• Journal of Environmental Health Sciences
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• v.44 no.4
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• pp.397-407
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• 2018

Objectives: The purpose of this study is to investigate human health risk assessment of indoor air pollutants at small-sized public-use facilities (e.g., daycare centers, hospital and elderly care facilities) that the susceptible population is mainly used. Methods: To assess indoor air quality (IAQ), the concentrations of indoor air contaminants such as HCHO, benzene, toluene, ethylbenzene, xylene, styrene, PM-10, CO, $NO_2$ and $O_3$ in air samples were measured according to the Indoor Air Quality Standard Method. By conducting the questionnaire survey, the major factors influencing IAQ were identified. Human health risk assessment was carried out in the consideration of type of use (user and worker) at 75 daycare centers, 34 hospitals and 40 elderly care facilities. Results: As a result of measurement of indoor air contaminants, the average concentration of HCHO and TVOCs in hospitals was higher than daycare centers and elderly care facilities, about 8.8 and 23.5% of hospitals were exceeded by IAQ standard. In human health risk assessment, for the user of daycare centers and elderly care facilities, the mean carcinogenic risk of HCHO inhalation was higher than acceptable value. Except for HCHO, other values were determined under acceptable risk. Similarly, for the worker of hospitals, the mean carcinogenic risk of HCHO inhalation was higher than acceptable value and other values were evaluated under acceptable risk. In contrast, the risk levels of other contaminants measured in elderly care facilities were acceptable. In the determination of factors influencing IAQ, the construction year, building type, ventilation time, and the use of air cleaner were identified. Conclusions: This study provides the information for establishing the plans of public health management of IAQ at small-sized public-use facilities that have not yet been placed under the regulation. The findings suggest the consideration of human health risk assessment results for the IAQ standards.

• Clean Technology
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• v.8 no.4
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• pp.205-215
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• 2002

Can industry has grown up with growth of packing industry and its recycling activation in recent years. But profit has became low by oversupply. Therefore, can industry needs a reduction of environmental load and official loss by an optimization of process in order to maintain its competitiveness. In this study, the main issues of aluminium can production was investigated by life cycle assessment. As a result of LCA, it examined closely by main issues that reduce defective cans and remove tramp oil. In the present work, it was recommended that setup of R/O system, sterillizing tramp oil separation, and heating system of DI water. The ROI investigated 6.4 months. The operating cost with the advanced processes could be reduced annually by 300 million won.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.5
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• pp.1-12
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• 1989

This short report describes the trend of exhaust emission control of the diesel engine vehicles in Korea, which originally was motivated from the newly proposed Emission Control Regulation of Diesel Engine Vehicles possible to be activated in 1991 by Korean Environmental Protection Agency. This short survey report has been prepared by the special working group of The Korea Society of Automotive Engineers (KSAE) on this particular subject. This report includes (1) estimation of portions of contribution of diesel engine vehicle emission to total air pollution, (2) comparison of proposals of new articles/regulations/laws in Korea with those of other selected countries such as USA, European countries, and Japan, (3) comparison of vehical emission control regulations in Korea with those in other selected countries, (4) technical aspects of possibilities of reduction of diesel engine vehicle emissions, (5) additional administrational aspects of technology development program, (6) social impact resulted from the severe emission control regulation on diesel engine vehicles, and (7) proposals, prepared by the special working group of the KSAE, on the emission control regulation of diesel engine vehicles, which can possibly bring better cleaner air released from the air pollution resulted from diesel engine exhaust emissions in real sense with minimal financial contribution, with optimal technological efforts, with less social impacts, within five to ten year period.

• Clean Technology
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• v.22 no.1
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• pp.62-72
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• 2016

These days, it seems to be a core time to build proactive prevention systems for small and medium sized enterprises due to the reinforced safety in the production process and the strong environmental regulations (ES) both at home and abroad. On the other hand, a network of experts that combines the industrial environment and production safety as well as even the knowledge services companies are not quite enough to prepare to support them. In this study, through a survey of experts the current statue of the convergence of industrial environment and production safety were reviewed, and the structure of knowledge ES cluster was proposed to overcome this current state. Detailed strategies such as the development and distribution of ES convergence methodology, ES efficiency analysis and an ES roundtable.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1326-1327
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• 2008

Recently, the air pollution is supposed is to be the most serious environmental problem. Therefore, a small air cleaner is asked to make comfortable indoor environment for the moderns who have frequent indoor activity. In this study, without generating of the second pollution source, dust in the air and harmful microorganisms can be removed by the electric dust collecting technology which has high reliability and efficiency to be able to remove the impurities even though it is just 0.01${\mu}m$. Accordingly, power sources of the dust collector use, it is not inefficiency and offering to dust collector unstable. In order to overcome the point at issue, a this study, for power factor compensating use the PFC circuit, for removing the noise use EMI filter and for generating the hight voltage use the Cockcroft Walton Circuit. And we study power source on characteristic and improvement.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.52-59
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• 2012

Objectives: The purpose of this study was to evaluate the exposure possibility of by-products during the semiconductor manufacturing processes. Methods: The authors investigated types of chemicals generated during semiconductor manufacturing processes by the qualitative experiment on generation of by-products at the laboratory and a literature survey. Results: By-products due to decomposition of photoresist by UV-light during the photo-lithography process, ionization of arsine during the ion implant process, and inter-reactions of chemicals used at diffusion and deposition processes can be generated in wafer fabrication line. Volatile organic compounds (VOCs) such as benzene and formaldehyde can be generated during the mold process due to decomposition of epoxy molding compound and mold cleaner in semiconductor chip assembly line. Conclusions: Various types of by-products can be generated during the semiconductor manufacturing processes. Therefore, by-products carcinogen such as benzene, formaldehyde, and arsenic as well as chemical substances used during the semiconductor manufacturing processes should be controlled carefully.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.1-15
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• 2018

Nation-wide systematic and comprehensive measurements of air quality criteria species have been made over 340 sites currently in Korea since 1990. Using these data, temporal and spatial trends of $SO_2$, $PM_{10}$, $NO_2$, $O_3$, CO and $O_x(NO_2+O_3)$ were analyzed to characterize and evaluate implementing efficiency of air quality policy and regulations. Due to strict and effective policy to use cleaner fuels in late 1980s and 1990s, the primary pollutants, such as $SO_2$, CO, and $PM_{10}$ decreased sharply by early 2000s in all parts of Korea. After this period, their concentrations declined with much lower rates in most parts of Korea. In addition, isolated but noticeable numbers of places, especially in major ports, newly developing towns and industrial parks, sustained high levels or even showed further degradation. Despite series of emission control strategies were enforced since early 1990s, $NO_2$ concentrations haven't changed much till 2005, due to significant increase in number of automobiles. Nevertheless, we confirmed that the staggering levels of $NO_2$ and $PM_{10}$ improved evidently after 2005, especially in Seoul Metropolitan Area (SMA), where enhanced regulations for $NO_2$ and $PM_{10}$ emissions was imposed to automobiles and large emission sources. However, their decreasing trends were much lessened in recent years again as current air quality improvement strategies has been challenged to revise further. In contrast to these primary species, annual $O_3$, which is secondary product from $NO_2$ and volatile organic compounds (VOCs), has increased consistently with about 0.6 ppbv per year in every urban part of Korea, while yearly average of daily maximum 8-hour $O_3$ in summer season had a much higher rate of 1.2 ppbv per year. Increase of $O_3$ can be explained mainly by reductions of NO emission. Rising background $O_3$ in the Northeast Asia and increasing oxidizing capacity by changing photochemistry were likely causes of observed $O_3$ increase. The future air quality policy should consider more effective ways to lower alarming level of $O_3$ and $PM_{10}$.

• Particle and aerosol research
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• v.18 no.3
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• pp.51-59
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• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.

• Clean Technology
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• v.18 no.4
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• pp.440-445
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• 2012

15 carbon footprint product (CFP) schemes, including Korea Carbon Footprint Label, UK Carbon Trust's Carbon Reduction Label and Japan CFP are implemented in the world. A CFP describes green house gases (GHGs) emissions emitted throughout product's life cycle and is intended to reduce GHGs emissions by labeling a CFP result on product. This study calculates Korea, UK and Japan CFP result of vacuum cleaner, detergent, packagin material in order to analyze the Korea, UK and Japan CFP standards. Our results demonstrate significant differences among then calculated results because of criteria, emission factors, etc. Therefore, there are many difficulties in providing various CFP results and the international standard and guidelines for product category are needed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.5
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• pp.1-14
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• 2020

In order to improve the urban thermal environment, efforts are being made to increase green areas in cities that include park construction, planting, and green roofing. Among these efforts, urban parks play an important role not only in improving the urban thermal environment, but also in terms of ecosystem services (serving as resting places for citizens, providing cleaner air quality, reducing noise, etc.). Therefore, the purpose of this study is to suggest planning and management guidelines for urban parks that are effective in improving the thermal environment, by analyzing the urban surface temperature reduction performance of urban parks. To do this, first, land surface temperature was calculated by using Landsat 8 images. Second, the PCI (Park Cool Island) index was calculated to identify the temperature reduction performance of urban parks. Third, the characteristics of parks (area, shape, vegetation) and the surrounding spatial characteristics (land cover, building-related variables, etc.) were identified. Finally, the relationship between the PCI indices (PCI scale, PCI effect, PCI intensity) and the characteristics of the parks and their surroundings were analyzed. The results revealed that the parks consisting of a larger area, simple shape, and higher tree coverage ratio had increased PCI performance, and were advantageous for improving the urban thermal environment. Meanwhile, PCI performance was found to have decreased in areas with a higher impermeable area ratio and building coverage ratio. The outcomes of this study can be used to identify priority areas for planning and management of urban parks and can also be utilized as planning and management guidelines for improving urban thermal environment.