• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E1
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• pp.45-48
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• 2006

Mass size distributions of atmospheric particles in Cheonan were determined using a high volume air sampler equipped with a 5-stage cascade impactor. Bimodal distributions that are typical for urban atmospheric particles were obtained. A MMD of the fine particle mode was $0.47{\pm}0.05{\mu}m$ with a GSD of $2.72{\pm}0.21$, and those of the coarse particles were $5.15{\pm}0.18{\mu}m\;and\;2.09{\pm}0.09$, respectively. The annual average concentrations of TSP, PM10, PM2.5, and PM1 were 74.1, 67.5, 54.2, and $42.3{\mu}g/m^3$, respectively. Although the daily PM10 concentrations were under the current National Standard, the daily PM2.5 concentrations frequently exceeded the US Standard even in non asian dust periods. The fractions of PM 10, PM2.5, and PM1 in TSP were $0.905{\pm}0.013,\;0.723{\pm}0.022,\;and\;0.572{\pm}0.029$, respectively, and fine mode particles occupied $57{\sim}72%$ of the total particle mass. The results indicate that fine particles were at the concerning level, and should be the target pollutant for the regional air quality strategy in Cheonan.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.132-140
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• 2007

Concentrations of atmospheric fine particles in Chungnam were measured at 7 sampling sites during 2005. The daily average concentrations of PM 10, PM2.5, and PM1 ranged from 14.9 to $136.5{\mu}g/m^3$, 8.2 to $113.2{\mu}g/m^3$, and 5.7 to $107.5{\mu}g/m^3$, respectively, and the highest levels were observed at Yeongi site. The lowest concentrations for the all size fractions of particulate were observed at Taean located at the west end of the peninsula. The daily average PM10 concentrations were below the current National Standard at all sites, while the daily average PM2.5 concentrations frequently exceeded the US Standard at Cheonan, Dangjin, Boryeong, and Yeongi sites. The frequencies of PM2.5 concentrations exceeding the US standard at Cheonan, Dangjin, Boryeong, and Yeongi were 10.8%, 6.7%, 6.7%, and 26.7%, respectively. In addition, $68{\sim}80%$ of PM10 was in the PM2.5 fraction indicating that fine particles were the major component of atmospheric particles in Chungnam.

• Journal of Environmental Health Sciences
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• v.34 no.2
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• pp.137-147
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• 2008

This study evaluated the effects of the human activity and outdoor air on concentrations of size-selective particulate matters (PM) by conducting a realtime measurement in classrooms and on roofs at 4 elementary schools, 3 middle schools and 3 high schools in Incheon City. PM concentrations featured repetitive pattern of increasing during break time (including lunch hours) and cleaning time while decreasing during class hours. This trend was more prominent with inhalable PM and PM10 than fine PMs (PM2.5, PM1.0). The indoor/outdoor (I/O) ratio of inhalable PM and PM10 exceeded 1 while that of fine PMs was close to or below 1. The PM2.5 (out)/PM10 (out) ratio stood at 0.59 (${\pm}0.16$) and the PM2.5 (in)/PM10 (in) ratio was 0.29 (${\pm}0.09$), suggesting that occupant activity had a greater effect upon coarse particles (PM10-PM2.5) than upon fine particles (PM2.5, PM1.0). The correlations between the indoor and the outdoor PM concentrations showed a stronger positive correlation for fine particles than that of coarse particles. The linear regression analysis of PM concentrations indoor and outdoor indicated a higher determinant coefficient ($r^2>0.9$), and consistency for fine particles than in case of coarse particles. In conclusion, the results of this study suggest that the indoor coarse particle concentration is more attributed to occupant activity and the indoor fine particle concentration is more influenced by outdoor air pollution.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.367-375
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• 2008

To characterize atmospheric particles in Cheonan area, 5 monitoring sites representing highway area, commercial area, residential area, and industrial areas were selected, and the mass concentrations of PM10 and PM2.5 were monitored for 14 days at each site during 2007. The daily average PM10 and PM2.5 concentrations were in the range from 18.5 to $140.9{\mu}g/m^3$ and 8.2 to $116.6{\mu}g/m^3$, respectively, showing the highest mean concentrations at the commercial area site and the lowest concentration at the residential area site. The daily average PM 10 concentrations at Shinan (Commercial area) and Bakseok (Industrial area) sites were exceeded the current National Standard for 1 and 2 days during the monitoring periods. The fractions of PM2.5 in PM10 were above 70% for all sites, indicating fine particles are the major constituent of atmospheric particles in Cheonan. The results indicate that PM10 concentrations in Cheonan are at the concerning level, and the control strategy for fine particles is necessary to address this issue.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.358-359
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• 2002

Particulate matter smaller than $10{\mu}textrm{m}$ in aerodynamic diameter (PM10) is known as thoracic particles that are capable of reaching the thoracic region of humans. PM10 is further divided into two size ranges, which are fine particles (nuclei mode plus accumulation mode) and coarse particles, based on different sources and chemical composition. Fine particles can penetrate deep into the alveolar region of the human lungs, while coarse particles be deposited in the upper respiratory system. (omitted)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1349-1353
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• 2008

Size-segregated mass and ion concentrations of atmospheric aerosols in Cheonan City were measured using a high volume air sampler equipped with a 5-stage cascade impactor and a ion chromatography between March 2006 and April 2007. The mean values of 24-hr average concentrations of TSP, PM10, PM2.5, and PM1 were 61.7, 55.2, 43.7, $33.2{\mu}g/m^3$, respectively. Mass size distributions of atmospheric aerosols were bimodal distributions with a saddle point in $1.5\;{\sim}\;3.0{\mu}m$ range in diameter separating coarse and fine particle modes. Fine particles, PM2.5 were 70.8% of the total mass of aerosols. Major ion components in aerosols were ${NH_{4}}^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ for cations, and ${SO_{4}}^{2-}$, ${NO_{3}}^-$, $Cl^-$ for anions. ion components occupied 37.4% of coarse particles and 46.2% of fine particles in mass.

• Particle and aerosol research
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• v.19 no.2
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• pp.31-42
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• 2023

The charge and magnetic characteristics of LM (Low-metallic) and NAO (Non-asbestos-organic) brake wear particles were analyzed. The ratio of charged particles from total particles is about 86% of the LM pad and about 92% of the NAO pad. Number of charge per particle from the NAO pad is also higher than that of the LM pad. The ratio of magnetic particles from total particles increases with the particle size. The ratio of magnetic particles from the LM pad is about 15% for the particles with the size of 1 ㎛, and about 74% for ones with 5 ㎛. The ratio from the NAO pad is about 5% for the particles with the size from 0.5 ㎛ to 2 ㎛, and about 80% for the particles with 5 ㎛. Through the analysis of the components of the two pads with SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), it was found that the LM pad was occupied with more iron fraction than the NAO pad and that PM_2.5-10 was occupied with more iron fraction than PM_2.5. The particles smaller than 10 ㎛ (i.e. PM₁₀) from the LM pad contained about 83% of charged particles, about 43% of magnetic particles, and about 93% of charged or magnetic particles. PM₁₀ from the NAO pad contained about 88% of charged particles, about 15% of magnetic particles, and about 89% of charged or magnetic particles.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.289-296
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• 1996

Effects of crustal species on the characteristics of ambient particles were studied by applying a gas-particle equilibrium model, SCAPE, to the measurements at Kosan, Cheju Island during the spring and summer, 1994. Two cases were simulated; the measured composition was used without any modification (case 1), and the metal ion concentrations originated from crust were subtracted from the measured particle composition (case 2). Total suspended particles (TSPs) were collected by an automatic high volume tape sampler during spring period and by high volume samplers during summer period. The fine particles, PM 2.5, and gaseous volatile species were collected using a filter pack smapler during summer period. The water soluble ion concentrations were analyzed from all the particle samples. According to the simulation results, the effect of crustal elements on the chemical composition of particles is negligible for both TSP particles and PM 2.5 particles. Acidity of particles measured at Kosan, however, is affected by the change of the concentrations of crustal species, stronger effects for TSP particles than for PM 2.5 particles during summer, and stronger effects during summer than spring for TSP particle. The average pH decrease due to the absence of crustal species was about 0.10 for PM 2.5 particle during summer and 1.51 and 0.85 for TSP particles during summer spring, respectively. Water contents of PM 2.5 particles for both cases are comparable to each other. Estimated water content of TSP particles for case 2 is higher than that for case 1 by about 4 $\sim 6 \mum/m^3$ because salts of metal ions are not hygroscopic.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.781-791
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• 2022

In order to investigate the characteristics of the effects of various emission sources such as ships around the Busan North Port area, PM_2.5 samples were analyzed by SEM/EDS (scanning electron microscopy with energy dispersive x-ray spectrometer). In the port city Busan, the main emission source of PM_2.5 is ships, and soot was observed as the main exhaust particles of a ship diesel engine. As a result of the individual particle analysis of PM_2.5 at the sampling site, carbonaceous particles such as soot and water droplet-shaped, which are considered to be exhausted from ships, were constantly observed. And some spherical Fe-rich particles also appeared.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.185-188
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• 2007

PM10 and PM2.5 in ambient air were collected in Seongbuk-gu area of Seoul for one year, from April 2005 to February 2006, and the concentration of PM-bound mercury was monitored. The annual concentrations of particles were $66.4{\pm}43.2{\mu}g/m^3\;(47.6{\pm}19.1{\mu}g/m^3-106.1{\pm}78.0{\mu}g/m^3)$ in PM10 and $37.2{\pm}20.4{\mu}g/m^3\;(28.0{\pm}23.4{\mu}g/m^3{\sim}42.7{\pm}21.4{\mu}g/m^3)$ in PM2.5, which is about 56% of PM10 concentration. The annual average concentrations of mercury were $0.125{\pm}0.078ng/m^3\;in\;PM10\;and\;0.141{\pm}0.080ng/m^3$ in PM2.5, respectively. In April of Asian dust season in Korea, mercury showed the highest concentration in both PM10 and PM2.5.