• 한국산업보건학회지
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• 제3권2호
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• pp.152-165
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• 1993

This study was performed at eleven small-sized plating factories located in Seoul, Incheon, Ansan, and Taejeon from July 21 to October 6, 1992. The major objectives of this study were to evaluate worker exposure to hexavalent chromium and local exhaust ventilation (L.E.V.) systems at the chromium plating operations. The most suitable L.E.V. systems for chromium plating tanks were designed as examples for recommendation to the industry. The results are summarized as follows. The range of chromium plating operations investigated included decorative, hard, and black chromium plating on several kinds of parts. Most of plating tanks were not equipped with proper control methods against emission of hexavalent chromium mists and workers were not wearing appropriate personal protectives. The ariborne hexavalent chromium concentrations showed an approximate lognormal distribution. The geometric means of both personal and area samples were within the Korean and ACGIH standards, $50{\mu}g/m^3$. However, in comparison with the NIOSH criterion, $1{\mu}g/m^3$, the geometric means of personal samples at two factories and the geometric means of area samples at two factories exceeded it. The geometric means of personal and area samples of high exposure groups (above the NIOSH criterion) were 7 and 27 times higher than those of low exposure groups (below the NIOSH criterion), respectively. The L.E.V. systems of high exposure groups were improperly designed, and the factory with the highest exposure level had no L.E.V. systems at all on chemical etching process. Whereas at factories of low exposure groups, mist control methods such as mist suppressants, tank cover, and/or auxillary L.E.V. systems were added to L.E.V systems. The evaluation of L.E.V. systems showed that there was no chromium plating operation satisfying the ACGIH criteria for capture velocity, slot velocity, and exhaust rate simultaneously. To increase performance of L.E.V. systems, it must be designed to minimize the impact of boundary layer separation. Push-pull ventilation hood and downward plenum ventilation hood were suggested for the Korean industry.

• 지역사회간호학회지
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• 제15권2호
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• pp.289-297
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• 2004

Purpose: This study was conducted to determine factors affecting workers' physiological somatic complain using the Job Stress Model proposed by the National Institute for Occupational Safety and Health (NIOSH). Method: Data were collected from the 1st to the 30th of December 1999. The subjects were 2.123 workers employed at 155 work sites. Collected date were analyzed through SAS/PC program. Result: According to individual characteristics, younger and women groups showed significantly higher physiological somatic complaint than elder men groups. By work condition, groups with higher physiological somatic complaint included workers of irregular shift work. Dark lighting, improper temperature in winter, improper ventilation, inappropriate humidity, unpleasant work environment and crowded work place were significantly related with physiological somatic complaint. By work-related factor, physiological somatic complaint was high in those with higher variance in work load, quantitative work load, role conflict, job burden, role ambiguity and future ambiguity. On the other hand, physiological somatic complaint was low in those with little underutilization of ability. As for the relationships between physiological somatic complaint and non-work related factors, physiological somatic complaint was high in workers who had a side job, were bringing up infants alone, cleaned the house alone, cared for the elderly and disabled persons, were studying, were volunteering at another organization, and were spending 5-10 hours in religious activities per week. Physiological somatic complain was in significantly negative correlations with overall social support, supervisory support and family support, but in significantly positive correlations with co-worker support. Conclusion: The main predictors of physiological somatic complain were gender, shift work pattern, overtime work, ventilation, role ambiguity, role conflict, future ambiguity, job control, variance in work load, overall social support, worker with side job, worker who cleans the house alone, worker who is studying. These predictors explained 19.10% of the total variance of physiological somatic complain.

• 한국산업보건학회지
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• 제26권1호
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• pp.20-29
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• 2016

Objectives: The purpose of this study is to simplify and standardize analytical method of polar solvents(methanol, isopropanol, n-butanol, acetone, methylene chloride and MIBK) in the working environmental by GC. Because NIOSH methods are various and complicated. Methods: The method is using the same stationary phase(5% phenyl 95% dimethylpolysiloxane), absorbent(silica gel) and desorption solvent(DMSO) for above 6 solvents. For the 6 solvents desorption efficiency, calibration curve, and limit of detection were studied Results: As the results, 6 solvents{2 groups ; first group(methanol/isopropanol/butanol) and second group(acetone/methylene chloride/MIBK)} could be separated and quantified within 10 minutes. Desorption efficiency from silica gell of 6 solvents using dimethylsulfoxide(DMSO) was methanol 86.2%, isopropanol 103.2%, n-butanol 101.8%, acetone 98.2%, methylene chloride 103.9% and MIBK 106.2% in the range of 0.2, 0.5, 2.0 times of TWA, consequently, satisfied NIOSH estimation level(beyond 75%). Correlation coefficient(r)in the range of 0.2~2.0 times of TWA, was above 0.999 for 6 solvent. LOD(mg/DMSO ml) using calibration curve in the range of 0.2~2 times of TWA was methanol 0.11, isopropyl alcohol 0.20, n-butanol 0.03, acetone 0.50, methylene chloride 0.05, MIBK 0.04 respectably. Conclusions: This method can be used at the sampling and analytical method for polar solvents by GC. Also, will be able to be applied with NIOSH methods.

• 한국환경보건학회지
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• 제47권3호
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• pp.292-301
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• 2021

Objectives: Wearing medical masks has been recommended since the declaration of coronavirus disease-19 (COVID-19) as a pandemic disease. Certified medical masks are evaluated according to filtration efficiency and facial inhalation resistance. However, some people use non-certified common masks. This study aimed to evaluate various non-certified commercial masks based on the certification criteria for medical masks. Methods: Twenty mask products (three anti-droplet, three disposable dental, eight fashion, three cotton, and three children's masks) were selected. For performance evaluation, filtration efficiency and facial inhalation resistance tests were conducted. The evaluation method followed the certification method for KF-certified masks of the Ministry of Food and Drug Safety (MFDS) and the N95 respirator of the National Institute for Occupational Safety and Health (NIOSH). Results: None of the 20 masks met the KF94 certification standard set by the MFDS. Four and three masks respectively met the KF80 certification standard and the N95 standard of NIOSH. Filtration efficiency was significantly higher in three-layer masks than in single layer masks. Pleated-type masks had higher filtration efficiency than cone-type masks. There was no correlation between the structure of masks and facial inhalation resistance. Conclusion: While no masks complied with the KF94 certification standard, a few masks met the KF80 and the N95 certification standards of NIOSH. Although some people wear non-certified commercial masks, protection from aerosols is not guaranteed by such masks. Evaluation of the protection efficiency of non-certified mask against microbiological infection is needed for the prevention of infectious disease.

• 한국산업보건학회지
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• 제33권3호
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• pp.284-290
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• 2023

Objectives: Work environment assessments were conducted to investigate epidemiologically several cases of lung cancer and COPD (chronic obstructive pulmonary disease) among workers in domestic quarries. Methods: We visited three quarries in South Korea where an epidemiological investigation was requested and measured total dust, respirable dust, and crystalline silica on rock drilling workers (4 people) and rock chipping workers (13 people). Measurement and analysis were conducted according to NIOSH (National Institute for Occupational Safety & Health) method 0500, NIOSH method 0600 for respirable dust, and NIOSH method 7500 for crystalline silica. Results: Among rock drilling workers the AMs (arithmetic mean) of total dust concentrations, respirable dust concentrations, and crystalline silica concentrations were 3.462 mg/m³ (range: 0.764~6.085 mg/m³), 0.613 mg/m³ (range: 0.153~1.251 mg/m³), and 0.105 mg/m³ (range: 0.012~0.228 mg/m³), respectively. Among rock chipping workers, the AMs of total dust concentrations, respirable dust concentrations, and crystalline silica concentrations were 2.446 mg/m³ (range: 0.156~8.494 mg/m³), 0.488 mg/m³ (range: 0.028~1.536 mg/m³), and 0.099 mg/m³ (range: 0.004~0.274 mg/m³), respectively. Conclusions: Although it cannot be said that the dust concentrations were high for both rock drilling workers and rock chipping workers, the concentrations of crystalline silica were found to be high. If such work is performed for a long period of time, diseases such as lung cancer and COPD may occur, so the work environment needs to be improved.

• 한국산업보건학회지
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• 제8권1호
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• pp.1-23
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• 1998

Work-related Low Back Pain(LBP) is one of tile most important Issues in the field of industrial safety and health. Particularly, manual lifting is known as a major cause of work-related LBP and impairment. Total number of 163 manual lifting tasks in motor assembly processes were investigated. The 1981 and the 1994 equations developed by National Institute for Occupational Safety and Health(NIOSH) were applied to evaluate potential hazards of lifting-related LBP. Comparisons between the 19R I and 1994 NIOSH criteria were made. The relationships between the NIOSH criteria and lifting-related LBP were also analyzed. The results of this study are as follows: 1. The values of Action Limit(AL) by the NIOSH 1981 lifting equation. Recommended Weight Limit(RWL) by the 1994 equation and the weight of the load handled at each manual lifting task were shown log-normal distributions. 2. LI'(the weight of tile load/AL) and LI(the weight of the load/RWL) were calculated estimate the physical stress imposed by each individual lifting task. As a result. 76.7% of the total LI' value exceeded 1 and 12.9% exceeded 3, and 84.7% of the total LI values exceeded 1 and 20.9% exceeded 3. 3. Bus 2 Department showed the highest rate of LI'>1 and LI>1 and Bus 1 Department showed the highest rate of LI'>3 and LI>3 4. In general, the RWLs by the 1994 equation were found lower than the ALs by the 1981 equation. It is assumed to he resulted from the fact that the 1994 equation includes methods evaluating asymmetrical lifting tasks and lifts of objects with less then optimal hand-container couplings, and also covers a larger range of work durations and lifting frequencies than the 1981 equation. 5. Significant correlations were found between LI' and incidence of LBP (R=0.734, p<0.05). LI and incidence of LBP(R=0.671. p<0.10) and load-weights and incidence of LBP(R=0.797, p<0.05). 6. Control measures are required to achieve the value of LI less than 1 for some tasks having high LI values. Engineering control is highly recommended for some tasks having the value of LI above 3.

• Safety and Health at Work
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• 제10권4호
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• pp.428-436
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• 2019

Background: Metalworking fluids (MWFs) are mixtures with inhalation exposures as mists, dusts, and vapors, and dermal exposure in the dispersed and bulk liquid phase. A quantitative risk assessment was performed for exposure to MWF and respiratory disease. Methods: Risks associated with MWF were derived from published studies and NIOSH Health Hazard Evaluations, and lifetime risks were calculated. The outcomes analyzed included adult onset asthma, hypersensitivity pneumonitis, pulmonary function impairment, and reported symptoms. Incidence rates were compiled or estimated, and annual proportional loss of respiratory capacity was derived from cross-sectional assessments. Results: A strong healthy worker survivor effect was present. New-onset asthma and hypersensitivity pneumonitis, at 0.1 mg/㎥ MWF under continuous outbreak conditions, had a lifetime risk of 45%; if the associated microbiological conditions occur with only 5% prevalence, then the lifetime risk would be about 3%. At 0.1 mg/㎥, the estimate of excess lifetime risk of attributable pulmonary impairment was 0.25%, which may have been underestimated by a factor of 5 or more by a strong healthy worker survivor effect. The symptom prevalence associated with respiratory impairment at 0.1 mg/㎥ MWF was estimated to be 5% (published studies) and 21% (Health Hazard Evaluations). Conclusion: Significant risks of impairment and chronic disease occurred at 0.1 mg/㎥ for MWFs in use mostly before 2000. Evolving MWFs contain new ingredients with uncharacterized long-term hazards.

• 한국산업보건학회지
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• 제15권3호
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• pp.176-182
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• 2005

American Conference of Governmental Industrial Hygienists (ACGIH) adopted the Lifting Threshold Limit Values ($TLVs^{(R)}$) in 2005 as a guideline for protecting the workers from work-related low back and shoulder disorders associated with repetitive lifting tasks. The TLVs consist of three tables with recommended weight limits for lifting tasks and their determination procedures are simple. The TLVs sans the material weight/the recommended values (LITLVs) were obtained from 45 lifting tasks in ship engine manufacturing factories. These values were compared and correlated with the Recommended Weight Limits (RWLs) and lifting indices (LIs) determined by the Revised Lifting Equation (LE) of the National Institute for Occupational Safety and Health (NIOSH). The average ratio, LITLVs/LIs, was 0.8 (LITLVs: $1.3{\pm}0.8$, LIs: $1.6{\pm}0.7$). Thus, the TLVs underestimated the risk than the LE. The LITLVs were highly correlated with LIs (r=0.82). The predicted value of LITLVs when LIs=1 wa 0.76. Using the predicted TLVs the higher risk ones of a large number of tasks can be screened to be further investigated.

• 반도체디스플레이기술학회지
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• 제21권2호
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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.

• Safety and Health at Work
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• 제13권4호
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• pp.507-511
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• 2022

Law enforcement officers (LEOs) often encounter rapidly changing and uncontrolled situations that expose them to various hazards. A law enforcement agency requested an evaluation by the National Institute for Occupational Safety and Health (NIOSH) when multiple LEOs reported illness after executing a search warrant and taking a suspect into custody. NIOSH investigators interviewed LEOs and reviewed medical records, forensic laboratory results for collected evidence, and environmental testing results of samples taken after the operation. Two-thirds (25 of 38) of LEOs who participated in the operation reported ≥1 symptom. Eleven LEOs met a case definition for influenza-like illness (ILI). Members of one unit were more likely to have ILI than non-members (prevalence ratio (PR), 4.1; 95% confidence interval (CI): 1.3-13.0; p = 0.01). Influenza vaccination was associated with a lower prevalence of ILI (PR, 0.2; 95% CI, 0.1-0.9; p = 0.02). Preventing employees from working while ill and annual influenza vaccination might prevent similar occurrences.