• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1172-1176
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• 2003

This study aims to investigate the applicability of Sd/StFFF and to develop a method for size characterization of urban airborne particles, focusing primarily on particles larger than about 1 mm. It was found that the airborne concentration vary with time, although no particular seasonal trend was observed. When averaged over time, the airborne concentration was the lowest in the park areas with 99 ㎍/m³. The apartment, industrial, and central city area showed similar levels of the airborne concentrations with 166, 170, and 171 ㎍/m³, respectively. The housing area showed the highest airborne concentration with 201 μg/m³ among all tested areas. A power-programmed Sd/StFFF was used for size analysis of airborne particles with the initial field strength of 300 rpm, $t_a$ = 4, $t_i$ = -16, p = 8, and the flow rate of 7 mL/min. It was found that urban airborne samples were mostly populated by particles having diameters between about 5 to 20 ㎛, although all have broad size distributions ranging up to about 50 ㎛. Under the Sd/StFFF condition used in this study, no significant differences were found in size distributions among the airborne particles collected at different urban sites, and also among those collected at different times.

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.152-156
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• 2011

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto ($134^{\circ}45'E$, $32^{\circ}28'N$), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 ${\mu}m$ were distinguished by their morphologies, fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.201-208
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• 2001

To investigate the physio-chemical components and properties of aerosol particles in urban area sampling of aerosol particles was carried out in the campus of Hokkaido University, Sapporo, Japan, during snowfall. Aerosol particles were collected on millipore filter papers using a low volume air sampler. Their shapes, sizes and chemical components were analyzed by a SEM(Scanning Electron Microscope) and an EDX(Energy Dispersive X-ray). As a results, ice crystals of dendrite and column types were predominantly shown at mature and developing stage of snowfall intensity. The denerite and sector plate types of ice crystals were mainly originated from the sea but column types were come from soil. Scavenging effect by snowfall was greatly also shown at dendrite type ice crystals that embryo was fully developd. Al, Si elements were shown at high frequencies as compared with others. Na, Cl components were especially shown at high frequencies under the sea-breeze wind during snowfall. Anthropogenic aerosol particles had shown with irregular shapes and sizes, relatively. Mainly 3-7$\mu$m aerosol particles were abundant and coarse particles also could be seen during snowfall. Ca, Zn, Fe components mainly caused by spike tires from vehicles in winter season were dominant before snowfall, however the element S mainly caused by human activity was rich after snowfall. The pH values of snow in Sapporo city were higher than those at coastal area. The concentration of chemical components in aerosol particles was also affected by surface winds. Aerosol particles in urban area, Sapporo were mainly affected by human activities like vehicles and combustion with wind system. And their types were related with snowfall intensity.

• Journal of Korean Society for Atmospheric Environment
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• v.1 no.1
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• pp.71-82
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• 1985

The effect on the particulate matters in the atmosphere was investigated in Seoul area from March, 1984 to Aprill, 1985. Aerosols were collected by filters on nine stages Andrsen Air Sampler, and size distribution and total concentration of the aerosols, Fe and Pb were measured. In spring with Yellow Sand the concentration of particles in aerosols was 185.55$\mug/m^3$ and CP/TA was 65.9%. But in spring without Yellow Sand those of particles was 135.45$\mug/m^3$ and CP/TA was 58.6%. Accordingly the concentration of coarse particles with Yellow Sand was higher than without them in Spring. Above results indicate that in Seoul Area the main source of air pollution originated from natural burdens, especially from soil. The concentration of Pb was similarly valued through both seasons in Seoul area but fine particles valued above coarse particles. On the other hand, in urban area, the natural and anthropogenic sources have influenced on the concentration of Pb. With referred to particle size distribution for Fe, the concentration of coarse particles was 0.168$\etag/m^3$ (CP/TA: 74.3%) in Spring with Yellow Sand, 0.096$\mug/m^3$ (CP/TA: 71.6%) without Yellow Sand and 0.083$\mug/m^3$ (CP/TA: 67.4%) in winter, respectively. Compared with fine particles, all of them were higher. It indicated that the origin of coarse particles in urban air was not related to anthropogenic source. The concentration of Fe was influenced by Yellow Sand and contributed to air pollution.

• Particle and aerosol research
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• v.6 no.2
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• pp.91-103
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• 2010

Size-segregated number concentration and scattering coefficient of urban aerosols were measured using an SMPS (scanning mobility particle sizer) and a nephelometer, respectively in Seoul, Korea, during the winter season of 2003. The average number concentrations of ultrafine particles (20~100 nm) and accumulation mode particles (100~600 nm) were $2,170\;particles\;cm^{-3}$ and $1,521\;particles\;cm^{-3}$, respectively. The scattering coefficient at the wavelength of 550 nm ranged from $62.6Mm^{-1}$ to $330.1Mm^{-1}$ and average value was $163.4Mm^{-1}$. The peak concentrations of ultrafine particles and accumulation mode particles were simultaneously recorded between 6:00 and 9:00 A.M., indicating the effect of vehicle emissions which are major air pollution sources in the urban atmosphere. On average, the number concentration of ultrafine particles was 1.4 times higher than that of accumulation mode particles, although it was a little higher during the morning peak time. The variation of aerosol scattering coefficient was in good agreement with that of accumulation mode particle number concentration rather than that of ultrafine particle number concentration.g coefficient was in good agreement with that of accumulation mode particle number concentration rather than that of ultrafine particle number concentration.

• Asian Journal of Atmospheric Environment
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• v.6 no.4
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• pp.288-303
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• 2012

In this study, real time measurements of particle number size distribution in urban Gwangju, coastal Taean, and industrial Yeosu in Korea were conducted in 2008 to understand the occurrence of ultrafine particle (UFP) (<100 nm) events, the variation of its concentration among different sampling sites, and UFP formation pathways. Also, to investigate seasonal and long-term variation of the UFP number concentration, data were collected for the period of 5 years (2007, 2008, 2010, 2011, and 2012) in urban Gwangju. Photochemical and combustion events were found to be responsible for the formation of UFP in the urban Gwangju site, whereas only photochemical event led to the formation of UFP in the coastal Taean site. The highest UFP concentration was found in industrial Yeosu (the average UFP number fractions were 79, 59 and 58% in Yeosu, Gwangju, and Taean, respectively), suggesting that high amount of gas pollutants (e.g., $NO_2$, $SO_2$, and volatile organic carbon (VOC)) emitted from industries and their photochemical reaction contributed for the elevated UFP concentration in the industrial Yeosu site. The UFP fraction also showed a seasonal variation with the peak value in spring (61.5, 54.5, 50.5, and 40.7% in spring, fall, summer, and winter, respectively) at urban Gwangju. Annual average UFP number concentrations in urban Gwangju were $5.53{\times}10^3\;cm^{-3}$, $4.68{\times}10^3\;cm^{-3}$, $5.32{\times}10^3\;cm^{-3}$, $3.99{\times}10^3\;cm^{-3}$, and $2.16{\times}10^3\;cm^{-3}$ in the year 2007, 2008, 2010, 2011, and 2012, respectively. Comparison of the annual average UFP number concentration with urban sites in other countries showed that the UFP concentrations of the Korean sites were lower than those in other urban cities, probably due to lower source strength in the current site. TEM/EDS analysis for the size-selected UFPs showed that the UFPs were classified into various types having different chemical species. Carbonaceous particles were observed in both combustion (soot and organics) and photochemical events (sulfate and organics). In the photochemical event, an internal mixture of organic species and ammonium sulfate/bisulfate was identified. Also, internal mixtures of aged Na-rich and organic species, aged Ca-rich particles, and doughnut shaped K-containing particles with elemental composition of a strong C with minor O, S, and K-likely to be originated from biomass burning nearby agricultural area, were observed. In addition, fly ash particles were also observed in the combustion event, not in the photochemical event.

• Atmosphere
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• v.28 no.3
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• pp.337-355
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• 2018

Ultrafine particles (< 100 nm in diameter, UFP) are known to be more toxic per unit mass than larger particles and contribute to more than 90% in particle number concentrations in urbanized cities but much less in mass. The major sources of UFP are vehicle emissions in urban areas. Due to their tiny size (the sizes of UFP from vehicle emissions range from 10 to 60 nm depending on engine and fuel types), inhaled UFP can reach the deepest area of respiratory track (e.g., pulmonary alveoli) as well as all of the body via lymph and blood circulation causing various adverse health effects. This article reviews the sources and emission factors of UFP, temporal and spatial distributions in urban areas and their health effects reported by toxicological and epidemiological studies. We also compared the levels of UFP concentrations measured in other countries with those in Korean cities to evaluate the public exposure to UFP in Korea. Ultimately, we expect this study can contribute to developing the risk assessment techniques for public exposure to UFP in the urbanized cities in Korea.

• Asian Journal of Atmospheric Environment
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• v.1 no.1
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• pp.1-8
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• 2007

Vehicle exhaust is a dominant source of air pollutants in urban areas. Since people are easily exposed to vehicle exhaust particles while driving a car and/or traveling via public transportation, air pollution near traffic has been extensively studied in developed countries. In this paper, investigations on vehicle-related fine particulate air pollution at roadsides and on roads in Seoul, Korea were reviewed to understand air pollution near traffic. Comparison of $PM_{10}$ concentrations in Seoul showed that roadside air is more contaminated than urban air, implying that exposure levels near vehicular emissions are more critical to sensitive persons. Concentrations of ultrafine particles and BC (black carbon) at roadsides of Seoul fluctuate highly for short durations, responding to traffic situations. Diurnal variations of ultrafine particles and BC concentrations at roadsides seem to be affected by traffic volume, mixing layer height, and wind speed. Concentrations of ultrafine particles and BC decrease as distance from the road increases due to dilution during transport. On-road air pollution seems to be more severe than roadside air pollution in Seoul. Since nearby traffic air pollution has not been well understood in Seoul, further studies including various vehicular air pollutants and representative locations are needed.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.214-218
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• 1989

Atmospheric particulate matters (A. P. M. ) were collected on quartz-fiber filters from March 1985 to May 1986, using the Andersen high-volume air sampler and contents of six heavy metals (Fe, Mn, Cu, Zn, Pb Ni) in the A. P. M. were determined by atomic absorption spectrophotometry. These heavy metals were divided into the three groups with respect to their particle size distribution. Fe and Mn were mainly associated with coarse particles (diameter > 2.0 $\mu$m), but Pb and Ni were related fine particles (diameter < 2.0 $\mu$m). Cu and Zn had mized size distributions in both of them. In the seasonal variation of heavy metals, the contents of Fe and Mn in spring and Ni and Pb in winter were higher than any other season. There were high mutual correlation between Fe and Mn coarse particles, and between Pb and Ni in fine particles.

• Particle and aerosol research
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• v.7 no.1
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• pp.21-30
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• 2011

The spatial distributions of air pollutants, in particular, ultrafine particles near traffic congestion roads at urban areas need to reduce human exposure levels for protecting public health. In this study, the number concentrations of ultrafine particles larger than 5 nm were measured every second during driving on the major roads of Nowon-gu, Seoul for 1.6 h using a mobile emission laboratory on October 5, 2010. The ultrafine particle number concentrations ranged from 7,009 to $265,600particles/cm^3$ with an average of $55,570particles/cm^3$, and these levels were comparable to concentrations of ultrafine particles larger than 3 or 7 nm on the arterial roads at urban areas in Los Angeles, USA and Zurich, Switzerland. It was frequently observed that the ultrafine particle number increased rapidly when vehicle speed was accelerated and it decreased sharply when vehicle speed was decelerated. The high peak events of ultrafine particle concentration larger than $200,000particles/cm^3$ were observed seven times during the measurement period. From the three repeated measurements during the short period of 50 min, it was concluded that the ultrafine particle number concentration on the road was significantly time-dependent. This on-road measurement approach can be utilized to manage vehicle-related air pollution in urban.