• Journal of Environmental Science International
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• v.22 no.6
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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.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.667-676
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• 2006

The reduction of $Hg^{2+}$ in the aqueous phase results in the production of dissolved gaseous mercury(DGM), and the volatilization of DGM has been identified as an important mechanism for the loss of Hg from waterbodies to the atmosphere. Although mercury emission in the world is known to be mostly from Asia, there have been few studies of measuring DGM concentrations in lakes in Asia. In this study, DGM concentrations were measured at Juam reservoir($35^{\cir}00'N,\;127^{\circ}14'E$), Korea. The results showed that the average concentrations of DGM at the upper and down stream of the lake during summer time were $95{\pm}8\;and\;130{\pm}15$ pg/L, respectively and the concentration of total mercury(TM) at the upper and down stream was $2.1{\pm}0.7,\;1.7{\pm}0.3$ ng/L respectively. Average DGM concentration during summer time($101{\pm}14pg/L$) was approximately 5.5 times higher than that during fall($18{\pm}0.1pg/L$). The DGM concentrations ai the midstream decreased from 32 to 13.7 pg/L during rain event, while the TM concentrations increased from 2.2 ng/L to 2.7 ng/L indicating the deposition of mercury from the atmosphere. Also, the diurnal patterns between DGM concentrations and UV intensities were observed. Water temperatures and DOC concentrations were significantly related to DGM concentrations, while TM concentrations were negatively related to DGM concentrations(p<0.0001). Comparing with the study of Dill et al.,(2006) the average concentrations of DGM $(109{\pm}15pg/L)\;and\;TM(2.2{\pm} 0.4ng/L)$ at Juam reservoir were approximately 3 and 2.2 times higher than those measured in other lakes(DGM: $38{\pm}16pg/L$, TM: $1.0{\pm}1.2ng/L$).

• Journal of Environmental Health Sciences
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• v.39 no.2
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• pp.144-150
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• 2013

Objectives: Cooking activity in indoor environments can generate particulate matter. The objective of this study was to determine the concentrations of ultrafine particles (UFP), $PM_{2.5}$, and $PM_{10}$ in cooking and non-cooking areas of major department stores in Seoul. Methods: Eighteen department stores in Seoul, Korea were measured for concentrations of particulate matter. Using real-time monitors, concentrations of UFP, $PM_{2.5}$ and $PM_{10}$ were simultaneously measured in cooking and non-cooking areas on the floor with a food court and a non-cooking floor. Results: The concentrations of UFP, $PM_{2.5}$ and $PM_{10}$ were significantly higher in cooking areas than in noncooking areas and non-cooking floors (p<0.05). UFP and $PM_{2.5}$ were significantly correlated in cooking areas and non-cooking areas but not in non-cooking floors. $PM_{2.5}$ were consisted of approximately 81% in $PM_{10}$ and highly correlated with $PM_{10}$ in all places. Conclusion: A higher correlation between UFP and $PM_{2.5}$ was shown on cooking floor than on non-cooking floor in department stores. High levels of fine particles were caused by cooking activities at food courts. The further management of PM is needed to improve the indoor PM levels at food courts in department stores.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.2
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• pp.143-156
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• 2015

The literature data of the mass concentrations of TSP, $PM_{10}$, and $PM_{2.5}$, and chemical composition of $PM_{2.5}$ (sulfate, nitrate, ammonium, OC, and EC) from 1985 and 2013 at Seoul were collected and the temporal trends were discussed in relation with the policy directions. Generally, the mass concentrations of TSP, $PM_{10}$, and $PM_{2.5}$ at Seoul have showed decreasing trends. However, it is not clear what might be the major reason(s) for the trends. The concentrations of ionic component in $PM_{2.5}$ showed different trends, sulfate being reduced during the 1990s but no trend during the 2000s. The concentrations of nitrate and ammonium were increasing during the 2000s. The concentrations of OC show no apparent trend while that of EC decreased. Further policy directions are suggested based on the temporal trends of the chemical composition in $PM_{2.5}$.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.567-580
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• 2010

Organic carbon (OC) and elemental carbon (EC) concentrations were determined for $PM_{10}$, $PM_{2.5}$ and $PM_{1.0}$ aerosols particles collected at Gosan Superstation on Jeju Island from August 2007 to September 2008. Aerosols were collected on quartz filters for 24 hours and then OC and EC were analyzed by TOR/IMPROVED method. Mean concentrations of OC and EC were $4.66\;{\mu}g/m^3$ and $1.69\;{\mu}g/m^3$ for $PM_{10}$, $3.95\;{\mu}g/m^3$ and $1.69\;{\mu}g/m^3$ for $PM_{2.5}$, and $3.16\;{\mu}g/m^3$ and $1.42\;{\mu}g/m^3$ for $PM_{1.0}$, respectively. The concentrations of OC and EC comprised 16.4% and 6.0% of $PM_{10}$, 22.9% and 9.8% of $PM_{2.5}$, and 23.0% and 10.0% of $PM_{1.0}$. OC and EC showed a clear seasonal variation with the highest in winter and the lowest in summer. The correlations between the two were also the best during the winter ($R^2$=0.87, 0.94, and 0.95 for $PM_{10}$, $PM_{2.5}$ and $PM_{1.0}$). The ratio of OC/EC exhibited the maximum (7.24) during an Asian dust event due to an increase of OC, which was possibly derived from soil. The mass fraction of both OC and EC was the highest in fall. When OC and EC concentrations were highly elevated, EC1 (the first EC fraction determined at $550^{\circ}C$) and pyrolyzed OC (POC) were dominant subcomponents in winter and OC3 (the third OC fraction determined at $450^{\circ}C$) and POC in spring.

• Asian Journal of Atmospheric Environment
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• v.2 no.2
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• pp.90-101
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• 2008

The chemical compositions of $PM_{2.5}$ and $PM_{10}$ and associated high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) were investigated during winter and summer at a roadside and an urban background site in Saitama, Japan. The average concentrations of $PM_{2.5}$ exceeded the United States Environmental Protection Agency standards during both periods. Carbonaceous components were abundant in both the observed and calculated (by means of a mass closure model) chemical composition of $PM_{2.5}$. Traffic-related pollutants (elemental carbon and high-molecular-weight PAHs) were strongly associated with $PM_{2.5}$ rather than with larger particles. The mass concentrations of $PM_{2.5}$, as well as those of EC and PAHs associated with the particles, at the two sites were strongly correlated. Comparison of our data with source profile ratios indicates that diesel-powered vehicles were probably the main source of the measured PAHs. The PAHs concentrations were affected by meteorological conditions during our study. Our results highlight the need for the establishment of standards for $PM_{2.5}$ in Japan.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.27-37
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• 2020

As domestic meat consumption increases, the broiler production industry has been larger and denser. The concentration of particulate matter (PM) and harmful gases generated is also increasing inside livestock house. However, the current research status of PM exposed to farm workers and the health effects are in the early stage. To understand PM concentration affecting workers in the broiler house, field monitoring was conducted according to its size distributions. Concentrations of PM₁₀, PM_2.5, and TD (Total Dust) were monitored using personal air samplers with teflon filter during working and moving periods considering the ventilation systems of 6 broiler houses. The purpose of this study is to monitor the PM concentration in the experimental broiler houses operated by forced ventilation system generally used in Korea and to evaluate the regional concentrations through airflow pattern. The PM concentrations were increased from inlet to outlet vents resulting in 1,872 of TD, 1,385 of PM₁₀, and 209 ㎍/㎥ of PM_2.5, respectively. The TD and PM₁₀ concentrations were increased when the workers and broilers were moving. Among them, the particle size that occupied the largest amount of PM was 13.75 ㎛. These results suggest that personal protection equipments are important to reduce the health effect from PM inhalation.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.42-48
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• 2008

The objectives of this study were to measure ambient TGM concentrations in Seoul Korea, to determine the temporal variation of TGM, and to analyze the relationships among TGM, meteorological data and PM2.5 measured at the same time. Ambient TGM and PM2.5 concentrations were measured at the roof of the Graduate School of Public Health building in Seoul, Korea for the period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17ng/m^3$. The average TGM was at a low concentration similar to those of background sites in other countries. The temporal variations and meteorological phenomena of TGM were not statistically significant. There was a positive link between TGM and PM2.5. It didn't indicate that reduction of $Hg^{2+}$ to Hg0 had occurred in liquid water contained in smog as in a previous study, but it shows that PM2.5 and TGM could be emitted from the same sources such as power plants and combustion engines. Also, the strong correlation between TGM and $SO_2$ concentrations indicated that the source of TGM was from fossil fuel combustions including coal combustion. Specifically, $SO_2\;and\;SO_4{^2-}$ concentrations correlated to TGM concentrations could be linked to TGM emitted from local and regional sources as well.

• Korean Journal of Animal Reproduction
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• v.5 no.1
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• pp.64-72
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• 1981

This experiment was carried out to study on changing phases of the concentrations of serum testosterone and metabolites in the various grwoing stages of male pigs. The eight males were used to obtain serial blood samples at a, pp.oximately 20kg body weight intervals from birth to 130kg body weight. The blood samples were taken from the jugular veins and serum was stored at -20$^{\circ}C$ until assay. Testosterone concentrations in the serum were analyzed by radioimmunoassay. The result obtained are as follows: 1. Serum testosterone concentrations were elevated at birth and were reached a maximum level between 50 and 70kg body weight, which was when sexual maturity was reached. 2. Calcium values did not vary a, pp.eciably with body weight, and ranged from 9.6${\pm}$0.6 to 11.9${\pm}$0.8mg/100$m\ell$. Potassium and sodium concentrations ranged from 38.5${\pm}$2.9 and 233.9${\pm}$2.1mg/100$m\ell$ to 64.2${\pm}$6.5 and 269.1${\pm}$9.5mg/100$m\ell$, respectively. Magnesium values dro, pp.d at birth and then rose to peak at 15kg of body weight. Iron concentrations was 0.12${\pm}$0.02mg/100$m\ell$ at birth, rose to 0.20${\pm}$0.04mg/100$m\ell$ at 15kg of body weight and then gradually increased to 0.29${\pm}$0.04mg/100$m\ell$ at 30kg of body weight. Serum zinc concentrations rose from a low of 56${\pm}$3.3mg/100$m\ell$ at birth to a high of 83.3${\pm}$3.4mcg/100$m\ell$ at 15kg of body weight. Co, pp.r values rose from a low of 25${\pm}$2.5mcg/100$m\ell$ at birth to a high of 183${\pm}$4.3mcg/100$m\ell$ at 15kg of body weight. 3. Serum cholesterol concenrtration did not vary a, pp.eciably with body weight, and ranged from 90.5${\pm}$6.0mg/100$m\ell$ to 95.0${\pm}$6.3mg/100$m\ell$. Glucose concentrations ranged from 80.5${\pm}$1.2mg/100$m\ell$ to 108.7${\pm}$8.4mg/100$m\ell$. Serum total protein rose from alow of 2.7${\pm}$0.8mg/100$m\ell$ at birth to a rapidly high of 4.3${\pm}$0.1mg/100$m\ell$ at 15kg of body weight and then gradually increased to 7.3${\pm}$0.4mg/100$m\ell$ at 130kg of body weight. Serum albumin values ranged from 0.5${\pm}$0.1$m\ell$ to 3.0${\pm}$0.3mg/100$m\ell$. 4. The total concentrations of essential/nonessential amino acid were 944.7mg/100$m\ell$ and 934.4mg/100$m\ell$ at birth, respectively. The values of essential/nonessential amino acid gradually rose from a low level at birth to a high level at 130kg of body weight. The total concentrations of essential/non-essential amino acid ratios remained from birth to 130kg of body weight.

• Journal of Environmental Health Sciences
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• v.45 no.2
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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.