• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.1
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• pp.32-40
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• 2008

Methyl bromide has been used as a representative fumigant for quarantine, and several poisoning cases have occurred recently by this chemical in Korea. The purpose of this study is to evaluate workers' exposures to airborne methyl bromide in the importing and exporting plant products quarantine companies. Air samples were collected 400/200 mg Anasorb 747TM and were analyzed by gas chromatograph /flame ionization detector according to the Occupational Safety and Health Agency (OSHA) Method PV2040. Geometric mean (GM) and arithmetic mean (AM) of total 27 workers' exposure concentrations to airborne methyl bromide were 1.12 ppm and 0.24 ppm, respectively. Two exposures(12.1 ppm and 12 ppm as 8hr-TWA) of total 27 workers' exposures exceeded the Korean standard (5 ppm) of Ministry Labor, while 4 exposures (15%) exceeded the Threshold Limit Value (TLV) (1 ppm) of American Conference of Governmental Industrial Hygienists (ACGIH). Seven samples (11%) of total 63 short-term air samples exceeded the OSHA Permissible Exposure Limit (PEL) 20 ppm (Ceiling). The opening (management) task in wood fumigation by tent showed the highest short-term exposure concentrations (AM: 18.6 ppm, GM: 0.58 ppm, maximum: 340.7 ppm). The maximum level in treatment task of the same process was 2.01 ppm. Methyl bromide concentrations in opening operation was significantly higher than that in treatment operation (p<0.05). In conclusion, the GM of workers' 8hr-TWA exposures to airborne methyl chloride in the importing/exporting plant quarantine industry was estimated below the ACGIH TLV (1 ppm). However, opening task in the fumigation of wood being covered with tent or fumigation of pant products in container showed the levels exceeding ACGIH TLV (1 ppm), and opening task in the fumigation of wood being covered with tent showed the level exceeding the Korean standard of Ministry of Labor (5 ppm).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.50-57
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• 2020

Objectives: Methyl bromide is a highly toxic substance that can cause systemic poisoning, neurotoxicity, pulmonary edema. Methyl bromide is a widespread fumigation agent used for import and export quarantine, but there is little data on exposure assessment of workers participating in such fumigation. Therefore, this study aims to investigate the exposure level of methyl bromide among workers and the concentration distribution of methyl bromide in the workplace during fumigation. Methods: For this study, one wood tent and one container fumigation area in Pusan, and one wood tent fumigation area in Incheon were investigated over three months from June 2001. Results: Methyl bromide exposure levels for container fumigation workers were from undetected to 1.86 ppm and from undetected to 2.28 ppm for tent fumigation workers as an 8 hr TWA. After opening the container door, the methyl bromide concentration in the container decreased rapidly over time, but the concentration remained over 1 ppm even after about one hour. The concentrations around the tent during its removal were highly affected by wind, but were detected in a range from undetected to 11.97 ppm. Conclusions: This study confirmed that both container and tent fumigation caused workers to exceed the exposure limit of 1 ppm as an 8 hour TWA. In particular, it could be confirmed that a situation exists in which the worker may be exposed to high concentrations of methyl bromide when opening the container or removing the tent due to the nature of the work. Therefore, it is very important to improve working methods and to wear appropriate personal protective equipment.

• Toxicological Research
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• v.12 no.1
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• pp.1-8
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• 1996

The variation in the enzyme activities of human liver usually represents the particular physiological conditions of each individuals. Thus, we investigated the variation in the activities of SOD, HR and LPO of (1) non-exposed workers (56 subjects), and (2) exposed workers to DMF (43 subjects) in synthetic leather process. Serum levels of enzyme activities of exposed workers (AST:$30.26{\pm}20.041$U/L, ALT:$32.72{\pm}23.393$U/L, GGT:$28.47{\pm}18.635$ U/L, ALP:$81.77{\pm}34.879$ U/L)were slightly higher than those in nonexposed workers (AST:$24.00{\pm}9.441$ U/L, ALT:$23.89{\pm}18.305$U/L, GGT:$21.95{\pm}17.970$U/L, ALP:$70.84{\pm}24.678$U/L), but only the level of ALT was statistically significant (p< 0.05). Serum levels of LDH, TRF and CHOL in non-exposed workers were slightly higher than those of exposed workers. However, they were not statistically significant (p > 0.05). Serum levels of HR and LPO of the exposed workers appeared to be reduced, but not those of the non-exposed workers. The SOD activities of exposed workers were also slightly higher than those of non-exposed workers, but the results were not statistically significant (p > 0.05). The level of HR was increased with age, but the SOD level was not. These results suggest that the intermittent exposure to DMF at time-weighted average (TWA) level (10 ppm/$m^3$) has affected on the activities of enzymes such as AST, ALT, TRF, but not on the generation of HR, activity of SOD. However, if high dose of DMF was used, there would be severe effects for the generation of HR and LPO.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.257-267
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• 2004

Our study investigated the association between solvent exposure and acquired color vision loss using the Lanthony D-15 desaturated panel in petrochemical industry. Since neurotoxic effects associated with chronic solvent exposure, subjects with more than 6 months of exposure were included. Exposure assesment was estimated mean, maximum and cumulative 8hr TWA from individual 8-hour sampling. Exposure status were classified into two groups, occupationally exposed group to solvent and a non-exposed group. The results showed that CCI was positively related for age. According to the results of qualitative analysis, there was no significant difference in the prevalence of specific Type of dyschromatopsia the two examined group. However, the prevalence showed a higher proportion of dyschromatopsia to solvent exposure. It was affect with acquired dyschromatopsia(Type II, III and Complex) in exposed worker group(5.9%,7.86%,14.99%, respectively) than in the nonexposed group(6.16%,7.55%,13.71%, respectively). After each variable was adjusted for age, alcohol and tobacco consumption, a relationship between acquired dyschromatopsia and exposure showed an increase in the Odds ratio as compared to the nonexposed group at only left. The results showed that acquired dyschromatopsia was positively related to age (p<0.001). The results showed that solvent exposure, although not significant, could cause the acquired dyschromatopsia and visual system can serve important information on early neurotoxic effects in generally. Therefore, we need to concerns about eye health in workers.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.209-220
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• 2021

The noise is defined as unwanted sound that causes discomfort and physical changes. This study was conducted to evaluate intensity of noise in the pediatric dental clinic and to investigate noise environment of a pediatric dentist. Human ear shaped microphone and mobile noise level meter were used for recording noise and calculating intensity of noise. By recording according to the method specified by Korea Occupational Safety and Health Agency (KOSHA) of Korea Ministry of labor and employment, the following results were obtained. For 16 experimental days, 8 hour time weighted average (8hr-TWA) was 49.33 dBA (A-weighted deci-Bell) on daily average with maximum 58.54 dBA and minimum 33.97 dBA. And Dose was 0.49% on daily average with maximum 1.28%, minimum 0.04%. These values are less than criteria of KOSHA standard (85 dBA, 100%). Comparing the highest noise level for each patient, pulp therapy group and Frankel grade I group were the highest. The intensity of dental noise of pediatric dental clinic didn't meet standard of KOSHA. It is necessary to re-evaluate noise environment by establishing new standards considering environment of pediatric dental clinic.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.3
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• pp.147-155
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• 2010

This study was conducted to investigate the benzene exposure levels in coal chemical and petrochemical refining industries during BTX turnaround (TA) processes where benzene was being produced. Three companies producing benzene were selected, one coal chemical and two petrochemical industries. TA processes were classified into three stages: shut down, maintenance, and start up. Data was analyzed by classifying the refining method into 2 groups (Petrochemistry, Coal chemistry) for 823 workers. Comparing the data from petrochemical industries with data from a coal chemical refining industry, while benzene concentration levels of long-term samples during TA were not statistically different (p> 0.05), those levels of short-term samples were significantly different (p< 0.001). About 4.79 % of data in petrochemical industries exceed the occupational exposure limits (OELs) of benzene, 1 ppm. In a coal refining methods, about 15.7% exceeded the benzene OELs. The benzene concentrations in maintenance and start up stage of TA for petrochemical refineries were higher than those in a coal chemical refinery (p <0.01). These findings suggest that the coal chemical refining site requires more stringent work practice controls compare to petrochemical refining sites during TA processes. Personal protective equipments including organic respirators should be used by TA workers to protect them from benzene overexposure.

• Journal of Environmental Health Sciences
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• v.33 no.6
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• pp.506-512
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• 2007

This study was conducted to describe the exposure levels of welding fumes by the type of manufacturers, work process, welding type and the size of manufacturers, and to find out the trend of chronological changes of airborne welding fume levels. The subjects of this study were 509 manufacturers, consisting of 11 types of manufacturers, 3 work processes, 7 welding types, in Busan from January, 1997 to December, 2005. Airborne concentration of welding fume was determined by manual of National Institute for Occupational Safety and Health (NIOSH), and the data were analyzed by using SPSS 10.0 for Windows program. The mean concentration of airborne welding fume in all manufacturers was $1.29\;mg/m^3$ (Range: $0.01{\sim}3.00\;mg/m^3)$. The level of welding fume was the highest, as $1.96\;mg/m^3$, for manufactures of motor vehicles, trailers and semi-trailers, which was lower than $5.0\;mg/m^3$ of 8 hr-TWA in Korean permissible exposure limit for welding fume. There was a significant difference in the mean levels of welding fumes by work process, showing the highest in welding workshop ($1.39\;mg/m^3$), followed by pipeline welding workshop ($1.26\;mg/m^3$) and engineering workshop ($1.20\;mg/m^3$). Among welding types, the mean level of welding fume was the highest in the type of $CO_2$ & arc welding, as $1.46\;mg/m^3$, followed by $CO_2$ welding ($1.40\;mg/m^3$), shielded metal arc welding ($1.31\;mg/m^3$), spot welding ($1.27\;mg/m^3$), and so on. The highest mean level of welding fume was $1.58\;mg/m^3$ in work process of pipe line welding workshop for the manufacturers of basic iron and steel, and $2.27\;mg/m^3$ in the type of arc welding for the manufactures building ship and boats. By the size of manufacturers, the mean concentration of welding fume for manufactures in small scale with less than 50 workers was the highest as $1.45\;mg/m^3$ (Range: $0.07{\sim}3.00\;mg/m^3)$. The mean level of welding fume was the highest as $1.39\;mg/m^3$ both in 1997 and in 2005, showing a trend of fluctuating periodically within a range of $1.10{\sim}1.39\;mg/m^3$. The above results suggested that more effective control program for work environment producing welding fumes should be developed and applied since there were significant variations in welding fume levels by the type of manufacturers, work processes, welding types, the size of manufactures, and by year.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.321-327
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• 2009

1,3-butadiene is classified as suspected human carcinogen, group A2(American Conference of Governmental Industrial Hygienists, ACGIH). In Korea, 1,3-butadiene has been used as a raw material; monomer, homopolymer, polybutadiene latex, acrylonitrile-butadiene-styrene(ABS) and styrene-butadiene rubber(SBR), in the petrochemistry and precision chemistry industry. As petrochemistry industry in Korea has been developed, the potential exposure possibility of 1,3-butadiene to workers can be increased. Therefore the purpose of this study is to evaluate airborne 1,3-butadiene concentration and workers' exposure levels in the workplace using 1,3-butadiene. Air samples were collected with 4-tert-butyl catechol(TBC) charcoal tube(100 mg/50 mg) and were analyzed by gas chromatograph/flame ionization detector(GC/FID) according to the Choi's method(2002). Geometric mean (GM) and arithmetic mean (AM) of total 59 workers' exposure concentrations to airborne 1.3-butadiene were 0.042 ppm and 1.51 ppm, respectively. Although most samples were lower than 1ppm, 2 samples(21.5ppm and 33.1ppm as 8hr-TWA) were exceeded the Korean standard(2ppm) over 10 times at the repair process in synthetic rubber and resin manufacture industry. 14 samples(41%) of total 34 short-term air samples were exceeded the Korean standard(10ppm as STEL) of Ministry Labor. 1,3-butadiene concentration(GM) in the synthetic rubber and resin manufacture industry(7.87ppm) was significantly higher than that in the monomer manufacure industry (0.35ppm)(p<0.05). Also in the sampling and repair process, each GM(range) was 1.39ppm(N.D.-469.6ppm) and 7.85ppm(N.D.-410.2ppm). In conclusion, it depends on the industry and process, 1,3-butadiene can be exposed to workers as high concentration for short-term.