• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.345-352
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• 2014

Objectives: This study is aimed to describe the current situation about urinary biomarker N-methylformamide(NMF) for workers exposed to N,N-dimethylformamide(DMF) according to industrial classification. Materials: Special health examination records of the workers who had undergone urinary biological monitoring in 2013 were collected. The numbers and percentage of workers, whose urinary NMF values were above the limit of detection(LOD) and above the biological exposure index(BEI) were calculated. Health relatedness with DMF as judged by their doctors was also described. All description was classified according to the $9^{th}$ Korean Standard Industrial Classification(KSIC). Results: It appeared that most workers exposed to DMF belong to manufacturing section(80.7%). The geometric mean(GM) values of urinary NMF were 6.25 mg/L, 3.54, and 3.86 for the manufacturing section, professional, scientific and technical activities section, and for the construction section respectively. In detail, it seemed that division of textiles(except apparel) (GM 7.51 mg/L), division of leather, luggage and footwear(11.59 mg/L), and division of rubber and plastic products(6.89 mg/L) were highly exposed to DMF with a high percentage of workers with urinary NMF values above BEI. This was probably due to the effect of skin absorption that the division of leather, luggage and footwear showed the highest urine NMF GM. Conclusions: It seemed that workers in manufacture industries such as textile, leather, luggage, footwear, rubber and plastic products were highly exposed to DMF. So, efforts should be focused on those industries in order to effectively diminish worker's exposure. Further studies to compare DMF air-monitoring with bio-monitoring according to industrial classification should be considered.

• Journal of Labour Economics
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• v.44 no.2
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• pp.33-69
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• 2021

This study estimates the employment relationship of domestic and foreign workers by establishing 16 municipal and provincial panel data for the period 2010-2018. It attempts to analyze industry-specific (manufacturing and construction), scale-specific (5-29, 5-29, 5-299 and 5 above) and uses the foreign worker's national share (foreigner's concentration index) as an instrumental variable to control the endogeneity of foreign workers. Finally, it compares the results of panel GLS, which does not consider the endogeneity of foreign workers, with the results using instrumental variable method that considers it. As a result of the analysis, the complementary relationship between domestic and foreign workers was confirmed in the panel GLS analysis. However, although the employment relationship between domestic and foreign workers was not statistically significant in the instrumental variable method, the analysis of the combination of manufacturing and construction industry showed a statistically significant substitute relationship. This study is highly regarded for the first time in Korea that an instrumental variable method was created to identify and control the endogeneity of foreign workers in estimating employment relationships between domestic and foreign workers.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.451-470
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• 2023

Purpose: Since COVID-19 was first discovered in China in December 2019, it has rapidly spread around the world, causing serious economic and social problems not only in individuals' lives, but also in businesses and countries. Individuals, businesses, and governments have all made various efforts to prevent the spread of COVID-19. Although the roles of individuals, companies, and the government are important to respond to and manage infectious diseases, previous studies have only partially studied the roles. Therefore, in this study, the roles of individuals, companies, and the government to achieve results in responding to infectious diseases disaster management A comprehensive study was conducted on this issue, and it was attempted to understand the impact of workers' perceptions of infectious disease disaster management and government and corporate capabil]ities on disaster response performance. Method: The survey was conducted for workers in the automobile manufacturing industry in Ulsan, Gyeongju, and Yangsan, and frequency analysis, factor analysis, correlation analysis, and regression analysis were performed. Result: It was found that worker perception had a positive effect on both government and corporate capabilities as well as disaster management performance. In addition, government capacity and corporate capacity had a positive effect on disaster management performance. Conclusion: The results of this study are meaningful in that they reveal that not only workers' perceptions but also the capabilities of the government and companies are important to achieve disaster response performance. In addition, workers should make good use of opportunities for education and participation provided by the government and corporations, and make the most social efforts that workers can make.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.93-108
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• 2023

In manufacturing productivity analysis, understanding the intricate interplay among factors like facility performance, layout design, and workforce allocation within the production line is imperative. This paper introduces a simulation-based methodology tailored to food manufacturing, progressively expanding scenarios to analyze production enhancement. The target system is a food processing plant, encompassing production processes, including warehousing, processing, subdivision, packaging, inspection, loading, and storage. First, we analyze the target system and design a simulation model according to the actual layout arrangement of equipment and workers. Then, we validate the developed model reflecting the real data obtained from the target system, such as the workers' working time and the equipment's processing time. The proposed model aims to identify optimal factor values for productivity gains through incremental scenario comparisons. To this end, three stages of simulation experiments were conducted by extending the equipment and worker models of the subdivision and packaging processes. The simulation experiments have shown that productivity depends on the placement of skilled workers and the performance of the packaging machine. The proposed method in this study will offer combinations of factors for the specific production requirements and support optimal decision-making in the real-world field.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.230-238
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• 2023

Small and medium-sized food manufacturing enterprises are largely reliant on manual labor, from inputting raw materials to palletizing the final product. Recently, there has been a trend toward smartness and digitization through the implementation of robotics and sensor data technology. In this study, we examined the effectiveness of improvement through 3D simulation on two repetitive work processes within a food manufacturing company. These processes involve workers whose speed cannot match the capacity of the applied equipment. Two manual processes were selected: the weighing and packing process performed by workers after skewer assembly, and the manual batch process of counting randomly delivered frozen foods, packing (both internal and external), and palletizing. The production volume, utilization rate, and number of workers were chosen as verification indicators. As a result of the simulation for improving the 3D process, production increased by 13.5% and 56.8% compared to the existing process, respectively. This was particularly evident in the process of applying palletizing robots. In both processes, as the utilization rate and number of input workers decreased, robots could replace tasks with high worker fatigue, thereby reducing work overload. This study demonstrates the potential to visually compare the process flow improvement using 3D simulations and confirms the possibility of pre-validation for improvement.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.85-97
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• 2024

Objectives: This study was intended to investigate the revision status of the occupational exposure standards for aluminum at home and abroad; to investigate worker exposure at domestic aluminum manufacturing and handling workplaces; to conduct social and economic evaluation for the revision of domestic aluminum exposure limits. Methods: We investigated the current status of occupational exposure limits for aluminum at home and abroad, and analyzed supporting data. An exposure survey was conducted targeting domestic aluminum manufacturing and handling workplaces. Based on these, revised aluminum occupational exposure limits were proposed. Results: The major aluminum exposure limits at home and abroad show a notable difference. The toxicity of aluminum, which was revealed through animal experiments and epidemiological investigations. The average concentration of aluminum in the air at 12 workplaces was 0.016 mg/m³, and the maximum was 0.0776 mg/m³. When total dust and respiratory dust were measured side by side and simultaneously for the same process, 12.1% of the total mass concentration of aluminum dust was respiratory dust. As a result of measuring and comparing the size distribution of dust with an optical particle counter in real time, 48.1% of the total dust in the form of welding fume and pyro-powder was respiratory dust. Based on the literature review and workplace survey, three proposals for changing the aluminum exposure limit were proposed. Proposal (1): For all types, 10 mg/m³ is unified as the exposure limit except for soluble salts and alkyls. Proposal (2): 1(R) mg/m³ as the exposure limit for all forms except soluble salts and alkyl. Proposal (3): 1(R) mg/m³ for pyro-powder and welding fume, and 10 mg/m³ for metal dust, aluminum oxide, and insoluble compounds as exposure standards. A pyro-powder was defined as dry aluminum powder of 200 mesh size (74 ㎛) or smaller (larger size classified as metal dust). Reason for setting: In the workplace survey, the ratio of respiratory dust to total dust was analyzed to be about 1:10, so it was judged that the domestic standard and the ACGIH standard were compatible. Conclusions: In all scenarios according to the revision of the exposure standard, the B/C ratio was greater than 1 or only benefits existed, so it was evaluated as sufficiently reasonable as a result of the socio-economic evaluation.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.78-94
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• 1991

The purpose of this study is to research the actual conditions of industrial accident patients and to produce worker satisfaction and a rational and effective counter measure pain. Direct interviews with 179 cases (in and out patients) were carried out during a three month period from April to July 1990, at six hospitals two general hospitals Sun Lin and Sung Mo in Po Hang, and four general hospitals in Taegu Kyung Pook University Hospital, Dong San Medical Center, Young Nam Medical Center and Catholic Hospital. The results of this study are summarized as follows: 1. Among the 179 cases, 51.6 % were male and 48.4 % were female. The two largest age groups were 30~39, 31.8 % and 20~29, 27.4 %. Among the 179 cases, 51.6% were married, the largest family number was 2 to 3, 41.1% and 4 to 5, 25.6%. Educationally, graduation from high school was the largest group, 46.4% among the patients, followed by middle school and primary school. The largest group income level was from 40~69만원, 45.2%. The largest group of patients who worked over 50 hrs. a week was 52.0%. The largest group of patients who worked less than 1 year was 44.7%, of the patients in work places of less than 100 people, 60.3% were injured and in work places of 100~299 people, 20.1% were injured. In manufacturing, the lagest group injured was 55.3%, the next group was transport, stroage, communication. The largest group of production workers injured was 40.2%. 2. The cause of injury in the largest group was facility problems, 33.5%. The next group was unsafe habits, 30.2% a lack of safety knowledge, 17.9% and insufficient supervision, 12.3%. The 30~39 year age group was head the highest number of injuries, 40.4% work places with more than 10 yeras of work, 44.4% work palces with more than 1000 people, 56.3% and mining accidents, 80.0%. Among these groups the highest cause of injury was due to facility problems. 3. The accident pattern showed machinery injuries 28.5% as the largest group, followed by falls & falling objects 17.3%, fire & electric 15.1%, struke by an object 14.5%, followed by overaction and vehicular accidents. The accident pattern showed 46.4 % among workers over the 50 year age group, workers in the 5~10 year group, 50.0 % places employing more than 1000 workers, 35.3 % : construction 73.7%, and construction workers 57.1%, among these fall & falling objects caused the greatest number of injuries. 4. The largest group of injuries was fractures 54.8%, trauma 14.5%, amputation 11.7%, open wound, and burns. The largest number of fractures occurred in people in the 30~39 year age group, 63.2 % over 10 years of work, 55.6% in work places of 300~400 people, 63.6% construction 63.2% and general workers 57.2 %. 5. The largest group of injuries was upper extremity 45.3%, lower extremity 24.0%, trunk 18.5 % and head or neck 12.2%. Of these groups, upper extremity injuries were the highest in those less 20 years old 75.0%, less than 1 years of work 59.5%, in work places of 500~999 people 60.0%, manufacturing 56.6 % and production workers 55.6%. 6. Periods of injury showed 34 people injured in September, to be the largest followed by October, 32 August, 22 people July, 19 people and the lowest December, 2 people. During the week, Friday had the largest group injured, 35 people followed by Saturday, 26 people and the lowest was Wednesday, 17 people, During the day 1400 hours had the largest group injured, 38 people followed by 800 hours, 31 people. 7. On a basis of 5 as the highest mark, the average, according to worker satisfaction showed facility safety 3.55, work environment 3.47, income 3.44, job 3.21 and treatment 2.98. 8. The correlation between general characteristics and injury showed that age was directly correlated to the duration of work(r=.2591) p<0.01, age was directly correlated to industry (r=2311) p<0.01, and the duration was directly correlated to occupation(r =.4372) p<0.001.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.151-174
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• 1991

The purpose of this study is to research the actual conditions of industrial accident patients and to produce worker satisfaction and a rational and effective counter measure plan. Direct interviews with 179 cases (in and out patients) were carried out during a three month period from April to July 1990, at six hospitals : two general hospitals Sun Lin and Sung Mo in Po Hang, and four general hospitals in Taegu : Kyung pooh University Hospital, Dong San Medical Center, Young Nam Medical Center and Catholic Hospital. The results of this study are summarized as fellows : 1. Among the 179 cases, $51.6\%$ were male and $48.4\%$ were female. The two largest age groups were 30-39, $31.8\%$ and 20-29, $27.4\%$. Among the 179 cases, $51.6\%$ were married, the largest family number was 2 to 3, $41.1\%$ and 4 to 5, $25.6\%$. Educationally, graduation from high school was the largest group, $46.4\%$ among ,the patients, followed by middle school and primary school. The largest group income level was from 40-69 만원, $45.2\%$. The largest group of patients who worked over 50 hrs. a week was $52.0\%$. The largest group of patients who worked less than 1 year was $44.7\%$, of the patients in work places of less than 100 people, $60.3\%$ were injured and in work places of 100-299 people, $20.1\%$ were injured. In manufacturing, the largest group injured was $55.3\%$, the next group was transport, storage, communication. The largest group of production workers injured was $40.2\%$. 2. The cause of injury in the largest group was facility problems, $33.5\%$. The next group was unsafe habits, $30.2\%$ ; a lack of safety knowledge, $17.9\%$ ; and insufficient supervision, $12.3\%$. The 30-39 year age group head the highest number of injuries, $40.4\%$ ; work places with more than 10 years of work, $44.4\%$ ; work places with more than 1000 people, $56.3\%$ and mining accidents, $80.0\%$. Among. these groups the highest cause of injury was due to facility problems. 3. The accident pattern showed machinery injuries $28.5\%$ as the largest group, followed by falls & falling objects $17.3\%$, fire & electric $15.1\%$, strucke by an object $14.5\%$, followed by overaction and vehicular accidents. The accident pattern showed $46.4\%$ among workers over the 50 year age group, workers in the 5-10 year group, $50.0\%$ ; places employing more than 1000 workers, $35.3\%$ ; construction $73.7\%$, and construction workers $57.1\%$, among these fall & falling objects caused the greatest number of injuries. 4. The largest group of injuries was fractures $54.8\%$, trauma $14.5\%$, amputation $11.7\%$, open wound, and burns. The largest number of fractures occurred in people in the 30-39 year age group, $63.2\%$ : over 10 years of work, $55.0\%$ ; in work places of 300-490 people, $63.6\%$ ; construction $63.2\%$ and general workers $57.2\%$. 5. The largest group of injuries was upper extremity $45.3\%$, lower extremity $24.0\%$, trunk $18.5\%$ and head or neck $12.2\%$. Of these groups, upper extremity injuries were the highest in those less than 20 years old $75.0\%$, less than 1 year or work $59.5\%$, in work places of 500-999 people $60.0\%$, manufacturing $56.6\%$ and production workers $55.6\%$. 6. Periods of injury showed 34 people injured in September, to be the largest followed by October, 32 ; August, 22 people : July, 19 people and the lowest December, 2 people. During the week, Friday had the largest group injured, 35 people ; followed by Saturday, 26 people and the lowest was Wednesday, 17 people, During the day 1400 hours had the largest group injured, 38 people ; followed by 800 hours, 31 people. 7. On a basis of 5 as the highest mark, the average, according to worker satisfaction showed facility safety 3.55, work environment 3.47, income 3.44, job 3.21 and treatment 2.98. 8. The correlation between general characteristics and injury showed that age was directly correlated to the duration of work (r=2591) p<0.01, age was directly correlated to industry (r=2311) p<0.01, and the duration was directly correlated to occupation (r=4372) p<0.001.

• Korean Journal of Occupational Health Nursing
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• v.7 no.2
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• pp.164-176
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• 1998

This study deals with the current medical utilization for migrant workers and the characteristics of them. The purpose of this study is to provide the basic information to establish proper medical policy. For the study self-made questionnaire was used, which was answered by 453 migrant workers working in the area of manufacturing and non-technical work in 10 cities like Seoul, Inchon, Namyangju, Sungnam, Kwangju, Pyungchon, Kunpo, Kimpo, Masuk in Kyungki-do and Chunan in Chungchungnam-do. Besides, 303 medical records of those who had visited free medical check-up center were analyzed. The period of accumulating data is 6 months, from November 1st, 1996 to April 30th, 1997. The characteristics of migrant workers and current medical utilization are analyzed by percentage and the relation between characteristics and current medical utilization were analyzed using ${\chi}^2$-test, t-test, ANOVA. The finding of this study was as follows : 1) The number of nationality was 16. The first majority was Philippians as 32.0%. Among 16 nationalities Southeastern and Northern Asians were 48.9%, Southwestern Asian was 46.5%, the rest was 7.3%. Men were 81.0%, those who are aged from 26 to 30 were 39.0%, Graduatee from high school 92.7%, Christians 56.3%, unmarried 55.4% and salary from 600,000 Won to 800,000 Won 53.8% averaging monthly payment 669,810 Won. As for their residence, those who resided over 3 years were 31.9% and the illegal residence reached 77.4%. As for Korean language, those who speak in middle level were 5.6%. 2) As for kind of work and circumstances, manufacturing was 81.1%, 4 off-days per month 72.2% and 9-10 working hours per day 42.1%. As for accommodation, residence in fabric was 62.6% and one or two members as roommate 40.2%. 3) The characteristics of health behavior showed that 89.4% of migrant workers had 3 meals, 70.9% of them did not drink alcohol, 73.5% of them did not smoke. 4) As a characteristic of health status, 71.8% of them perceived of their health. 76.1% thought that they had no illness before coming Korea. Among them who recognized their illness, those who had problem in circulatory system was 35.3%, respiratory system ENT 19.1% and nervous system 19.1%.66.2% of those having illness had already had sickness when coming to Korea. 5) During last one month, 79.2% of them were known as ones having no illness. Among the sick, those who had problem in circulatory system was 31.6%, nervous system 23.7% and respiratory system 21.1%. 60.3% of the sick were not cured at that time. 6) Sorting the symptom of those who visited free medical check up, dental care was 24.2%, orthopedic 14.0% and digestive system 13.8%. Teethache was 34.4%, stomach problem 11.6%, upper respiratory inflammation 10.2% and back pain 5.9%. Averagely they visited free medical check up 1-2 times. According to symptom, epilepsy 25.5 times, heart and vascular disease 9 times, constipation 2.8%, neurosis 2.38 times and stomach problem 2.34 times. 7) The most frequently visited medical service by migrant workers was hospital. The most mentioned reason was good healing as 36.3%. The medical service satisfied migrant workers mostly was hospital as 64.3%. The reason of satisfaction was also good healing as 45.9%. 8) 77.2% of respondents did not spend money for medical check. Average monthly medical cost was 25,100 Won, 3.7% of income. Those who had no medical security was 73.4%. In their case, 67.7% got discount from hospital or support from working place and religious organization. 9) As for the difference of medical utilization according for the characteristics of migrant workers, legal workers and no-Korean speaker used hospital more frequently. 10) Those who were satisfied most of all with the service of hospital were female workers, hinduists and buddhists, legal workers or manufacture workers. 11) Christians, those who have 3 meals or recognize themselves as healthy ones mostly had no illness. As a result, the most of migrant workers in Korea are from Asia. They are good educated but are working in manufacturing and illegal. Their average income is under 700,000 Won which in not enough for medical cost. They have no medical security and medical fee is supported by religious organization or discounted. Considering these facts the medical policy by government is to be established.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.190-197
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• 2001

Noise-induced hearing loss(NIHL) was the highest rate (43.5%~58.5% from 1996 to 1998) of positive findings through specific medical program in Korea. There were much more NIHL at workers of automobile manufacturing factories than other manufacturing factories. The specific aim of the present study was to determine the noise exposure of automobile press lines, according to their job titles, press line types(auto, semiauto), dosimeter parameters setting. There were a total 11 press lines sampled at a automobile manufacturing company. Among those press lines, 10 press lines were autolines with acoustic enclosure, one semiauto press line was no aucostic enclosure Noise exposure data were sampled for an work shift using noise dosimeter, which recorded both time-weighted average(TWA) and 1-min average. The mean OSHA TWA(Korea TWA with threshold 90) was $80.7dB(A){\pm}4.7dB(A)$ for leader, $82.8dB(A{\pm}4.5dB(A)$ for pallette man, $76.7dB(A){\pm}4.3dB(A)$ for press operators, $76.6dB(A){\pm}5.6dB(A)$ for crane operators, $77.1dB(A){\pm}2.8dB(A)$ for forklift drivers, whereas the mean NIOSH TWA was $88.9dB(A){\pm}1.7dB(A)$ for leader, $89.6dB(A){\pm}2.1dB(A)$ for pallette man, $86.7dB(A){\pm}1.8dB(A)$ for press operators, $88.5dB(A){\pm}2.0dB(A)$ for crane operators, $87.7dB(A){\pm}1.0dB(A)$ for forklift drivers. While L10 for NIOSH TWA samples was 84.8 dB(A) ~ 87.3 dB(A), L10 for OSHA TWA samples was 69.5 dB(A) ~ 77.4 dB(A). L10 means that the TWA for 90% of the samples exceeded L10. Among OSHA TWA(Korea TWA with threshold 90) samples for pallette man, 7.7 % exceeded 90 dB(A), the OSHA permissible exposure level, but OSHA TWA samples for the other job titles didn't. Among NIOSH TWA samples, the samples over 85 dB(A), the NIOSH recommended exposure limit, was 100% (leaders), 83.3 %(operators), 97.4%(palletteman), 100%(forklift drivers), 91.7 %(crane operator). The results of One-way random effects analysis of variance models shows that the difference between job titles was significant by OSHA TWA(p<0.05), but not significant by NIOSH TWA(p>0.05). NIOSH TWA samples were significantly higher than OSHA TWA samples(P<0.05). Regression analysis was used to obtain relationships between OSHA TWA samples and NIOSH TWA samples. In this case the coefficient of determination = 0.90, which shows the high degree association between two methods. Regression equation, NIOSH TWA = 0.552 * OSHA TWA + 42.13 dB(A), shows that if OSHA TWA is known, NIOSH TWA can be predicted by the equation. The mean TWA difference between threshold 80 dBA and 90 dBA was significant(p<0.01). While the TWA noise exposures were 7.7% above the Korea(OSHA) PEL, they were more than 83.3% over NIOSH REL. Automobile workers were exposed to noise level that could be potentially damaging to their hearing. It found that there is approximately 25% excess risk of hearing loss even if a worker is protected to the PEL in according to NIOSH study.