• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.117-122
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• 2022

This paper proposes a method for evaluating the work of manufacturing workers using MediaPipe as a risk factor for musculoskeletal diseases. Recently, musculoskeletal disorders (MSDs) caused by repeated working attitudes in industrial sites have emerged as one of the biggest problems in the industrial health field while increasing public interest. The Korea Occupational Safety and Health Agency presents tools such as NIOSH Lifting Equations (NIOSH), OWAS (Ovako Working-posture Analysis System), Rapid Upper Limb Assessment (RULA), and Rapid Entertainment Assessment (REBA) as ways to quantitatively calculate the risk of musculoskeletal diseases that can occur due to workers' repeated working attitudes. To compensate for these shortcomings, the system proposed in this study obtains the position of the joint by estimating the posture of the worker using the posture estimation learning model of MediaPipe. The position of the joint is calculated using inverse kinetics to obtain an angle and substitute it into the REBA equation to calculate the load level of the working posture. The calculated result was compared to the expert's image-based REBA evaluation result, and if there was a result with a large error, feedback was conducted with the expert again.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.1-7
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• 2024

Objectives: The study was performed to investigate characteristics of hazardous factors regarding chemical(liquid lime) tank dredging workers by case survey. Methods: Field data such as working condition, MSDS and respirators applied to chemical tank dredging work were analyzed and the work environmental factors of noise and indoor air quality were measured to compare existing data with actual work situations. Results: No health hazards to workers due to working conditions were confirmed during dredging work inside the chemical storage tank. All air quality measurement data during dredging work satisfied the management standards, and there were no by-products. During dredging work, there was a significant change in noise depending on the type of work, but considering the noise reduction rate(NRR) of the earplugs worn by workers, there was no actual health hazard due to noise exposure. Conclusions: A fit test for respirator and the expiration date of the safety helmet should be observed to ensure an appropriate level of safety and health for dredging workers in the chemical storage tank.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.95-104
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• 2024

Nanoparticles are commonly used to avoid the opaque white color of TiO₂ based sunscreen. However, a dispersing agent is typically required because of the tendency of the nanoparticles (NPs) to agglomerate. Stearic acid is one kind of dispersing agent often used for sunscreen products. However, according to the MSDS data sheet on stearic acid, stearic acid is highly hazardous to aquatic life and causes irritation on human skin. To avoid this problem, in this study a safer organic dispersing agent extracted from Korean seaweed has been studied to disperse TiO₂ nanoparticles, and further use as an active agent in sunscreen products. The presence of phytochemicals in seaweed extract, especially alginate, can disperse TiO₂ nanoparticles and improve TiO₂ dispersion properties. Results show that seaweed extract can improve the dispersion properties of TiO₂ nanoparticles and sunscreen products. Reducing the agglomeration of TiO₂ nanoparticles improves sunscreen properties, by making it less opaque white in color, and increasing UV protection value. It was also confirmed that adding seaweed extract into sunscreen products had no irritating effects on the human skin, making it more desirable for cosmetics application.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.179-207
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• 2000

Hazardous organic solvents management as prescribed by presidential decree in Korea is reviewed. The status of import, manufacture, and circulation of organic solvents was investigated. Problems inherent in the management of organic solvents in the electroplating, metal degreasing, and dry cleaning industries were discussed. The chemical substance management system in Korea was compared to those of foreign organizations. A walk-through check list was developed and then used to assess the actual conditions and potential hazards of chemical substances in these industries. The questionnaire could be used to develop a chemical management system and protect workers from hazardous substances. Based on the results of the site survey, MSDSs were not integrated appropriately into the workers education and were not readily accessible to employees. In the case of the dry cleaning industry, the new dry cleaning solvent used as a substitute includes a lot of potentially hazardous organic solvents. This research is preliminary. It is recommended that a national survey be performed to better identify the current situation. Because chemical substances are regulated by thirteen laws in seven executive branches, management systems often overlap, resulting in ineffective control. Using the above results, a model for managing chemical substances was developed. This will more efficiently provide MSDS information to workers covered by the presidential decree and allow the construction of a management system database for better cooperation with the executive branches in Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.307-314
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• 2013

Objectives: The aim of this study was to determine the prevalence of symptoms relating to musculoskeletal disorders (MSDs) and investigate the risk factors among researchers at university laboratories. Methods: 209 researchers were included in this study, drawn from 27 laboratories at three universities in Korea. Checklists for MSD symptoms and risk factor assessment were utilized. Results: The symptoms checklist showed reliable results with Cohen's Kappa 0.33-0.56, percent agreement 81.0-96.8%, and correlation coefficient 0.41-0.63. The overall prevalence of MSD symptoms was 68.9%, while the prevalence in specific parts of body were as follows: shoulders (47.6%), lower back (46.9%), neck (46.9%), knees (25.4%), wrists (20.1%), elbows (13.6%). The symptom prevalence among women was higher than among men (OR 2.67, 95% CI 1.37-5.18). Daily exposure time was observed to be a significant risk factor for developing MSD symptoms (OR 2.14-6.07). Conclusions: This study suggested that repetitive pipetting and static work posture are the most significant risk factors for MSD symptoms among laboratory researchers.

• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.671-685
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• 2012

Objective: This study aims to investigate subjects in recuperation to identify the following factors with regard to work-related musculoskeletal diseases: diagnosis in the context of occupational and environmental medicine; assessment systems for judging work-relatedness; recuperation management; workplace management; prevention programs; and care after returning to work. This study intends to analyze differences between subjects and determine what characteristics of subjects account for the differences. Method: A survey was administered to 1,664 workers who were approved by the Korea Worker's Compensation & Welfare Service between 2003 and 2005 for recuperation due to work-related musculoskeletal diseases. The data of 229 subjects who responded the survey questionnaire related to recuperation were analysed. Results: According to the results, demographic, occupational, and musculoskeletal disease-related factors were significant. The demographic factors included gender, age, marital status, and region, while occupational factors included working period, work type, size of workplace, and industry type. The factors related to musculoskeletal diseases were the part of the body in pain, the tissues in pain, and the existence of dysfunction. The above factors were associated with statistically significant differences in the following areas: revealed symptom period, symptoms-diagnosis period, and application for recuperation approval periods; diagnosis and care institutes for recuperarion; the state of patients (body parts in pain, tissues in pain, and existence of dysfunction); return to work; and care after returning to work. Conclusion: The results of this study can serve as basic data in setting priorities for prevention programs for work-related musculoskeletal diseases and selecting target groups.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.281-289
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• 2012

Objective: The purpose of this study is to evaluate the potential risk of shoulder muscle at particular working postures in sitting. Background: The cause of shoulder pain needs to be specifically studied in relation with particular shoulder postures to prevent shoulder MSDs in workplace. Method: In this study MVC, fatigue and subjective workload were investigated depending on the change of shoulder posture. An experiment was designed to evaluate the six shoulder muscles at nine shoulder postures including the combination of 30(adduction), 0, 30(abduction) degrees and 60, 90, and 120 degrees of shoulder flexion. Surface electrodes were attached to the middle trapezius, inferior middle trapezius, anterior deltoid, posterior deltoid, serratus anterior and teres major. Thirteen subjects participated in the experiment. Dependent variables were RPE (rating of perceived exertion), MVC(maximum voluntary contraction) and MPF(mean power frequency) shift by EMG (electromyography). Results: The middle trapezius and inferior middle trapezius were not significantly fatigued at all postures. The decline of MPF slope was less than 10% at all postures. The anterior deltoid was significantly fatigued all postures. The decline of MPF slope was more than 10% at all postures. The posterior deltoid was significantly fatigued 30 degrees of adduction and 90 degrees of flexion. And, neutral and 30 degrees of abduction postures were fatigued more than 90 degrees of flexion. The serratus anterior was significantly fatigued except for 30 degrees of adduction and 60 degrees of flexion posture. The teres major was significantly fatigued except for neutral and 60 degrees of flexion, 30 degrees of abduction and 60 degrees of flexion posture. Conclusion: It was found that a certain muscle was fatigued fast at particular posture compared to other muscles, which would mean that a certain shoulder muscle at particular posture could be easily exposed to the risk of musculoskeletal disorders than other muscles. Application: It is expected that the result can be applied to design workplace using shoulder muscles.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.618-622
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• 2017

Gasoline is a widely used product as a source for energy in homes, the automotive industry, and for industrial power generation, and it is also a product with a high risk of fire and explosion. In this study, to examine the risk for explosion for gasoline, PG, MG and RG, which are categorized according to octane number, were used as test specimens to measure their explosion limit according changes in oxygen concentration. The explosion limit for 21% oxygen concentration in air were confirmed to be 1.5~10.9%, 1.4~8.1%, and 1.3~7.6%, respectively, and the MOC for each of the test sample were confirmed to be 10.9%. The explosion limit measured in the test performed in this study confirmed between a 1.2%~7.6% wider explosion limit for the currently accepted MSDS for gasoline, and therefore it is considered that the results of this study can provide significant reference for preventing fires and explosions for process used gasoline.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.446-464
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• 2015

Objectives: This study was conducted to evaluate the task-specific hazards of chemicals used by nail technicians in Daegu Metropolitan City. Materials: A total of 30 nail shops located in Daegu City were surveyed to investigate the major tasks and practices performed by nail technicians and the ingredients listed in nail care products used in shops. We also collected instructions for use and material safety data sheets(MSDSs) of nail care products and compared CAS Nos. of ingredients with the lists of chemicals regulated by the Industrial Safety and Health Act(ISHA) and Chemical Substances Control Act(CSCA). Results: A total of 125 chemical ingredients were found in 468 nail care products used at the 30 nail shops. The most frequently found ingredients were ethyl acetate(72%), followed by n-butyl acetate(71.8%), isopropanol(56%), benzophenone(51.1%), nitrocellulose(46.4%) and ethanol(45.3%). Comparing six tasks, the task of manicuring used the most products at 222 products containing 91 ingredients. Among the 125 ingredients, there are 31 chemicals with occupational exposure limits(OEL) designated by the Ministry of Employment and Labor(MoEL), eight categorized as carcinogens, one mutagen and two reproductive toxic chemicals. In terms of carcinogens, formaldehyde was identified as the only confirmed human carcinogen(1A). We found that there was one chemical with a permissible limit, one special management substance, 18 workplace monitoring substances and ten special health diagnosis substances regulated by ISHA. For CSCA, nine poisonous substances, six substances requiring preparation for accidents and one restricted substance were identified. Conclusions: Based on these findings, formaldehyde was identified as one of the chemicals that should most strictly be controlled for the protection of the health of nail technicians and customers. At the same time, it is necessary to distribute materials with detailed hazardous information of nail care products for nail shop technicians.