• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.112-124
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• 1999

The purposes of this study were to provide the data for composition of ethylene glycol ethers and 2-ethoxyethyl acetate(EEA) exposure assessment of workers in various industrial operations. In this study, 80 thinners were analyzed to identify their composition and the air concentration of 2-ethoxyethyl acetate(EEA) and urinary 2-ethoxyacetic acid(EAA) were measured. In this study the subjects were the total of 183 drawn from 98 workers who were occupationally exposed to EEA and 85 workers who were not. The results were as follows: 1. There were found average 4.2 components in each thinner. 2. There were 90 components(26.9%) in ethylene glycol ethers of total of 334 detected organic solvents 3. Ethoxyethyl acetate, ethoxyethanol, buthoxyethanol, methoxy-ethanol were found in 30(37.5%), 27(33.8%), 19(23.8%), 2thinners(2.5%), respectively and their contents were average 18.5%. 4. Benzene was found 8 thinners(10.0%) of the total 80 surveyed. 5. In the electronic painting workers EEA exposure concentration was the highest, as showed 2.88ppm(0.01~15.1ppm), cases of exceeded threshold limit value(TLV=5ppm) were 7(10.6%) workers among the total of 98 exposed workers. 6. The geometric mean of urinary EEA in exposed workers was 1.61 mg/gcreatinine, and was higher than that of workers who were not exposed. In the electronic painting workers and offset printers, the geometric mean of urinary EAA was the highest showing 2.8 mg/gcreatinine. 7. The correlation coefficient between urinary concentration of EAA and air concentration of EEA was 0.90(P<0.05). The present results suggest that composition of ethylene glycol ethers in thinners must be evaluated when industrial hygiene surveys and biological monitoring are performed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.146-155
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• 2015

Objectives: The aims of this study were to set up benzene exposure matrices according to industry and process and to assess the risk of those occupational exposure to benzene. Methods: The benzene exposure matrices were assembled depending on industry and process, based on an exposure database provided by KOSHA(the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. These exposure matrices were assessed by Hallmark Risk Assessment tool. Results: The benzene was treated 412 industries sector(36%), 2,747 business places, and 471 industrial processes according to database. The arithmetic mean of past decade 8 hours time-weighted average of airborne benzene concentrations in the workplace was 0.10722 ppm. 1.07% of the total sample were greater than OEL, and 59.8% were showed less than the limit of detection. The highest risk values(Danger Value) were seen 36 industries including manufacture of general paints and similar product and 12 processes, such as other painting of manufacture of metal fabricated members. Exposure matrices based on employee exposure data base may provide exposure histories and can be used in epidemiological studies. Conclusions: It was found that more attentions should be paid to 36 among 412 industries and 12 of 471 processes, with a higher risk value.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.52-58
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• 2014

Objectives: Using laborers participating in the petrochemical factory turnaround process as subjects, this study aims to identify exposure to benzene in the air and examine the relationship between exposure and the excretion of urinary metabolites by measuring concentrations of urinary trans, trans-muconic acid (t,t-MA). Methods: A passive sampler was used to measure the level of benzene in the air. In order to analyze urinary metabolites, the urine of laborers participating in the turnaround process was collected twice daily, both before and after work. In addition, a survey was conducted on work factors and lifestyle habits as factors affecting the concentration of urinary metabolites. Results: During the survey period, benzene was detected in the samples from all workers, and its average concentration was $0.16{\pm}0.22ppm$. The average concentration of t,t-MA after work was $1.20{\pm}1.86mg/g$ creatinine, and the results of analyzing urinary metabolites concentration before and after work showed statistically significant differences(p=0.003). There was also a statistically significant correlation (r=0.52, p=0.002) between benzene in the air and the concentration of after-work urinary t,t-MA. Conclusions: During the turnaround process, the average benzene concentration in workers was $0.16{\pm}0.22ppm$, which was below the exposure limit. However, their average t,t-MA concentration was $1.20{\pm}1.86mg/g$ creatinine, which exceeded the exposure limit of 1mg/g creatinine. The characteristics of turnaround process work require considerations such as underestimating the passive sampler being used and the skin absorption of benzene, and there needs to be a simultaneous assessment of working environment measurements and biological monitoring.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.391-401
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• 2010

A reduction in risk of occupational exposure to chemical hazards within the workplace has been the focus of attention both through industry initiatives and legislation. The aims of this study were to develop an exposure matrix by industry and process, and to apply this matrix to control the risk of occupational exposure to Dichloromethane (DCM). The exposure matrix is a tool to convert information on industry and process into information on occupational risk. The exposure matrix comprised industries and processes involving DCM, based on an exposure database provided by KOSHA (the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. The risk assessment of the exposure matrix was performed using Hallmark risk assessment tool. The results of the risk assessment were indicated by a Danger Value (DV) calculated from the combination of hazard rating (HR), duration of use rating (DUR), and risk probability rating (RPR) of exposure to the chemical, and were divided into four control bands which were related to control measures. The applicability of the risk assessment of the exposure matrix was evaluated by a field study, and survey of the employees of the exposure matrix groups. Among 45 industries examined, this study found that greater attention should be paid to two industries: the manufacture of other optical instruments and photographic equipment, and the manufacture of printing ink, and to one process among 47 examined, the packing process in the manufacture of printing ink, because these were regarded as carrying the highest risk. This tool of a risk assessment for the exposure matrix can be applied as a general exposure information system for hazard control, risk quantification, setting the occupational exposure limit, and hazard surveillance. The exposure matrix includes workforce data, and it provides information on the numbers of exposed workers in Korea by agent, occupation, and level of exposure and risk.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.108-113
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• 2013

Objectives: Although several cases of lung diseases caused by indium have been reported in Japan, the United States and China, South Korea, which is estimated to have been the world's largest consumer of indium, has not yet established a criteria for the diagnosis of lung diseases caused by indium exposure. In this study, we tried to determine the applicability of the Krebs von den lungen-6, which has been widely recognized for its use with interstitial lung disease in Japan, as a biological exposure index for indium. Methods: Methods: The analysis of indium in serum was conducted by inductively coupled plasma mass spectrometry and the analysis of KL-6 in serum was carried out using enzyme-linked immunosorbent assay kit. Results: The indium levels in serum were distributed from below the detection limit to a peak of $125.78{\mu}g/L$, and the values of the KL-6 were distributed from 104.5 U/mL to 2162.2 U/mL. The serum indium and KL-6 showed good correlation ($R^2$=0.389,pfortrend=0.000) and smoking did not affect the KL-6. Conclusions: The usefulness of KL-6 as a specific biomarker for interstitial lung disease has been recognized. In addition, it is expected that effective prevention of health problems can be achieved by determining the lung-damage progress at an early stage according to individual susceptibility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.184-195
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• 2013

Objectives: The purpose of this study is to provide information in reference to the health hazards of asbestos substitutes. Methods: This study was conducted by reviewing the literature on the types of asbestos substitutes, product development using alternative materials and the health effects associated with asbestos substitutes. Results: Synthetic or natural fibers such as synthetic vitreous fiber, polyamide, attapulgite, sepiolite and wollastonite are known as asbestos substitutes. According to the patents data of the United States and Europe since the 1970s, many asbestos-free products have been developed in a variety of industries. Health hazards of some asbestos substitutes including synthetic vitreous fibers have been evaluated by many experts, however, additional researches are required to be carried out in the future. Conclusions: Alternatives to asbestos are necessary to develop the asbestos-free products. Health hazards for only several asbestos substitutes have been assessed so far and occupational exposure limit has not been established for many asbestos substitutes yet. Therefore, even though workers are handling asbestos-free products, it is recommended to control the working environment well enough in order to minimize the exposure of workers to dusts or fibers caused during the working process.

• Safety and Health at Work
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• v.11 no.2
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• pp.235-240
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• 2020

Background: Cadmium exposure may induce chronic intoxication with renal damage. Silver soldering may be a source of cadmium exposure. Methods: We analyzed working environment measurement data and periodic health screening data from a small-scale silver soldering company with ten workers. Concentrations of cadmium in air from working environment measurement data were obtained. Concentrations of blood and urinary cadmium, urine protein, and urine β2-microglobulin (β2M) were obtained. The generalized linear model was used to identify the association between blood and urine cadmium and urine β2M concentrations. Clinical features of chronic cadmium intoxication focused with toxicological renal effects were described. Results: The mean duration of work was 8.5 years (standard deviation [SD] = 6.9, range = 3-20 years). Cadmium concentrations in air were ranged from 0.006 to 0.015 mg/㎥. Blood cadmium concentration was elevated in all ten workers, with a highest level of 34.6 ㎍/L (mean = 21.288 ㎍/L, SD = 11.304, range = 9.641-34.630 ㎍/L). Urinary cadmium concentration was elevated in nine workers, with a highest level of 62.9 ㎍/g Cr (mean = 22.151 ㎍/g creatinine, SD = 19.889, range = 3.228-62.971 ㎍/g creatinine). Urine β2M concentration was elevated in three workers. Urinary cadmium concentration was positively associated with urine protein concentration (beta coefficient = 10.27, 95% confidence interval = [4.36, 16.18]). Other clinical parameters were compatible with renal tubular damage. Conclusion: Cadmium intoxication may occur at quite low air concentrations. Exposure limit may be needed to be lowered.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.232-233
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• 2010

This paper investigates occupational exposure to time-varying magnetic field generation in high power rectifier systems. Two different kinds of high power rectifier systems of 25kA are modeled and analyzed. The performance is compared and evaluated on the basis of exposure guidelines from ICNIRP. In order to focus on the qualitative effect of rectifier operation, the mechanical structure of current carrying conductors is simplified as infinite long bus-bar model and low frequency harmonic contents up to 65kHz are considered. Thyristor rectifier generates a significant amount of low frequency magnetic field harmonic contents both at ac and dc side of rectifier infringing the limit from ICNIRP. The multilevel rectifier-IGCT type has almost negligible field generation from ac input side and smaller harmonic contents in dc load side complying with ICNIRP guideline. This remarkable advantage of multilevel rectifier-IGCT type can lead to very simple site layout design for installation and cost-effective compliance to guideline of occupational exposure against magnetic field.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.46-58
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• 2017

Objectives: Particulate matter (PM) at construction sites mostly originates from either construction activities or the atmospheric environment. This study was conducted to evaluate the exposure level to PM and the contribution ratio of atmosphere sources at construction sites. Methods: We reviewed literature and governmental systems related to PM exposure in occupational settings and summarized them. In the field evaluation, five construction sites and one golf course were selected: two from Gyeonggi-do Province and four from North Gyeongsang-do Province. For each site, personal samples from outdoor construction workers and area samples from the outdoor area around the construction site office were collected according to construction work types. PM concentrations reported from nearby National Ambient Air Monitoring Stations were recorded. Respirable dust concentrations, respirable silica concentrations, and several metal concentrations including Cd, Cr, Pb, and As were monitored over four months. In the end we suggested how to manage particulate matter exposure at construction sites. Results: There was little literature reporting on exposure levels of construction workers to PM. Respirable dust concentrations measured in Gyeonggi-do Province were higher than those measured in North Gyeongsang-do Province. The geometric means of respirable dust concentrations in personal samples and area samples were $37.89{\mu}g/m^3$ and $92.86{\mu}g/m^3$, respectively. The respirable dust concentrations were higher than the PM concentrations reported from nearby National Ambient Air Monitoring Station. The geometric means of respirable silica concentrations of personal samples and area samples were $1.3{\mu}g/m^3$ and $1.1{\mu}g/m^3$, respectively. All metal concentrations were lower than 10% of individual Korean occupational exposure limits. Conclusions: Assuming that personal samples consisted of ambient PM and dust originating from work activities and area samples only collected ambient PM, we concluded that the dust exposure of outdoor construction workers originated 40.8% from the atmosphere and 59.2% from construction activities. PM exposure at construction sites should be controlled by employers, as in the case of outdoor heat stress. The Korean government needs to consider setting an occupational exposure limit for respirable dust.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.271-277
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• 2019

Objectives: A 46-year-old woman who had worked on cleaning stainless steel containers with Initially unknown powders died from acute silicosis. To determine whether the acute silicosis was related to his work environment, we conducted exposure assessment the level of exposure to respirable crystalline silica(RCS) during cleaning stainless steel containers with unknown powders. Methods: The exposure assessment of RCS were undertaken according to the National Institute for Occupational Safety and Health(NIOSH) method 7500. The components of the unknown powder were analyzed using X-ray Diffraction. Results: The unknown powder was found to be natural diatomaceous earth, which contained 12% and 9% quartz and cristobalite, respectively, crystalline silica. In the case of cleaning stainless steel containers with diatomaceous earth powder, the primary measurement resulted in 1.3 times higher occupational exposure limit of MOEL(in sum of quartz and cristobalite concentration) and 3.9 times higher in secondary measurement. The workbench was equipped with a local exhaust system, but because there was no hood at the end of the duct, the wind speed at the opening of the duct was 12 m/sec, whereas the controlled wind speed at the working position was only 0.3 m/sec below the legal standard. Conclusions: There is an urgent need to install the hood, conduct safety and health education for employers and workers, and periodically monitoring and manage the working environment.