• Journal of Environmental Science International
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• v.11 no.10
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• pp.1081-1087
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• 2002

This study was performed to research the characteristics of suspended particulate for Yellow Sand of January, 1999 in Busan. Yellow Sand frequency during 13 years(1988~2000) in Busan showed maximum in April(57%), next to March(21%), May(16%). According to result of 850hPa weather map and backward isentropic trajectory, this event originated from the Gobi Desert and the Loess Plateau of China. And three mode was found in time series of TSP and PM10 concentration, primary peak showed the maximum hourly concentration at ali station. Gamjeondong as industrial site showed the highest TSP concentration and also had the longest high concentration($geq700\mu\textrm{g}/m^3$). In PM10, concentration of primary peak showed maximum value at Yeonsandong, maximum concentration of secondary and third peak was Deokcheondong. Lasted time from primary peak to secondary peak was about 30 hours, between secondary peak and third peak was 18 hours in Busan, The traveling time between occurrence of Yellow Sand the finding of it was 8~9 hours in Busan and 4~5 hours in central area.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.1
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• pp.23-35
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• 2000

PM10, which is below 10 ${\mu}{\textrm}{m}$ in a diameter, has a high deposition in the lung or the bronchus by breathing and is generally composed of a lot of organic matters, viruses, algae, mold, and metallic elements that are very toxic to people. This study identified the characteristics of concentration of PM10 and air-borne jmetallic elements produced in the industrial city, Ulsan, and analyzed the correlatuion between sources and generation patterns of PM10 and metallic elements. We classified the five areas(green, residential, heavy traffic, mechanic, and petrochemcal and non-ferrous metal) which might have different characteristics of sources of PM10 and metallic elements. The average concentrations of PM10 in the five areas were as follows(petrochemical and non-ferrous metal(99.9$\mu\textrm{g}$/㎥)>mechanic(77.5 $\mu\textrm{g}$/㎥)>heavy traffic(47.1 $\mu\textrm{g}$/㎥)>residential(39.3 $\mu\textrm{g}$/㎥)>green(32.8 $\mu\textrm{g}$/㎥)). Those of petrochemical and non-ferrous metal areas were higher than other areas. In this study, the average concentration trend of metallic elements contained in PM10 are shown as follows: Fe>Zn>Pb>Cu>Mn>Cr>As>Cd>Sn>Hg, respectively. The metallic elements identified in PM10 showed the highest concentration in the petrochemical and non-ferrous areas. Metal combinations showed that a high correlation among concentrations of heavy metals were as follows: As, Cd and Fe in the residential area; Zn, Mn, Cu and Pb in the mechanical area; and Zn, Cu, As, Pb in the petrochemical and non-ferrous industrial area.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.408-421
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• 2007

The concentration characteristics of atmospheric particle matters (PM) including $PM_{2.5},\;PM_{10}$, and TSP were evaluated through the measurement data of PM_{2.5}$ (fine particulate), PM_{10-2.5}$ (coarse particulate), and PM_{over-10}$ collected using a MCI (multi-nozzle cascade impactor) sampler of a three-stage filter pack in spring of 2006 in Iksan area. During the sampling period of 10-15 March and 24 days from 8 April to 2 May, 32 samples for PM of each size fractions were collected, and then measured for PM mass concentrations and water-soluble inorganic ion species. Average concentrations of $PM_{2.5},\;PM_{10}$, TSP were $57.9{\pm}44.1mg/m^3$, $96.6{\pm}89.1mg/m^3$, and $114.8{\pm}99.7mg/m^3$, respectively. Water-soluble inorganic ion fractions to PM mass were found to be 36.5%, 18.0%, and 11.1% for $PM_{2.5}$, $PM_{10-2.5}$ and $PM_{over-10}$, respectively. By showing the high concentrations of PM samples during Asian dust events, those three fractions of PM were distinguished between the samples of Asian dust event and the samples of no event. However, the increase of PM concentrations observed during Asian dust events showed a different pattern for some Asian dust events. The differences of those three fractions in the size distribution may depend on differences on place of occurrence of Asian dust storm and course of transport from China continent to Iksan area in Korea. However, the extent of PM mass contribution during Asian dust events was generally dominated by the coarse particles rather than the fine fraction of PM. The variations of water-soluble inorganic ion species concentration in those three PM fractions between the samples of Asian dust event and the samples of no event were also discussed in this study.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.651-658
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• 2018

Particulate matter (PM) emitted from fossil fuel-combustion facilities can be classified as either filterable or condensable PM. The U.S. Environmental Protection Agency (EPA) defined condensable PM as material that is in the phase of vapor at the stack temperature of the sampling location which condenses, reacts upon cooling and dilution in the ambient air to form solid or liquid in a few second after the discharge from the stack. Condensable PM passed through the filter media and it is typically ignored. But condensable PM was defined as a component of primary PM. This study investigates the change of condensable PM according to the variation in the sulfur dioxide of combustion gas. Domestic oil boilers were used as the source of emission ($SO_2$) and the level of $SO_2$ concentration (0, 50, 80, and 120 ppm) was adjusted by diluting general light oil and marine gas oil (MGO) that contains sulfur less than 0.5%. Condensable PM was measured as 2.72, 6.10, 8.38, and $13.34mg/m^3$ when $SO_2$ concentration in combustion gas were 0, 50, 80, and 120 ppm respectively. The condensable PM tended to increase as the concentration of $SO_2$ increased. Some of the gaseous air pollutants emitted from the stack should be considered precursors of condensable PM. The gas phase pollutants which converted into condensable PM should reduced for condensable PM control.

• Particle and aerosol research
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• v.13 no.2
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• pp.87-95
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• 2017

Radon ($Rn^{222}$) is a radioactive gas and is found at high concentrations underground. Investigations were done in many years specifically on public transportations such as in the subway stations, concourses and platforms for these are located underground areas. This study correlates the $Rn^{222}$ concentrations with the Particulate Matter (PM) concentration for the gas could be attached or trapped inside these particles. It was done on the opening subway tunnel of Miasageori Station going to Mia Station (Line 4) last August 2016. Based on the result, the $Rn^{222}$ were more influenced on the mass ratio (%) of PM present in the air instead of its mass concentration (${\mu}g/m^3$). As the $PM_{10}$ mass ratio increases ($42.32{\pm}1.03%$) during morning rush-hours, radon starts to increase up to $0.97{\pm}0.03pCi/L$. But during the afternoon $Rn^{222}$ concentrations decreased while the composition were stable at $22.96{\pm}3.0%$, $39.04{\pm}0.6%$ and $38.01{\pm}0.3%$ in $PM_1$, $PM_{2.5}$ and $PM_{10}$ respectively. It was then assumed that it could be the composition of the morning hours of the station were influencing the concentration of the radon.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.1-6
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• 2016

The performance of a set of low-cost optical components used for measuring the optical density of PM particles was evaluated in the present study. To this end, the set of low-cost optical components was replaced with that of general optical components used to measure the PM optical density under identical experimental conditions. The optical densities measured from the set of general optical components were then compared to those obtained from the set of low-cost optical components. While the optical density is measured, another key parameter, the dimensionless extinction constant of PM particles (which is needed to optically measure the PM concentration) was also determined in the present study. The experimental results indicate that the optical density and PM concentration measurements performed by low-cost optical components are feasible, producing trackable variations in the OD and concentrations compared to values obtained from the set of general optical components.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.466-482
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• 2020

This study used 3D computational fluid dynamics (CFD) in the ENVI-met program to investigate how particulate matters (PM) generated on roads disperse through adjacent urban neighborhoods according to the urban development pattern. An urban area centered on a six-lane road in the vicinity of Miryang City Hall in Gyeongnam Province was selected to simulate the effect of the green space and building height on the PM concentration. The ENVI-met model considered the presence of green space and different building heights (high/low) on both sides of the road to examine the dispersion of PM. The result showed that the area of high-rise buildings and green space had the lowest PM concentration dispersed to the adjacent area, followed by the area of high-rise buildings and no green space. In contrast, the PM concentration remained relatively high for low-rise buildings, regardless of the green space. The reason for the low PM concentration in the area with high-rise buildings was a strong building wind, which caused PM to disperse to the outside, lowering the PM concentration quickly. These results indicate that the PM can disperse faster, and the PM concentration remains low in the urban neighborhood. On the other hand, green space had no significant effect on reducing PM in the urban neighborhood. In particular, when there are low-rise buildings on both sides of the road, the green space has no effect on the PM concentration in the urban neighborhood. Since this study considered only the case of PM emitted from the road, future studies should investigate other factors to figure out the dispersion model of PM and conduct on-site experiments.

• The Korean Journal of Nuclear Medicine
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• v.19 no.1
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• pp.103-111
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• 1985

Recently changes in thyroid physiology during acute and chronic medical illness were demonstrated. The serum $fT_3,\;rT_3,\;T_4,\;T_3,\;fT_4$, and TSH concentration were measured by radioimmunoassay method in 49 patients with critical illness and 10 normal subjects to assess the change of thyroid function in critical illness. The results were as follows; 1) The mean serum $fT_3$ concentration was $6.68{\pm}1.05pmol/ml$ in normal subjects while in patients with critical illness the serum $fT_3$ concentration was significantly lowered to $1.55{\pm}1.15pmol/ml$(p<0.001). 2) The mean serum $rT_3$ concentration was $0.22{\pm}0.44ng/ml$ in normal subjects and $0.42{\pm}0.37ng/ml$ in patient with critical illness. There was increment in critically ill patients as compared to normal subjects but no statistically significant difference(p>0.05). 3) The mean serum $T_3$ concentration was $1.24{\pm}0.25ng/ml$ in normal subjects and $0.56{\pm}0.56ng/ml$ in patients with criticial illness and there was significant difference in each other(p<0.005). 4) The mean serum $T_4,\;fT_4$, and TSH concentrations were $7.80{\pm}1.02{\mu}g/dl,\;1.26{\pm}0.39ng/dl,\;1.87{\pm}0.45{\mu}U/ml$ in normal subjects respectively and $6.02{\pm}3.06{\mu}g/dl,\;1.46{\pm}0.80ng/dl,\;1.74{\pm}0.79{\mu}U/ml$ in patients with critical illness and there was no significant difference between critically ill patients and normal subjects. 5) The ratio of mean serum concentration of $fT_3$ and $rT_3(fT_3/rT_3)$, $30.42{\pm}5.58$ in normal subjects was significantly higher(p<0.005) than the coresponding patients with critical illness. 6) The mean serum $fT_3$ concentration in expired cases(n=12) during admission was significant difference between expired and survived cases(p<0.005). The mean serum $rT_3$ centration was $0.67{\pm}0.58ng/ml$ in expired cases and $0.34{\pm}0.22ng/ml$ in survived cases with significant difference(p<0.005). Half of the cases who showed less than $3{\mu}g/dl$ of serum $T_4$ level were expired.

• Asian Journal of Atmospheric Environment
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• v.12 no.2
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• pp.109-126
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• 2018

This paper presents seasonal variation of $PM_{10}$ over five urban sites in Sabah, Malaysia for the period of January through December 2012. The variability of $PM_{10}$ along with the diurnal and weekly cycles of CO, $NO_2$, $SO_2$, and $O_3$ at Kota Kinabalu site were also discussed to investigate the possible sources for increased $PM_{10}$ concentration at the site. This work is crucial to understand the behaviour and possible sources of $PM_{10}$ in the urban atmosphere of Sabah region. In Malaysia, many air pollution studies in the past focused in west Peninsular, but very few local studies were dedicated for Sabah region. This work aims to fill the gap by presenting the descriptive statistics on the variability of $PM_{10}$ concentration in the urban atmosphere of Sabah. To further examine its diurnal and weekly cycle pattern, its responses towards the variations of CO, $NO_2$, $SO_2$, and ozone were also investigated. The highest mean value of $PM_{10}$ for the whole study period is seen from Tawau ($35.7{\pm}17.8{\mu}g\;m^{-3}$), while the lowest is from Keningau ($31.9{\pm}18.6{\mu}g\;m^{-3}$). The concentrations of $PM_{10}$ in all cities exhibited seasonal variations with the peak values occurred during the south-west monsoons. The $PM_{10}$ data consistently exhibited strong correlations with traffic related gaseous pollutants ($NO_2$, and CO), except for $SO_2$ and $O_3$. The analysis of diurnal cycles of $PM_{10}$ levels indicated that two peaks were associated during the morning and evening rush hours. The bimodal distribution of $PM_{10}$, CO, and $NO_2$ in the front and at the back of ozone peak is a representation of urban air pollution pattern. In the weekly cycle, higher $PM_{10}$, CO, and $NO_2$ concentrations were observed during the weekday when compared to weekend. The characteristics of $NO_2$ concentration rationed to CO and $SO_2$ suggests that mobile sources is the dominant factor for the air pollution in Kota Kinabalu; particularly during weekdays.

• Land and Housing Review
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• v.12 no.3
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• pp.39-50
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• 2021

This research aims to provide guidelines with the appropriate type of smart bus stop to reduce the concentration of fine dust. To this end, we divided smart bus stops into two types: closed and open bus stops. The estimated reduction effect was compared and analysed by measuring the estimated PM₁₀ and the estimated PM_2.5 at five locations inside and outside a smart bus stop located in Gangnam gu, Seoul. The effect of reducing the amount of the fine dust concentration in external space was insignificant for both types of bus stops. The different effect of reducing the concentration of the amount between in internal space was relatively significant: the fine dust concentration was 26.0 ㎍/m³ for PM₁₀ and 20.2 ㎍/m³ for PM_2.5 at open-type bus stops; whilst was 2.4 ㎍/m³ for PM₁₀ and 1.8 ㎍/m³ for PM_2.5 at closed type bus stops. Based on the findings, a closed type bus stop is recommended when considering the cost of reducing fine dust. In addition, due to the ineffectiveness of reducing the amount of fine dust from the outside of the bus stop, additional provision of smart bus stops is required particularly in locations where demand exceeds the capacity of the inside. A clear definition of smart bus stop and it's minimum standard should also be considered.