• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.66-71
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• 1998

This study was investigated to evaluate worker exposures to organic solvents by type of print industry. Results were as follows; 1. Workers were exposed to mixture of toluene, isopropyl alcohol(IPA), methyl ethyl ketone(MEK), n-hexane, ethylacetate(EA), acetone. The components of high exposure solvents were toluene, IPA and MEK. 2. Considering additive effects of the compounds, exposure indices(Em) were calculated. The Mean of exposure indices were 1.79 for Gravere, 0.41 for Screen and 0.14 for Opset workplace. The workers of Gravere workplace were estimated to overexpose for solvents. 3. The highest overexposed solvent was toluene for a single component. The rate of overexposed level for toluene was 7.41% for some print workplace and for mixed solvent was 1.85％. 4. Local exhaust systems were inappropriate and respiratory protective devices were not supplied to the workers. 5. Sound level was over 90dB(A) in Opset print workplace and some measures should be performed to get down the sound level.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.13-20
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• 2019

Objective: This study was performed to propose a domestic occupational exposure limit(OEL) following a health hazard assessment, calculation of a non-carcinogenicity reference concentration worker($RfC_{worker}$) value, and examination of international agencies' exposure limits. It also recommends legal management within the Occupational Safety and Health Act for PHMG-Phosphate(CAS No. 89697-78-9), It is a humidifier disinfectant that generated many lung injuries. Methods: We have investigated the recommendation or guidelines of foreign OEL for PHMG-Phosphate and the actual state of legal management in Korea. To examine the procedures and methods for recommendation OEL. Toxicological hazard and health hazard classifications were examined and a non-carcinogenicity $RfC_{worker}$ value was calculated for PHMG-Phosphate. An OEL and the necessity of legal management were recommended as well. Results and Conclusions: The OEL for PHMG-Phosphate is recommended to be $0.01mg/m^3$. The recommended OEL is close to 10 times the RfCworker value of $0.000833mg/m^3$ calculated from the chemical dose-response hazard assessment, which is a 2017 study. The CMIT/MIT(3:1) mixture, which was a social issue as a humidifier disinfectant substance, was also exposed to the same ratio in March 2018, establish the OEL. It is recommended to establish OEL for PHMG-Phosphate to prevent worker health hazards and for chemical safety management.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.843-852
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• 2017

Recently, as the WHO IARC has classified radio frequency electromagnetic fields as possibly carcinogenic (group 2B) to humans, there is increasing concern about the health effects of overexposure from electromagnetic fields. Especially, the workers are exposed to higher level of electromagnetic radiation than the general public. As a result, in Europe, the protection guidelines for the worker are developed and the exposure of the worker is strictly controlled. In this paper, the EU directive, standards and guidelines of the EMF exposure for the worker were reviewed, and the exposure assessment of EMF was performed for the arc welding. Based on that, we propose a way to introduce a national policy to protect the workers from EMF exposure in working environment.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.577-582
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• 1998

In nuclear power plant, it has been the important object to reduce the occupational radiation exposure (ORE). Recently, the optimization concept of management science has been studied to reduce the ORE in nuclear power plant. In optimization of the worker allocation, the collective dose, working time, individual dose, an total number of worker must be considered and their priority orders must be thought because the main constraint is necessary for determining the constraints variable of the radiological worker allocation problem. The ultimate object of this study s to look into the change of the optimal allocation of the radiological worker as priority order changes. In this study, the priority order is the characteristic of goal programming that is a kind of multi-objective linear programming. From a result of study using goal programming, the total number of worker and collective dose of worker have changed as the priority order has changed and the collective dose limit have played an important role in reducing the ORE.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.91-98
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• 1993

This study was carried out to investigate characteristic of vinyl chloride emissioned from poly vinyl chloride extrusion process and to evaluate the efficiency of local exhaust ventilation system. Before local ventilation facility was constructed in poly vinyl chloride extrusion process, the average worker exposure to vinyl chloride was 3.15 ppm, which exceeded Threshold Limit Value of American Conference of Gorvernmental Industrial Hygienists (ACGIH-TLV), 1 ppm. lt is possible that vinyl chloride residues in the poly vinyl chloride resin was released or degased due to extrusion heat. The larger the width of vinyl tube become, the higher worker exposure to vinyl chloride was. It is estimated that vinyl chloride from vinyl chloride resin increased as amount of poly vinyl chloride resin extruded in the extrusion process increased. Canopy hood was an appropriate type for poly vinyl chloride resin extrusion process. This local exhaust ventilation has fan static pressure of 7.65 inch wg($190mmH_2O$, total volumetric flowlate of 4,796 CFM ($135.8m^3$/min) and fan power requirement of 12 hp (8.952 Kw). After this local exhaust ventilation was constructed there, the average concentration of worker exposure to vinyl chloride was reduced to be 0.46 ppm, which was below the Threshold Limit Value, 1 ppm. Also, the removal efficiency rate of vinyl chloride attained by local exhaust ventilation was 85.3%. It was a statistically significant (p<0.01).

• Safety and Health at Work
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• v.10 no.4
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• pp.437-444
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• 2019

Background: Headache/eyestrain symptoms are common health problems that people experience in daily life. Various studies have examined risk factors contributing to headache/eyestrains, and physicochemical exposure was found to be a leading risk factor in causing such symptoms. The purpose of this study was to examine the relationship of headache/eyestrain symptoms with physicochemical exposure among Korean construction workers depended on worksite. Methods: This study used data from the 4th Korean Workers Conditions Survey and selected 1,945 Korean construction workers as participants. Multivariable logistic regression analysis was used to determine the relationship. Results: Exposure to vibrations among all construction workers affected the moderate exposure group [odds ratio (OR) 1.53, 95% confidence interval (CI) 1.01-2.32], the high exposure group (OR 1.77 95%CI 1.17-2.67), and the indoor high exposure group (OR 1.61, 95%CI 1.02-2.55) and among outdoor construction workers, the moderate group (OR 6.61, 95%CI 15.4-28.48) and the high group (OR 6.61, 95%CI 1.56-27.98). When exposed to mist, dust, and fumes, the indoor high exposure group was significantly affected (OR 1.63, 95%CI 1.07-2.47). All construction workers exposed to organic solvents were affected, high exposure group (OR 1.69, 95%CI 1.15-2.49) and indoor high exposure group (OR 1.77, 95%CI 1.08-2.89). The high exposure group in all construction worker (OR 1.70, 95%CI 1.20-2.42) and the indoor high exposure group (OR 1.83, 95%CI 1.17-2.89) also were affected by secondhand smoking exposure. Conclusion: Many physicochemical exposure factors affect headache/eyestrain symptoms among construction workers, especially indoor construction workers, suggesting a deficiency in occupational hygiene and health environments at indoor construction worksites.

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.197-201
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• 2002

The healthy worker effect is an important issue in occupational epidemiology. We proposed a new statistical method to test the relationship between exposure and time to death in the presence of the healthy worker effect. In this study, we considered the healthy worker hire effect to operate as a confounder and the healthy worker survival effect to operate as a confounder and an intermediate variable. The basic idea of the proposed method reflects the length bias-sampling caused by changing one's employment status. Simulation studies were also carried out to compare the proposed method with the Cox proportional hazards models. According to our simulation studies, both the proposed test and the test based on the Cox model having the change of the employment status as a time-dependent covariate seem to be satisfactory at an upper 5% significance level. The Cox models, however, are inadequate with the change, if any, of the employment status as time-independent covariate. The proposed test is superior in power to the test based on the Cox model including the time-dependent employment status.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.2
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• pp.106-111
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• 2018

Recently, due to the effect of global warming, the high temperature phenomenon continues, and the time for workers exposed to high temperature, cold and infrared is increasing and then safety is threatened. Due to the nature of on-site work, the work is being carried out in an unreasonable manner due to the process, which is exposed to disasters due to high temperature and cold. Even though the injured skin may be damaged, the worker may not be aware of it and may be injured. By understanding the working environment of the worker and calculating the risk index and expressing it on the helmet, the surrounding colleagues inform the worker of the risk and take appropriate measures so that the accident can be prevented in advance. This study was conducted to investigate the effect of exposure duration on the workers' by measuring the exposure time, the risk index is displayed in the form of a traffic light to the helm, informing neighboring workers and managers, and transmitting to the workers by voice.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1781-1788
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• 2022

The containment building Kori Unit 1 may require sequential steps for full decommissioning. This study assumes that the containment building is to be used as an auxiliary building that handles nuclear power systems and materials during decommissioning before conversion into a greenfield. Through the derivation of guidelines and dose evaluation, it was confirmed whether the radiation workers were satisfied with the ALARA decision. The specific modeling of the external radiation exposure was performed based on the facility investigation procedures. The external radiation specific derived concentration guideline levels (DCGLs) for radiation workers in containment building were obtained using the RESRAD-BUILD code and were applied to the VISIPLAN 3D ALARA Planning Tool code to calculate the working dose and check worker safety. The derivation of site-specific and realistic DCGLs and dose evaluation via 3D modeling can contribute to the scenario development for the decommission and remediation of containment building.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.725-733
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• 2023

The Korea Institute of Radiological and Medical Sciences has started a radiation epidemiological study, titled "Korean Radiation Worker Study," to evaluate the health effects of occupational exposure to radiation. As a part of this study, we investigated the methodologies and results of reconstructing organ-specific absorbed doses based on personal dose equivalent, H_p(10), reported from 1984 to 2019 for 20,605 Korean radiation workers. For the organ dose reconstruction, representative exposure scenarios (i.e., radiation energy and exposure geometry) were first determined according to occupational groups, and dose coefficients for converting H_p(10) to organ absorbed doses were then appropriately taken based on the exposure scenarios. Individual annual doses and individual cumulative doses were reconstructed for 27 organs, and the highest values were observed in the thyroid doses (on average 0.77 mGy/y and 10.47 mGy, respectively). Mean values of individual cumulative absorbed doses for the red bone marrow, colon, and lungs were 7.83, 8.78, and 8.43 mSv, respectively. Most of the organ doses were maximum for industrial radiographers, followed by nuclear power plant workers, medical workers, and other facility workers. The organ dose database established in this study will be utilized for organ-specific risk estimation in the Korean Radiation Worker Study.