• 한국산업보건학회지
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• 제17권3호
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• pp.212-223
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• 2007

18 Local exhaust ventilation systems in 10 melting companies located in an industrial complex were tested to know the status of maintenance. Test items were fan flowrates, fan static pressures, rotational speeds and differential pressures of bag filters. Only 22% of the tested fans has more than 80% flowrate efficiency. 44% of the fans has lower than 60% efficiency. The performance of the fans are not in a good status. For the fans with lower than 60% efficiency, the analysis shows that the lower flowrate might be caused by the degradation of fan performance. On the other hand, for the fan s with higher than 60% efficiency, the main cause of flowrate reduction might be too much pressure losses due to clogging of filter bags. The degradation of fans usually lead the reduction of hood capture efficiency, resulting in the increase of contaminant concentrations in workplace. To keep fans in good status, self inspections should be periodically conducted. This inspection should include the measurements of flowrate and pressures. The most important thing to be performed is the initial test of local exhaust ventilation system because the initial test data should be used to know the level of system degradation.

• 한국산업보건학회지
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• 제19권4호
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• pp.336-346
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• 2009

As a follow-up survey of A Study of Monitoring Method on Exposure Level and Biomarkers of Environmental Pollutants-Focused on Ulsan Industrial Comlpex Area, published in 2005, a close examination of the health status was conducted for selected Ulsan residents. Based on the previous study, a total number of 129 subjects were divided into two groups: the exposure group consisted of 39 residents whose blood levels of lead, mercury and/or cadmium were higher than international reference values, and 90 residents of control group with normal levels. Environmental exposure level and its association with health condition were examined by various methods such as questionnaire, analyses of lead, mercury and cadmium in blood and medical examinations. The geometric mean concentrations of lead, mercury and cadmium in blood were respectively $2.07{\mu}g/d{\ell}$ (exposure $2.54{\mu}g/d{\ell}$, control $1.90{\mu}g/d{\ell}$), $5.94{\mu}g/L$ (exposure $8.57{\mu}g/L$, control $5.07{\mu}g/L$), $1.32{\mu}g/L$ (exposure $1.30{\mu}g/L$, control $1.33{\mu}g/L$). The concentrations of the three heavy metals in blood showed lower levels than internationally recommended values except for blood mercury. Also, any abnormal or, peculiar disease, or target tissue damage related to the heavy metals was not observed among the all subjects. Therefore, it can be said that no significant difference of heavy metal concentrations and health conditions was found between the two groups.

• 대한치과기공학회지
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• 제34권4호
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• pp.403-412
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• 2012

Purpose: This study is conducted to evaluate the job stressors for dental technicians in Ulsan city. Methods: The Korean standard job stressors assessment tool developed by Korea Occupational Safety and Health Agency (KOSHA) was used to compare the survey result with Korean reference value. The questionnaire on the social, demographic and job characteristics of dental technicians was also used to find the factors affecting to job stressors by using multiple linear regression analysis. Results: A total of 155 questionnaire was collected from 2010 to 2011. Among the eight fields of stressors, the physical environment (men 50.0, women; 58.3) and job demands (men 57.1, women 57.1) were higher than the median value of the Korean Workers. By multiple linear regression analysis, the significant factors to the physical environment were the satisfaction degree of indoor odor, number of employee, duty and working hours. In terms of the job demand, duty, working hours, age, and the satisfaction to the efficiency of space utilization were significantly associated to the score of job demand. Conclusion: Based on these results, it is necessary to manage appropriate workload, control indoor odor and design an efficient work space for prevention of job stress of dental technicians.

• 한국환경보건학회지
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• 제28권2호
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• pp.109-116
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• 2002

The purpose of this study was to evaluate a new sampling and analytical method for the determination of airborne hexavalent chromium, Cr(Ⅵ), in a field plating operation. The procedures of this new method (Shin & Paik's Method) are as the following: Airborne hexavalent chromium is collected on polyvinyl chloride (PVC) filter according to the National Institute iota Occupational Safety and Health (NIOSH) Method 7600, and the filler sample is placed in a screw-capped vial and soaked with 2% NaOH/3% Na₂CO₃ solution immediately after sampling. The Cr(Ⅵ) sample is analyzed by ion chromatography/visible spectrophotometry (IC/VS) according to the U.S. Environmental Protection Agency (EPA) Method 218.6. The airborne Cr(Ⅵ) concentrations measured by this method were compared with those determined by three reference methods: One (NIOSH/EPA Method) consisted of sampling airborne Cr(Ⅵ) on PVC filters and storing the sample filters in strew-capped vials according to the NIOSH method, and analyzing Cr(Ⅵ) in samples using IC/VS according to the EPA method. The second method (Impinger Method/NaHCO₃) consisted of absorbing airborne Cr(Ⅵ) into 0.02 M NaHCO₃ solution in midget impinger, and analyzing the Cr(Ⅵ) in samples using IC/VS. The third method was the OSHA Method ID-215. Using these four different methods, lour replicates of air samples were collected at an electroplating process and analyzed simultaneously. Two-way ANOVA and paired t-test were used to test difference among values determined by the methods. There was no significant difference and a strong correlation (r²:0.99) between Cr(Ⅵ) concentrations measured by the Shin & Paik's Method and an impinger method (p>0.05). However, Cr(Ⅵ) concentrations determined by Shin & Paik's Method were significant1y different from those by the NIOSH/EPA Method (p<0.05) or the OSHA method (p<0.05). The Cr(Ⅵ) concentrations of Shin & Paik's Method were significantly higher than those of the NIOSH/EPA Method or the OSHA method. This result indicated that the Shin & Paik's Method may prevent Cr(Ⅵ) losses caused by reduction and give more reliable results of airborne Cr(Ⅵ) concentrations in work environments.

• 한국환경보건학회지
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• 제32권5호
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• pp.506-514
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• 2006

The objectives of this study were to evaluate personal exposure estimated using a time activity pattern and microenvironmental model. The study was carried out for 44 children attending a primary school nearby the lines (school A) and 125 children attending a school away from 154 kV power lines (school B). For children attending school A, the estimated personal level was a little weak correlated with the measured level($Pearson\;r\;=0.34{\sim}0.35$). For children attending school B, the correlation was very low ($Pearson\;r\;=\;0.09{\sim}0.16$) using the TW A Model II, otherwise, TWA Model II-I which considered the average residential MF level according to the distance from the power line and home explained $39{\sim}53%$ of the correlation in MF personal exposures. The estimated personal exposure level was very well represented by the measured exposure level using TWA Model II-2 which consisted on spot and 24 h stationary measurements at subject's home ($Pearson\;r\;=\;0.65{\sim}0.85$). In conclusion, personal magnetic field expsoure estimated using a TWA Model II-2 should be provided for a reasonable estimate of measured exposure in schoolchildren living near the power line.

• 한국산학기술학회논문지
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• 제19권6호
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• pp.154-159
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• 2018

도시가스 회사는 설비의 유지보수 및 점검을 수행할 경우에 가스를 방산하는 경우가 있는데, 가스누출 오인으로 신고 및 주민불안이 발생하게 됨에 따라 활성물질을 통한 천연가스의 부취냄새를 효과적으로 탈취하는 방법을 연구하는데 그 목적을 두었다. 본 연구에서는 천연가스 부취냄새 탈취를 위해 활성물질인 차아염소산나트륨을 이용한 산화법을 통해 천연가스 부취제와 활성물질간 효율적 혼합방법을 위해 간이 탈취방산장치를 제작하여 현장에서 실험을 통해 부취농도를 확인하였다. 탈취실험장치의 기본원리는 방산되는 가스(0.8~1.0MPa)의 에너지를 이용하여 활성물질용액이 첨가되도록 하여 가스 내 부취제와 혼합과정을 거친 후 방출구를 통해 대기로 방산된다. 도시가스 부취제의 활성물질인 차아염소산나트륨을 이용하여 산화반응을 통해 벤츄리와 혼합용기의 직렬연결방식을 적용하여 제작한 장치를 통해 현장에서 효과적으로 부취냄새를 제거할 수 있었다. 하지만, 실질적인 효과를 거두기 위해서는 도시가스의 다량과 고압에서 방산되는 조건에서의 적용하는 문제해결 과제가 남아 있다.

• 생물정신의학
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• 제18권4호
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• pp.225-231
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• 2011

Objectives Atypical antipsychotics show better treatment efficacy, safety and tolerability than typical antipsychotics. Among the adverse events observed during treatment with antipsychotics, extrapyramidal syndrome (EPS) and negative symptoms has been greatly reduced. But still, weight gain is receiving growing attention. The aim of this study was to investigate the association between therapeutic response to atypical antipsychotics and weight gain in admission status. Methods The study was conducted for Korean inpatients with schizophrenia in a university hospital in Seoul, between Jan 2006 and Dec 2010. Data was collected by reviewing the medical record of 39 consecutively hospitalized patients with Schizophrenia (DSM-IV) at a university hospital. Positive and Negative Symptom Scale (PANSS), Body Mass Index (BMI) and body weights were measured. Results No significant difference was observed for sex, age, illness onset age, family history of schizophrenia, numbers of hospitalization before treatment, educational years, marriage status, occupational status and subtype of schizophrenia between weight gainers and non-weight gainers. Regarding treatment response to atypical antipsychotics, weight gainers show significantly more PANSS decrease than non-weight gainers during admission period. Conclusions Our findings suggest that it appears to be more likely to respond to atypical antipsychotics in weight gainers than non-weight gainers (that weght gainers appear to be more likely to respond to atypical antipsychotics than non-weight gainers). These results show that the antipsychotic-induced body weight gain is associated with therapeutic response of antipsychotics in Korean inpatients with schizophrenia.

• 한국산업보건학회지
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• 제15권3호
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• pp.270-276
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• 2005

This study was conducted to examine whether a specific synthetic metalworking fluid (MWF), "A", in use for 10 months without replacement, displayed microbial resistance and to identify the additives associated with the control of microbial growth. Three synthetic MWF products ("A", "B", and "C") were studied every week for two months. Microbial deterioration of the fluids was assessed through evaluation by endotoxin, bacteria and fungi levels in the MWFs. In addition, formaldehyde, boron, ethanolamine, and copper levels were also studied to determine whether they influence microbial growth in water-based MWFs. Throughout the entire study in the sump where MWF "A" was used, bacteria counts were lower than 103 CFU/mL, and endotoxins never exceeded 103 EU/mL. These levels were significantly lower than levels observed in sumps badly deteriorated with microbes. Boron levels in MWF "A" ranged from 91.7 to 129.6 ppm, which was significantly higher than boron levels found in other MWF products. The total level of ethanolamine (EA) in MWF "A" ranged from 35,595 to 57,857 ppm (average 40,903 ppm), which was over ten times higher than that found in other MWFs. Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) concentrations in MWF "A" were also significantly higher than seen in other MWFs. However, although EA and boron might improve anti-microbial performance, their abuse can pose a serious risk to workers who handle MWFs. From an industrial hygiene perspective, our study results stress that the positive synergistic effect of boron and EA in reducing microbial activity in MWF must be balanced with the potentially negative health effects of such additives. Our study also addresses the disadvantage of failing to comprehensively report MWF additives on Material Safety Data Sheets (MSDS). Future research in MWF formulation is needed to find the best level of EA and boron for achieving optimal synergistic anti-microbial effects while minimizing employee health hazards.

• 한국산업보건학회지
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• 제9권1호
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• pp.1-13
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• 1999

Even though there is no fit test regulations in Korea, in many developed countries, respirator fit testing is required before entering specific work environment to ensure that the respirator worn satisfies a minimum of fit and that the user knows when the respirator fits properly. Due to no regulation for fit test, a lot of Korean workers wearing respirators may be potentially exposed to hazards. Anthropometric test panels for testing the fit of respirators are very important to develop respirators fitted properly for Korean workers. To evaluate the fitting performance, 304 workers (272 males, 32 females) and 536 students (268 male, 268 females) were fit tested for 4 full-facepieces (2 domestic-made S, C, and 2 foreign-made T, N), 2 half masks (1 domestic-made S, and 1 foreign-made T) and 3 quarter masks (2 domestic-made S, C, and 1 foreign-made T) with PortaCount 8020. Fit factors of foreign-made masks were higher than those of domestic-made masks in all types. Males were fitted more properly than females. A facial dimension survey of 364 workers (339 males, 25 females) and 158 students (69 males, 89 females) was conducted to develop test panels for fit testing. Subjects were selected on the basis of face length and face width to wear full-facepiece masks in test. For testing half- and quarter masks, face length and lip length were used. Test panels containing 25 male-and-female subjects and 16 male subjects were respectively developed for full-facepiece, and half-and quarter masks to represent a majority of population surveyed.

• 대한물리의학회지
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• 제8권2호
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• pp.183-192
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• 2013

PURPOSE: The purpose of this study was to research the effect of self-Stretching Exercise on musculoskeletal Symptom and job Stress for care helpers who work at geriatric hospital and come up to NIOSH standard. METHODS: The effect of self-Stretching Exercise was measured using 'musculoskeletal symptom survey table' and 'Job stress measurement scale for korean' from the Korea Occupational Safety and Health Agency(KOSHA) for 40 care helpers. The paired t-test and independent t-test was used for statistical analysis. RESULTS: The pracitce of Self-Stretching Exercise was showed significant effect reducing the stress for care helper's total job Stress and inappropriate compensation, job instability, job requirement, relationship conflict, physical environment(p<.05), and significant difference for their total score, relationship conflict, structure and organization, physical environment, inappropriate compensation improvement on variations on job stress in groups(p<.05). However, self-Stretching Exercis was showed no significant effect on physcial burden. CONCLUSION: The self-Stretching Exercise was the most effect way to reduce Musculoskeletal Symptom and job Stress for a care helpers through the guidance of physical therapist.