• Journal of Preventive Medicine and Public Health
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• 제29권4호
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• pp.747-764
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• 1996

This study intended to obtain an useful information for health management of lead exposed workers and determine biological monitoring interval in early period of exposure by measuring the lead exposure indices and work duration in all male workers (n=433 persons) exposed less than 1 year in 6 storage battery industries and in 49 males who are not exposed to lead as control. The examined variables were blood lead concentration (PBB), Zinc-protoporphyrin concentration (ZPP), Hemoglobin (HB) and personal history; also measured lead concentration in air (PBA) in the workplace. According to the geometric mean of lead concentration in the air, the factories were grouped into three categories: A; When it is below $0.05mg/m^3$, B; When it is between 0.05 and $0.10mg/m^3$, and C; When it is above $0.10mg/m^3$. The results obtained were as follows: 1. The means of blood lead concentration (PBB), ZPP concentration and hemoglobin(HB) in all male workers exposed to lead less than 1 year in storage battery industries were $29.5{\pm}12.4{\mu}g/100ml,\;52.9{\pm}30.0{\mu}g/100ml\;and\;15.2{\pm}1.1\;gm/100ml$. 2. The means of blood lead concentration (PBB), ZPP concentration and hemoglobin(HB) in control group were $5.8{\pm}1.6{\mu}g/100ml,\;30.8{\pm}12.7{\mu}g/100ml\;and\;15.7{\pm}1.6{\mu}g/100ml$, being much lower than that of study group exposed to lead. 3. The means of blood lead concentration and ZPP concentration among group A were $21.9{\pm}7.6{\mu}g/100,\;41.4{\pm}12.6{\mu}g/100ml$ ; those of group B were $29.8{\pm}11.6{\mu}g/100,\;52.6{\pm}27.9{\mu}g/100ml$ ; those of group C were $37.2{\pm}13.5{\mu}g/100,\;66.3{\pm}40.7{\mu}g/100ml$. Significant differences were found among three factory group(P<0.01) that was classified by the geometric mean of lead concentration in the air, group A being the lowest. 4. The mean of blood lead concentration of workers who have different work duration (month) was as follows ; When the work duration was $1\sim2$ month, it was $24.1{\pm}12.4{\mu}g/100ml$, ; When the work duration was $3\sim4$ month, it was $29.2{\pm}13.4{\mu}g/100ml$ ; and it was $28.9\sim34.5{\mu}g/100ml$ for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 5. The mean of ZPP concentration of workers who have different work duration (month) was as follows ; When the work duration was $1\sim2$ month, it was $40.6{\pm}18.0{\mu}g/100ml$, ; When the work duration was $3\sim4$ month, it was $53.4{\pm}38.4{\mu}g/100ml$ ; and it was $51.5\sim60.4{\mu}g/100ml$ for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 6. Among total workers(433 person), 18.2% had PBB concentration higher than $40{\mu}g/100ml$ and 7.1% had ZPP concentration higher than $100{\mu}g/100ml$ ; In workers of factory group A, those were 0.9% and 0.0% ; In workers of factory group B, those were 17.1% and 6.9% ; In workers of factory group C, those were 39.4% and 15.4%. 7. The proportions of total workers(433 person) with blood lead concentration lower than $25{\mu}g/100ml$ and ZPP concentration lower than $50{\mu}g/100ml$ were 39.7% and 61.9%, respectively ; In workers of factory group A, those were 65.5% and 82.3% : In workers of factory group B, those were 36.1% and 60.2% ; In workers of factory group C, those were 19.2% and 43.3%. 8. Blood lead concentration (r=0.177, P<0.01), ZPP concentration (r=0.135, P<0.01), log ZPP (r=0.170, P<0.01) and hemoglobin (r=0.096, P<0.05) showed statistically significant correlation with work duration (month). ZPP concentration (r=0.612, P<0.01) and log ZPP (r=0.614, P<0.01) showed statistically significant correlation with blood lead concentration 9. The slopes of simple linear regression between work duration(month, independent variable) and blood lead concentration (dependent variable) in workplace with low air concentration of lead was less steeper than that of poor working condition with high geometric mean air concentration of lead. The study result indicates that new employees should be provided with biological monitoring including blood lead concentration test and education about personal hygiene and work place management within $3\sim4$ month.

• Journal of Preventive Medicine and Public Health
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• 제43권3호
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• pp.265-273
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• 2010

Objectives: Due to the economic crisis and globalization, many workers have been suffering from severe occupational stress due to job insecurity and struggles related to downsizing and restructuring. This study aims to assess the stress levels among workers involved in fierce labor disputes and massive layoffs and to evaluate their specific needs and satisfaction with counseling services set up to help workers cope with severely stressful situations? Methods: The authors provided crisis intervention to workers in traumatic situations to compare the differential level of stress responses and needs among the workers remaining employed in a large auto factory, those laid off by it, and those laid off by other companies in the same region (Pyeongtaek, Gyeonggi Province). We measured stress levels using the worker's stress response inventory (WSRI) and heart rate variability (HRV), and assessed workers' satisfaction with the counseling services. Results: 502 workers participated in the program. Fifty-seven percent of them consulted with occupational problems. The mean WSRI score of the workers remaining employed in the automobile factory was higher than that of the unemployed (employed: $39.8{\pm}19.9$ unemployed: $29.3{\pm}18.8$). Ninety-five percent of workers responded that they were satisfied or very satisfied with the counseling services. Conclusions: This study suggests the urgent need for the establishment of a national crisis intervention program dedicated to supporting workers in severely stressful situations.

• 한국게임학회 논문지
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• 제20권3호
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• pp.85-94
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• 2020

작업자-로봇 간 협업은 다품종 소량생산 기반의 스마트팩토리에서 중요한 요소가 된다. 기존 제조 공장을 스마트화하기 위해 AI 기반의 기술이 도입되고 있지만 이 경우 단기적 생산성 향상에 그친다. 이를 해결하기 위한 협업 지성은 인간의 팀워크, 창의력 등과 AI의 속도, 정확성 등이 결합되어 서로의 단점을 적극적으로 보완 할 수 있다. 그러나 현재 자동화설비는 돌발사태 발생 시 재해강도가 높기 때문에 안전대책이 요구된다. 따라서 본 논문에서는 깊이 영상 카메라를 이용하여 작업자 및 설비를 가상 세계에 구현하고, 시뮬레이션을 통해 작업자의 안전을 판별하는 공장 안전 제어 시스템을 설계하고 구현한다.

• 대한안전경영과학회지
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• 제23권4호
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• pp.1-9
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• 2021

This study examines the trends of domestic and foreign smart industries and discusses safety and security issues. Based on the actual situation survey and interview of the smart factory, we would like to examine the perspectives on risks and threats. We will examine safety and health issues related to new harmful and risk factors that may occur in smart factories and suggest institutional development directions for future safety and health. First, a safety and health-related work environment for smart factory workers is investigated and interviews are conducted. Second, we investigate new risk factors and threats to prevent industrial accidents for workers in smart factories. The purpose of this study is to examine what are the new risk factors in the smart factory. In addition, we will try to find reasonable improvement measures by finding out the risks and threats of smart factories through case studies in advanced countries, on-site interviews and surveys.

• Journal of Preventive Medicine and Public Health
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• 제29권3호
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• pp.617-637
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• 1996

Occupational dermatosis is one of the most prevalent occupational disorders. However, the extent of the occupational dermatoses including incidences and prevalencies of each disease entity, and etiologic materials are not yet welt stated in Korea. Authors reviewed the literatures on the statistic data and reports on the occupational dermatoses, and surveyed on the occupational dermatoses in two factories, and surveyed the physicians responsible to the occupational dermatoses with formed questionnaire. The results are as follows; 1. Among medical journals published since 1964, there were 31 articles on the occupational dermatoses. Of 31 articles, 18 were case reports and all others were review articles. Of 18 case reports, 9 were epidemiologic survey. The Workers' Periodic Health Examinations revealed that prevalence of the occupational dermatoses was highest(4.36 per 10,000 workers) in 1974, but number of the cases reported were decreased sharply since 1978 with some tendency to increase since 1981. There were 2,240 reported cases of occupational dermatoses between 1966 and 1992, which is 1.90% of all the reported occupational diseases. Skin infection and injuries due to chemicals were most frequent and there were 6 cases of skin cancer. 2. In an epidemiological survey on the dermatoses among 995 workers in a metal product manufacturing factory and 225 workers in a coal chemical factory, there were 794 with dermatomycosis, 296 workers with acne, 130 workers with scar, 123 workers with deformity of toe nails. Scars, photosensitivity dermatitis, deformity of finger and toe nails, and acne were more prevalent in the metal product manufacturing factory(p<0.05). In the metal prouct manufacturing factory, workers treating organic solvents and oils had more dermatoses than those without treating the materials(p<0.05). On the skin patch performed on 16 workers in the metal product manufacturing factory, there were 8 cases of irritation dermatitis and 5 cases of contact dermatitis. Prevalence of contact dermatitis in the metal product manufacturing factory was 1.3%. 3. On the questionnaire survey, 34 dermatologists, 29 doctors of preventive medicine, and 22 family physician replied. The proportion of occupational etiology among all dermatoses assumed by the physicians were below 9%, and the most important occupational dermatosis in Korea was contact dermatitis. Main etiologic materials related to the occupational dermatosis were organic solvent, acid and alkali, and metals. The reason for the scarcity of report of occupational dermatoses were difficulty in diagnosis and physician's ignorance of the occupational etiology. They replied that to prevent the occupational dermatoses in the workplace, the use of protective devices was most important, and development of diagnostic criteria on the occupational dermatoses is urgent. Above results shows us that there is many workers with occupational dermatoses, but they are mostly unreported. Measures to prevent and manage the occupational dermatoses are not satisfactory at present. Hence, authors suggest measures for the precise diagnosis, report and prevention of the occupational dermatoses. a. Dermatologist, preventive physician, and industrial hygienist should work as a team to examine the high risk group and establish the preventive measures. b. Disease entities, diagnostic criteria of occupational dermatoses should be listed, criteria for the compensation and job fitting at recruitment should be established, and manual for the proper treatment and effective prevention of each occupational dermatosis should be developed. c. Patch test antigens against each occupational category should be developed and it should be available to any physicians responsible. d. To facilitate the diagnosis of occupational dermatoses by the doctors responsible for the Workersr Periodic Health Examination, development of standardized questionnaire, education on the techniques of the patch test, and cooperation with the dermatologist in diagnosis of occupational dermatoses is essential.

• Journal of Preventive Medicine and Public Health
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• 제37권2호
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• pp.182-189
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• 2004

Objectives : The objective of this study is to compare the circadian patterns of heart rate variability assessed by 24-hour ambulatory electrocardiographic (ECG) recordings during day shift and night shift among the workers in the 5 days-concecutive-12-hour shift in an automobile factory in Korea. Methods : The study population consisted 300 workers, who were randomly selected among the 8700 total workers in one car factory. To analyse circadian variation, the 24-hour ECG recordings (Marquette) were measured during day shift (08:00-20:00 h) and night shift (20:00-08:00 h). Analysis was performed for all time and frequency domain measures of HRV. 233 workers completed taking 24-hour ECG recordings. Results : This study shows that the 24 hourcircadian variation mainly follows work/sleep cycle rather than day/night cycle among shift workers. This study also shows that among the night shift, the circadian variation between work and sleep cycle decreased compared to the work/sleep cycle among day shift workers. All time and frequency domain parameters (except LF/HF ratio) show significantly different between work and sleep in the day shift and night shift. Conclusion : These changes in heart rate variability circadian rhythms reflect significant reductions in cardiac parasympathetic activity with the most marked reduction in normal vagal activity among the shift workers. Especially, it suggests the circadian rhytm has blunted among the night workers. The quantification of the circadian variation in HRV can be a surrogates of workers' potential health risk, as well as suggests possible mechanisms through which the shift works compromise workers' health.

• Journal of Preventive Medicine and Public Health
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• 제25권1호
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• pp.26-33
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• 1992

반복작업에 종사하는 모 사업장 포장부서 근로자 42명을 대상으로 수근터널증후군에 대한 중상, 이학적 검사 및 근전도 검사를 1991년 11월부터 1992년 3월까지 실시하였다. 양손 모두에서 근전도상 이상소견을 보인 경우가 4명, 오른쪽 손에만 이상소견을 보인 경우가 4명 그리고 왼손이 1명 등 총 9명으로서 21.4%의 높은 유병률을 나타내었다. 임상중상은 전체 42명중 66.7%에 해당되는 28명에서 나타났다. Tinel과 Phalen sign 등 이학적 검사에서 이상소견을 보인 경우는 14명으로 전체의 33.3%를 차지하였다. 그리고 키와 임신 횟수를 제외한 수근터널증후군에 대한 다른 일반적 위험요인은 환자군과 비환자군에서 유의한 차이는 없었다. 근전도 검사를 기준으로 하였을 때 임상증상에 대한 민감도는 0.89, 특이도는 0.39이었고 Tinel sign에서는 각각 0.33, 0.88 그리고 Phalen sign에서는 0.56, 0.82 등이었다. 임상증상이 있고 Tinel과 Phalen sign에서 어느 하나 양성으로 나타나는 것을 선별기준으로 하였을 경우의 민감도와 특이도는 0.57, 0.76이었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.705-706
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• 2008

When heat generated inside a large factory building is not discharged due to a stagnant flow, the working environment of workers becomes worse and the cooling of high-temperature products such as hot-rolling coils is delayed. To investigate the natural ventilation inside a large factory building, experimental studies were carried out using wind-tunnel tests. The scale-down factory building models were placed in an atmospheric boundary layer (ABL) and the mean and fluctuating velocity fields were measured using a particle image velocimetry (PIV) technique. For the prototype factory model, the outdoor air is only entrained into the factory building through the one-third open windward wall, and stagnant flow is formed in the rear part of the target area. In order to improve the indoor ventilation environment of the factory building, three different louver-type ventilators were attached at the upper one-third open windward wall of the factory model. Among the three louver ventilators tested in this study, the ventilator model #3 with the outer louver (${\theta}_o$ = 90$^{\circ}$) and the inner louver (${\theta}_i$ = -70$^{\circ}$) was found to improve the natural ventilation inside the factory building model effectively. The flow rate of the entrained air was increased with aligning the outer louver blades with the oncoming wind and guiding the entrained air down to the ground surface with elongated inner louver blades.

• 한국인터넷방송통신학회논문지
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• 제18권1호
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• pp.23-28
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• 2018

본 연구에서는 팩토리 작업장에 설치된 여러 종류의 멀티터치 기술 기반 센서로부터 수집된 이벤트와 데이터를 제공함으로써 작업장의 상태 감시와 이벤트 관리를 용이하게 할 수 있는 플랫폼을 개발하였다. 영상인식 기술을 활용하여 팩토리 작업장 내 사람들의 얼굴을 인식하여 작업자별 맞춤형 콘텐츠를 제공하며, 얼굴인식을 통한 개별 작업자 인증으로 콘텐츠 보안을 강화하도록 하였다. 제스처 인식을 통한 콘텐츠 제어 기능을 구축하여 작업자가 간단하게 문서를 검색할 수 있도록 하였고, 모바일 장치에서도 얼굴인식 기능을 구현하여 작업자를 위한 콘텐츠 제공이 가능하게 하였다. 본 연구의 결과를 작업장 안전, 콘텐츠 보안, 작업자 편의 등을 향상시키는데 이용할 수 있으며 향후 스마트 팩토리 구축을 위한 기반기술로 활용할 수 있다.

• Journal of Preventive Medicine and Public Health
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• 제28권1호
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• pp.1-12
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• 1995

Diatomaceous earth, quarried from the remains of aquatic plants deposited millions of years ago, continues to be a very important raw material with many industrial uses. In its natural state, diatomaceous earth is an amorphous silica with no crystalline pattern. For many uses, however, it is calcinated and calcination converts a portion of the amorphous silica to a crystalline form, cristobalite which is far more fibrogenic. In a factory which produces calcinated diatomaceous earth, seven workers were proved as pneumoconiosis on 1991 and 1992. Authors reviewed medical chart and current status of them. Authors also examined thirty one subjects from the factory with questionnaire, physical examination, spirometry and chest radiography on August 13th 1993. The radiographs were independently interpreted by two radiologists and their findings were classified by International Classification of Radiography of Pneumoconiosis(ILO, 1980). Total and respirable dust of diatomaceous earth were measured on October 1993. The results were as follows; 1. Of 31 workers, 6 (19.4%) were diagnosed as diatomaceous earth pneumoconiosis. There was an increasing tendency in prevalence of pneumoconiosis as the duration of dust exposure gets longer. 2. There were no significant differences in age, smoking rate, alcohol drinking rate, and pulmonary function test results between cases and non-cases. 3. The means of total dust exposures at flour manufacturing, fire brick grinding and packaging, ceramic raws packaging processes exceeded Korean and ACGIH standards, $10mg/m^3$. Above results suggest that engineering controls, periodic environmental and medical surveillance are important for preventing pneumoconiosis in the diatomite factory.