Because of the population growth and industrialization in recent decades, the air quality over the world has been worsened with the increase of PM10 concentration. Korea is located near the eastern part of China which has many industrial complexes, so the consideration of China’s air quality is necessary for the PM10 prediction in Korea. This paper examines a machine learning-based modeling of the prediction of tomorrow’s PM10 concentration in the form of a gridded map using the AirKorea observations, Chinese cities’ air quality index, and NWP (numerical weather prediction) model data. A blind test using 23,048 cases in 2019 produced a correlation coefficient of 0.973 and an MAE (mean absolute error) of 4.097㎍/㎥, which is high accuracy due to the appropriate selection of input variables and the optimization of the machine learning model. Also, the prediction model showed stable predictability irrespective of the season and the level of PM10. It is expected that the proposed model can be applied to an operative system if a fine-tuning process using a larger database is accomplished.

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.

In order to investigate the PM10 concentration trend and its characteristics over five different sub area in Busan from 2013 to 2015, data analysis with considering air flow distribution according to its topography was carried out using statistical methodology. The annual mean concentrations of PM10 in Busan tend to decrease from 49.6㎍/m³ in 2013 to 46.9㎍/m³ in 2015. The monthly mean concentrations value of PM10 were high during spring season, from March to May, and low during summer and fall due to frequent rain events. The concentration of PM10 was the highest in five different sub-area in Busan. High concentration episodes over 90 percentile of daily PM10 concentration were strongly associated with mean daily wind speed, and often occurred when the westerly wind or southwesterly wind were dominant. Regardless of wind direction, the highest correlation of PM10 concentrations was observed between eastern and southern regions, which were geographically close to each other, and the lowest in the western and eastern regions blocked by mountains. Wind flow along the complex terrain in Busan is also one of the predominant factors to understand the temporal variation of PM10 concentrations.

The classification of airflow patterns during high ozone (O3) and PM10 episodes on Jeju Island in recent years (2009-2015), as well as their correlation with meteorological conditions according to classified airflow patterns were investigated in this study. The airflow patterns for O3 and PM10 were classified into four types (Types A-D) and three types (Types E-G), respectively, using the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and synoptic weather charts. Type A was the most dominant airflow pattern for O3 episodes, being characterized by the transport of airflows from urban and industrial areas in China with the highest frequency (about 69%, with a mean of 67 ppb). With regard to the PM10 episodes, Type E was the most dominant airflow pattern, and was mostly associated with long distance transport from Asian dust source regions along northwesterly winds, having the highest frequency (about 92%, with a mean of 136 μg/m3). The variations in the concentration of O3 and PM10 during the study period were clarified in correlation with two pollutant and meteorological variables; for example, the high (low) O3 and PM10 concentrations with high (low) air temperature and/or wind speed and vice versa for precipitation. The contribution of long-range transport to the observed PM10 levels in urban sites for different airflow patterns (Types E-F), if estimated in comparison to the data from the Gosan background site, was found to account for approximately 87-93% (on average) of its input. The overall results of the present study suggest that the variations in O3 and PM10 concentrations on Jeju Island are mainly influenced by the transport effect, as well as the contribution of local emissions.

This study analyzes the PM10 characteristics (particulate matter with aerodynamic diameter less than 10 ㎛), concentration, and emissions in eight large South Korean cities (Seoul, Incheon, Daejeon, Daegu, Gwangju, Ulsan, Busan, Jeju). The annual median of PM10 concentration showed a decline of 0.02~1.97 ㎍/㎥ in the regions, except for Incheon, which recorded an annual 0.02 ㎍/㎥ increase. The monthly distribution levels were high in spring, winter, fall, and the summer, but were lower in summer for all regions except for Ulsan. These differences are thought to be due to the dust in spring and the cleaning effect of precipitation in summer. The variation in concentrations during the day (diurnal variation) showed that PM10 levels were very high during the rush hour and that this was most extreme in the cities (10.00 and 18.00-21.00). The total annual PM10 emissions analysis suggested that there had been a general decrease, except for Jeju. On-road mobile (OM) sources, which contributed a large proportion of the particulates in most regions, decreased, but fugitive dust (FD) sources increased in the remaining regions, except for Daegu. The correlation analysis between PM10 concentrations and emissions showed that FD could be used as a valid, positive predictor of PM10 emissions in Seoul (74.5% (p<0.05)), Dajeon (47.2% (p<0.05)), and Busan (59.1% (p<0.01)). Furthermore, industrial combustion (IC) was also a significant predictor in Incheon (61.7% (p<0.01)), and on-road mobile (OC) sources were a valid predictor in Daegu (24.8% (p<0.05)).

This study investigates the characteristics of metallic and ionic elements concentration, concentration according to transport path, and factor analysis in PM10 at Guducsan in Busan in the springtime of 2015. PM10 concentration in Guducsan and Gwaebeopdong were 59.5± 9.04 ㎍/㎥ and 87.5±20.2 ㎍/㎥, respectively. Contribution rate of water-soluble ions and secondary ion in PM10 concentration in Guducsan were 37.0% and 27.8% respectively. [NO3 -/SO4 2-] ratio and contribution rate of sea salt of PM10 in Guducsan and Gwaebeopdong were 0.91 and 1.12, 7.0% and 5.3%, respectively. The results of the backward trajectory analysis indicates that PM10 concentration, total inorganic water-soluble ions and total secondary ions were high when the air parcels moved from Sandong region in China than non-Sandong and northen China to Busan area. The results of the factor analysis at Guducsan indicates that factor 1 was anthropogenic source effects such as automobile emissions and industrial combustion processes, factor 2 was marine sources such as sea salts from sea, and factor 3 was soil component sources.

Long-term variations of PM10 and the characteristics of local meteorology related to its concentration changes were analyzed at 4 air quality sites (Ido-dong, Yeon-dong, Donghong-dong, and Gosan) in Jeju during two different periods, such as PI (2001-2006) and PII (2007-2013), over a 13-year period. Overall, the long-term trend of PM10 was very slightly downward during the whole study period, while the high PM10 concentrations in PII were observed more frequently than those in PI. The concentration variations of PM10 during the study period was clarified in correlation between PM10 and meteorological variables, e.g. the low (high) PM10 concentration with large (small) precipitation or high (low) radiation and in part high PM10 concentrations (especially, Donghong-dong and Gosan) with strong wind speed and the westerly/northwesterly winds. This was likely to be caused by the transport effect (from the polluted regions of China) rather than the contribution of local emission sources. The PM10 concentrations in “Asian dust” and “Haze” weather types were higher, whereas those in “Precipitation”, “Fog”, and “Thunder and Lighting” weather types were lower. The contribution of long-range transport to the observed PM10 levels in the urban center (Ido-dong, Yeon-dong, and Donghong-dong), if estimated by comparison to the data of the background site (Gosan), was found to explain about 80% (on average) of its input.

The production of highly concentrated PM10 is in the spotlight as a social issue, and it increases the attack rate of Asthma. This study aimed to analyze the characteristics of concentration and distribution for PM10 from 2000 to 2011, and investigate its correlation with the death from Asthma. Furthermore, this study was designed to analyze it by dividing into two cases like including Asian dust and excluding Asian dust because it presented the high concentration when Asian dust was occurred in the spring. This study has found that the annual average concentration distribution of PM10 in Seoul was higher in the central area than the peripheral area. The annual average concentration of PM10 and death from asthma displayed the tendency to gradually decrease. The correlation coefficient for all period was 0.92(p=0.000), and the correlation was 0.84(p=0.001) in case of remove Asian dust. The monthly average concentration of PM10 has increased in the winter and decreased in the summer. The death from Asthma and correlation coefficient for all period was 0.588(p=0.044) and 0.640(p=0.025) in case of removing Asian dust. Although the causes of Asthma had a great diversity, the similar tendency by a factor of PM10 meant that the correlation was high.

This study aims to investigate the indoor air quality by analyzing PM10 concentration and metallic elements collected from high school( classroom, science room, assembly room). PM10 concentration of a classroom, a science room, and an assembly hall during the research period was 87.7 ㎍/m3, 75.3㎍/m3, 64.6㎍/m3, respectively. Si of PM10 had highest concentration with 15,427 ng/m3 followed by Na which had 7,205 ng/m3, and the order was Si>Na>Ca>Mg>Fe>K in the classroom. PM10 concentration of a classroom and a science room was each 104.8 ㎍/m3 and 75.3 ㎍/m3 during the semester and PM10 concentration of a classroom and an assembly hall was each 80.9 ㎍/m3 and 64.6 ㎍/m3 during the summer vacation. Based on PM10 and metallic concentration at a classroom on day of week, the concentration of Friday was highest with 112.0 ㎍/m3, and that of Monday was lowest with 65.3 ㎍/m3.

PM10 concentration is related to the meteorological variables including to local and synoptic meteorology. In this study the PM10 concentrations of Busan in 2007~2011 were analyzed and the days of yellow sand or rainfall which is more than 5 mm were excluded. The sections of PM10 concentration were divided according to 10-quantiles, quartiles and 90-quantiles. The 90-quantiles of daily PM10 concentration were selected as high concentration dates. In the high concentration dates the daily mean averaged cloudness, mean daily surface wind speed, daily mean surface pressure and PBL height were low and diurnal variation of surface pressure and daily maximum surface temperature were high. When the high PM10 dates occurred, the west and south wind blew on the ground and the west wind blew strongly on the 850 hPa. So it seemed that long range transboundary air pollutants made effects on the high concentration dates. The cluster analysis using Hysplit model which is the backward trajectory was made on the high concentration dates. As a result, 3 clusters were extracted and on the short range transboundary cluster the daily mean relative humidity and cloudness were high and PBL height was low.

The purpose of this study was to analyze the meteorological characteristics of wintertime high PM10 concentration episodes in Busan. PM10 concentration has been reduced for the past four years and recorded near or exceeded 100 ㎍/㎥ (national standard of PM10). High concentration episodes in Busan were 6 case, PM2.5/PM10 ratio was 0.36∼0.39(mean 0.55). High PM10 concentration occurred during higher air temperature, more solar radiation and sunshine, lower relative humidity, and smaller cloud amount. Synoptically, it also occurred when Busan was in the center or the edge of anticyclone and when sea breeze intruded. An analysis of upper air sounding showed that high PM10 concentration occurred when surface inversion layer and upper subsidence inversion layer existed, and when boundary layer depth and vertical mixing coefficient were low. An analysis of backward trajectory of air mass showed that high PM10 concentration was largely affected by long range transport considering that it occurs when air mass is intruded from China.

The purpose of this study was to analyze the characteristics of spacio-temporal variation for PM10 and PM2.5 concentration in Busan. PM10 concentration has been reduced for the past three year and exceeded 50 ㎍/㎥ of the national standard for PM10. PM2.5 concentration showed gradual decrease or stagnant trends and exceeded the U.S. EPA standard. Seasonal analysis of PM10 and PM2.5 suggested spring>winter>fall>summer(by Asian dust) and winter>spring>summer>fall(by anthropogenic effect) in the order of high concentration, respectively. Characterization of diurnal variations suggests that PM10 levels at all the three sites consistently exhibited a peak at 1000LST and PM2.5 at Jangrimdong experienced the typical PM2.5 diurnal trends such that a peak was observed in the morning and the lowest level at 1400LST. In the case of seasonal trends, the PM2.5/PM10 ratio was in the order of summer>winter>fall>spring at all the study sites, with a note that spring bears the lowest concentration. During AD events, PM10 concentration exhibited the highest level at Jangrimdong and the lowest level at Joadong. And PM2.5/PM10 ratio in AD was 0.16∼0.28.

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of PM10 for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is 43.27 ㎍/㎥ for new classrooms while 53.38 ㎍/㎥ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors 46.71 ㎍/㎥, outdoors 50.46 ㎍/㎥, and personal 41.62 ㎍/㎥. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors 39.11 ㎍/㎥, outdoors 34.86 ㎍/㎥, and personal 49.01 ㎍/㎥. 2. Cr concentration level within dust was slightly higher in summer indoors (101.50±32.10 ng/㎥) and outdoors (100.89±35.18 ng/㎥) than winter indoors (85.80±48.95 ng/㎥) and outdoors (74.43±38.93 ng/㎥), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of PM10 concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

This study is designed to investigate the characteristics of PM10 concentration and the chemical composition of heavy metallic components in the PM10 sampled in western Busan from March to May, 2003. PM10 measurement was done during springtime of 2003, totaling 29 days: 9 days in March, 10 days in April and 10 days in May. With a sampling time of 24 hours, it started 9:00 AM on that day and ended 9:00 AM the next day. The mean contribution ratio of soil during springtime was 10.3 %. Al had a significant correlation with Ca, Fe, Mg and Si and little correlation with Na, Ni and Zn.

Hourly data of PM10 concentration collected from nine automatic air quality monitoring stations in Busan from 1999 to 2002 were analyzed to evaluate the spatio-temporal variation and meteorological characteristics of PM10 episodes in Busan metropolitan area. Mean concentrations ranged from 47㎍/m3 to 77㎍/m3. For most stations, mean seasonal hourly concentrations are lowest in summer and highest in spring. PM10 episode above daily mean standard(150㎍/m3) exhibited a maximum frequency at Gamjeondong and a minimum at Dongsamdong, and a maximum in March and a minimum in July and August. The diurnal variation of PM10 episode days is strongly influenced by traffic loads and meteorological conditions.

The PM10 concentration and chemical composition in an western area of Busan were surveyed between March, 2001 and February, 2002. The mean concentration was 98.2 ㎍/㎥ with a range of 18.1 to 330.6 ㎍/㎥. The magnitude of metallic elements in PM10 is as follows in decreasing order: K>Ca>Na>Al>Fe. The mean values of crustal enrichment factors for four elements (Cd, Ni, Pb and Zn) were all higher than 10, which presumably resulted from the effect of anthropogenic origin. Moreover, the wintertime values were higher than springtime and summertime values, possibly due to emissions westerly transported from industries around this area. The contribution of soil particle to airborne particle in the study area was estimated to be 9.5%.

PM10 concentrations were measured in underground stores located in 4 major cities, Chunchon, Wonju, Donghae and Sockcho, in Kangwon-Do using scattering light integrated type digital dust indicator. Personal exposure to PM10 for two women(housekeeper and graduate student) and a man(undergraduate student) were measured also. The dimensional conversion factors for mass concentrations(K) showed some difference among underground stores which were 2.0, 2.7, 3.4, 2.6 ㎍/㎥·CPM in chunchon, Wonju, Donghae and Sockcho, respectively. Average PM_10 concentrations at underground stores were 178 ㎍/㎥ in Chunchon, 141 ㎍/㎥ in Wonju, 125 ㎍/㎥ in Donghe and 59 ㎍/㎥ in Sockcho. The portion of PM10 in total suspended particles was about 50∼60 % as weight. The exposure of graduate student, housekeeper and undergraduate to PM10 during 12 hours were 1004.3 (㎍/㎥)·hr, 907.0 (㎍/㎥)·hr and 691.2 (㎍/㎥)·hr, respectively. Personal exposure to PM10 showed very different according to their activity pattern and they had more than 90 % of their PM10 exposure at indoor environment.