• 한국환경과학회지
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• 제22권6호
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• pp.651-666
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• 2013

This study introduces a novel approach to the differentiation of two phenomena, Asian Dust and haze, which are extremely difficult to distinguish based solely on comparisons of PM10 concentration, through use of the Optical Particle Counter (OPC), which simultaneously generates PM10, PM2.5 and PM1.0 concentration. In the case of Asian Dust, PM10 concentration rose to the exclusion of PM2.5 and PM1.0 concentration. The relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration were below 40%, which is consistent with the conclusion that Asian Dust, as a prime example of the coarse-particle phenomenon, only impacts PM10 concentration, not PM2.5 and PM1.0 concentration. In contrast, PM10, PM2.5 and PM1.0 concentration simultaneously increased with haze. The relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration were generally above 70%. In this case, PM1.0 concentration varies because a haze event consists of secondary aerosol in the fine-mode, and the relative ratios of PM10 and PM2.5 concentration remain intact as these values already subsume PM1.0 concentration. The sequential shift of the peaks in PM10, PM2.5 and PM1.0 concentrations also serve to individually track the transport of coarse-mode versus fine-mode aerosols. The distinction in the relative ratios of PM2.5 and PM1.0 concentration versus PM10 concentration in an Asian Dust versus a haze event, when collected on a national or global scale using OPC monitoring networks, provides realistic information on outbreaks and transport of Asian Dust and haze.

• 한국입자에어로졸학회지
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• 제15권2호
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• pp.45-56
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• 2019

The public's concern on ambient $PM_{2.5}$ has been increasing in Korea. We have estimated (1) the annual and monthly mean $PM_{2.5}$ concentrations, (2) the frequency by the $PM_{2.5}$ concentration interval, and (3) the high concentration occurrence duration time between 2015 and 2018 at 16 administration regions. We found that there have been differences in all three above parameters' trends among the studied 16 regions in Korea. Still, Jeonbuk showed the highest rank in all three parameters' trends. In Jeonbuk, the average $PM_{2.5}$ concentration and the sum of the frequency fraction when the $PM_{2.5}$ concentration being over $75{\mu}g/m^3$ between 2016 and 2018 was $28.4{\mu}g/m^3$ and 9.0%, respectively. And the days when the $PM_{2.5}$ concentration is over $50{\mu}g/m^3$ between 2015 and 2018 were 149. Chungbuk was the only region with the increasing trend of $PM_{2.5}$ concentration between 2016 and 2018. And in Seoul and Gyeonggi, the average $PM_{2.5}$ concentrations decreased whereas the high concentration frequency fraction increased between 2016 and 2018. Also, it is found that there have been differences in the trends of the frequency by the $PM_{2.5}$ concentration interval and the high concentration occurrence duration time between $PM_{10}$ and $PM_{2.5}$.

• 한국환경보건학회지
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• 제45권2호
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• pp.186-191
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• 2019

Objectives: Subway is one of the most common transportation modes in Seoul, Korea. The objectives of this study were to determine characteristics of in-cabin $PM_{2.5}$ concentration in Seoul Metro Line Number 2 and to identify factors of the $PM_{2.5}$ concentration. Methods: In-cabin $PM_{2.5}$ concentrations in Seoul Metro Line Number 2 were measured using real-time monitors and the factors affecting $PM_{2.5}$ concentration in cabin were observed. Linear regression analysis of in-cabin $PM_{2.5}$ concentration and indoor/outdoor (I/O) ratio were performed. Results: In-cabin $PM_{2.5}$ concentration was associated with the in-cabin $PM_{2.5}$ concentration in previous station. In-cabin $PM_{2.5}$ concentration was correlated with ambient $PM_{2.5}$ concentration and associated with underground station with control of the in-cabin $PM_{2.5}$ concentration in previous station. I/O ratio increased as the number of passengers increased and when passing through the underground station with control of I/O ratio in previous station. Conclusion: In-cabin $PM_{2.5}$ concentration was affected by ambient $PM_{2.5}$ concentration. Therefore, management of in-cabin $PM_{2.5}$ concentrations should be based on outdoor air quality.

• 한국대기환경학회지
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• 제28권6호
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• pp.666-674
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• 2012

The purpose of this study is to propose management strategies to lower the level of $PM_{10}$ concentration. First, this study analyzes the characteristics of particle sizes in three different areas, the residential, the roadside, and the industrial areas. Second, it has examined the size of particles which can influence on the increase of $PM_{10}$ concentration level. The distribution of particle size for $PM_{10}$ concentration was not different by regions. The highest portion in the observed $PM_{10}$ is near $0.3{\mu}m$. In addition, both near $2.5{\mu}m$ and near $5.0{\mu}m$ are found higher in portion. The fractions of $PM_{1.0}$ and $PM_{2.5}$ in $PM_{10}$ are 68.2% and 75.8% respectively. The fraction of $PM_{1.0}$ in $PM_{2.5}$ is 89.8%. The particle diameters contributed to the increase of $PM_{10}$ concentration are different by regions. In the residential area, the sizes of near $0.6{\mu}m$ and near $3.3{\mu}m$ particles are found to be the cause for the increase of $PM_{10}$ concentration level. However the particle sizes for the increase of $PM_{10}$ concentration level are $0.8{\mu}m$ and $0.5{\mu}m$ in roadside and industrial area respectively. Therefore, fine particles are found as the key factors to raise $PM_{10}$ concentration level in the two areas, while both fine and coarse particles are in the residential areas. When examined the $PM_{10}$ concentration level change, it was categorized by two different time zones, the high concentration level time and the lower concentration time. In high concentration time, the $PM_{10}$ concentration has increased in the morning in the residential and roadside areas. On the contrary, the level has increased in the evening in the industrial area. In low concentration time, the level of $PM_{10}$ concentration in the roadside area is significantly higher in the morning than the concentration level of other times. There is no significantly different concentration level found in the both residential and industrial areas throughout the day.

• 한국가시화정보학회지
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• 제20권1호
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• pp.45-51
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• 2022

Airborne particulate matter(PM) has been a global environmental problem. PM whose diameter is smaller than 10 ㎛ can permeate respiratory organs and has harmful effects on human health. Therefore, PM monitoring systems are necessary for management of PM and prevention of PM-induced negative effects. Conventional PM monitoring techniques are expensive and cumbersome to handle. In the present study, two types of PM monitoring devices were designed for measuring indoor PM concentration, portably. We experimentally investigated the performance of three commercial PM concentration measurement sensors in a closed test chamber. As a result, PM2008 sensor showed the best PM concentration measurement accuracy. Linear regression method was applied to convert PM concentration value acquired from PM2008 sensor into ground truth value. A mobile application(app.) was also created for users to check the PM concentration, easily. The mobile app. also provides safety alarm when the PM₁₀ concentration exceeds 81 ㎛/m³. The developed hand-held system enables the facile monitoring of surrounding air quality.

• 한국환경과학회지
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• 제19권8호
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• pp.1013-1023
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• 2010

The purpose of this study was to analyze the characteristics of spacio-temporal variation for $PM_{10}$ and $PM_{2.5}$ concentration in Busan. $PM_{10}$ concentration has been reduced for the past three year and exceeded $50\;{\mu}g/m^3$ of the national standard for $PM_{10}$. $PM_{2.5}$ concentration showed gradual decrease or stagnant trends and exceeded the U.S. EPA standard. Seasonal analysis of $PM_{10}$ and $PM_{2.5}$ suggested spring>winter>fall>summer(by Asian dust) and winter>spring>summerenlifall(by anthropogenic effect) in the order of high concentration, respectively. Characterization of diurnal variations suggests that $PM_{10}$ levels at all the three sites consistently exhibited a peak at 1000LST and $PM_{2.5}$ at Jangrimdong experienced the typical $PM_{2.5}$ diurnal trends such that a peak was observed in the morning and the lowest level at 1400LST. In the case of seasonal trends, the $PM_{2.5}/PM_{10}$ 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, $PM_{10}$ concentration exhibited the highest level at Jangrimdong and the lowest level at Joadong. And $PM_{2.5}/PM_{10}$ ratio in AD was 0.16~0.28.

• 한국환경과학회지
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• 제29권7호
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• pp.749-760
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• 2020

This study investigates the characteristics of diurnal, seasonal, and weekly roadside and residential concentrations of PM₁₀ and PM_2.5 in Busan, as well as relationship with meteorological phenomenon. Annual mean PM₁₀ and PM_2.5 concentrations in Busan were 44.2 ㎍/㎥ and 25.3 ㎍/㎥, respectively. The PM_2.5/PM₁₀ concentration ratio was 0.58. Diurnal variations of PM₁₀ and PM_2.5 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 PM_2.5 concentration was highest on Monday and Tuesday and lowest on Friday. PM₁₀ and PM_2.5 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.

• 한국대기환경학회지
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• 제19권2호
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• pp.231-245
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• 2003

Hourly PM$_{10}$ concentrations measured at 11 sites in Seoul and 10 sites in the large cities over South Korea for the period from March 1995 to February 2000 are analyzed to examine annual trend and monthly variations of the PM$_{10}$ concentrations. Further analysis has been carried out by using the one year data from March 1999 to February 2000 to see the seasonal variation, diurnal variation and weekly variation of the seasonally averaged PM$_{10}$ concentrations at each site. Weekly variations of the CO concentrations at the same sites for the same one year period are compared with that of the PM$_{10}$ concentration. There is no significant annual trend in the variation of the PM$_{10}$ concentration at all the sites analyzed. The seasonal and monthly mean concentrations show a minimum concentration in summer and alternative maximum concentration in spring and winter for most sites. The diurnal variation of the seasonally averaged mean PM$_{10}$ concentrations is strongly affected by traffic loads and meteorological conditions. The weekly variation of seasonal averaged concentrations of CO and PM$_{10}$ shows a high concentration for weekdays in spring, autumn and winter while high concentration for weekends in summer.nds in summer.

• 한국환경과학회지
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• 제24권6호
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• pp.777-784
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• 2015

This study investigates weekday/weekend characteristics of $PM_{10}$ and $PM_{2.5}$ concentration and metallic elements in Busan in the springtime of 2013. $PM_{10}$ concentration on weekday/weekend were 77.54 and $67.28{\mu}g/m^3$, respectively. And $PM_{2.5}$ concentration on weekday/weekend were 57.81 and $43.83{\mu}g/m^3$, respectively. Also, $PM_{2.5}/PM_{10}$ concentration ratio on weekdays/weekend was 0.75 and 0.65, respectively. The contribution rates of Na to total metallic elements in $PM_{10}$ on weekday/weekend were 38.3% and 38.9%, respectively. It would be useful in control effectively with management of urban fine particle to understand characteristics of fine particle concentration on weekday/weekend.

• 한국환경과학회지
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• 제24권7호
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• pp.883-892
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• 2015

The study investigates the characteristics of $PM_{10}$ concentration in Guducsan air quality observatory and in particular, analyzes the relationship between sudden increase of $PM_{10}$ concentration in the morning of spring 2014 and meteorological parameters. $PM_{10}$ concentration in April was $46.9{\mu}g/m^3$, the highest, followed by $45.5{\mu}g/m^3$ and $44.6{\mu}g/m^3$ in March and May, and $21.9{\mu}g/m^3$ in August. The low concentration in the early morning appeared on 0800 LST in spring, summer, and fall, whereas it emerged on 0900 LST in winter. High concentration in daytime lasted from 1200 LST to 1500 LST in spring and fall, whereas it continued from 1300 LST to 1600 LST in winter. The findings of $PM_{10}$ concentration and change of meteorological parameters in Guducsan from April 20th to 27th in 2014 are as follows. The low concentration at dawn and in the morning decreased due to strong land breeze. Also, the sudden increase of $PM_{10}$ concentration in the morning was attributable to low wind speed. Lastly, the sudden decrease of $PM_{10}$ concentration in the afternoon was attributed to diffusion by strong sea breeze.