• Journal of Environmental Health Sciences
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• v.37 no.5
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• pp.369-375
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• 2011

Objectives: Exposure to hazardous chemicals during pregnancy may result incritical reproductive health outcomes. Indoor residential levels are significant component of personal exposure. The collection of residential exposure data has been hampered by the cost and participant burden of health studies of indoor air pollution. This study utilized a participant-based approach to collect volatile organic compounds concentration from homes. Methods: Four hundred thirteen women were recruited from three major hospitals in Seoul and Gyeongi Provence and 411 agreed to participate. A passive sampler (OVM 3500, 3M, USA) with instructions were given to the participants, as well as a questionnaire. They were asked to deploy the sampler in their homes for three to five days and return them viapre-stamped envelope. Results: Three hundred forty six participants returned the sampler. Among the returned samplers, three hundred samplers satisfied our monitoring quality criteria. The success rate of the monitoring method was 73%. The geometric mean of TVOC level was 429(2) ${\mu}g/m^3$. The TVOC guideline of 500 ${\mu}g/m^3$ was exceeded in 38% of the houses. The residential VOC levels were significantly associated with remodeling of the house. Conclusions: The results suggested that a participant-based sampling approach may be a feasible and costeffective alternative to exposure assessment involving home visits by a field technician.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.283-292
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• 2018

Objectives: This study was conducted to identify hazardous factors that reflect the characteristics of the academy and to provide basic data of environmental safety standard. Methods: Heavy metals, volatile organic compounds, formaldehyde, pesticides and phthalates were measured in 20 academies, which were supplementary, music, art and physical education institutes. Results: In case of heavy metals, the 12 locations were detected for lead (Pb) over the standard value, and 15 locations were exceeded for the total heavy metal. In six locations, the concentrations of volatile organic compounds were exceeded the standard value of $400{\mu}g/m^3$, and two locations for formaldehyde were exceeded the standard value of $100{\mu}g/m^3$. The most commonly detected agents in the air dust were chlorpyrifos and diazinon. The concentrations of DEHP, DINP, and DBP were detected and exceeded in several academies, The risk assessment results showed that HCHO as carcinogen had a safety level of 10-7 to 10-6, and DEHP and DINP as non-carcinogens had a safety level as assessed to be under than 0.1. Conclusions: Through the investigation of long-term environmental and health effects related laws on academies, indoor air quality management might be needed because there were cases of exceeding standard.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.317-331
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• 2023

Objectives: Construction workers are exposed to various hazardous substances simultaneously. However, little is known about the exposure hazards in construction industry. This study was aimed at identifying the risk of exposure hazards among construction workers. Methods: The expert survey (n=29) was conducted, including construction industry health managers (n=11) and work environment monitoring experts (n=18), on exposure probability, intensity and risk of hazardous substances by construction occupations Results: The exposure hazards of 30 construction occupations were identified and summarized through a literature review and expert survey. The most prevalent hazards were in order of noise, awkward posture, heat/cold, crystalline silica, cement/concrete dust, metal fumes, and volatile organic compounds. The hazards with highest risk score(over seven points) at construction occupations were noise(formwork carpenter, concrete finisher, rebar worker, demolition worker, driller/rock blaster), hazardous rays(welder), heat/cold (earthworks, formwork carpenter, rebar worker, concrete placer, scaffolder), awkward posture(bricklayer, caulker/tile setter, rebar worker) and heavy lifting(bricklayer, rebar worker). Among construction workers, the job types with the highest risk of exposure to carcinogens, and in which occupational cancer has been reported, were in order of stonemason, concrete finisher, rock blaster, welder, insulation installer, painter, scaffolder, plant worker and earthworks in order Conclusions: Systematic research and discussion on occupational disease among construction workers and its various hazardous factors are needed to establish job exposure matrix for facilitating standard for promptly processing the workers' compensation.

• Safety and Health at Work
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• v.9 no.3
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• pp.352-355
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• 2018

Hazardous work zones (i.e., hot, warm, and cold) are typically established by emergency response teams during hazardous materials (HAZMAT) calls but less consistently for fire responses to segment personnel and response activities in the immediate geographic area around the fire. Despite national guidelines, studies have documented the inconsistent use of respiratory protective equipment by firefighters at the fire scene. In this case-series report, we describe warm zone gas levels using multigas detectors across five independent fire incident responses all occurring in a large South Florida fire department. Multigas detector data collected at each fire response indicate the presence of sustained levels of volatile organic compounds in the "warm zone" of each fire event. These cases suggest that firefighters should not only implement strategies for multigas detector use within the warm zone but also include respiratory protection to provide adequate safety from toxic exposures in the warm zone.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.86-94
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• 2020

This study serves as basic research for the development of a new wood-based building finishing material that improved the weakness of inorganic materials such as gypsum board and magnesium board widely used as interior finishing materials and brought out the strength of the wood. The results of evaluating the physical and mechanical properties and the environmental effect related to hazardous substance discharge having manufactured a wood-magnesium laminated composite are as follows. The thermal conductivity and thermal resistance of WML board was improved by about 28~109 percent over magnesium board due to the low thermal conductivity of wood. The adhesive strength of WML board showed a similar result to that of plywood as it exceeds 0.7N/㎟, the adhesive standard of wood veneer which is presented by KS F 3101. Bending strength and screw holding strength were more improved by manufacturing WML board than magnesium board. The WML board manufactured in this study satisfied the criteria for emissions of hazardous substances prescribed in the Indoor Air Quality Control Act, and confirmed the possibility of development as a new wood-based composite material that can replace existing inorganic materials.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.272-280
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• 2014

Objectives: The purpose of this study was to evaluate the characteristics of worker exposure to hazardous chemical substances and propose the direction of work environment management for protecting worker's health in the semiconductor assembly process. Methods: Four assembly lines at two semiconductor manufacturing companies were selected for this study. We investigated the types of chemicals that were used and generated during the assembly process, and evaluated the workers' exposure levels to hazardous chemicals such as benzene and formaldehyde and the current work environment management in the semiconductor assembly process. Results: Most of the chemicals used at the assembly process are complex mixtures with high molecular weight such as adhesives and epoxy molding compounds(EMCs). These complex mixtures are stable when they are used at room temperature. However workers can be exposed to volatile organic compounds(VOCs) such as benzene and formaldehyde when they are used at high temperature over $100^{\circ}C$. The concentration levels of benzene and formaldehyde in chip molding process were higher than other processes. The reason was that by-products were generated during the mold process due to thermal decomposition of EMC and machine cleaner at the process temperature($180^{\circ}C$). Conclusions: Most of the employees working at semiconductor assembly process are exposed directly or indirectly to various chemicals. Although the concentration levels are very lower than occupational exposure limits, workers can be exposed to carcinogens such as benzene and formaldehyde. Therefore, workers employed in the semiconductor assembly process should be informed of these exposure characteristics.

• Safety and Health at Work
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• v.10 no.1
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• pp.114-121
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• 2019

Background: The photolithography process in the semiconductor industry uses various chemicals with little information on their constitution. This study aimed to identify the chemical constituents of photoresist (PR) products and their by-products and to compare these constituents with material safety data sheets (MSDSs) and analytical results. Methods: A total of 51 PRs with 48 MSDSs were collected. Analysis consisted of two parts: First, the constituents of the chemical products were identified and analyzed using MSDS data; second, for verification of the by-products of PR, volatile organic compounds were analyzed. The chemical constituents were categorized according to hazards. Results: Forty-five of 48 products contained trade secrets in amounts ranging from 1 to 65%. A total of 238 ingredients with multiple counting (35 ingredients without multiple counting) were identified in the MSDS data, and 48.7% of ingredients were labeled as trade secrets under the Korea Occupational Safety and Health Act. The concordance rate between the MSDS data and the analytical result was 41.7%. The by-product analysis identified 129 chemicals classified according to Chemical Abstracts Service No., with 17 chemicals that are carcinogenic, mutagenic, and reprotoxic substances. Formaldehyde was found to be released from 12 of 21 products that use novolak resin. Conclusion: We confirmed that several PRs contain carcinogens, and some were not specified in the toxicological information in the MSDS. Hazardous chemicals, including benzene and formaldehyde, are released from PRs products as by-products. Therefore, it is necessary to establish a systematic management system for chemical compounds and the working environment.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.305-319
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• 2016

This study was carried out to evaluate the performance of two sampling methods, i.e., adsorbent tubes and canisters, for the measurement of ambient volatile organic compounds (VOCs). A total of 24 target VOCs were selected from a list of 48 priority hazardous air pollutants (HAPs) in Korea. The two sampling methods were investigated with a wide range of performance criteria such as repeatability, linearity, and lower detection limits. In addition, mean relative errors (MRE) and mean duplicate precisions (MDP) were estimated by inter-lab comparison studies for duplicate field samples. Precisions for the two methods appeared to be well comparable with the performance criteria recommended by USEPA TO-15 and TO-17 for canister and adsorbent methods, respectively. Correlations and variations between the VOCs concentrations determined by the two methods were generally good in most cases. However, MREs and MDPs for individual VOCs appeared to be widely ranged, depending on each VOC. This implies that the two methods have its own advantages and disadvantages in determining a variety of VOCs in ambient air, and neither of which has absolute superiority. Finally, 9 of 24 VOCs were found to be difficult to determine by either methods due to their unstability in a canister, and lack of appropriate standard materials. Thus, it is suggested that development of measurement methods for such unstable VOCs is an urgent task from a viewpoint of HAPs management.

• Journal of Environmental Health Sciences
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• v.33 no.4
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• pp.242-249
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• 2007

Indoor air quality has become a topic of interest and concern. Especially changes in construction design and the increased use of synthetic products may result in an increasing of complaints and health effects about the quality of indoor air at home. In this study, nitrogen dioxide($NO_2$) and volatile organic compounds(VOCs) within new and established apartments on the basis of 4 years of building year were measured every 3 days consecutively during 60 days. We selected each 10 house in Seoul, Asan and Daegu, respectively, and produced risk numbers for hazard quotients, and predicted increases in incidence of cancer. The calculations were made for the adult with default exposure values and also made for a worst case scenario using Monte-Carlo simulation as describing the reasonable exposure(RME). Mean of Monte carlo analysis by benzene, in the construction under 4 years (male: $9.2{\times}10^{-5}$, female: $1.0{\times}10^{-4}$) and over 4 years (male: $6.8{\times}10^{-5}$, female: $8.3{\times}10^{-5}$) exceeded $10^{-6}$ of permitted standards in US EPA, RME of Monte carlo analysis. In construction under 4 yews (male: $9.9{\times}10^{-3}$, female: $9.6{\times}10^{-3}$) and over 4 years (male: $9.8{\times}10^{-3}$, female: $7.8{\times}10^{-3}$) exceeded $10^{-4}$ of maximum permitted standards in US EPA. The hazard index of non-carcinogenic pollutants by nitrogen dioxide, toluene, m,p-xylene and o-xylene, both male and female in apartment constructed under 4 yews and over 4 years was found less than the permitted standards of hazardous health effects in CTE. Significant cancer risks and non-cancer hazard quotients were predicted in under 4 yews of building year.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.280-287
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• 2009

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.