Subway trains with air cleaners have been newly deployed in the Seoul Metro system. The purpose of this study was to determine differences regarding in-cabin particulate matter with respect to concentrations less than 10 um (PM10) and 2.5 um (PM2.5) through the operation of air cleaners in subway trains. One subway train newly installed with in-cabin air cleaners on Seoul Metro Line number 2 was chosen monitoring in 2020. In-cabin air cleaners were turned-on at both front and back areas while those in the middle area were turned-off while the train was running. In-cabin PM10 and PM2.5 concentrations were measured in each area using a real-time aerosol monitor. Average in-cabin PM10 concentrations were statistically significantly lower (by 15%) in areas with air cleaners turned-on (43.8±12.1 μg/m3) compared to those areas where the air cleaners were turned-off (51.4±15.0 μg/m3). Average incabin PM2.5 concentrations were significantly lower (by 14%) in areas with air cleaners turned on (33.7±12.2 μg/m3) compared to those areas where air cleaners were turned-off (39.2± 14.4 μg/m3). In-cabin PM10 and PM2.5 concentrations ratios were similar regardless of area with air cleaners turned-on or turned-off. The in-cabin PM10 and PM2.5 concentrations were not associated with commute time. Use of air cleaners in subway trains effected reductions in in-cabin PM10 and PM2.5 concentrations.

이 연구의 목적은 일기도, 850 hPa 면의 유선, 후방궤적과 기상, 그리고 대기질 모델을 이용하여 비황사기간 동안 청주시 미세먼지 PM2.5의 고농도 원인을 분석하는 것이다. 청주시 PM2.5 고농도 사례일 동안 시계열과 일기도를 분석한 결과, 중국 또는 주변 지역으로부터 PM2.5의 장거리 수송과 관련된 기상 패턴을 나타내었다. 실제로 PM2.5 시계열 에서 자체 기여 농도보다 2-3배 이상 증가한 60-80 μg m−3가 장거리 수송과 관련된 배경농도로 관측되었다. PM2.5의 고 농도는 대체로 상층 제트류가 한반도를 통과하면서 지상 고기압과 저기압의 발달 위치에 따라 분포하였다. 결과적으로 청주시 PM2.5 고농도 발생 원인은 중국 북경이나 기타 인근 지역에서 산업, 가정 및 에너지 연소 기원으로 발생한 스모그 형태의 대기 오염물질 덩어리가 장거리 수송의 기압배치에 따라 빠른 풍속 대를 타고 이동했기 때문이다. PM2.5를 포함한 대기오염물질이 지상 고기압 확장역이나 절리저기압 또는 지상저기압 배치에 따라 벨트나 띠 형태의 오염 덩어리로 북쪽에서 남쪽으로 청주시 분지 지형을 통과하는 M자형 패턴을 나타내거나, 강줄기 형태의 띠들이 바람의 영향을 받아 U자형으로 변하는 점진적 증가형 패턴으로 나타난다.

본 연구에서는 서울지역의 지상 미세먼지(PM2.5) 농도를 산출하기 위하여 경험적인 모델들을 개발하였다. 연구에 이용한 자료는 2012년 1월 1일부터 2013년 12월 31일까지이며 Terra와 Aqua위성의 MODIS센서에서 산출되는 에어로 졸 광학두께, 옹스트롬 지수, 기상변수들과 행성경계층두께와 관련된 6개의 다중 선형 회귀모델들의 차이를 분석하였다. 그 결과 에어로졸 광학두께와 옹스트롬 지수, 상대습도, 풍속, 풍향, 행성경계층두께, 기온 자료를 입력 자료로 사용한 M6모델이 가장 좋은 결과를 보였다. 통계적인 분석에 따르면 M6 모델을 사용하여 계산된 PM2.5와 관측된 PM2.5농도 사 이의 결과는 상관계수(R=0.62)와 평균제곱근오차(RMSE=10.70 μg m−3)이다. 또한 산출된 계절별 지표면 PM2.5농도는 여름철(R=0.38)과 겨울철(R=0.56)보다 봄(R=0.66)과 가을철(R=0.75)에 상대적으로 더 좋은 상관 관계를 보였다. 이러한 결과는 에어로졸 광학두께의 계절별 관측 특성으로 인한 것으로써 다른 계절에 비하여 여름과 겨울철 에어로졸 광학두께 관측이 구름과 눈/얼음 표면에 의한 관측 제한과 오차를 가져온 것으로 분석되었다. 따라서 본 연구에서 사용한 경 험적 다중선형회귀 모델은 위성에서 산출된 에어로졸 광학두께 자료가 지배적인 변수로 작용하며 PM2.5산출 결과들을 향상시키기 위해서는 추가적인 기상 변수를 이용해야 할 것이다. 또한 경험적 다중선형회귀 모델을 이용하여 PM2.5를 산출한 결과는 인공위성 자료로부터 대기환경 감시를 가능하게 하는 방법이 될 수 있어 유용할 것이다.

The concern of fine particle (PM2.5) management of outdoor environments has been increasing due to its exposure and related health effects in Korea. As a result, PM2.5 standard in atmosphere environment was regulated in 2015. On the other hand, indoor PM2.5 standard has been required because most people spent their times in indoor environments. In this study, we measured the PM2.5 and PM10 concentrations both indoor and outdoor environments of public-use facilities such as underground stations, underground shopping centers, and nurseries for 24 hour with filter-weighing method in Seoul and Daegu. Measurement duration was from March to April in 2014 during the Asian dust period. At all measurements, indoor to outdoor (I/O) concentration ratios exceeded 1 except 1 day nursery in Daegu in spite of Asian dust period. The ratios of PM2.5 to PM10 concentrations ranged from 0.63 to 0.75 in indoor environments, and from 0.63 to 0.82 in outdoor, indicating that PM2.5 should be carefully managed in indoor environments as well as outdoor atmosphere.

This study was conducted to determine the impact of smoke-free regulations on the environment in personal computer(PC) rooms by measuring indoor levels of particulate matter smaller than 2.5 μm(PM2.5) before and after the implementation of the regulations. PM2.5 concentrations of 34 PC rooms in Seoul were measured before and after the regulations took effect. A real-time monitor was used to measure PM2.5 concentrations. A field technician recorded the characteristics of PC rooms including indoor volume, number of floors, and the presence of a smoking room and counted the number of burning cigarettes, cigarette butts, vents, and patrons. While outdoor PM2.5 concentrations and the number of patrons were not changed, indoor PM2.5 concentrations, the number of burning cigarettes and cigarette butts in PC rooms were significantly decreased after the regulations were implemented (p < 0.001). Geometric mean(GM) of indoor PM2.5 concentrations in the PC rooms was 139.6 μg/m3 before the regulations took effect and 55.7 μg/m3 after the regulations implemented. After the regulations, smokers were observed in 11 of the 34 PC rooms in which PM2.5 concentrations were not significantly decreased(p = 0.18). When smokers were not observed after the regulations, the GM of indoor PM2.5 concentrations was 37.2 μg/m3. Although PM2.5 concentrations in some PC rooms were decreased after the regulation, higher PM2.5 concentrations were observed in PC rooms with smokers. As such, compliance with the smoke-free regulations should be strictly ensured to achieve a better indoor air quality.

본 연구는 3년(2005. 12. 1-2008. 11. 30) 동안 부산의 PM2.5 대기오염자동관측소(장림동: 공업지역, 좌동: 주거지역) 측정자료 중 고농도 PM2.5(24시간 환경기준 50μg/m3)에 대한 PM2.5 및 PM2.5/PM10 농도비의 일변화 특성과 함께 시 공간적 풍계(풍향 및 풍속)에 따른 특성을 분석하고자 하였다. 고농도 PM2.5는 장림동과 좌동 각각 182일 및 27일이었다. 장림동에서 고농도 PM2.5의 시간평균농도 및 PM2.5/PM10 농도비의 일변화는 모든 계절에서 오후에 비해 새벽과 오전 및 야간에 높은 비슷한 패턴을 나타내었다. 좌동의 여름 주간에 PM2.5/PM10 농도비가 증가하는 것은 해양조건에서 광화학반응에 의해 생성되는 이차 입자상물질 중 PM10의 거대입자 농도가 미세입자인 PM2.5 농도보다 더 감소하기 때문이다. 시간대별로 시 공간적 풍계(풍향 및 풍속등급) 특성을 분석하였다. 그 결과, 고농도 PM2.5는 장림동에서 공업단지의 산업활동에 의한 오염물질 정체와 주변지역의 오염물질 이동에 의해 발생되었다. 좌동에서는 주로 주거와 상업활동으로 인한 지역적 오염물질 정체로 발생하는 것으로 나타났다.

This study was performed in the 48 selected public facilities in three metropolitan cities (Seoul, Daejeon, and Kwangjoo) and three general cities (Suncheon, Gwangyang, and Yeosu) to measure of the characteristics from May to October 2011. Air samples (PM2.5) were collected at the indoor and outdoor places for 24-hrs using the mini volume air sampler and analyzed 24 gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) through the GC/MS. The recoveries of gaseous and particulate PAHs ranged between 60.7% to 127.2% and 57.7% to 132.5% respectively and its relative standard deviation (RSD) was 11.1%. This QA/QC results about the were adequate for the Korean national standards. The concentration levels of the PAHs in present study were acenaphthene 〉dibenz(a,h)anthracene 〉benzo(g,h,i)perylene 〉3-methylcholanthrene 〉 indeno[1,2,3-cd]pyrene for the particulate PAHs in the 48 selected public facilities. In the case of acenaphthene, the mean concentration showed the highest levels of 22.42 ng/㎥ and 34.57 ng/㎥ in the level of gaseous and particulate phase, respectively. The total PAHs concentration for the PC room is the highest in surveyed public facilities of this study and the smoking/non smoking ratio in the PC room was 3.45. This results indicated that smoking in the PC room is seemed to play a major source and the effective risk management strategies were needed to minimize or eliminate the public health effect for customers in the PC room.

The aim of this study is to analyze the distribution of particulate matters including PM_2.5 which is known for severe adverse health effect than PM₁₀ in public facilities. The total 40 public buildings are investigated in this study and they are classified into 11 sub-groups as follows : child-care centers, medical centers, libraries, museums, bus terminals, ports, airports, railway terminals, subway stations, large-scale stores, and indoor parking lots. The mean concentration of PM₁₀ was 38.6㎍/㎥ and that of PM₁₀ in all studied facilities were lower than the Ministry of Environment's control standards. The average concentration of PM_2.5 was 27.2㎍/㎥ and that of PM_2.5 in 18 facilities were exceed the guideline of WHO (24h average value : 25㎍/㎥). The subway stations had the highest indoor level of particulate matters and the waiting area in bus terminals, railway terminals, indoor parking lots had followed in order. When comparing mean value of I/O ratio of PM₁₀, the only I/O ratio of subway stations were greater than one. In the case of PM_2.5, however, the average concentrations of PM_2.5 in indoors of subway stations, bus terminals, and indoor parking lots were higher than those of PM_2.5 in outdoors. The mean concentration of PM₁₀ and PM_2.5 were gradually increased between 6 A.M and 10 A.M and after 6 P.M in most of target buildings with increasing the number of users in thest facilities.

본 연구에서는 2006년부터 2008년까지 3년간 봄철에 PM10과 PM2.5를 채취하여 질량농도와 금속원소의 화학적 특성, 기상인자와의 관계 분석, 황사 및 비황사시의 미세먼지 특성 그리고 이동경로에 따른 농도의 특성을 고찰하였다. 연구기간동안의 PM10, PM2.5, PM10-2.5평균농도는 각각 126.2±89.8, 85.5±41.6, 40.7±54.9μg/m3이었으며 PM2.5/PM10 및 PM10-2.5/PM2.5 비는 각각 0.70, 0.48이었다. 우리나라의 북서쪽인 북경을 포함한 지역과 서쪽인 상해를 포함한 지역에서 공기덩어리가 이류 할 때 가장 높은 미세먼지농도를 나타내었다.

부산지역에서 PM10 과 PM2.5중의 금속 성분 농도를 파악하기 위하여 2004년 3월부터 2004년 12월까지 조사하였다. PM10의 평균농도는 58.2μg/m3 농도범위는 8.3~161.1μg/m3이었으며, PM2.5의 평균농도는 29.3μg/m3, 농도범위는 2.8~65.3μg/m3였다. PM10의 평균 질량농도는 황사시 121.5μg/m3, 비황사시 56.0μg/m3로 나타났다. 10 이상의 지각농축계수를 보인 성분은 Cd, Cr, Cu, Ni, Pb 및 Zn로서 인위적기원을 받은 것으로 추정된다. PM10과 PM2.5 중 미량금속 성분의 지각농축계수는 황사시보다 비황사시에 높게 나타났으며, 인근의 공단지역으로부터 인위적 오염물질이 수송된 것으로 추정된다. PM10과 PM2.5의 토양입자의 평균 기여율은 각각 15.2%와17.5%였다. 토양기여율의 황사/비황사비는 PM10과 PM2.5에서 각각 1.9와 2.1로 나타났다.

This study, conducted from April to May 2004 in the metropolitan and surrounding areas of Seoul, Korea, was performed to show the relationship between indoor and outdoor levels of PM10 and PM2.5 concentrations in 14 residential houses. In addition, indoor/outdoor ratios of PM10, PM2.5 concentrations were calculated. The relationship between the PM10, PM2.5 concentrations and respiratory symptoms by self recording questionnaire of 14 houses was investigated. In conclusion, although the results of this study failed to establish the relationship between PM10, PM2.5 concentrations and respiratory symptoms among residents, the levels of indoor PM2.5 were significantly higher than those of outdoor levels. The indoor PM10, PM2.5 concentrations were increased by the amount of time spent of residents. Further research should be directed to establish the relationship between PM10, PM2.5 concentration and respiratory symptoms.

서울시에서 설치하여 운영중인 대기질 측정소의 입자상물질을 대표하는 PM2.5, PM10, TSP와 황사기간 중 고용량고기포집기로 채취한 먼지성분을 분석, 평가하였다. 1990년도부터 2002년 11월까지 서울에서 관측된 황사일수는 2000년 이후 발생빈도가 증가하였으며 황사지속시간도 길어지는 경향을 보였다. PM10/TSP 비율은 황사시 2000년, 2001년도에 각각 52.9%, 59.4%로 비황사시에 비해 PM10의 비율이 약 10% 정도 낮은 것으로 미루어 황사시 10 μm이상의 입경이 큰 입자 영향이 컸던 반면에 2002년 황사시에는 PM10의 영향이 오히려 크게 나타나 PM10이 TSP 중의 71.4%에 달하였다. 황사가 전체 먼지농도에 미치는 기여율은 2002년도에 PM2.5 11.9%, PM10 23.1%, TSP 19%로 가장 높은 기여도를 보여 황사가 전체 면지농도에 미치는 영향이 매우 크다는 것을 알 수 있었다.

To investigate the reason for the spatial difference in PM2.5 (Particulate Matter, < 2.5 ㎛) concentration despite a similar synoptic pattern, a synoptic analysis was performed. The data used for this study were the daily average PM2.5 concentration and meteorological data observed from 2016 to 2020 in Busan and Seoul metropolitan areas. Synoptic pressure patterns associated with high PM2.5 concentration episodes (greater than 35 ㎍/㎥) were analyzed using K-means cluster analysis, based on the 900 hPa geopotential height of NCEP (National Centers for Environmental Prediction) FNL (Final analysis) data. The analysis identified three sub-groups related to high concentrations occurring only in Busan and Seoul metropolitan areas. Although the synoptic patterns of high PM2.5 concentration episodes that occur independently in Busan and Seoul metropolitan areas were similar, there was a difference in the intensity of pressure gradient and its direction, which tends to be an important factor determining the movement time of pollutants. The spatial difference in PM2.5 concentration in the Korean Peninsula is due to the difference and direction of the atmospheric pressure gradient that develops from southwest to northeast direction.

In this study, the contributions of emissions (foreign and domestic) and atmospheric physical and chemical processes to PM2.5 concentrations were evaluated during a high PM2.5 episode (March 24-26, 2018) observed on the Jeju Island in the spring of 2018. These analyses were performed using the community multi-scale air quality (CMAQ) modeling system using the brute-force method and integrated process rate (IPR) analysis, respectively. The contributions of domestic emissions from South Korea (41-45%) to PM2.5 on the Jeju Island were lower than those (81-89%) of long-range transport (LRT) from China. The substantial contribution of LRT was also confirmed in conjunction with the air mass trajectory analysis, indicating that the frequency of airflow from China (58-62% of all trajectories) was higher than from other regions (28-32%) (e.g., South Korea). These results imply that compared to domestic emissions, emissions from China have a stronger impact than domestic emissions on the high PM2.5 concentrations in the study area. From the IPR analysis, horizontal transport contributed substantially to PM2.5 concentrations were dominant in most of the areas of the Jeju Island during the high PM2.5 episode, while the aerosol process and vertical transport in the southern areas largely contributed to higher PM2.5 concentrations.

In this study, surface particulate matter (PM2.5) concentrations were calculated based on empirical equations using measurements of ceilometer backscatter intensities and meteorological variables taken over 19 months. To quantify the importance of meteorological conditions on the calculations of surface PM2.5 concentrations, eight different meteorological conditions were considered. For each meteorological condition, the optimal upper limit height for an integration of ceilometer backscatter intensity and coefficients for the empirical equations were determined using cross-validation processes with and without considering meteorological variables. The results showed that the optimal upper limit heights and coefficients depended heavily on the meteorological conditions, which, in turn, exhibited extensive impacts on the estimated surface PM2.5 concentrations. A comparison with the measurements of surface PM2.5 concentrations showed that the calculated surface PM2.5 concentrations exhibited better results (i.e., higher correlation coefficient and lower root mean square error) when considering meteorological variables for all eight meteorological conditions. Furthermore, applying optimal upper limit heights for different weather conditions revealed better results compared with a constant upper limit height (e.g., 150 m) that was used in previous studies. The impacts of vertical distributions of ceilometer backscatter intensities on the calculations of surface PM2.5 concentrations were also examined.

This study investigated the variations in monthly PM2.5 concentrations and their characteristics at the sampling site (35.075°N, 129.080°E) around the Busan seaport area for six months (from August 2020 to January 2021). Monthly PM2.5 concentrations in the filtered samples ranged from 8.4 to 42.3 ㎍/m3 (average=19.6±8.2 ㎍/m3, n=50) and were generally high in August, December, and January, and low in September, October, and November. The variations of monthly PM2.5 concentrations showed similar patterns to those of the neighboring national air quality monitoring sites. The contents of Total Carbon (TC), Organic Carbon (OC), Elemental Carbon (EC), and OC/EC ratios in PM2.5 showed large variability during the study period. The OC/EC ratios ranged from 4.2 to 34.4, suggesting that the relative contributions of OC and EC to the PM2.5 concentrations changed temporally and might be related to their formation sources. Variations in the chemical components of and particle size distributions in PM2.5 showed that high PM2.5 concentrations were affected by various sources, such as sea salt and ship emission. The precursor gas concentrations were discussed in terms of monthly variations and their contributions to PM2.5 concentrations. However, further research is needed to understand the characteristics and behaviors of PM2.5 concentrations around the Busan seaport area.

This research investigated the meteorologically relevant characteristics of high PM2.5 episodes in Busan. The number of days when daily mean PM10 concentration exceeded 100 ㎍/m3 and the PM2.5 concentration exceeded 50 ㎍/m3 over the last four years in Busan were 24 and 58, respectively. Haze occurrence frequency was 37.6% in winter, 27.4% in spring, 18.6% in fall, and 16.4% in summer. Asian dust occurrence frequency was 81.8% in spring, 9.1% in fall and winter, and 0% in summer. During summer in Busan, high PM2.5 episode occurred under the following meteorological conditions. 1) Daytime sea breeze. 2) Mist and haze present throuout the day. 3) Anti-cyclone located around the Korean peninsula. 4) Stable layer formed in the lower atmosphere. 5) Air parcel reached Busan by local transport rather than by long-range transport. These results indicate that understanding the meteorological relevance of high PM2.5 episodes could provide insight for establishing a strategy to control urban air quality.

This study investigates the characteristics of diurnal, seasonal, and weekly roadside and residential concentrations of PM10 and PM2.5 in Busan, as well as relationship with meteorological phenomenon. Annual mean PM10 and PM2.5 concentrations in Busan were 44.2 ㎍/m3 and 25.3 ㎍/m3, respectively. The PM2.5/PM10 concentration ratio was 0.58. Diurnal variations of PM10 and PM2.5 concentrations in Busan were categorized into three types, depending on the number of peaks and times at which the peaks occurred. Roadside PM10 concentration was highest on Saturday and lowest on Friday. Residential PM10 concentration was highest on Monday and lowest on Friday. Residential PM2.5 concentration was highest on Monday and Tuesday and lowest on Friday. PM10 and PM2.5 concentrations were highest on Asian dust and haze, respectively. The results indicate that understanding the spaciotemporal variation of fine particles could provide insights into establishing a strategy to control urban air quality.

Asthmatics are more susceptible to fine particulate matters (PM2.5), compared to the general population. It has been reported that indoor PM2.5 is mainly generated by combustion of fossil fuels, meat or fish In particular, asthmatics are known to be more susceptible to indoor PM2.5 because 65 ∼ 95% of child or adult asthmatics stay inside the house. Thus, understanding the association between indoor activity patterns and variations in indoor PM2.5 levels is important. The purpose of this study is to determine the distribution of hourly indoor PM2.5 concentrations in asthmatics’ homes, and to evaluate its association with pan-frying cooking activity patterns, the most common PM2.5 emission related activity. From November 2017 to February 2018, real-time PM2.5 concentrations were measured in the living room of each asthmatic’s house (n = 35) for three weeks at 1 minute intervals. At the same time, self-reported daily activity patterns, hourly proportion (%) of cooking activities, were also recorded every hour over three weeks for each patient. In this study, we provided quantitative evidence that the distribution patterns of indoor hourly PM2.5 concentrations were associated with indoor cooking activities, especially in the homes of adult asthmatics. In addition, we observed that PM2.5 emitted by pan-frying could maintain even over up to 2 hour lagtime.

This research investigated the characteristics of PM10 and PM2.5 concentrations at the main subway stations in Busan. Annual mean PM10 concentrations at the Seomyeon 1- waiting room and platform were 51.3 ㎍/㎥ and 47.5 ㎍/㎥ , respectively, and the annual PM2.5 concentration at the Seomyeon 1- platform was 28.8 ㎍/㎥ . PM2.5/PM10 ratio at Seomyeon 1-platform and Dongnae station were 0.58 and 0.53, respectively. Diurnal variation of PM10 concentration at subway stations in Busan was categorized into four types, depending on the number of peaks and the times at which the peaks occurred. Unlike the areas outside of the subway stations which reported maximum PM10 concentration mostly in spring across the entire locations, the interiors of the subway stations reported the maximum PM10 concentration in spring, winter, and even summer, depending on their location. PM10 concentration was highest on Saturday and lowest on Sunday. The numbers of days when PM10 concentration exceeded 100 ㎍/㎥ and 80 ㎍/㎥ per day over the last three years at the subway stations in Busan were 36 and 239, respectively. The findings of this research are expected to enhace the understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.