• 한국산업보건학회지
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• 제8권1호
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• pp.76-87
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• 1998

The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess proability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30cm of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p<0.05). Logit(welding fume TLV) = 0.1296 ${\times}$ wlding currnet - 28.8750 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value a, a dependent variable (p<0.05). Logit (welding fume TLV) = -0.6809 ${\times}$ distance between helmet and arc +25.1665 4) Considering both cases or 2) and 3). the result equation is following. (p<0.05). Logit (welding fume TLV) = 0.1346 ${\times}$ welding current -0.3859 ${\times}$ distance between helmet and arc -15.7382 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was 100% in below 34cm of distance between helmet and arc. Thus, over 38cm can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below 15% of welding fume excess probability for the welders who works in distance of 34-37cm. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38cm in 220 Ampere and 32cm in 200 Ampere. 8) To reduce the average exposure concentration of welding fume ($8.21{\pm}5.83mg/m^3$), the movable local exhaust system equipped with flexible hoods can be used.

• 한국산업보건학회지
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• 제19권4호
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• pp.328-334
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• 2009

There are various methods for welding fume control. These methods can be divided into local exhaust system, general ventilation system and integrated control system. With the general ventilation system, we should have a good prediction tool for testing various appropriate control options. But, until now there are not many studies about how to predict the welding fume concentrations. Especially, the prediction of welding fume concentration is not a very easy task because welding fume is the particulate matters. In this study, we tried to measure $CO_2$ concentrations and welding fume concentrations in a small single room with a small ventilation opening. Using commercially available CFD (Computational Fluid Dynamics) software, we tried to predict $CO_2$ concentrations under the exactly same conditions. Then, we tried to compare the numerical $CO_2concentrations$ with the experimental results to know whether we could predict $CO_2$ concentrations. Then we tried to compare $CO_2$ concentrations with experimental welding fume concentrations to know whether we can use the numerical $CO_2concentrations$ to predict the welding fume concentration indirectly.

• Safety and Health at Work
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• 제14권4호
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• pp.384-389
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• 2023

Background: Exposure to welding fume is associated with adverse effects on worker health. The use of various control measures can reduce levels of exposure and the resulting health effects. However, little is known about the factors that may influence workers' use of control measures in the workplace and their perceived intervention needs. This study aimed to investigate workers' and other stakeholders' views on ways to improve the use of welding fume control measures in Australian workplaces. Methods: We conducted a series of online focus group discussions and individual interviews with participants who have some occupational involvement in welding, whether as workers, employers or industry representatives, union representatives, or regulators. A semi-structured question guide was used, and all discussions and interviews were recorded and transcribed for analysis. Results: Five focus group discussions and five individual interviews were conducted with a total of 21 participants. Three major themes emerged. The first addressed the current awareness of welding fume harms and concern about exposure; the second focussed on the current use of control measures, and barriers and facilitators to their use; and the last centred around intervention needs and the contents of a potential effective intervention. Conclusion: Improving the use of control measures to prevent exposure to welding fume requires knowledge around the barriers and facilitators of control, use, and the intervention needs of stakeholders. This study has provided such knowledge, which will facilitate the design and implementation of an intervention to reduce welding fume exposure and ultimately protect the health of workers.

• 한국환경보건학회지
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• 제33권6호
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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.

• Toxicological Research
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• 제20권1호
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• pp.55-61
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• 2004

Respiratory effects in full time welders include bronchitis, airway irritation, lung function changes, and lung fibrosis. Welder's pneumoconiosis has been generally determined to be benign and not associated with respiratory symptoms based on the absence of pulmonary function abnormalities in welders with marked radiographic abnormalities. Accordingly, to investigate pulmonary function changes during 60 days induced by welding-fume exposure, male Sprague-Dawley rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes with concentrations of 64.8$\pm$0.9 mg/$m^3$ (low dose) and 107.8 $\pm$ 2.6 mg/$m^3$ (high dose) total suspended particulates for 2 hr/day, 5 days/week in an inhalation chamber for 60 days. Pulmonary function was measured every week with whole body plethysmograph compensated (WBP Comp, SFT38116, Buxco Electronics, Sharon, CT). The rats exposed to the high dose of welding fumes exhibited statistically significant (p<0.05~0.01) body weight decrease as compared to the control whereas cell number increase of the bronchoalveolar lavage fluid (BALF) (total cell, macrophage, polymorphonuclear cell and lymphocyte) during the 60 days exposure period. And only tidal volume was significantly decreased in dosedependantly during 60 days of MMA-SS welding fume exposure. This pulmonary function change with inflammatory cell recruitment confirms the lung injury caused by the MMA-SS welding fume exposure.

• 한국산업보건학회지
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• 제10권2호
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• pp.98-108
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• 2000

Controlling the over-exposure of welding fumes is not an easy problem because neither general nor local exhaust ventilation systems could be successfully applied. A jet air supplying welding mask was development to reduce the exposure level of welding fumes. The jet airs tream pushes the welding fumes away from the breathing zone by using the frictional characteristic of jet. Laboratory experiments were conducted to optimize the efficiency of controlling welding fumes. Thereafter, its performance was tested in a laboratory and an industrial field. The efficiencies of reducing the welding fume exposure were about 90% and 80% in a laboratory and an industrial field, respectively. Additionally, it resulted in elimination of heat inside the mask and enhancement of clear visuality.

• 한국환경보건학회지
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• 제27권4호
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• pp.51-62
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• 2001

Geometric mean of airborne welding fume concentration at technical high schools was 4.80mg/㎥)N.D~35.39 mg/ ㎥ and the percentage of samples exceeded TLV of the Korean ministry of labor was 43.6%, Geometric mean of airborne Mn concentration was 0.06 mg/㎥(N.D~0.42mg/㎥) and the percentage of samples exceeded TLV of ACGIH was 15.4 % In case of airborne Me concentration, there is a significant difference among schools (p<0.05) Mn concentrations in blood of the exposed and control groups were 1.84$\mu\textrm{g}$/dl and 1.91 mg/dl respectively. Mn concentrations in urine of the exposed and control groups were 1.36$\mu\textrm{g}$/ιand 0.57$\mu\textrm{g}$/ι respectively. In case of Mn concentrations in urine there is a significant difference between both groups(P<0.001) and among schools(p<0.05) Mn concentrations in blood and urine of exposed group were not over BEIs of the Korean ministry of labor. Mn levels in blood and urine were not significantly affected by smoking, drinking and residence, There was no correlation between Mn concentration in air and blood but there was a statistically significant correlation between Mn concentration in air urine(r=0.323). There was no a statistically significant correlation between Mn concentration in blood and urine.

• Journal of Preventive Medicine and Public Health
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• 제22권3호
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• pp.328-336
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• 1989

27 shipyard welders were diagnosed as pneumoconiosis and suspected pneumoconiosis(1976-1988) by chest radiographs and were observed over three years. 27 welders were divided into three groups by the state of exposure to welding fume i.e. cessation, decresase or continuity of exposure. And we observed the changing pattern of the chest radiographs of 27 welders with the passage of time. The results were as follows; 1. Grour I (ceased exposure to welding fume) were 10 cases(3 cases: suspected pneumoconiosis,7 cases: pneumoconiosis). Chest radiographs of all cases were improved. The shape and size of small opacities was improved in 6 cases(85.7%) and did not changed in 1 case(14.3%) out of 7 pneumoconiosis welders. 2. Group II (decreased exposure to welding fume) were S cases(2 cases: suspected pneumoconiosis, 3 cases: pneumoconiosis). Chest radiographs were progressed in 2 cases(40%), did not changed in 1 case(20%), were improved in 2 cases(40%) out of 5 cases. The shape and size of small opacities was progressed in 1 case(33.3%) and was improved in 2 cases(66.7%) out of 3 pneumoconiosis welders. 3. Group III(continued expoxsure to welding fume) were 12 cases(1 case: suspected pneumoconiosis, 11 cases: pneumoconiosis). Chest radiographs were progressed in 9 cases(75%), did not changed in 3 cases(25%) out of 12 cases. The shape and size of small opacities was progressed in 1 case(9.1%) and did not changed in 10 cases(90.9%) out of 11 pneumoconiosis welders. 4. The average duration for development into suspected pneumoconiosis was 6.6 years and for progression of each one category after that was 2.2 years(p<0.01). The radiological appearance of pneumoconiosis had disappeared or decreased after cessation of exposure to the welding fume. So that, early detection and control e.g., change of department of pneumoconiosis of welders by screening program will be important for medical surveillance of welders.

• Journal of Preventive Medicine and Public Health
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• 제28권1호
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• pp.43-57
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• 1995

In order to study the effect of welding fume exposure upon the pulmonary function test, we examined 131 shielded arc welding workers, and 152 $CO_2$ arc welding workers as cases and 177 control workers for their general characteristics, and forced vital capacity (FVC), forced expiratory volume in one second $(FEV_{1.0})$, forced expiratory volume in one second as a percent of FVC $(FEV_{1.0}%)$, and maximal mid-expiratory flow (MMF) were obtained from the spirogram. In shielded arc welding group and $CO_2$ arc welding group, FVC, $FEV_{1.0},\;FEV_{1.0}%$, and MMF were significantly decreased than control group, especially marked in the MMF finding. The distribution of workers below normal range was as follows. in the shielded arc welding group, 2 workers(1.5%) for FVC, 17 workers(13.0%) for $FEV_{1.0}$, 5 workers(3.8%) for $FEV_{1.0}%$, 28 workers(21.4%) for MMF, and in the $CO_2$ arc welding group, 3 workers(2.0%) for FVC, 25 workers(16.4%) for $FEV_{1.0}$, 8 workers(5.3%) for $FEV_{1.0}%$, and 37 workers(24.3%) for MMF, and significant increase by exposure duration was found in MMF. The distribution of workers who had ventilation impairment was as follows: 5 workers(3.8%) for obstructive type, 2 workers(1.5%) for restrictive type in the shielded arc welding group, and 7 workers(4.6%) for obstructive type, 2 workers(1.3%) for restrictive type, and 1 worker(0.6%) was combined type of the $CO_2$ arc welding group. In the respect of these results, the significant pulmonary function and ventilatory impairment were observed in welding fume exposed workers who had not abnormal finding in chest X-ray, and MMF considered as the most sensitive pulmonary function index by welding fume exposure. Therefore even if it is hard to doing pulmonary function test in the first health examination of workers according to the Industrial Safety Health Act in the welding fume exposure workers, it is desirable to consider doing PFT. Also evaluating the ventilation impairment, it is necessary, to observe the change of MMF that marker of effort-independent portion.

• 한국산업보건학회지
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• 제9권2호
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• pp.135-144
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• 1999

The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.