• 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.

• Safety and Health at Work
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• v.14 no.3
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• pp.279-286
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• 2023

Background: This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. Methods: This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012-2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. Results: The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36-1.54) and workers who were exposed to noise (1.15:1.07-1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. Conclusions: Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.

• Safety and Health at Work
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• v.8 no.1
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• pp.1-10
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• 2017

Considerable effort has been made to address the issue of occupational health and environmental exposure to mercury. This review reports on the current literature of mercury exposure and health impacts on dental personnel. Citations were searched using four comprehensive electronic databases for articles published between 2002 and 2015. All original articles that evaluated an association between the use of dental amalgam and occupational mercury exposure in dental personnel were included. Fifteen publications from nine different countries met the selection criteria. The design and quality of the studies showed significant variation, particularly in the choice of biomarkers as an indicator of mercury exposure. In several countries, dental personnel had higher mercury levels in biological fluids and tissues than in control groups; some work practices increased mercury exposure but the exposure levels remained below recommended guidelines. Dental personnel reported more health conditions, often involving the central nervous system, than the control groups. Clinical symptoms reported by dental professionals may be associated with low-level, long-term exposure to occupational mercury, but may also be due to the effects of aging, occupational overuse, and stress. It is important that dental personnel, researchers, and educators continue to encourage and monitor good work practices by dental professionals.

• Safety and Health at Work
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• v.11 no.4
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• pp.509-516
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• 2020

Background: Meta-analyses have shown firefighters to be at an increased risk of several cancer types. Occupational carcinogen exposure may explain these increased risks. This study aims to describe Norwegian fire departments' work conditions from 1950 until today, focusing on factors relevant for potential occupational carcinogen exposure. Methods: With the help of a reference group, we developed a questionnaire on topics related to occupational exposure to carcinogens for the period 1950-2018. Selected Norwegian fire departments provided department-specific responses. Results: Sixteen departments, providing fire services for 48% of the Norwegian population as of 2019 and mainly consisting of professional firefighters, responded to our questionnaire. The introduction of synthetic firefighting foams, more regular live fire training, the introduction of chemical diving, and a higher number of diesel-driven fire service vehicles were identified as changes thought to increase exposure to occupational carcinogens. Changes thought to decrease exposure included the switch from negative to positive pressure self-contained breathing apparatuses, the use of self-contained breathing apparatuses during all phases of firefighting, the use of ventilating fans during firefighting, increased attention to flammable materials used during live fire training, increased attention to handling and cleaning of turnout gear and other equipment, and installment of exhaust removal systems in apparatus bays. Conclusion: Norwegian fire departments' work conditions have seen several changes since 1950, and this could influence firefighters' occupational carcinogen exposure. A peak of carcinogen exposure may have occurred in the 1970s and 1980s before recent changes have reduced exposure.

• Safety and Health at Work
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• v.8 no.1
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• pp.105-115
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• 2017

Background: The goal of this study is to develop a general population job-exposure matrix (GPJEM) on asbestos to estimate occupational asbestos exposure levels in the Republic of Korea. Methods: Three Korean domestic quantitative exposure datasets collected from 1984 to 2008 were used to build the GPJEM. Exposure groups in collected data were reclassified based on the current Korean Standard Industrial Classification ($9^{th}$ edition) and the Korean Standard Classification of Occupations code ($6^{th}$ edition) that is in accordance to international standards. All of the exposure levels were expressed by weighted arithmetic mean (WAM) and minimum and maximum concentrations. Results: Based on the established GPJEM, the 112 exposure groups could be reclassified into 86 industries and 74 occupations. In the 1980s, the highest exposure levels were estimated in "knitting and weaving machine operators" with a WAM concentration of 7.48 fibers/mL (f/mL); in the 1990s, "plastic products production machine operators" with 5.12 f/mL, and in the 2000s "detergents production machine operators" handling talc containing asbestos with 2.45 f/mL. Of the 112 exposure groups, 44 groups had higher WAM concentrations than the Korean occupational exposure limit of 0.1 f/mL. Conclusion: The newly constructed GPJEM which is generated from actual domestic quantitative exposure data could be useful in evaluating historical exposure levels to asbestos and could contribute to improved prediction of asbestos-related diseases among Koreans.

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.651-657
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• 1994

To assess quantitatively the association between benzene exposure and leukemia, we examined the mortality rate of a cohort with occupational exposure to benzene. Cumulative exposure for each cohort member was estimated from historical air-sampling data and, when no sampling data existed, from interpolation on the basis of existing data. The overall standardized mortality ratio (a measure of relative risk multiplied by 100) for leukemia was 337 (95 percent confidence interval, 154 to 641), and that for multiple myeloma was 409 (95 percent confidence interval, 110 to 1047). With stratification according to levels of cumulative exposure, the standardized mortality ratios for leukemia increased from 109 to 322, 1186, and 6637 with increases in cumulative benzene exposure from less than 40 parts per million-years (ppm-years), to 40 to 199, 200 to 399, and 400 or more. respectively. A cumulative benzene exposure of 400 ppm years is equivalent to a mean annual exposure of 10 ppm over a 40-year working lifetime; 10 ppm is the currently enforceable standard in the United States for occupational exposure to benzene. To examine the shape of the exposure-response relation, we performed a conditional logistic-regression analysis, in which 10 controls were matched to each cohort member with leukemia. From this model, it can be calculated that protection from benzene induced leukemia would increase exponentially with any reduction in the permissible exposure limit.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.35-40
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• 2013

Objectives: Asbestos contents of crushed serpentine rocks and airborne fiber concentrations of workers were determined at two serpentine quarries and a steel mill. Methods: Bulk samples of uncrushed and crushed serpentine rocks were collected and analyzed by PLM and TEM. Airborne asbestos samples were collected from the breathing zone of workers and the vicinity of working area and analyzed by PCM and TEM. Results: Chrysotile was identified with antigorite, lizardite and non-asbestiform actinolite in bulk samples. The arithmetic means of chrysotile contents in crushed serpentines were 0.11, 0.01, 0.42%(W/W) by quarry A, quarry B and a steel mill, respectively. The asbestos concentrations of all personal samples were less than 0.1 f/cc which is the permissible exposure limit of workers in Korea. The arithmetic means of airborne asbestos concentrations were 0.017 f/cc and 0.009 f/cc in personal samples collected from two serpentine quarries. The asbestos concentrations of all personal samples collected from a steel mill were less than LODs by PCM analysis but asbestos was detected in area samples by TEM. By the job tasks of serpentine quarries, crusher/separator operation generated the highest exposure to airborne asbestos. Conclusions: Although chrysotile contents in crushed serpentines of quarries were less the permissible level, the highest exposure of workers in serpentine quarries reached up to 76% of the permissible level of airborne asbestos. There were also possibilities of occupational exposure to airborne asbestos in a steel mill. The present exposure study should encourage further survey and occupational control of quarries producing serpentine or other types of asbestos-bearing rocks.

• Safety and Health at Work
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• v.12 no.1
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• pp.74-95
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• 2021

Background: A job-exposure matrix (JEM) is an important surrogate indicator to evaluate past exposure levels. Although a Korean asbestos JEM has been constructed previously, this JEM includes only a few industrial and occupational groups. This study aimed to reconstruct the JEM by integrating the latest organized data to improve its utility. Methods: We used recent Korean standard industry and occupation codes and extracted 36 articles from a systematic literature review to initiate the reconstruction of the previous Korean asbestos JEM. The resulting data consisted of 141 combinations of industrial and occupational groups. Data from the Netherlands's JEM were also reviewed and categorized into 70 industrial and 117 occupational groups by matching with the Korean data. We also utilized Germany's data, which consisted of 10 industrial and 14 occupational groups. Results: The reconstructed Korean asbestos JEM had 141 combinations of industries and occupations. The time periods are from the 1980s to the 2000s in 10-year intervals. Most of the data were distributed between the 1990s and the 2000s. Occupations with high exposure to asbestos included knitting and weaving machine operators, automobile mechanics or assemblers, ship mechanics or assemblers, mineral ore and stone products processing mechanics, and metal casting machine operators or mold makers. Conclusions: The reconstructed Korean asbestos JEM has expanded the type and duration of the occupational groups of the previous JEM and can serve as an important reference tool for evaluating asbestos exposure and designing compensation and prevention policies in Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.191-199
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• 2012

Objectives: The study aim was to evaluate the application of a chemical exposure assessment tool for the Korean workplace. The Ministry of Employment and Labor in Korea (KMOEL) introduced the need for workplace risk assessments in 2011, requiring the Korean chemical industry to consider both domestic and international chemical regulation policies (e.g., estimations of exposure scenarios). Exposure scenarios are required in the European Union as part of material safety data sheets (MSDS) under the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) system. Methods: Although many programs for the estimation of exposure have been developed worldwide, to date there is no standard for the Korean workplace. To develop programs suitable for the Korean workplace, we examined the applicability of the European Center for Ecotoxicology and Toxicology of Chemicals target risk assessment (ECETOC TRA), which is recommended by the European Chemical Agency (ECHA). Results: To investigate the applicability of the ECETOC TRA to Korean industry, this study simulated 15 industrial processes. The predicted respiratory exposures for four processes using origin input parameters were underestimated compared to the measured respiratory exposure. Using calibrated input parameters, results for two processes were underestimated compared to the measured respiratory exposure. This result suggests that the use of calibrated input parameters reduces the differences between predicted and measured respiratory exposure. Conclusions: we developed applicable exposure estimating method by modifying the ECETOC TRA program; one suggested the development of exposure estimating program that explains Korea domestic workplace exposure scenario.This study will support the introduction of exposure scenario in MSDS system and protect health of worker from hazardous chemical.

• Safety and Health at Work
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• v.2 no.2
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• pp.122-134
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• 2011

Objectives: Seven cases of malignant lymphohematopoietic (LHP) disorder were claimed to have developed from occupational exposure at two plants of a semiconductor company from 2007 to 2010. This study evaluated the possibility of exposure to carcinogenic agents for the cases. Methods: Clinical courses were reviewed with assessing possible exposure to carcinogenic agents related to LHP cancers. Chemicals used at six major semiconductor companies in Korea were reviewed. Airborne monitoring for chemicals, including benzene, was conducted and the ionizing radiation dose was measured from 2008 to 2010. Results: The latency of seven cases (five leukemiae, a Non-Hodgkin's lymphoma, and an aplastic anemia) ranged from 16 months to 15 years and 5 months. Most chemical measurements were at levels of less than 10% of the Korean Occupational Exposure Limit value. No carcinogens related to LHP cancers were used or detected. Complete-shielded radiation-generating devices were used, but the ionizing radiation doses were 0.20-0.22 uSv/hr (background level: 0.21 ${\mu}Sv/hr$). Airborne benzene was detected at 0.31 ppb when the detection limit was lowered as low as possible. Ethylene oxide and formaldehyde were not found in the cases' processes, while these two were determined to be among the 263 chemicals in the list that was used at the six semiconductor companies at levels lower than 0.1%. Exposures occurring before 2002 could not be assessed because of the lack of information. Conclusion: Considering the possibility of exposure to carcinogenic agents, we could not find any convincing evidence for occupational exposure in all investigated cases. However, further study is needed because the semiconductor industry is a newly developing one.