This study was carried out to evaluate a musculoskeletal symptom and the work posture of the nurses in an operating room who have worked in the present department for more than one year. The job analysis of operating room nurses for ergonomic work posture analysis is divided into 14 tasks. On the basis of that, a survey research and ergonomic work posture analysis are also carried out. Among 41 operating room nurses of a cancer center in Kyonggi province who responded to the self-administered questionnaire, 20 nurses were observed and videorecorded to apply Rapid Entire Body Assessment(REBA) to ergonomic work posture analysis from April 16, 2007 to May 18, 2007. The results of analysis are as follows. The prevalence rate of musculoskeletal symptoms was 75.6% and its prevalence rates by part of the body are these followings; lower back and leg/foot 43.9%, shoulder 36.6%, neck 34.1%, hand/wrist/ finger 22.0%, arm/elbow 14.6%. In accordance with the results of ergonomic work posture analysis, 4 tasks that have a REBA score of 8 have high-risk levels and require an immediate management. It shows there is a significant correlation with overall musculoskeletal symptoms and objective workloads that are estimated by REBA. In conclusion, the work conditions of operating room nurses should be improved. It is also necessary that inappropriate work postures and ergonomic work conditions are improved to prevent musculoskeletal disorders of operating room nurses.

This study was conducted to evaluate health status and to propose health protection measures of irregular plant construction workers in Yoesu National Industrial Complex (YNIC). The status of safety and health management was examined in five areas including safety and health education, work environment monitoring, health examination, health management record, and personal protective equipment (PPE) for plant construction workers. The safety training rate for plant construction workers was reached high at 91%, The training was mostly consisted of safety accident related things, but training on hazardous materials was found to be insufficient. Workplace monitoring results showed that the compliance rate for work environment for irregular construction workers was 54% and workplace monitoring during turnaround (TA) period with high risk of exposure to hazardous agents has not been implemented. While 61.4% of irregular workers received the general health examination but only 36.8% received the special health examination. The special health examination was found to be conducted only upon welders from 2-3 years ago. The issue of health management record upon irregular construction workers was not being implemented. In case of PPE, basic safety protective equipments such as safety shoes, safety belt, safety helmet were being supplied well while the supply rate of respirator for organic vapor was relatively low at 40%. Based on this study, two suggestions to maximize the utilization of the current safety and health program were made while boosting its effectiveness in protecting workers' health. First, the role of owners (petrochemical plant) related to safety and health should be strengthened. Second, in consideration of the characteristics of construction workers who usually engage in short term employment and frequent movement, community based health management organization is suggested that can overcome such structural problem and carry out the implementation of health examination and sustained health management.

To identify relationship between the airborne concentrations of formaldehyde and the causal factors in the endoscope unit of hospitals, a total of 48 workers selected from 4 hospitals (3 university hospitals and 1 national hospital) were investigated. Airborne formaldehyde samples were collected using passive samplers and subsequently analyzed by HPLC according to the OSHA method 1007. The geometric mean(GM) of airborne formaldehyde concentrations was 0.056 ppm (range: 0.003~0.923 ppm). The rates of exceeding exposure limits of OSHA PEL-TWA and NIOSH REL-TWA were 4.2 % and 83.3%, respectively. The STEL GM concentration was 1.428 ppm(range: 0.103~14.773 ppm). Ventilation condition (p=0.001) and temperature (p=0.017) were statistically significant causal factors for the airborne exposure concentration of formaldehyde in the endoscope unit of hospitals. In conclusion, the workers in the endoscope unit of hospitals were highly exposed to formaldehyde, and adequate controls such as appropriate management of ventilation and temperature are recommended to reduce over exposure to formaldehyde.

Objectives : The purpose of this study was to examine the relationship of stress, health problems, absenteeism, productivity and presenteeism in Korean and Japanese workers. Methods : Data was collected from April 12 to July 18, 2008 in both countries. The content of questionnaires was demographic factors, stress and the Stanford Presenteeism Scale. Korean data from 810 workers was collected and Japanese data from 822 workers was collected by same questionnaires of both language. SPSS 12.0 and AMOS 5.0 programs were used for data analysis. Results : The major health problems in relation to the impaired presenteeism of Korean workers were dizziness, allergy, headache and dysmenorrhea, and for Japanese workers were arthritis, depression, and diabetes mellitus. Impaired presenteeism was increasing when the numbers of health problems were increasing in both countries. In Korean workers, job-related stress and the numbers of health problems directly affected presenteeism. In Japanese workers, job-related stress, life-related stress and the numbers of health problems directly affected presenteeism. Conclusions : Health managers should include physical and psychological health management programs for presenteeism control in workplace. They can obtain a greater benefit through both programs.

This document was prepared to review and summarize the analytical methods for airborne and bulk asbestos. Basic principles, shortcomings and advantages for asbestos analytical instruments using phase contrast microscopy(PCM), polarized light microscopy(PLM), X-ray diffractometer (XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM) were reviewed. Both PCM and PLM are principal instrument for airborne and bulk asbestos analysis, respectively. If needed, analytical electron microscopy is employed to confirm asbestos identification. PCM is used originally for workplace airborne asbestos fiber and its application has been expanded to measure airborne fiber. Shortcoming of PCM is that it cannot differentiate true asbestos from non asbestos fiber form and its low resolution limit ($0.2{\sim}0.25{\mu}m$). The measurement of airborne asbestos fiber can be performed by EPA's Asbestos Hazard Emergency Response Act (AHERA) method, World Health Organization (WHO) method, International Standard Organization (ISO) 10312 method, Japan's Environmental Asbestos Monitoring method, and Standard method of Indoor Air Quality of Korea. The measurement of airborne asbestos fiber in workplace can be performed by National Institute for Occupational Safety and Health (NIOSH) 7400 method, NIOSH 7402 method, Occupational Safety and Health Administration (OSHA) ID-160 method, UK's Health and Safety Executive(HSE) Methods for the determination of hazardous substances (MDHS) 39/4 method and Korea Occupational Safety and Health Agency (KOSHA) CODE-A-1-2004 method of Korea. To analyze the bulk asbestos, stereo microscope (SM) and PLM is required by EPA -600/R-93/116 method. Most bulk asbestos can be identified by SM and PLM but one limitation of PLM is that it can not see very thin fiber (i.e., < $0.25{\mu}m$). Bulk asbestos analytical methods, including EPA-600/M4-82-020, EPA-600/R-93/116, OSHA ID-191, Laboratory approval program of New York were reviewed. Also, analytical methods for asbestos in soil, dust, water were briefly discussed. Analytical electron microscope, a transmission electron microscope equipped with selected area electron diffraction (SAED) and energy dispersive X-ray analyser(EDXA), has been known to be better to identify asbestiform than scanning electron microscope(SEM). Though there is no standard SEM procedures, SEM is known to be more suitable to analyze long, thin fiber and more cost-effective. Field emission scanning electron microscope (FE-SEM) imaging protocol was developed to identify asbestos fiber. Although many asbestos analytical methods are available, there is no method that can be applied to all type of samples. In order to detect asbestos with confidence, all advantages and disadvantages of each instrument and method for given sample should be considered.

The regulatory recognition, regulatory approval, and observance for employer, inspector, and worker groups were investigated for the Korean measurement system in working environments. The employer, worker, and inspector showed an agreement of 90~97 % for the measurement of working environments. This survey showed that the measurement system of working environments has been settled in Korea. However, this survey showed an agreement of 81~87 % for reporting the results of working environment, involvement of worker representative, improvement of working environment, and holding presentations for working environment measurement. The employer recognized well for the measurement of working environments, involvement of worker representative, improvement of working environment, and holding presentations for working environment measurement, but the employee did not recognize well them as much as the employer did. Thus, the improvements for the recognition for involvement of worker representative, improvement of working environment, and holding presentations for working environment measurement by the employee are needed.

HRSG(Heat Recovery Steam Generator) building is large enclosed structure included various heat sources. This building needs to appropriately keep internal air temperature for worker's safety and operability of control devices. In this study, ventilation analysis is performed to find proper ventilation method for temperature control. Ventilation analysis is applied to entire internal space of the building with standard $k-{\varepsilon}$ model and enhanced wall treatment because of large size of the structure. And the ventilation method is considered natural and forced convection with two louver structures which has damper or not. Louver structure affect directly air circulation in near HRSG and lower region of the building. Forced ventilation provides strong inertial force which cause upward airflow. From the analysis, it is found that design requirement for internal air temperature can be satisfied by forced ventilation method with louver structure without damper.

To improve work environment for health managers, it was investigated about effect of job stress, psychosocial stress and job satisfaction of health managers on job commitment. The sample used in this study consisted of 166 persons of industrial health managers. The data were collected with self-administered questionnaires between November 2007 and January 2008, and the results analyzed with ANOVA and multiple regression analysis. Job stress was evaluated by using a Korean Occupational Stress Scale(KOSS), and Psychosocial wellbeing index-Short Form(PWI-SF) was used for a psychosocial stress level evaluation. Organized commitment evaluated loyalty, compensation, welfare, job immersion, external employment opportunity, total agreement with employer and personal ability development. In path analyses, interpersonal conflict, lack of reward, psychosocial distress were associated with job satisfaction. And psychosocial distress, job demand, job insecurity, organizational system, occupational climate were associated with organizational commitment. In considering above findings, the health program for psychosocial distress, improvement of job demand, job insecurity, organizational system, occupational climate would be implemented to increase organizational commitment of Health manager.

To evaluate the effect of antioxidant on the cytotoxicity induced by oxidative stress of reactive oxygen species (ROS) in cultured human skin melanocytes, colorimeric assay of XTT and tyrosinase activity assay were adopted after human skin melanocytes were preincubated for 2 hours in the media containing various concentrations of superoxide dismutase (SOD) before the treatment of hydrogen peroxide. Light microscopic study was carried out in same cultures. The results of this study were as follows 1. Cell viability of human skin melanocytes was significantly decreased by 30 and $40{\mu}M$ of hydrogen peroxide($H_2O_2$), respectively. 2. XTT50 was determined at $30{\mu}M$ after human skin melanocytes were treated with $10{\sim}40{\mu}M$ of hydrogen peroxide for 6 hours. 3. The cell viability of cultured human skin melanocytes pretreated with SOD was increased than that of cultured human skin melanocytes treated with $H_2O_2$ dose-dependently. 4. In tyrosinase activity of human skin melanocytes, the cell treated with SOD showed brown stain compared with $H_2O_2$ treated cells, dark stain. 5. In light microscopy, cultured human skin melanocytes exposed to $H_2O_2$ showed morphological changes such as the decreased cell number and cytoplasmic processes, compared with control. 6. In light microscopy, cultured human skin melanocytes pretreated with SOD showed the increase of cell number and cytoplasmic processes compared with $H_2O_2-treated$ group. From these results, it is suggested that oxidative stress of ROS such as $H_2O_2$ has cytotoxicity by showing the decreased cell viability, the increased tyrosinase activity and mophological changes of the decreased cell number and cytoplasmic processes. While, antioxidant like SOD was effective in the prevention of oxidative stress-mediated cytotoxicity by the increased cell viability, decreased tyrosinase activity and the protection of degenerative morphological changes in cultured human skin melanocytes.

In order to check a necessity of health control for the laborers who are in use of mixed organic solvents in the printing industries, this study evaluated the use status of mixed organic solvents, health subjective symptoms on the exposure of the solvents, health hazard for each kind of printings for the employees who work for the printing industries located in Seoul and Gyeonggi. The study analyzed 228 sites and 311 people responded of the total 250 sites surveyed from March to September 2007, and obtained the following results; 1) Estimating the exposure of the mixed organic solvents, the study found that estimation of mixture(EM) was different for each kind of printings at a level of significance, excessiveness of EM was 7.5%, the highest, for gravure printing, 5.6% for screen printing, 4.7% for master printing, 2.9% for offset printing. 2) As to the mean scores of health subjective symptoms for each kind of printings, workers in screen printing showed high scores in every subjective symptom, of which symptom of central nervous system was 3.75, the highest, and the difference was statistically at a level of significance(p<0.01). 3) Results of the hazard analysis for carcinogens and non-carcinogens contained in the mixed organic solvents exposed to the workers showed that cancer risk of offset printing workers was $7.8{\times}10^{-9}$ for benzene, the mean cancer risk was $2.02.{\times}10^{-8}$ from Monte-Carlo simulation, and both risks did not exceed the US EPA permissible standard of $1{\times}10^{-6}$. The total hazard indices of the non-carcinogens estimated was 3.523, the highest, for gravure printing, 2.381 for master printing, 1.125 for screen printing, respectively, and all exceeded 1.

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.

We conducted validation for asbestos quality control (QC) samples made by the developed method which was presented in our published paper. The main results of the validation study are as follows. The pooled coefficient variations of analytical results in three different concentrations (low, medium, and high concentration) for amosite and chrysotile were less than 20 %, which met the sample homogenicity criteria of NIOSH. Also we confirmed the homogenicity of asbestos samples by using the relocatable field slide. To evaluate the field applicability of the developed asbestos QC samples, the field validation was performed with four proficient asbestos analysts by using the statistical methods of AIHA asbestos PAT program. All analytical results from four asbestos analysts were located in the acceptable range.

The purposes of this study were to investigate whether the program of health promotion and follow up feedback by periods could improve physical fitness related to work ability of the middle-aged and aged workers. Subjects were composed of two groups; workers aged below forty five and forty five and over who had measured their health-related physical fitness twice for 2 years (2006 & 2007) through the program of health promotion operated by Korea Occupational Safety & Health Agency. Paired t-test was used to evaluate the difference between the first measurement and re-measurement of health-related fitness which was operated after six to twelve months from the first one. We used 0.05 level for statistical significance. The results of this study were as follows. All measurement items including body fat ratio(%), $VO_2max$, grip strength, sit-up, and trunk flexion were significantly improved in both groups. The improvement(%) of $VO_2max$, grip strength of workers of forty five and above was lower than those of workers of below forty five. Servicing the program of health promotion and follow up feedback by periods may help workers' improvement of health-related physical fitness related to work ability.

This study was conducted not only to review airborne asbestos levels reported in workplaces in Korea, but also to analyze their levels according to various characteristics All asbestos concentration reported as either geometric mean (GM) and geometric standard deviation (GSD) or ranges were transformed to arithmetic mean to estimate exposure level. In addition, weighted arithmetic means (WAMs) were calculated to weigh asbestos levels based on the different number of samples. Differences of asbestos levels among several characteristics such as industry type, decade, operation and sampling and analytical methods were analyzed using analysis of variance (ANOVA). The number of articles studying asbestos levels from workplaces was found to be 9 including two report types. Five of those were reported prior to 1990s and rest of them after 1990s. Only several industries such as asbestos textile, asbestos cement, brake-lining repair shops were studied, while various industries using asbestos or asbestos containing materials (ACMs) were not studied. ANOVA found that asbestos exposure levels (WAM = 5.26f/cc) reported from textile industry were significantly higher than those from other industries (cement = 0.63f/cc, brake-lining = 0.2f/cc - 0.47f/cc) (p < 0.0001). Average exposure levels studied prior to the 1990s (3.13f/cc) were found to be significantly higher than that (0.86f/cc) after the 1990s (p<0.0001). All WAMs reported until the 1994 were found to be higher than the current occupational exposure limits (0.1f/cc). This study recommends that retrospective exposure to asbestos based on various industry types and operations should be assessed.