at the exhaust pipes of the engine, generator and incinerator, and boiler steam pipes where exhaust gases or steam of high temperature pass through. In most cases, types of ACMs were asbestos-containing fabrics such as asbestos tape. Friable ACMs were also found in some cases. Use of ACMs on ships was relevant to built time and owner of the ships rather than type and tonnage of the ships. Conclusions: ACMs were found from most ships built prior to 2000s. Therefore, measures for preventing asbestos-related diseases such as preparation of asbestos map on the ship and installation of warning signs, hazard communication with workers (ship-repairing workers, engine room workers and etc.), and follow-up for worker`s health management are needed.
정은교 ( Eun Kyo Chung ),유계묵,신정아 ( Jung Ah Shin ),권지운 ( Ji Woon Kwon ),박현희 ( Hyun Hee Park ),정광재 ( Kwang Jae Chung ),이인섭 ( Seop In Lee ),강성규 ( Seong Kyu Kang ),류향우 ( Hyang Woo Ryu ),김영선 ( Yong Sun Kim ) 한국산업위생학회 2010 한국산업보건학회지 Vol.20 No.3
This study was conducted to investigate the benzene exposure levels in coal chemical and petrochemical refining industries during BTX turnaround (TA) processes where benzene was being produced. Three companies producing benzene were selected, one coal chemical and two petrochemical industries. TA processes were classified into three stages: shut down, maintenance, and start up. Data was analyzed by classifying the refining method into 2 groups (Petrochemistry, Coal chemistry) for 823 workers. Comparing the data from petrochemical industries with data from a coal chemical refining industry, while benzene concentration levels of long-term samples during TA were not statistically different (p>0.05), those levels of short-term samples were significantly different (p<0.001). About 4.79 % of data in petrochemical industries exceed the occupational exposure limits (OELs) of benzene, 1 ppm. In a coal refining methods, about 15.7% exceeded the benzene OELs. The benzene concentrations in maintenance and start up stage of TA for petrochemical refineries were higher than those in a coal chemical refinery (p<0.01). These findings suggest that the coal chemical refining site requires more stringent work practice controls compare to petrochemical refining sites during TA processes. Personal protective equipments including organic respirators should be used by TA workers to protect them from benzene over-exposure.
김영빈(Young Bin Kim),강대영(Dae Young Kang),유형민(Hyung Min Yu),한승오(Seung Oh Han),김수인(Su In Kim),권지운(Ji Woon Kwon),조용근(Yong Geun Cho) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4
본 논문은 굴착기용 전자제어 컨트롤 밸브의 신뢰성 평가를 위한 장비개발 방안을 기술하였다. 현재 개발 중인 굴착기 전자제어 컨트롤 밸브 신뢰성 평가 장비는 100 톤 급 이하 굴착기에 장착되는 컨트롤 밸브에서 발생되는 고장을 파악하기 위해 내구수명 시험과 압력 손실, 내·외부 누유, 스풀 습동, EPPR Valve 응답성, Relief Valve 특성 및 미터링 특성의 성능시험 등이 가능하다. 본 신뢰성 평가 장비 개발 연구를 통해 국산 컨트롤 밸브의 신뢰성 확보를 위한 기초 자료로 활용할 예정이다. This paper describes an equipment development plan for the reliability evaluation of electronic control valves for excavators. Excavator electronic control valve reliability evaluation equipment currently under development is a durability test and pressure loss, internal/external oil leakage, spool sliding, EPPR valve responsiveness, and relief to identify failures occurring in control valves mounted on excavators below 100ton class. It is possible to perform performance tests of valve characteristics and metering characteristics. This reliability evaluation equipment development study will be used as basic data for securing the reliability of domestic control valves.