• 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.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.4.1-4.11
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• 2015

Objectives: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). Methods: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. Results: Pb and Cd were the highest (median value) in the seaweed ($94.2{\mu}g/kg$ for Pb; $594{\mu}g/kg$ for Cd), and Hg was the highest in the fish ($46.4{\mu}g/kg$). The dietary exposure level (median value) of Pb was $0.14{\mu}g/kg$ body weight (bw)/d, $0.18{\mu}g/kg$ bw/d for Cd, and $0.07{\mu}g/kg$ bw/d for Hg. Those with a blood Pb level of less than $5.00{\mu}g/dL$ (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than $0.30{\mu}g/L$ (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than $5.00{\mu}g/L$ (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. Conclusions: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.506-511
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• 2022

In the Chemicals Control Act, a system was implemented to unify off-site risk assessment and risk management plan into the prevention and management system for chemical accidents. Among the hazardous chemicals which have been covered in system, the accident preparation substances are designated as chemical substances that are likely to occur and of which damage scale are likely to be large in the event of chemical accidents. In this study, risks were compared by selecting accident preparation substances with similar regulated quantities. In addition, risk assessment studies were conducted applying the accident scenarios. Four types of materials such as ammonia, hydrogen chloride, carbon disulfide and benzene were selected for the study, and risks were finally analyzed using Safeti 8.0, a quantitative risk assessment program by DNV. As a result, some materials are identified to have high risks comparing to other substances having similar regulated quantities.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.1
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• pp.141-160
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• 2021

Unit 1 of the Kori Nuclear Power Plant (NPP) and Unit 1 of the Wolsong NPP are being prepared for decommissioning; their decommissioning is expected to generate large amounts of intermediate-level, low-level, and very low level Waste. Mixed waste containing both radioactive and hazardous substances is expected to be produced. Nevertheless, laws and regulations, such as the Korean Nuclear Safety Act and Waste Management Act, do not define clear regulatory guidelines for mixed waste. However, the United States has strictly enforced regulations on mixed waste, focusing on the human health and environmental effects of its hazardous components. The U.S. Nuclear Regulatory Commission and the U.S. Department of Energy regulate the radioactive components of mixed waste under the Atomic Energy Act. The U.S. Environmental Protection Agency regulates the hazardous waste component of mixed waste under the Resource Conservation and Recovery Act. In this study, the laws, regulations, and authorities pertaining to mixed waste in the United States are reviewed. Through comparison and analysis with waste management laws and regulations in Korea, a treatment direction for mixed waste is suggested. Such a treatment for mixed waste will increase the efficiency of managing mixed waste when decommissioning NPPs in the near future.

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.176-184
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• 2017

Objectives: Excluding in their homes, children spend most of their time at an elementary school, daycare center, and/or kindergarten. For educational or recreational purposes, they make use of many children's goods at these places. Some children's goods contain phthalates and heavy metals with polyvinyl chloride (PVC), so due to their physiological and behavioral characteristics children are exposed to high concentrations of phthalates and heavy metals. This study aims to measure PVC and heavy metals, which are harmful substances in children's goods which can have an effect on children's health. Methods: Six samples of children's goods were selected through cases of detected harmful substances and the results of previous research, including assembly blocks, model toys, household toys, bags, indoor play equipment, and floor mats. The selected items were measured using X-Ray Fluorescence (XRF), and the presence and content of environmentally harmful substances such as PVC or heavy metals in the materials of children's goods were examined. Results: The highest detection rate for PVC was observed in floor mats, and bags and indoor play equipment were higher than other goods in this regard. The highest detection rate for heavy metals was found in bags, followed by indoor play equipment, assembly blocks, household toys, model toys and floor mats. Except for bags containing heavy metals, five goods showed the highest level of Pb compared to other heavy metals. Floor mats contained the highest level of Pb, Cr, and Cu among all goods. Conclusion: Many children's goods contain PVC and heavy metals, and high levels of heavy metals have been detected in some goods. It is necessary to manage children's goods to support their health.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.226-233
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• 2018

Small-scale wastewater discharge facilities account for 98% of all workplaces, but in the generation and emission of major pollutants, they account for 27.5 % and 23.5 %, respectively. Since the proportion of the emission load of the small-scale workplace is not large, the national environmental policy has been established mainly around large-scale wastewater discharge facilities. However, in the case of specific hazardous substances in water, the amount of the discharge load of the small-scale wastewater discharge facility was 2.4 times higher than that of the generation load. Certain types of specific hazardous substances in water, which have a higher discharge load than large-scale wastewater discharge facilities, account for 24 ~ 32 %. There are also cases in which the discharge load from a small-scale discharge facility is more than four times higher, depending on the specific kind of water pollutant. As a result of inspections, the violation rate of the small-scale wastewater discharge facility among the total violations by facilities is 93.9 ~ 97.5 %. As a result, the ecotoxicity value of small-scale wastewater discharge facilities was high in most industries, and there was a fluctuation in the measured value. This indicates that the ecological integrity of the water system can be largely influenced by small-scale wastewater discharge facilities. Therefore, it is necessary to expand the environmental management of small-scale wastewater discharge facilities, and in some cases, the effect of the improvement in quality may be more significant than in the management of large-scale wastewater discharge facilities.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.107-115
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• 2011

The purpose of the study is to analyze the environmental characteristics of fish acute toxicity that is dependent on the harmfulness of ACQ (Alkaline Copper Quat)-Treated Wood and Oryzias latipes mortality in a comprehensive way, provide objective verification method on the eco-toxicity and environment-friendliness of landscaping materials and methods, and utilize it as a basic datum for evaluation criteria. The main results are summarized as follows : 1. As a result of analysis on the harmfulness characteristics, each experimental plot showed different values respectively. In particular, it has been found that in proportion to the volume of testing materials, COD and Cu increases at a constant rate, compared to the input water. In the plot C with three testing materials, COD increased 67 times more than that of the input water, and Cu increased up to 12.36mg/L. 2. In case of fish toxicity, plot C, B, A all showed a mortality rate of 100%, indicating that fish toxicity is strong. In particular, the mortality rate of each plot within the initial time of one and a half hour showed clearly, which suggests that the fish toxicity is influenced by the increased concentration of hazardous substances depending on the volume ratio of testing materials. 3. As a result of comparison and analysis on the harmfulness and fish toxicity, the harmfulness showed different values on each experimental plot but, we found that the changing rate of values of toxicity of COD and Cu is mutually similar to that of mortality in the initial hour according to the experiment of fish toxicity, which shows that COD and Cu are major factors to increase fish toxicity.

• Journal of Environmental Analysis, Health and Toxicology
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• v.21 no.4
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• pp.209-219
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• 2018

In the areas of RoHS, WEEE, ELV and REACH, reinforcement of environmental regulations against harmful substances is a global trend not only in EC but also in all over the world. In the fields of Korea's major export products such as material parts, electrical and electronic products and automobile parts, we are responding to these regulations consistently. To develop reference material for analyzing lead and cadmium in paints, the candidate materials were produced through the screening process which separated shapes and sizes. To secure the traceability of the candidate materials produced, the characteristics and uncertainties are estimated by ICP-AES analysis using the primary reference material. The short-term and long-term stabilities also are evaluated in parallel. In order to calculate the final certification value of the candidate material, the verification were carried out by the performance evaluation through the comparison among the KOLAS (Korea Laboratory Accreditation Scheme) laboratories, and the CRM was produced in accordance with ISO Guide 35. The certified values and uncertainties of Pb and Cd of the final paint standard, determined according to the joint analysis among laboratories, are Pb [($191.4{\pm}3.1$) mg/kg, ($944.1{\pm}5.6$) mg/kg] and Cd [($45.0{\pm}2.6$) mg/kg, ($225.5{\pm}3.5$) mg/kg]. These standard materials were developed to enhance the reliability of measurement analysis, including the validity and traceability of measurement results. Also it is expected that the CRM will be used as QCM (quality control material) for the product design and the process monitoring, so that regulation and management of hazardous heavy metals can be systematically implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.142-145
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• 2019

In recent years, the global GEF(Green Energy Family) activities to preserve the global environment due to energy consumption have been implemented under the Kyoto Protocol for the Prohibition of Carbon Dioxide Emissions, RoHS (Restriction of Hazardous Substances directive), and WEEE(Waste Electrical and Electronice Equipment) are required to collect waste for the purpose of minimizing waste by integrating lighting and communication. In this paper, we constructed a controller that can control the illumination of RGB LED module by using fuzzy inference system and checking environmental factors(Illumination, distance to the subject, etc.) using microprocessor in real time.

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.160-168
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• 2018

Objectives: The purposes of the study were to investigate hazardous pollutant emissions changes among group 1 carcinogens. The emissions characteristics were compared with national cancer registration statistics. Methods: A survey of group 1 carcinogen hazardous pollutant emissions (trichloroethylene, benzene, vinyl chloride, formaldehyde, 1,3-butadiene, ethylene oxide, chromium and its compounds, 3,3'-dichloro-4,4-diaminodiphenylmethane, chloromethyl methyl ether, arsenic and its compounds, cadmium and its compounds, o-toluidine) was conducted through a homepage for 2001-2015. The emission of hazardous chemicals and the cancer trend analysis for 2001-2015 were performed using the Korean statistical information service through its homepage as a reference. Results: Emissions of more than 95% of the substances listed as group 1 carcinogens over the last five years were made up of trichloroethylene, benzene, vinyl chloride, formaldehyde, 1,3-butadiene, and ethylene oxide. As a result of the comparison of emission results and cancer incidence rates, carcinogen pollutant emissions showed a tendency to decrease continuously. In addition, the incidence of cancer tended to increase, but showed a tendency to decrease from 2012. Conclusion: The results indicate hazardous pollutant emissions have continued to increase. However, no association between emissions and health effects was shown and more research is needed.