본 연구에서는 강화되는 황산화물 및 입자상물질의 배출규제를 만족시키기 위한 후처리장치로 습식전기집진기에 대한 실험적 연구를 수행하였다. 실험을 위해 선박용 중유(HFO, 황함유량 약 2.1%)를 연료로 사용하는 선박용 4행정 디젤엔진(STX-MAN B&W)을 활용 하였으며, 연돌에 설치된 습식전기집진기 입/출구에서 측정을 실시하였다. 미세먼지 측정을 위해서는 광학식 계측기(OPA-102) 및 중량농 도측정방식(Method 5 Isokinetic Train)을 이용하였으며, 황산화물 계측을 위해서는 FT-IR(DX-4000)을 사용하였다. 엔진부하는 50%, 75%, 100%로 변화시키면서 실험을 실시하였다. 실험 결과로, 엔진부하가 50%에서 100%로 변화함에 따라 미세먼지 저감 효율은 모든 부하 조건에서 94~98% 정도의 높은 저감 효율을 나타내었다. 추가적으로 습식전기집진기 퀜칭존에서 배기가스의 온도를 낮추는 과정 중 세정액에 의한 이산화황(SO2) 저감을 확인할 수 있었으며, 저감율은 엔진부하에 따라 55%~81%로 확인되었다.

도심 교통섬과 도시숲 내부에서 미세먼지 농도와 영향 인자를 조사하여 숲의 미세먼지 효과를 분석하였다. 서울시 동대문구 홍릉시험림(도시숲)과 동대문구 청량리역 교차로에 조성된 숲(교통섬)에서 미세먼지 농도를 2018년 1월부터 11월까지 광산란법 기기를 적용하여 측정하였다. 연구 기간 동안 도시숲과 교통섬의 PM10 평균농도는 12.5 ㎍/㎥, 15.7 ㎍/㎥으로 나타났으며, PM2.5의 평균농도는 6.6 ㎍/㎥, 6.9 ㎍/㎥으로 나타났다. 환경부 도시대기 측정망과 도시숲 의 농도를 비교해본 결과, PM10의 저감율은 도시숲에서 66.9±28.6%, 교통섬에서 58.6±44.1%로 나타났고, PM2.5의 경우 71.3±23.0%, 64.9±31.3%로 각각 나타났다. 미세먼지 저감율의 차이는 도시숲의 규모와 구조의 차이와 관련이 있을 것이며, 풍속은 저감 요인으로 판단된다.

In this paper, a survey on students’ perceptions of air pollution, particulate matter (PM) and indoor air quality (IAQ) in school classrooms was analyzed. A total of 174 students participated in the survey, where 127 and 47 participants were elementary school students and middle school students, respectively. The elementary school was located in a rural area of Korea, whereas the middle school was located in an urban area. The questionnaire of the survey was mainly composed of three parts: (1) students’ perceptions of air pollution, (2) students’ perceptions of IAQ in the classroom, and (3) students’ perceptions of how to improve IAQ in the classroom. Based on our study, the responses of the students for the given questionnaire showed an opposite tendency. The students in the rural area tended to have positive perceptions regarding IAQ in the classroom as well as air pollution, whereas the students in the urban area revealed negative perceptions for the same items. Our survey results can be used by school officials in order to maintain and improve IAQ in school classrooms based on the perceptions of the students.

Cooking, especially meat and fish grilling, is one of the representative sources of indoor and outdoor particulate matter (PM). Most of PM emitted from cooking is ultrafine dust (PM2.5). Since odorous organic acids, aldehydes, and volatile organic compounds are absorbed by PM and discharged, restaurants and food service industries are major sources of odorous PM emission that cause odor nuisance complaints in cities. PM emitted from cooking also contains polycyclic aromatic hydrocarbons (PAHs), which are carcinogens. In this paper, the domestic PM emission status of biomass combustion, especially meat and fish grilling, was analyzed temporally and spatially. The results of previous studies on PM emission concentrations, emission rates, emission factors and their compositions from cooking were comprehensively summarized. In addition, the effects of food ingredient types, cooking methods, seasoning and oil addition and fuel types on the PM emission were reviewed. Much more PM was produced when cooking with charcoal rather than electricity or gas. The higher the fat content of food ingredients such as intestines, the higher the PM emission concentration and emission rate. There was a difference in the PM emissions depending on the cooking oil types, and the PM emission concentration was high when olive oil or corn oil was used. It is necessary to accumulate more information through followup studies on the emission concentrations, emission factors and properties of PM emitted from cooking activities. This information can be used for controlling odorous PM in restaurants and food service industries, and predicting the impacts of odorous PM on air quality and human health.

PURPOSES : The objective of this study is to analyze the uniform diffusion mechanism of precursor gas species, and the effect of NOx reduction technology in a full-scale particulate matter testing facility, using computational fluid dynamics (CFD). METHODS : A full-scale environment chamber was constructed to evaluate the effects of particulate matter reduction technologies on the road. CFD analysis was conducted to simulate the road environment conditions in the chamber, and investigate the effect of the NOx removal panel. The time required to reach the NOx concentration to target value in the fluid field was determined at a given inflow velocity, inlet direction, and initial inflow concentration. The effect of the NOx removal panel, and solar energy on the reduction characteristics of the NOx concentration in the environment chamber was analyzed. RESULTS : The inflow velocity was determined to be the major factor affecting the time required to reach a uniform target NOx concentration in the environment chamber. The inlet location in the transverse direction requires additional time to approach the uniform target concentration, than the longitudinal direction at the same inflow velocity. Based on the CFD analysis in the 1ppm concentration condition of the chamber, a two-fold increase in the NOx removal panel efficiency can reduce the time to target concentration by approximately 50%. It is also observed that a 20% increase in solar energy can decrease the time to target concentration by 4%–12% depending on the panel efficiency. CONCLUSIONS : This study proved that a full-scale environment chamber can be effectively utilized to evaluate the particulate matter reduction technologies applied in road facilities

This study obtained the following conclusions using the measurement results of indoor and outdoor PM10 with regard to cardiovascular disease patients in Cheongju-area in November 2020. Most of the PM10 has an I/O ratio of less than 1, which is an outdoor source. Since we measured once and twice time, Without the air purifier device’s working status, there were no concentration changes of PM10 in the first and second indoor areas. As for the concentration of PM10 according to the living environment, the distribution of PM10 is higher indoors than outdoors when the residential area is 30 m2 or more, and the outdoor PM10 concentration tends to be high when the distance to the road is within 50 m. The more time spent indoors, the higher the indoor PM10 concentration. The smaller the ventilation time and frequency, the longer the cooking time was, and the higher the number of cooking times, the higher the concentration of PM10 could be. The indoor PM10 contribution ratio through multiple regression analysis showed the possibility of increasing indoor PM10 as β = 28.590 when the time spent indoors was longer than 16 hours (p<0.05). The result regarding PM10 exposure reveals that PM10 can be inhaled not only indoors but also outdoors, and the subjects of this study appear to have lived indoors for about 16 hours or longer on a daily basis, which may affect their health regardless of gender.

The emission of particulate matter and volatile organic compounds (VOCs) from a motor vehicle painting booth was quantitatively evaluated. Most particulate matter was emitted during the spraying process, in which the PM10 concentration was 16.5 times higher than that of the drying process. When the paint was being sprayed, the particles with a diameter of 1.0~2.5 μm accounted for 39.4% and particles greater than 2.5 μm in diameter accounted for 30.6% of total particles. On the other hand, small particles less than 0.5 μm in diameter accounted for 52.4% of total particles during the drying process. In contrast to the particulate matter, high concentrations of VOCs were emitted during both spraying and drying processes. Butyl acetate, xylene, toluene, and m-ethyltoluene were the most abundant VOCs emitted from the motor vehicle painting booth. Additionally, xylene, butyl acetate, toluene, and 1,2,3-trimethylbenzene were the dominant ozone precursors. Especially, xylene exhibited the highest ozone production contribution (32.5~44.4%) among 34 species of the ozone precursors. The information obtained in this study can be used to establish a suitable management strategy for air pollutants from motor vehicle painting booths.

대기 중 미세먼지가 환경과 인간의 공중 보건에 악영향을 미치고 있다는 사실은 점점 명확해지고 있다. 미세먼지가 식물의 잎에 침착, 흡수되므로 식물이 미세먼지를 제거 하는 바이오필터로 활용하기 위한 연구들이 활발히 진행 되고 있다. 또한, 식물에 흡수된 미세먼지는 식물에 다양한 생리적, 형태적 영향을 미치게 된다. 본 연구는 식물과 미세먼지간의 상호작용에 대해 국내외에서 수행되어온 연구들의 방법과 결과를 특히 생태적 관점에서 종합 정리하였다.

In this paper, we conducted a survey to reveal the general perception of parents toward outdoor air quality, particulate matter (PM), and indoor air quality (IAQ) at schools where their children attend. A total of 1,030 parents participated in this survey, where the age of their children ranged between 7 years to over 19 years of age. Each participant was either a member of a non-governmental organization (NGO) with a keen interest in air quality or an ordinary public panel member with less interest. The result of the survey indicated that the participants had a negative perception of air quality, and parents believed that the outdoor and indoor air is extremely polluted. The participants pointed out that they believe that the main reason for the pollution is due to particulate matter (PM) and school classrooms are the location where their children are exposed to PM the most. Based on our study, the majority of the participants prefer a mechanical ventilation system to reduce indoor air pollutants in schools. Our study should be referred to by school officials in order to maintain IAQ and as a way of addressing the concerns of parents who want to protect their children’s health.

본 연구는 도로에서 발생하는 미세먼지 농도가 도시 개발 형태에 따라 인접 생활권별로 어떻게 확산되는지 시뮬레이션을 통해 파악하고자 하였다. 연구는 경상남도 밀양시청 앞 6차선 도로를 중심으로 한 도로영향권 시가지를 대상으로 진행하였다. 시뮬레이션 프로그램인 ENVI-met 모델을 가로녹지 유무, 도로변 건축물의 높이에 따라 변수를 조정하여 미세먼지 농도의 확산정도를 파악하였다. 모델링 결과 도로변 건물이 고층으로 형성되어 있고 가로녹지가 조성되어 있는 경우 인접 생활권으로 확산된 미세먼지 농도가 가장 낮았으며, 다음으로는 고층건물군에 가로녹지가 없는 상태의 농도가 낮았다. 반면 저층건물군이 형성된 경우에는 가로녹지 유무에 관계없이 인접생활권으로 확산된 미세먼지 농도는 높게 나타났다. 고층건물의 경우 빌딩풍에 의해 건축물 주변으로 강한 바람이 형성되는 만큼 바람에 의해 미세먼지가 빠르게 외부로 확산되어 농도가 낮아지는 것으로 확인할 수 있었다. 반면 가로녹지 조성이 도로변 생활권에 미치는 미세먼지 저감효과는 뚜렷하지 않았다. 특히 도로변 건축물이 저층일 경우 가로녹지를 조성과 생활권미세먼지농도변화와 관련성은 없는 것으로 확인되었다. 본 연구는 미세먼지가 도로에서만 발생하는 것을 가정하여 모델링을 진행한 것으로 향후 다양한 변수에 따른 미세먼지 확산모형 연구 및 현장연구의 보완을 필요로 하였다.

PURPOSES : In this study, the characteristics of fine particulate matter (PM2.5) concentrations under different weather conditions of different types of bus stops, such as enclosed-type and open-type bus stops, were analyzed using statistical methods. METHODS : Data was collected inside and outside an enclosed bus stop on sunny and rainy days to compare and analyze the characteristics of fine particulate matter concentration in the target bus stop. The probability distributions were estimated for each data point using the Anderson–Darling test. Based on the estimated probability distributions, probability density functions were computed, and the values were used to estimate and compare probability for each air quality index inside and outside the bus stop under different weather conditions RESULTS : For the results of descriptive statistics, the average concentrations of fine particulate matter inside and outside the bus stop were 42.296 and 35.482 μg/m3 on a sunny day and 40.831 and 39.321 μg/m3 on a rainy day, respectively. Results of the statistical method, obtained using the Anderson-Darling test, indicate that the probability of the air quality index inside the bus stop reaching high concentrations on a sunny day was "high" or "very high," compared to that outside the bus stop. However, on rainy days, the differences in fine particulate matter concentrations inside and outside the bus stops were difficult to identify based on statistical evidence. CONCLUSIONS : It was found that the open-type bus stop had an advantage of preventing fine particulate matter effects on sunny days, compared to the enclosed-type bus stops. Furthermore, there were slight differences in fine particulate matter concentrations inside and outside the bus stop on a rainy day because of atmospheric flow and stormwater.

PURPOSES : A pilot experimental study on the formation of fine particulate matter through photochemical reactions using precursor gas species (volatile organic compounds (VOCs), NH3, SO2, and NOx) was conducted to evaluate the large-scale environment chamber for investigating the pathway of aerosol formation and the subsequent assessment techniques used for reducing fine particulate matter. Two small-scale environment chambers (one experimental group and one control group), each with a width, depth, and height of 3 m, 2 m, and 2.3 m, respectively, were constructed using ethylene tetrafluoroethylene (ETFE) films. METHODS : The initial conditions of the fine particles and precursor gases (NOx and VOCs) for the small-scale environment chamber were set up by injecting diesel vehicle exhaust. NH3 and H2O2 were added to the small-scale environment chamber for the photochemical reaction to form organic and inorganic aerosols. The gas phase of the VOCs and the chemical compositions of aerosols were investigated using a proton transfer reaction time-of-flight mass spectrometer and the aerodyne high-resolution time-of-flight aerosol mass spectrometer at 1 and 10 s time resolutions, respectively. Gas phases of NO and NO2 were measured using Serinus 40 NOx at a 20 s time resolution. RESULTS : The small-scale environment chambers built using ETFE films were proved to supply sufficient natural sunlight for the photochemical reaction in the environment chambers at an average of approximately 89% natural sunlight transmission at 300–1000 nm. When the intermediates of NH3 and H2O2 for the atmospheric chemical reaction were injected for the initial condition of the small-scale environment chamber, nitrate and ammonium in the experimental group increased to 4747% and 1837%, respectively, compared to the initial concentrations (5.4 μg/m3 of nitrate and 5.2 μg/m3 of ammonium), indicating the formation of secondary inorganic aerosols of ammonium nitrate (NH4NO3). This implies that it is necessary to inject intermediates (NH3 and H2O2) for the formation of fine particulate matter when simulating the atmospheric photochemical reaction for assessing the environment chamber. CONCLUSIONS : This study has shown that small-scale environment chambers can simulate the atmospheric photochemical reaction for the reduction of fine particulate matter and the formation of the aerosol pathway. The results of this study can be applied to prevent time and economic losses that may be incurred in a full-scale environment chamber.

PURPOSES : NOx is a particle matter precursor that is harmful to humans. Various methods of removing NOx from the air have been developed. TiO2 and activated carbon are particularly useful materials for removing NOx, and the method is known as particulate matter precursor reduction. The removal of NOx using TiO2 requires sunlight for the photocatalytic reaction, whereas activated carbon absorbs NOx particles into its pores after contact with the atmosphere. The purpose of this study is to evaluate the NOx removal efficiency of TiO2 and activated carbon applied to concrete surfaces using the penetration method. METHODS : Surface penetration agents, such as silane-siloxane and silicate, were used. Photocatalyst TiO2 and adsorbent activated carbons were selected as the materials for NOx removal. TiO2 used in this study was formed by crystal structures of anatase and rutile, and plant-type and coal-type materials were used for the activated carbon. Each surface penetration agent was mixed with each particulate matter sealer at a concentration ratio of 8:2, and the mixtures were sprayed onto the surface. The NOx removal efficiency was evaluated using NOx removal efficiency equipment fabricated in compliance with the ISO 22197-1 standard. RESULTS : Anatase TiO2 showed a maximum NOx removal efficiency of 48% when 500 g/m² was applied. However, 500 g/m² of rutile TiO2 showed a NOx removal efficiency of up to 10%. When 700 g/m² of coal-based activated carbon and plant-based activated carbon was used, NOx removal efficiencies of up to 11% and 14%, respectively, were obtained. CONCLUSIONS : Rutile TiO2, a coal-based activated carbon, and plant-based activated carbon have lower NOx removal efficiencies than anatase TiO2. A lower amount of anatase TiO2 (500 g/m²), compared to the other spraying volumes, yielded the most significant NOx removal efficiency under optimal conditions. Therefore, it is recommended that 500 g/m² of anatase TiO2 should be sprayed onto concrete structures to improve the economic and long-term performance of these structures.

목적 : 미세먼지가 콘택트렌즈 착용자의 눈물막에 영향을 미치는지 알아보고자 미세먼지 농도 수준에 따라 콘 택트렌즈 착용 후 눈물의 양과 안정성의 변화를 평가하였다. 방법 : 안질환이 없고 안경과 콘택트렌즈를 모두 착용하는 20대 근시안 31명을 대상으로, 하루 8시간씩 하루 착용 소프트 콘택트렌즈(L사, 함수율 55%)를 착용하도록 하였다. 대상자는 OSDI 값을 기준으로 정상안과 건성안 으로 세분하여 분석하였다. 미세먼지 농도는 한국환경공단에서 제공된 값을 기준으로 좋음(0~30 ㎍/m³)과 나쁨 (51~100 ㎍/m³) 수준으로 구분하고, 미세먼지 농도가 좋음과 나쁨 수준인 날에 모두 눈물검사를 실시하였다. 눈 물양은 OCCUTUBE(OccuTech Co., LTD, Seongnam, Korea)로, 안정성은 침습성눈물막파괴시간(TBUT)과 비 침습성눈물막파괴시간(NIBUT)으로 평가하였고, 미세먼지 수준에 따른 비교는 SPSS version 21.0(SPSS Inc, Chicago, IL, USA)를 사용하여 분석하였다. 결과 : 미세먼지 나쁨 수준에서 눈물의 양과 안정성은 안경 및 콘택트렌즈 착용 시 모두 유의하게 감소하여(p＜.050), 건성안 범주의 값으로 측정되었다. 콘택트렌즈 착용은 미세먼지 좋음 수준에서도 안경착용과 비교하여 눈물양이 감소하였고, 미세먼지 나쁨 수준에서는 TBUT가 감소하였다. 특히 건성안에서는 미세먼지 나쁨 수준에서 콘택트렌즈를 착용한 경우에 정상안보다 TBUT가 유의하게 감소하였다. 결론 : 미세먼지는 눈물의 양과 안정성을 모두 감소시켜 건성안 유발요인으로 작용하는 것으로 사료되며, 미세 먼지 나쁨 수준에서 콘택트렌즈 착용은 눈물막 안정성을 나쁘게 하여 건성안의 경우 증상이 더욱 악화될 수 있으 므로 미세먼지 나쁨 수준인 날에는 건성안 예방을 위하여 안경착용을 권고해야 할 것으로 생각된다.

PURPOSES : This study analyzes the characteristics of generated fine particulate matter (PM2.5) and nitrogen oxide (NOX) at roadsides using a statistical method, namely, a generalized linear model (GLM). The study also investigates the applicability and capability of a machine learning methods such as a generalized regression neural network (GRNN) for predicting PM2.5 and NOX generations. METHODS : To analyze the characteristics of PM2.5 and NOX generations at roadsides, data acquisition was conducted in a specific segment of roads, and PM2.5 and NOX prediction models were estimated using GLM. In addition, to investigate the applicability and capability of a machine learning methods, PM2.5 and NOX prediction models were estimated using a GRNN and were compared with models employing previously estimated GLMs using r-square, mean absolute deviation (MAD), mean absolute percentage error (MAPE), and root mean square error (RMSE) as parameters. RESULTS : Results revealed that relative humidity, wind speed, and traffic volume were significant for both PM2.5 and NOX prediction models based on estimated models from a GLM. In addition, to compare the applicability and capability of the GLM and GRNN models (i.e., PM2.5 and NOX prediction models), the GRNN model of PM2.5 and NOX prediction was found to yield better statistical significance for r-square, MAD, MAPE, and RMSE as compared with the same parameters used in the GLM. CONCLUSIONS : Analytical results indicated that a higher relative humidity and traffic volume could lead to higher PM2.5 and NOX concentrations. By contrast, lower wind speed could affect higher PM2.5 and NOX concentrations at roadsides. In addition, based on a comparison of two statistical methods (i.e., GLM and GRNN models used to estimate PM2.5 and NOX), GRNN model yielded better statistical significance as compared with GLM.

Particulate matter (PM) has recently been considered one of the most harmful air pollutants to public health. Plants have been known to degrade and deposit particle pollutants with epicuticular wax (EW), and this capacity can be influenced by environmental conditions including relative humidity (RH). The present study examined the effects of RH on EW generation and PM deposition upon leaf surfaces within Asplenium nidus ‘Avis’. The plants were treated in growth chambers with two levels of RH (low: 30% - 40% and high: 80% - 90%) for a period of four weeks, and subsequently exposed to a 30 μg･m-3 concentration of TiO2 particles as a PM resource for 72 hours. The EW ultrastructure on the leaf surface was observed as the thin films type, which was not morphologically changed in the condition of low or high RH treatment. For four weeks of RH treatment, the fresh weight and leaf area per plant were not significant between low and high RH treatment, while dry weight was significantly higher in the high RH condition. We also found that greater amounts of EW per fresh weight, dry weight and leaf area were generated in high RH. However, the total amounts of PM deposition (surface PM + in-wax PM) of the plants were higher within the low RH treatment with a higher proportion of surface PM. In contrast the proportion of in-wax PM was 15% higher within the high RH. These results suggest that EW generation is affected by air humidity and that proportion of PM deposition in the EW layer were influenced by the amount of total wax load.