• Journal of Korean Society of Environmental Engineers
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• 제36권8호
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• pp.528-533
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• 2014

Recently, people interest in environmental pollution and attempt to improve the indoor air quality contaminated with various pollutants since it is very important to construct healthy and comfortable living environment. In the current study, we used the technology that has first received the certification of green technology for improving the removal efficiency of malodor causing substances. This green technology is a new technology to increase the reactivity of the odorous substances with OH radicals for oxidation reaction by using an infrared lamp in the existing air purification system. Comparing the efficiency of the green technology with the infrared lamp to that of the existing technology of air cleaner, there was a difference in the decomposition efficiency depending on the initial concentrations and speciation of the odorous substances. The removal efficiencies of contaminants were enhanced by 16.9 and 13.2% at low and high concentrations, respectively.

• Analytical Science and Technology
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• 제30권6호
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• pp.329-337
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• 2017

A major concern regarding most auto-repair shops in residential areas is the emission of odorous volatile organic compounds (VOCs) into the local atmosphere, especially during painting operations. VOCs contribute to poor local air quality and are responsible for the perceived odor and discomfort experienced by local residents. Sixteen major VOCs (6 aromatic hydrocarbons and 10 aliphatic carbonyl compounds) were selected as potential target compounds. The site was an auto-repair shop located in a central region of Seoul, South Korea, where the air quality of the site has been a subject of residents' complaints. The sampling points were as follows: 1) in the painting booth with new (NB) or old (OB) removal system, (2) in the exhaust duct after new (ND) or old (OD) odor removal filter, and (3) 2 m below the discharge vent (4 m above the ground) (outdoor air, OA). Each sample was coded: (1) before painting (BP), (2) during painting (DP), and (3) after painting (AP). The toluene level in the duct with the new removal filter during painting (ND-DP) was 1.5 ppm (v/v), while it was 3.8 ppm (v/v) in the right duct with an old removal filter during painting (OD-DP). Accordingly, the effect of filter replacement was reflected by differences in VOC levels. Therefore, accurate monitoring of odorous VOCs is an important step to reduce odor nuisance from local sources.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제21권12호
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• pp.715-732
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• 2009

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

• KIEAE Journal
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• 제12권4호
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• pp.77-82
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• 2012

This study conducted the experiment of reduction of Volatile Organic Compounds(VOCs) and Formaldehyde concentration by Native plants, Fatsia japonica and Ardisia pusilla. The two plants are advantageous in that they are highly available as they grow wild, and being easy to get. Fatsia japonica is a plant of its wide and large leaf diverged 7 or 8 parts, which is thought to have a high effect of air purification. Ardisia pusilla has a smaller leaf than Fatsia japonica, which is characterized by more leaves and beautiful. Field measurements were performed using Fatsia japonica and Ardisia pusilla which were verified as air-purifying plants in Korea. The effect of reducing the concentration of VOCs and Formaldehyde by plant studied in a full scale mock-up model. The dimensions of the two models were equal. The concentration of Benzene, Toluene, Ethylbenzene, Xylene, Stylene, Formaldehyde were monitored, since they were known as most toxic materials. The concentration of VOCs was monitored three hours after the plants were placed and three days after the plants were placed. Field measurements were performed in models where the plants were placed and were not. As a result, they had all an effect of reducing pollution. In all cases of experiment of planting and growing volume, the more planting volume, the more excellent the effect. Toluene was more effective in Fatsia japonica and Ardisia pusilla planted, Formaldehyde was more effective in Fatsia japonica planted respectively. In planting and growing and placing experiment, the placement at sunny spot was more effective than that at scattered growing. When Fatsia japonica was placed at sunny spot, the reduction effect of Formaldehyde was the most excellent, and when Ardisia pusilla was placed at sunny spot, the reduction effect of Toluene was the most effective.

• Journal of Korean Society of Environmental Engineers
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• 제27권6호
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• pp.606-613
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• 2005

The badge-type diffusive sampler for the measurement of formaldehyde in indoor air using three types of colorimetric methods such as chromotrophic acid(CTA), 3-methyl-2-benzothiazolinone hydrazone(MBTH), and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole(AHMT) method. The washing of the collection filter with several cleaning solution was effected with satisfactory results, regardless of the types of cleaning solutions. The concentrations of absorbance solution in each colorimetric method were experimentally determined by considering the sampling rates. The variation blank values in each colorimetric method was below 15%. As compared with CTA and AHMT methods, the reproducibility of MBTH method was excellent and was below 10% relative standard deviation. The collected formaldehyde mass and time-weighted concentration had a good correlation (correlation coefficient > 0.93). The limit of detection and limit of quantitation, and minimum sampling time were closely correlated to the sampling rates for the measurement of formaldehyde in each method.

• Journal of Environmental Health Sciences
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• 제37권5호
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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 odor and indoor environment
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• 제16권3호
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• pp.277-286
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• 2017

The objectives of this study were to investigate the effects of $PM_{10}$ and $O_3$ concentration on the symptoms of allergic diseases. The questionnaire was used to determine whether or not symptoms of allergic diseases were present from September to October 2012. The air pollution concentration data used was the corresponding point CEM (continuous emission monitoring) data. The average concentration of $PM_{10}$ was $56.09{\mu}g/m^3$ in the control area, and the concentration in the exposed area was $40.44{\mu}g/m^3$. In the two areas, concentration of $O_3$ was 28.73 ppb and 28.74 ppb, respectively. The total average concentrations of $PM_{10}$ and $O_3$ were $45.66{\mu}g/m^3$ and 28.73 ppb in the Gwangyang area. The rate of asthma diagnosis was higher in the control area (9.6%) than in the exposed area (4.1%), but the rate of allergy eye disease was higher in the exposed area (23.9%) than in the control area (16.5%). There was a significant difference in the symptoms of some allergic diseases when the relative concentration of $PM_{10}$ and $O_3$ were high and low.

• Journal of Environmental Health Sciences
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• 제49권4호
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• pp.218-227
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• 2023

Background: Since 2019, the Ministry of Environment has implemented a seasonal fine dust management system from December to March, targeting high PM_2.5 levels with the aim of reducing PM_2.5 concentrations and protecting public health. The focus of improving the seasonal management system lies in the atmospheric PM_2.5 levels. Considering the primary goal of protecting public health, it is necessary to analyze the policy effects from an exposure perspective rather than a concentration-based approach. Objectives: This study aims to quantitatively assess the improvement of indoor PM_2.5 levels and the health impacts of the seasonal management system by comparing the periods before and during its implementation in residential environments. Methods: PM_2.5 concentrations within residential environments in a metropolitan area were measured using an optical particle counter (IAQ-C7, K-weather, Ltd, Korea) at one-minute intervals during the pre-implementation period (November 21~25, 2022) and during the implementation period (December 19~23, 2022). Based on the measured PM_2.5 concentrations, a quantitative evaluation of cancer and mortality risks was conducted according to age and gender. Results: The results of comparing indoor and outdoor PM_2.5 concentrations before and during the implementation of the seasonal management system showed a decrease of approximately 56.6% and 47.9%, respectively. Health risk assessments revealed that both the safety-limit-based and safety-target-based Hazard Quotients (HQ) exceeded the threshold of 0.1 for children under 19 years of age, both before and after the implementation. The mortality risk decreased by approximately 47.9% after the implementation, with children aged 0-9 showing the highest mortality risk at 0.9%. Conclusions: The findings of this study confirmed the positive health impacts of the seasonal management system across all age groups, particularly children under 19 who are more vulnerable to fine dust exposure.

• Environmental Engineering Research
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• 제21권3호
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• pp.241-246
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• 2016

This paper discusses the influence of organic matter contained in aggregate on the emission characteristic of ammonia ($NH_3$) from cement mortar. $NH_3$ can be released to indoor-outdoor environment through diffusion in mortar (or concrete) and have resulted in the increasing air pollution, and especially well known as a harmful gas for the human body. The concentration of $NH_3$ released from cement concrete was then compared to the contents of organic matter contained in the aggregate. The result indicates that the contents of organic matter in the aggregate significantly differ with types of aggregate from different areas of production. The organic matter becomes organic nitrogen through the process of microbial breakdown for a certain period and pure ammonium ion ($NH_4{^+}$) is produced from the organic nitrogen. The $NH_4{^+}$ was reacted with alkaline elements in the cement and released as $NH_3$ from cement concrete through a volatile process. The released $NH_3$ was proportional to the contents of $NH_4{^+}$ adsorbed in the aggregate from different areas of production and the concentrations of $NH_3$ emission from cement mortar according to the aggregate differ by more than 4 times.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 한국환경생물학회 2004년도 학술대회
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• pp.1-15
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• 2004

Higher plants can be valuable genetic assay systems for monitoring environmental pollutants and evaluating their biological toxicity. Two assays are considered ideal for in situ monitoring and testing of soil, airborne and aqueous mutagenic agents; the Tradescantia stamen hair assay for somatic cell mutations and the Tradescantia micronucleus assay for chromosome aberrations. Both assays can be used for in vivo and in vitro testing of mutagens. Since higher plant systems are now recognized as excellent indicators and have unique advantages over in situ monitoring and screening, higher plant systems could be accepted by regulatory authorities as an alternative first-tier assay system for the detection of possible genetic damages resulting from the pollutants or chemicals used and produced by industrial sectors. It has been concluded that potential mutagen and carcinogen such as the heavy metals among indoor air particulates, volatile compounds in the working places, soil, and water pollutants contribute to the overall health risk. This contribution can be considerable under certain circumstances. It is therefore important to identify the level of genotoxic activity in the environment and to relate it to the biomarkers of a health risk in humans. The results from the higher plant bioassays could make a significant contribution to assessing the risks of pollutants and protecting the public firom agents that can cause mutation anuor cancer. The plant bioassays, which are relatively inexpensive and easy to handle, are recommended for the scientists who are interested in monitoring pollutants and evaluating their environmental toxicity to living organisms.