• 한국산업보건학회지
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• 제19권3호
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• pp.307-320
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• 2009

This study was conducted not only to review airborne asbestos levels reported in workplaces in Korea, but also to analyze their levels according to various characteristics All asbestos concentration reported as either geometric mean (GM) and geometric standard deviation (GSD) or ranges were transformed to arithmetic mean to estimate exposure level. In addition, weighted arithmetic means (WAMs) were calculated to weigh asbestos levels based on the different number of samples. Differences of asbestos levels among several characteristics such as industry type, decade, operation and sampling and analytical methods were analyzed using analysis of variance (ANOVA). The number of articles studying asbestos levels from workplaces was found to be 9 including two report types. Five of those were reported prior to 1990s and rest of them after 1990s. Only several industries such as asbestos textile, asbestos cement, brake-lining repair shops were studied, while various industries using asbestos or asbestos containing materials (ACMs) were not studied. ANOVA found that asbestos exposure levels (WAM = 5.26f/cc) reported from textile industry were significantly higher than those from other industries (cement = 0.63f/cc, brake-lining = 0.2f/cc - 0.47f/cc) (p < 0.0001). Average exposure levels studied prior to the 1990s (3.13f/cc) were found to be significantly higher than that (0.86f/cc) after the 1990s (p<0.0001). All WAMs reported until the 1994 were found to be higher than the current occupational exposure limits (0.1f/cc). This study recommends that retrospective exposure to asbestos based on various industry types and operations should be assessed.

• 한국산업보건학회지
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• 제22권1호
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• pp.42-51
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• 2012

Objectives: To compare the exposure level of extremely low frequency (ELF) magnetic fields among semiconductor workers, shipyard welders and office workers. Methods: To measure the ELF magnetic field concentration, EMDEX LITE (Enertech, USA) were used and monitored for eight hours continuously. Five companies handling the electric and magnetic field (EMF) source were investigated, which the exposure groups were classified into three groups: semiconductor workers, welders, and office workers. Welder group was chosen as a high exposed group and office group as a low exposed group. Results: The arithmetic mean (${\pm}SD$) and geometric mean (GSD) of personal exposure level of semiconductor workers were 0.73 (${\pm}1.33$) ${\mu}T$, 0.43 (2.88) ${\mu}T$, respectively. The ceiling value ranged between 0.18 and 123.2 ${\mu}T$. Welders were exposed high with the arithmetic mean value of 3.46 (${\pm}\;13.46$) ${\mu}T$ and geometric mean value of 0.45 (4.70) ${\mu}T$, respectively, and ceiling value range of 75.5~129.6 ${\mu}T$. The exposure levels of office workers were low compared to other exposed groups; the arithmetic mean 0.05 (${\pm}0.13$) ${\mu}T$, geometric mean 0.03 (2.38) ${\mu}T$ and ceiling value range 0.37~3.35 ${\mu}T$. This study revealed statistically significant differences of the mean ELF magnetic field exposure doses among three groups (p < 0.01). Conclusions: The average ELF magnetic field exposure doses of semiconductor workers were much higher than those of office workers in control group, but were lower than those of welders in high exposure group.

• 한국산업보건학회지
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• 제20권1호
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• pp.63-69
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• 2010

This study was conducted to compare the concentration of various air contaminants in nine different laboratories during routine activities. Volatile organic compounds (VOC) were sampled and analyzed using NIOSH Method 1500 and asbestos fibers were sampled and analyzed using NIOSH Method 9002 and 7400. Detectable levels of acetone, toluene and ethanol were found in all the laboratories and xylene and n-hexane were detected in eight of the nine laboratories. All the VOC concentrations were well below the Korean Ministry of Labor's Exposure Limit and American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs). Total VOC concentrations at the university laboratories were significantly higher than those at governmental agency laboratories. Airborne fiber concentrations were below 0.01 fibers/cc, while the concentration of chrysotile was 2% in insulation materials sprayed on the ceiling of one laboratory. While all the governmental agency laboratories (n=4) had fume hoods, two out of the five university laboratories did not have fume hoods. The capture velocity of half of the fume hoods were below the maintenance standard(0.4 m/sec). In conclusion, the study suggests that the current controls in place at both university and government agency laboratories are not sufficient in limiting exposure to harmful chemicals to non-detectable levels, though they appear to be adequate in protecting workers to levels below applicable occupational exposure limits. The study also suggests that researchers working in university laboratories may be exposed to greater levels of contaminant than those working in government agency laboratories.

• 한국산업보건학회지
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• 제27권1호
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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.

• 한국환경보건학회지
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• 제44권5호
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• pp.460-467
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• 2018

Objectives: The objectives of this study are to estimate the inhalation exposure level of benzene for workers using Tier 1 exposure models ECETOC TRA (European Center for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment) and Stoffenmanager, and to investigate their reliability for exposure assessment in K-REACH. Methods: Two exposure scenarios, 'manufacture of benzene' and 'use as solvents,' were developed for assessment of workers' exposure to benzene. The Process Category (PROC) for ECETOC TRA was collected from the European Chemical Agency (ECHA) registration dossier, and the Activity for Stoffenmanager was converted from PROC using translation of exposure models (TREXMO). The information related to exposure, such as working duration, Respiratory Protective Equipment (RPE), Local Exhaust Ventilation (LEV), and Risk Management Measure (RMM) were classified into high, medium, and low exposure conditions. The risk was determined by the ratio of the estimated exposure and occupational exposure limits of benzene. Results: Under high exposure conditions, the worker exposure level calculated from all PROCs and Activities exceeded the risk level, with the exception of PROC 1 and Activity 1. In the medium exposure condition, PROC 8a, 8b, and 9 and Activity 3, 7, and 8 all exceeded the risk, whereas in the low condition, all PROCs and Activities were determined to be safe. As a result, action corresponding with the low exposure condition is required to reduce the risk of exposure among workers in workplaces where benzene is manufactured or used as a solvent. In addition, the predicted exposure levels derived from the exposure models were lower than measured levels. The exposure levels estimated from Stoffenmanager were more conservative than those from ECETOC TRA. Conclusions: This study demonstrates the feasibility of exposure models for exposure assessment through the example of occupational inhalation exposure assessment for benzene. For more active utilization of exposure models in K-REACH, the exact application of collected information and accurate interpretation of obtained results are necessary.

• 한국산업보건학회지
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• 제33권4호
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• pp.455-463
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• 2023

Objectives: The aim of this study was to develop an air sampling and analytical method for estimating worker exposure to linear carbonate solvents and to evaluate the method. Methods: The target substances were three linear carbonates: DMC, DEC, EMC. GC/FID was used for sample analysis. Laboratory experiments were conducted to determine desorption solvents and sample capacity, and to evaluate storage stability, accuracy, and precision. Results: Coconut Shell Charcoal (CSC, 100/50 mg) was used as the air sampling media, and a desorption solvent of 5% methanol/95% dichloromethane was selected. Recommended sampling capacities were 1~11 ℓ for DMC, 1~18 ℓ for DEC, and 1~24 ℓ for EMC. The stability of three linear carbonates was demonstrated over 30 days in a refrigerator (4℃). Detection limits were determined as follows: DMC 0.26 ㎍/sample, DEC 0.24 ㎍/sample, and EMC 0.25 ㎍/sample. The total coefficient of variation was calculated as DMC 0.064, DEC 0.079, and EMC 0.07. Conclusions: This sampling and analysis method is suitable for estimating personal exposure to linear carbonates in the workplace.

• Safety and Health at Work
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• 제2권4호
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• pp.355-364
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• 2011

Objectives: Though sulfur dioxide (SO2) is used widely at workplaces, itseffects on humans are not known. Thresholds are reportedwithout reference to gender or age and occupational exposure limits are basedon effects on lung functioning, although localized effects in the upper airways can be expected. This study's aim is to determine thresholds with respect to age and gender and suggests a new approach to risk assessment using breathing reflexes presumably triggered by trigeminal receptors in the upper airways. Methods: Odor thresholds were determined by the ascending method of limits in groups stratified by age and gender. Subjects rated intensities of different olfactory and trigeminal perceptions at different concentrations of $SO_2$. During the presentation of the concentrations, breathing movements were measured by respiratory inductive plethysmography. Results: Neither age nor gender effects were observed for odor threshold. Only ratings of nasal irritation were influenced bygender. A benchmark dose analysis on relative respiratory depth revealed a 10%-deviation from baseline at about 25.27 mg/$m^3$. Conclusion: The proposed new approach to risk assessment appearsto be sustainable. We discuss whether a 10%-deviation of breathingdepth is relevant.

• Safety and Health at Work
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• 제2권4호
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• pp.375-379
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• 2011

Control Banding (CB) strategies to prevent work-related illness and injury for 2.5 billion workers without access to health and safety professionals has grown exponentially this last decade. CB originates from the pharmaceutical industry to control active pharmaceutical ingredients without a complete toxicological basis and therefore no occupational exposure limits. CB applications have broadened into chemicals in general - including new emerging risks like nanomaterials and recently into ergonomics and injury prevention. CB is an action-oriented qualitative risk assessment strategy offering solutions and control measures to users through "toolkits". Chemical CB toolkits are user-friendly approaches used to achieve workplace controls in the absence of firm toxicological and quantitative exposure information. The model (technical) validation of these toolkits is well described, however firm operational analyses (implementation aspects) are lacking. Consequentially, it is often not known if toolkit use leads to successful interventions at individual workplaces. This might lead to virtual safe workplaces without knowing if workers are truly protected. Upcoming international strategies from the World Health Organization Collaborating Centers request assistance in developing and evaluating action-oriented procedures for workplace risk assessment and control. It is expected that to fulfill this strategy's goals, CB approaches will continue its important growth in protecting workers.

• 한국산업보건학회지
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• 제34권2호
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• pp.166-178
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• 2024

Objectives: The 12 occupational exposure limits(OELs) for chromium and its compounds in Korea were set by applying the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs). However, this is significantly different from the TLVs after the existing TLVs were integrated and withdrawn in 2018, so it is necessary to review the revision. Methods: Various documents related to chromium OELs were reviewed, including the ACGIH TLV Documentations for chromium and its compounds. A field survey was conducted targeting workplaces handling chromium and its compounds. Based on this, a revised OELs were proposed and a socio-economic evaluation was conducted. Results: The OELs for chromium compounds in Korea was first enacted in 2002, and in 2007, the OELs for chromium (hexavalent) compounds (insoluble) was lowered from 0.05 mg/m³ to 0.01 mg/m³. In 2008, the OELs for strontium chromate was newly established as 0.0005 mg/m³, and in 2018, the OELs for calcium chromate was newly established as 0.001 mg/m³. Total chromium and hexavalent chromium were measured for each of 6 samples at 2 welding sites, 4 plating sites, and 2 spray coating sites. When omparing the average of the results measured by ICP, a total chromium analysis method, and the analysis results by IC, a hexavalent chromium analysis method, only workplace 4 was the same, and total chromium was evaluated more, and total chromium was evaluated at 0.0004 to 0.0027 mg/m³. And hexavalent chromium was evaluated as non-detection ~ 0.0014 mg/m³. Amendment ①: The exposure standard for hexavalent chromium is not divided into water soluble, insoluble, chromium ore processing, and other hexavalent chromium compounds, and is integrated into 0.01 mg/m³, which is the level of chromium (hexavalent) compound (insoluble)., OELs for chromium (metal) and chromium (trivalent) compounds are integrated into chromium (trivalent) compounds, and the exposure level is maintained. Amendment ②: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.005 mg/m³, which is the OELs of OSHA, and there is a grace period of 4 years. Amendment ③: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.0002 mg/m³, which is the exposure standard of ACGIH, and there is a grace period of 5 years. Conclusions: Amendment ①: The change in the OELs is insignificant, so the cost required is small, and the benefit/cost ratio is greater than 1, so there is no problem in applying the amendment. Amendment ②: In all scenarios except chromium 6(insoluble), the benefit/cost ratio is greater than 1, so it is thought that there will be no major problem in applying the amendment. Amendment ③: Since the benefit/cost ratio is less than 1 in all scenarios, it is thought that the total social benefit that can be obtained when applying the amendment is not large.

• 한국환경보건학회지
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• 제49권2호
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• pp.57-65
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• 2023

Background: The association between exposure to extremely low frequency-magnetic fields (ELF-MF) and childhood leukemia has been controversial. There is a need to clarify this relationship by summarizing key conclusions from systematic review articles. Objectives: The major aim of this study is to summarize key conclusions from systematic review articles on the association between exposure to ELF-MF and childhood leukemia based on childhood exposure to ELF-MF, proximity from childhood household to high voltage cables, and parental occupational exposure to ELF-MF. Methods: This study was conducted through a brief literature review focusing on systematic, meta-analysis, and pooled analysis methods. We conducted a literature search in PubMed using the key words "ELF-MF" and "childhood leukemia" singly or combined. Results: In 2002, the World Health Organization (WHO)'s International Agency for Research on Cancer (IARC) reviewed two manuscripts to conduct pooled analysis and concluded that there is a significant association between exposure to >0.3 μT or 0.4 μT and childhood leukemia. We found a total of four manuscripts for systematic or pool analysis that have been published since the IARC's conclusion. They consistently concluded that there was a significant association between exposure to >0.4 μT and childhood leukemia compared to ELF-MF exposure to below 0.1 μT. The proximity of children's households to high voltage cable lines and occupational exposure by their parents to ELF-MF during certain periods prior to or during pregnancy were inconsistently associated with childhood leukemia. The study found that many EU countries have implemented precautionary policies to prevent potential childhood leukemia due to exposure to ELF-MF. Conclusions: This study recommends implementing a precautionary policy that includes legal exposure limits for ELF-MF to minimize exposure to ELF-MF.