그라인더(grinder) 사용에 의한 Hand-Arm Vibration Syndrome(HAVS)의 6예

임상혁,김록호,양길승,양정인,김상섭,전형준,박시복 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.3

목 적 : 수지증상이 있는 진동공구 작업자 8명에 대해 객관적이고 체계화된 진단방법을 이용하여 수지진동 증후군을 진단하고자 시행하였다. 방 법 : 과거병력, 가족력 등의 문진과 혈액 및 소변, 방사선 검사를 통해 다른 원인에 의한 레이노씨병을 배제하였고, 공구 측정 결과를 이용하여 작업과의 관련성을 보았으며, 냉수 침지검사와 근전도 검사를 통하여 수지진동 증후군을 진단하고자 하였다. 결 과 : 수지증상이 있는 진동공구 작업자 8명에 대해 과거병력, 가족력, 약물복용 및 과거 직업력 등 레이노씨병을 유발하는 요인에 대하여 조사하였고 특이점은 발견하지 못하였다. 다른 원인에 의한 레이노씨병을 배제하기 위해 혈액 및 소변, 방사선 검사를 하였고 8명 모두에서 특이 소견을 발견하지 못하였다. 위의 문진과 검사결과로 다른 원인에 의한 레이노씨병을 배제할 수 있었다. 해당사업장의 진동 공구 측정결과를 근거로 피검자의 공구가 ISO의 허용기준을 초과함을 알 수 있었다. 냉수 침지검사와 근전도 검사를 이용하여 피검자 8명중 6명이 말초 혈액순환 장해와 말초 신경염이 있는 것으로 진단되었다. 위의 내용을 근거로 6명은 진동에 의한 수지 진동 증후군으로 진단할 수 있었다. 결 론 : 수지증상이 있는 진동공구 작업자 8명에 대해 객관적이고 체계화된 진단방법을 이용하여 수지진동 증후군을 진단하였다. 해당 사업장의 진동 공구 작업자의 진동에 대한 검진이 필요할 것으로 생각된다. Objectives : To confirm the HAVS In workers exposed to hand-arm vibration with using the objective diagnostic methods. Methods : Several tests were used to help substantiate a clinical diagnosis of HAVS. Some other diseases were excluded by a medical interview, hematologic assessment, urinalysis, X-rays. The hand-arm vibration acceleration level of the grinder was evaluated for considering HAVS. Peripheral vascular changes were examined by a cold provocation test. An electromyography was implemented to ascertain the peripheral neural changes. Results : 8 workers with symptoms in hands & fingers, exposed to hand-arm vibration were examined. Some other diseases (primary Raynaud's disease, secondary Raynaud's disease in not occupational origin) were excluded by a medical interview, hematologic assessment, urinalysis, X-rays. The hand-arm vibration acceleration level of the grinder was 7.9 m/sec2. The recovery time of a skin temperature followed finger cooling was significantly prolonged in 6 workers with HAVS. The nerve conduction velocity was reduced in 6 workers with HAVS. Conclusions : So we report 6 cases of HAVS in grinding workers exposed to hand-arm vibration diagnosed objectively by an exclusion of some other disease, hand- arm vibration acceleration level, cold provocation test, electromyography.

체내 카드뮴 농도에 따른 신세뇨관 미세손상 유병률

임동혁, 문선인, 엄상용, 김용대, 강종원, 김헌 충북대학교 의과대학 충북대학교 의학연구소 2011 忠北醫大學術誌 Vol.21 No.2

-본문참고-

표면근전도의 근육 긴장도를 이용한 컴퓨터 단말기 작업자세 평가

임상혁,박희석,김현욱 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.4

목 적 : 본 연구는 VDT작업에서 작업동안 영향을 받는다고 알려진 5개의 근육을 표면근전도를 이용하여 근육의 긴장도를 측정, 평가하고자 하였다. 방 법 : 전화교환 및 고객상담 업무를 담당하고 있는 여성 작업자 11명을 대상으로, 책상의 높이, 모니터의 위치, 키보드의 거리를 달리하여 근육의 긴장도를 측정하였다. 실험장(workstation) 설계에서 높은 책상은 대상자가 속한 사업장의 책상으로 하였으며 높이는 72.8 cm이었고, 미국 국립표준원의 기준에 맞게 제작한 표준 책상의 높이는 65.0 cm이었다. 모니터의 위치는 목을 비틀지 않고 모니터를 주시하고 있는 경우와 약 45도 비틀면서 주시하는 경우로 나누어서 실험하였고, 키보드의 거리는 책상의 끝에서 15 cm 떨어진 것과 30 cm 떨어진 경우로 실험하였다. 실험에 사용된 근육은 paraspinal muscles, upper trapezium muscle, supraspinatus muscle, infrasplnatus muscle, rhomboid muscle이었으며, 실험은 하나의 조건에 대해 각각 5분씩 수행하였고, 각 실험후 10분간 손을 다리 위에 올려놓고 쉬게 하였다. 결 과 : Paraspinal muscles의 표면근전도 값은 모니터가 작업자로부터 45˚측면에 위치할 때가 작업자 중앙에 위치할 때보다 유의하게 높게 나타났다. Upper trapezium muscle, supraspinatus musscle, infraspinatus muscle의 표면근전도 값은 높은 책상에서 미국 국립표준연구원이 제시한 표준책상보다 유의하게 높게 나타났다. Rhomboid musscle은 책상의 높낮이에 따라 표면근전도 값이 차이가 있었으나 통계적 인 의미는 없었다. 결 론 : 이러한 결과로 볼 때 책상의 높낮이가 VDT 작업에서의 어깨 근육 긴장도에 중요한 영향을 미친다고 생각되며, 또한 표면근전도를 이용한 근육 긴장도의 평가가 인간공학적으로 적합한 VDT작업장 설계에 유용할 것으로 생각된다. Objects : Thls study was designed to assess muscle tensions while working at a YDT workstation with surface electromyography (SEMG). Methods : Variables texted were desk height, monitor positon on the desk, distance from edge of the desk to the keyboard. Eleven female volunteers working in the tele-com munication company were seated at an ergonomically adjusted workstation. They were assigned to a task of typing for 5 minutes and were given a 10 minutes resting with hands in their lap. For the initial experiment, the desk height was fixed to standard desk height(65.0 cm) recommended by ANSI and latter adjusted to a higher desk height (72.8 cm) for this study such that the subjects experienced slight elevation of shoulders. The monitor position initially at the center on the desk and latter left site of the desk (45o from monitorneck axles). The keyboard was positioned to an optimal distance (15 cm from the desk edge) and an abnormal distance (30 cm). Five muscle groups (paraspinal muscles, upper trapezium muscle, supraspinatus muscle, infraspinatus muscle, and rhomboid muscle) were selected for the study. The data of SEMG were analyzed by 2×2×2xs mixed factorial design. Results : The results were as follows: 1. SEMG activity recorded from the paraspinal muscles were significantly higher when the angle of the monitor adjusted to 45 degree from the center of the desk.. 2. SEMG activity recorded from the upper trapezius/supraspinatus/infraspinatus muscles were significantly higher when the hight of the desk was elevated from the recommended height. 3. SEMG activity from the rhomboid muscle showed no significantiy difference in all test conditions. Conclusions : The results of thls study confirm that the helght of a VDT workstation and the angle of the monitor are risk factors of upper extremity cumulative trauma disorders. Also SEMG would be useful for measuring muscle activities during workstation assessment.

파쇄골 이식술을 이용한 안정된 무시멘트 비구컵 주위의 골융해에 대한 치료

서유성,임강철,권혁룡,임수재,박종석,이병일 대한고관절학회 2003 Hip and Pelvis Vol.15 No.3

이황화탄소 중독과 심박동수 변이와의 관련성

전형준,임상혁,백도명 大韓産業醫學會 2004 대한직업환경의학회지 Vol.16 No.1

목적: 1980년대 말에 레이온 섬유를 생산하는 업체에서 대규모 이황화탄소 중독 사례가 발생하였으며 1998년까지 사망자 38명을 포함하여 830명의 근로자들이 이황화탄소 중독으로 진단되었다. 이황화탄소 중독으로 진단 받았던 환자들과 정상인들의 심박동수 변이를 측정하여 이황화탄소 노출이 중단된 상태에서의 건강영향에 대해 조사하였다. 아울러 환자군을 대상으로 이황화탄소 노출량과 심박동수 변이와의 사이에 양-반응 관계가 있는 지를 조사하였다. 방법: 이황화탄소 중독으로 진단된 71명의 남성 퇴직 근로자들을 환자군으로, 이황화탄소를 포함한 유기용제에 직업적으로 노출된 적이 없고 심혈관계질환이 없는 환자군과 같은 연령대의 남성 127명을 대조군으로 선정하였다. 두 군에서 자기 기입식 설문지를 이용하여 연령, 흡연, 음주, 규칙적인 운동, 과거의 직업력 및 질병력 등에 대한 정보를 수집하였다. 건강검진을 통해 신장, 체중, 혈압을 측정하고 심전도 검사, 흉부 방사선 촬영 등을 실시하였다. 심박동수 변이의 지표로서 시간 영역(maximum, average, minimum RR interval)과 주파수 영역(low frequency - LF, high frequency - HF, total power spectrum - TPS, LF/HF ratio)을 측정하였다. 환자군에서 과거의 이황화탄소 노출에 대한 지표들(근무기간, 근무부서별 노출량, 누적노출지수, 퇴사기간)을 조사하여 심박동수 변이와 양-반을 관계가 있는 지를 평가하였다. 결과: 단변량 분석에서 두 군의 시간 영역 측정치에는 유의한 차이가 없었다. 이에 비해 고주파 영역을 제외한 주파수 영역 측정치들은 환자군들이 대조군에 비해 유의하게 낮았다. 다중선형분석에서 이황화탄소 중독의 과거력은 모든 주파수 영역 변수들과 음의 관계를 나타냈으며, 특히 저주파 영역(p<0.05)과 저주파/고주파 비(p<0.05)에 유의한 영향을 나타냈다. 환자군에서 이황화탄소 노출 지표들과 심박동수 변이와의 양-반응 관계를 조사하였으나 유의한 관계는 나타나지 않았다. 결론: 환자군에서 이황화탄소와 심박동수 변이와의 사이에 양-반응관계를 확인할 수는 없었으나 환자군과 정상인을 비교했을 때 저주파 영역과 저주파/고주파 비 등에서 심박동수 변이의 감소가 있었다. 이황화탄소의 노출이 중단된 상태에서도 심혈관계 건강영향이 있을 가능성에 대한 연구가 더 필요하다. Objectives: Mass poisoning by carbon disulfide (CS_(2)) occurred in a viscose rayon factory in Korea. Up until 1998, 830 employees, including 38 who had died, were diagnosed with CS_(2) poisoning. Among the CS_(2) poisoned subjects, heart rate variability (HRV) was evaluated to investigate whether the toxic effect of CS_(2) persists after the exposure has ceased. The dose-response relationship between carbon disulfide exposure and HRV was also evaluated. Methods: The case group was comprised of 71 retired male workers diagnosed as being CS_(2) poisoned. The control group was comprised of 127 males of same age-range who had no history of CS_(2) exposure and cardiovascular diseases. Information on individual age, height, weight, weight, cigarette smoking, alcohol drinking, regular exercise, medical and occupational history, chest x-ray, and ECG recording of the two groups were collected through a self-administered questionnaire and with a medical examination, Time (maximum, average, minimum RR interval) and frequency domain measures (low frequency - LF, high frequency - HF, total power spectrum TPS, and LF/HF ratio) of the two groups were analyzed. CS_(2) exposure indices of the case group (duration of employment, exposure level per work department, cumulative exposure index and duration of retirement) were investigated. Results: Using a univariate analysis, the frequency domain measures for the case group were significantly lower than those in the control group, except for HF. In the multivariate analysis, previous history of CS_(2) poisoning was inversely related to all frequency domain parameters and it significantly affected the LF(p<0.05). There was no significant dose-response relationship between CS_(2) exposure indices and HRV parameters in the case group. Conclusion: This study suggests that further studies are necessary to evaluate the residual effects of CS_(2) poisoning even after the CS_(2) exposure has ceased.

일부 법인 택시 노동자의 교통사고와 볼안전운전행동에 미치는 인적요인

윤간우,이상윤,임상혁 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

목적: 본 연구는 택시 업종을 대상으로 택시노동자의 다양한 인적특성들이 불안전운전행동을 매개로 교통사고와 어떠한 관련성이 있는지 살펴보고자 한다. 방법: 총 6개 택시사업장에 335명의 택시노동자를 대상으로 연구를 수행하였다. 자기기입식 설문조사 방법으로 지난 1년간 교통사고 횟수와 운전 중 불안전한 행동수준을 파악하였다. 이에 영향을 미칠 것으로 예상되는 개별 노동자의 인적 특성을 수집하여 요인분석을 통해 직무요인, 정신건강요인, 연령요인, 건강습관요인, 수면요인으로 범주화 하였고 위계적 다중회귀분석을 통해 이들 요인들이 불안전운전행동을 매개로 교통사고 횟수에 미치는 영향을 살펴보았다. 결과: 위계적 다중회귀분석 결과, 직무요인(β: 0.122), 수면요인(β: 0.114), 그리고 불안전운전행동(β: 0.018)은 교통사고 횟수에 직접적인 영향을 미치는 요인으로 나타났다. 불안전운전행동을 통해 교통사고 횟수에 간접적인 영향을 미치는 요인은 직무요인(β: 1.319), 정신건강요인(β: 6.429), 건강습관요인(β: 1.177)이었다. 결론: 본 연구 결과 택시 교통사고는 택시노동자의 일반적 특성, 정신건강상태, 직업적 특성이 불안전운전행동을 매개로 직·간접적인 영향을 미치고 있었으며, 효과적인 택시 교통사고 예방을 위해서는 이들 인적 요인에 대한 적절한 대책이 필요할 것이다. Objective: This study investigated the driving habits of taxi drivers, in order to examine the characteristics of human factors causing traffic accidents and unsafe driving behavior and to determine any relevancy among them. Method: Taxi drivers (N=335) answered a questionnaire investigating various measures of human factors, unsafe driving behaviors, and number of traffic accident experiences in the previous year. In factor analysis, the characteristics of human factors were classified into 5 common factors: job, mental health, age, health habit and sleep factor. A contextual mediated model was proposed to distinguish the distal (5 common factors) and proximal (unsafe driving behaviors) factors in predicting traffic accident involvement by hierarchical multiple regression. Result: In hierarchical multiple regression, job factor(β: 0.122), sleep factor (β: 0.114) and unsafe driving behaviors (β: 0.018) yielded a direct effect on the rate of traffic accidents. Mental health factor β: 6.429), job factor (β: 1.319) and health habit factor(β: 1.177) yielded a indirect effect on the rate of traffic accidents by unsafe driving behaviors. Conclusion: Various human factors co-related by the unique characteristics that exist in the taxi service industry have significant effects on the rate of traffic accidents mediated by unsafe driving behaviors. Therefore a proper countermeasure against these factors should be established in order to effectively reduce the rate of taxi accidents.

A Proportionate Diffusion LMS Algorithm for Sparse Distributed Estimation

Sung-Hyuk Yim,Han-Sol Lee,Woo-Jin Song IEEE 2015 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.62 No.10

<P>We propose a new diffusion least mean squares algorithm that utilizes adaptive gains in the adaptation stage for the sparse distributed estimation problem. We derive the optimal gains that attain a minimum mean-square deviation and propose an adaptive gain control method. We provide the mean stability analysis to establish sufficient condition for the algorithm to converge in the mean sense. The algorithm achieves higher convergence speed than the sparsity-constrained algorithms, regardless of the sparsity of the vector of interest.</P>

Urethane으로 유발된 생쥐 페샘암종 발생과정에서 세포주기 관련인자(Cyclin D1, p21, and p27)에 대한 비소의 효과

임성혁(Sung Hyuk Yim),정지훈(Ji Hoon Jeong),견종만(Jong Man Gyeon),박언섭(Eon Sub Park) 대한약학회 2006 약학회지 Vol.50 No.2

The present study investigated an effect of arsenic trioxide on the urethane-induced lung carcinogenesis in mice. To understand its carcinogenesis, we examined proliferating cell nuclear antigen (PCNA), apoptotic index as well as cell cycle-related proteins (cyclin D l, p21, and p27). Urethane was injected intraperitoneally in ICR mice, and then they were sacrificed at 5, 15, or 25 weeks following treatment of arsenic trioxide. Arsenic trioxide was given with tap water at a concentration of 1 mg/l (low-dose) and 5 mg/l (high-dose) for 25 weeks. During the carcinogenesis, sequential histological changes from hyperplasia to adenomas, and ultimately to overt carcinomas were noted. The development of hyperplasias, adenomas, and carcinomas in the lung were slightly increased by the treatment of low-dose arsenic trioxide. However, there is no correlation between dose and tumor multiplicity. The administration of low-dose arsenic trioxide, significantly increased the tumor size. The proliferative index observed on 5 weeks after significantly increased. Cyclin D1 and p21 protein, cell cycle related proteins, were more significantly increased in hyperplasia and adenoma in low dose arsenic treated group than urethane alone group. The p27 protein expression did not show any significantly changes with arsenic treated or untreated group. Low dose exposure to arsenic trioxide resulted in increased expression of cyclin D1 and p21 protein. The present results indicate that low-dose treatment of arsenic trioxide, but not high dose of it, partly modulate the cellular proliferation, cyclin D1, and p21 protein expression, and that this effect may contribute to accelerated development of lung adenocarcinomas in urethane-induced mice.

Recrystallization of Adefovir Dipivoxil Particles Using the Aerosol Solvent Extraction System Process

Yim, Joon-Hyuk,Kim, Woo-Sik,Lim, Jong Sung American Chemical Society 2014 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.53 No.4

<P>In this study, the adefovir dipivoxil particles were recrystallized by using the aerosol solvent extraction system (ASES) process. Supercritical carbon dioxide, which is known to be a green solvent, was adopted as an anti-solvent. The effects of process parameters such as temperature, pressure, solution concentration, and solution injection rate on particle size and its distribution were investigated. To explore the influence of solvents on particle production, ethanol (C<SUB>2</SUB>H<SUB>5</SUB>OH), methanol (CH<SUB>3</SUB>OH), and IPA (isopropyl alcohol, C<SUB>3</SUB>H<SUB>8</SUB>O) were used as a dissolving solvent for adefovir dipivoxil. As a result, particle size decreased when the system temperature decreased and the system pressure increased. Higher concentration of adefovir dipivoxil in the solution and increasing the solution injection rate also increased particle size. When we use three different kinds of solvents, the order of recrystallized particle size and the width of particle size distribution was methanol < ethanol < IPA. A scanning electron microscope was used to observe the morphology and size of the adefovir dipivoxil particles recrystallized by the ASES process. The mean particle size and its distribution of processed particles were measured by image analysis software.</P>

Trace Organic Contaminants in Sediments from Deep-sea Basin near Dokdo, Korea

Yim, Un-Hyuk,Oh, Jae-Ryoung,Hong, Sang-Hee,Li, Dong-Hao,Shim, Won-Joon,Choi, Hye-Kyung,Kim, Eun-Soo,Shim, Jae-Hyung Korea Institute of Ocean ScienceTechnology 2002 Ocean and Polar Research Vol.24 No.4

Trace organic contaminants in deep-sea sediments near Dokdo were analyzed. Total PAMs concentration ranged 14.8-314 ng/g dry weight and high molecular weight PAHs were dominant. The highest PAHs concentration was detected at A19 which located at Ulleung Basin. Most of organochlorines were under detection limit. Among the detected organochlorines, DDT compounds were dominant and followed by HCHs and HCB. Butyltin compounds and most of organophosphorus pesticides were not detected. Vertical distribution of PAHs showed typical sub-surface maximum and decreasing trends depending on depth. The highest PAHs concentration reached 454ng/g. Some organochlorines, DDT, HCH was detected and also showed decreasing trends. Other target organic pollutants were not detected in core sediments. Abnormally high level of PAHs concentration in A19 was discussed and the input sources were inferred to be the transport of sludge derived pollutant dumped at dumping site 'Byung' by deep current.