• 유통과학연구
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• 제17권7호
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• 한국환경보건학회지
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• 제30권2호
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• pp.92-97
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• 2004

Three methods for VOCs emissions control in indoor air are reduction at the source, ventilation between indoor and outdoor, and removal. The best alternative should be to replace highly emitting sources with sources having low emissions, but the pertinent information on VOCs is not always available from manufactures. Other ways of improving indoor air quality are needed. It is to increase the outside fresh-air flow to dilute the pollutants, but this method would generally provide only a dilution effect without destruction in residence. An ideal alternative to existing technologies would be a chemical oxidation process able to treat large volumes of slightly contaminated air at normal temperature without additional oxidant such as ozone generator and ion generator. Photocatalytic oxidation(PCO) represents such a process. It is characterized by a surface reaction assisted by light radiation inducing the formation of superoxide, hydroperoxide anions, or hydroxyl radicals, which are powerful oxidants. In comparison with other VOCs removal methods, PCO offers several advantages. The purpose of this study was to explore the possibilities for photocatalytic purification of slightly contaminated indoor air by using visible light such as flurescent visible light(FVL). In this study, a PCO of relatively concentrated benzene using common FVL lamps was investigated as batch type and total volatile organic compounds(TVOCs) using a common FVL lamp and penetrated sun light over window. The results of this study shown the possibility of TiO$_2$ photocatalyst application in the area of indoor air quality control.

• 인간식물환경학회지
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• 제21권6호
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• pp.445-460
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• 2018

Exposure to indoor air pollution is an emerging world-wide problem, with growing evidence that it is a major cause of morbidity worldwide. Whilst most indoor air pollutants are of outdoor origin, these combine with a range of indoor sourced pollutants that may lead to high pollutant levels indoors. The pollutants of greatest concern are volatile organic compounds (VOCs) and particulate matter (PM), both of which are associated with a range of serious health problems. Whilst current buildings usually use ventilation with outdoor air to remove these pollutants, botanical systems are gaining recognition as an effective alternative. Whilst many years research has shown that traditional potted plants and their substrates are capable of removing VOCs effectively, they are inefficient at removing PM, and are limited in their pollutant removal rates by the need for pollutants to diffuse to the active pollutant removal components of these systems. Active botanical biofiltration, using green wall systems combined with mechanical fans to increase pollutant exposure to the plants and substrate, show greatly increased rates of pollutant removal for both VOCs, PM and also carbon dioxide ($CO_2$). A developing body of research indicates that these systems can outperform existing technologies for indoor air pollutant removal, although further research is required before their use will become widespread. Whilst it is known that plant species selection and substrate characteristics can affect the performance of active botanical systems, optimal characteristics are yet to be identified. Once this research has been completed, it is proposed that active botanical biofiltration will provide a cheap and low energy use alternative to mechanical ventilations systems for the maintenance of indoor environmental quality.

• Journal of Animal Science and Technology
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• 제63권4호
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• pp.790-798
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• 2021

The objective of this study was evaluation of pig behavior changes related to temperature, relative humidity, volatile organic compounds (VOCs), and illuminance. A total of 24 growing pigs ([Yorkshire × Landrace] × Duroc) were used in the experiment. A sensor was installed at a height of 0.5 m in the center of the pig house. In experiment 1, temperature was changed every four days to 18℃ (T1), 22℃ (T2), 26℃ (T3), and then 30℃ (T4). In experiment 2, relative humidity was adjusted to 45% (low humidity [LH]), 60% (middle humidity [MH]), and then 75% (high humidity [HH]) for four days. In experiment 3, after cleaning the pig house just before experiment, only minimal ventilation was provided. VOCs and pig behaviors were observed for 7 days without cleaning the pig house. In experiment 4, three light bulbs of 40 W (470 lumens / 45 lx; low illuminance [LI]), 75 W (1,055 lumens / 103 lx; middle illuminance [MI]), and 100 W (1,521 lumens / 146 lx; high illuminance [HI]) were used for four days each. Pig behavior analysis was performed for following criteria : Feed intake, Standing, Lying, Sitting, Drink water, Rooting, Posture transition (lying-standing), Posture transition (standing-lying), Wallowing, and Biting. In experiment 1, feed intake time was lower (p < 0.05) for the T3 than other treatment groups. Standing time was highest (p < 0.05) for the T1 and lowest (p < 0.05) for the T3. Lying time was shorter (p < 0.05) in T1 and T2 compared to T3 and T4. Drinking frequency was higher (p < 0.05) for the T4 than other treatment groups. In experiment 2, the frequency of rooting and wallowing increased (p < 0.05) with increasing humidity. LH showed the lowest (p < 0.05) rooting frequency and HH showed the highest (p < 0.05) rooting frequency. In experiment 3, VOCs concentration did not (p > 0.05) change pig behavior. In experiment 4, lying time was the longest (p < 0.05) at LI and shortest (p < 0.05) at HI. Therefore, pig behavior is heavily influenced by the environment, especially temperature and humidity. However, correlation between pig behavior to VOCs and illuminance seems to be needed more research.

• 한국대기환경학회지
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• 제29권3호
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• pp.307-316
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• 2013

The sensitivity of ozone to $NO_x$ and volatile organic compounds (VOCs) emission rates under different ventilation rates and $NO_2-to-NO_x$ emission ratios in a street canyon is investigated using a chemistry box model. The carbon bond mechanism IV (CBM-IV) with 36 gaseous species and 93 chemical reactions is incorporated. $NO_x$ and VOCs emission rates considered range from 0.01 to $0.30ppb\;s^{-1}$ with intervals of $0.01ppb\;s^{-1}$. Three different ventilation rates and three different $NO_2-to-NO_x$ emission ratios are considered. The simulation results show that the ozone concentration decreases with increasing $NO_x$ emission rate but increases with increasing VOCs emission rate. When the emission ratio of VOCs to $NO_x$ is smaller than about 4, the ozone concentration is lower in the street canyon than in the background. On average, the magnitude of the sensitivity of ozone to $NO_x$ emission rate is significantly larger than that to VOCs emission rate. As the $NO_x$ emission rate increases, the magnitude of the sensitivity of ozone to $NO_x$ and VOCs emission rates decreases. Because the ozone concentration is lower in the street canyon than in the background, the increased ventilation rate enhances ozone inflow from the background. Therefore, the increase in ventilation rate results in the increase in ozone concentration and the decrease in the magnitude of the sensitivity of ozone to $NO_x$ and VOCs emission rates when the emission ratio of VOCs to $NO_x$ is smaller than about 4. On the other hand, the increase in $NO_2-to-NO_x$ emission ratio results in the increase in ozone concentration because the chemical ozone production due to the $NO_2$ photolysis is enhanced. In the present experimental setup, the contribution of the change in $NO_2-to-NO_x$ emission ratio to the change in the sensitivity of ozone to $NO_x$ emission rate is larger than that of the change in ventilation rate.

• 토지주택연구
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• 제14권4호
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• pp.103-110
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• 2023

하루 평균 대부분을 실내에서 보내는 현대인들은 내외부적으로 발생하는 실내오염물질에 지속적으로 노출되고 있다. WHO(World Health Organization) 2022년 보고서에 따르면 매년 세계적으로 약 700만명 이상의 사망 원인이 공기오염으로 실내오염물질의 심각성을 강조하고 있다. 대기오염물질 중에는 인체에 심각한 영향을 끼치는 질소산화물(NOx), 폼알데하이드(HCHO), 휘발성 유기화합물(VOCs) 등이 포함되는데, 이러한 실내공기 오염물질을 제거할 수 있는 물질로 광촉매가 있다. 광촉매는 미세먼지 전구물질 제거 성능뿐만 아니라 향균, 살균, 탈취 성능 또한 가지고 있어, 실내공기질 개선에 효과적이다. 이에, 본 연구에서는 광촉매를 건축물에 적용할 수 있는 부위 및 방안을 제시하였다. 적용 가능한 부위로는 내외장재, 콘크리트 등을 포함한 건축자재, 유기도료, 환기장치 등이 있으며, 각 부위에 최적 적용 방안에 대한 연구를 진행하였다.

• 설비공학논문집
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• 제8권3호
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• pp.397-412
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• 1996

This study aims to present the fundamental strategies to improve the Indoor Air Quality (IAQ) in apartment buildings. To investigate the concentration of indoor air pollutants such as radon, formaldehyde, and VOCs, both the document survey and the field measurement were conducted. In addition, to identify the source of the air pollutants, the laboratory experiment was carried out for various building materials. Finally, the minimum period to be reserved befor3e building occupation to ensure healthy IAQ, which largely depends on the ventilation rates, was simulated using a simple compuer program. The results of this study can be summarized as follows: 1. In case of newly-constructed apartment houses, concentrations of formaldehyde, VOCs and radon were found to exceed the standard. Meanwhile, at existing apartment houses, concentrations of VOCs, particularly toluene and xylene, highly exceeded the standasrd level. Concentrations of formaldehyde and radon, however, had been lowered according to the duration of occupation. 2. The laboratory experiment of concentration of pollutants per square meter of building material surface area showed that radon gas was much emitted from the gypsumboard; formaldehyde from flooring and wallpaper; and VOCs from paints and kitchen furnishings. The emission rates of formaldehyde and VOCs were proportional to air temperature. 3. According to the simulation of the minimum period to be reserved before occupation, newly-constructed airtight houses required about 190-200 days, and naturally ventialted houses with fully-open-windows required about 20-45days, in order to keep the level of radon gas lower than standard. Therefore, with the current practice, the date of occupation should be delayed for about 15 days.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.293-298
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• 2005

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. The purpose of this study was to develop an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Indoor and outdoor NO$_2$ and VOCs(benzene, toluene, xylene) concentrations were measured every 3 days for 60 consecutive days in 30 houses in Seoul, Asan and Daegu, Korea. Using a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements. Subsequently, NO$_2$ and VOCs source strengths (ppb/hr) and deposition constant (K, hr$^{-1}$) were estimated. Deposition constants of NO$_2$, toluene and xylene were 0.98 ${\pm}$ 0.28, 0.71 ${\pm}$ 0.24 and 0.74 ${\pm}$ 0.53 hr$^{-1}$, respectively. Source strengths of NO$_2$, toluene and xylene were 16.28 ${\pm}$ 7.47,31.25 ${\pm}$ 38.45 and 23.45 ${\pm}$ 19.67 ppb/hr, respectively In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

• 한국환경보건학회지
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• 제30권5호
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• pp.481-486
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• 2004

Vehicle occupant exposure to air pollutants has been a subject of concern in recent years because of higher levels of air pollutants inside gasoline or diesel-using vehicle, comparing to the surrounding atmosphere. Contrary to previous studies, fuel of vehicles operated in this study was liquefied petroleum gas (LPG). This study examined the potential exposure and removal efficiency of selected volatile organic compounds (VOCs), nitrogen dioxide ($NO_2$) and respirable suspended particle (RSP) by commercial air cleaning device inside vehicle under different ventilation conditions. Vehicle concentrations inside of benzene, toluene, m,p-xylene, $NO_2$ and RSP were lower under the low ventilation condition. This was indicated that outdoor air pollutants could affect the vehicle air quality inside in case metropolitan cities such as Daegu. The urban vehicle concentrations inside of benzene, toluene, m,p-xylene, $NO_2$ and RSP with air cleaning device were higher than those without air cleaning device. This means that the use of air cleaning device equipped with activated carbon filter, which was used in this study, in the interior of vehicles could be expected to reduce the vehicle occupants exposure to air pollutants effectively. In batch type reactor of laboratory scale, removal efficiencies of air cleaning device used were $97.0\%,\;95.7\%,\;94.6\%\;and\;85.5\%$ respectively in benzene, toluene, m,p-xylene and $NO_2$.

• 환경영향평가
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• 제14권3호
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• pp.109-115
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• 2005

This study was conducted to evaluate the efficiency of indoor air cleaners and to inform how to select them correctly to the users. The efficiencies of removing suspended bacteria per hour were $64.3{\pm}13.1%$ for filter, wet, and complex type, respectively, which showed the complex type was the most efficient. The removal efficiencies of formaldehyde (HCHO) after two hours operation of air cleaners showed 88.3% and 81.1% for filter and wet type, respectively. The efficiency of complex type, with removal rate of 55.5~58.4%, was decreased after 30 minutes operation. Therefore, it is recommended to perform over 60 minutes when doing air cleaner certification test for HCHO removal efficiency. Generally, air cleaners having low wind volume showed higher efficiency. All tested air cleaners had no potential for removing of volatile organic compounds (VOCs), which is toxic substances, and it is desirable to develop a device which can control these substances. The results also confirmed that there was no ozone production from all tested air cleaners. And it is recommended to ventilate for 20 minutes every four hours to maintain 50% ventilation status.