• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.555-569
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• 2004

Size -segregated measurements of aerosol composition using 8-stage DRUM impactor are used to determine the transport of natural and anthropogenic aerosols at Gosan site from 29 March to 30 May in 2002. Separation of ambient aerosols by DRUM impactor offers many Advantages over other standard filtration techniques. Some of the most important advantages are the ability to segregate into details by particle tire, to better preserve chemical integrity since the air stream doesn＇t pars through the deposit, to collect samples as a function of time, and to have a wide variety of impaction surfaces available to match analytical needs. Although the transport of Yellow sand is a well-known phenomenon in springtime, the result of measurement shows that not only soil dust but also anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Ni, Zn. Cu, Cr, As, Se, Br, are transported to Gosan in springtime. This study combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of anthropogenic aerosols. As a result, during the NYS period, the average concentration of PM$_{10}$ was 46$\mu\textrm{g}$/㎥, Si, Al. S, Fe, Cl, K, Ca were higher than 1,000 ng/㎥ and Ti was about 100 ng/㎥. The concentrations of Zn, Mn, Cu. Pb, Br, Rb, V, Cr, Ni. At, Se ranged between 1 and 70 ng/㎥. More than 50% typical soil elements, tuck as Al, Si, Fe, Cd. Ti, Cr, Cu, Br. were distributed in a coarse particle range(5.0-12${\mu}{\textrm}{m}$). In other hand, anthropogenic pollutants, luck as S, N, Vi, were mainly distributed in a fine particle range (0.09-0.56${\mu}{\textrm}{m}$). During the YS period, PM$_{10}$ increased about 8 times than NYS period, and main soil elements, such as Al, Si, S, K, V, Mn, Fe also doubled in coarse particle range (1.15-12${\mu}{\textrm}{m}$). But Zn, As, Pb, Cu and Se, which distributed in the time aerosols (0.09-0.56${\mu}{\textrm}{m}$), were on the same level with or decreased than NYS period. Finally. except the YS Period, coarse particles (2.5-12${\mu}{\textrm}{m}$) are inferred to be influenced by soil, coal combustion, waste incineration, ferrous and nonferrous sources through similar pathways with Yellow Sand. But fine particles have different sources, such as coal combustion, gasoline vehicle, biomass burning, oil or coal combustion, nonferrous and ferrous metal sources, which are transported from China, Korea peninsula and local sources.ces.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.398-422
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• 2017

Objectives: The major aim of this study is to construct the database of retrospective exposure assessment for crystalline silica through reviews of literatures in South Korea. Methods: Airborne concentrations of crystalline silica were collected using an academic information search engine, Research Information Service System(RISS), operated by the Korea Education & Research Information Service(KERIS). The key words used for the literature search were 'silica', 'crystalline silica', 'cristobalite', 'quartz' and 'tridymite'. A total number of 18 published documents with the information of crystalline silica level in air or bulk samples were selected and used to estimate retrospective exposures to crystalline silica. Weighted arithmetic mean(WAM) calculated across studies was summarized by industry type. Industries were classified according to Korea Standard Industrial Classification(KSIC) using information provided in the literature. Results: A total of 2,131 individual air sampling data measured from 1987 to 2012 were compiled. Compiled individual measurement data consisted of 827 respirable crystalline silica (RCS), 31 total crystalline silica(TCS), 24 crystalline silica(CS), 778 respirable dust(RD) and 471 total dust(TD). Most of RCS measurements(68.9%) were collected from 'cast of metals(KSIC 243)'. Comparing industry types, 'mining coal and lignite(KISC 051)' showed the highest WAM concentration of RCS, $0.14mg/m^3$, followed by $0.11mg/m^3$ of 'manufacture of other non-metallic mineral products(KSIC 239)', $0.108mg/m^3$ of 'manufacture of ceramic ware(KSIC 232)', $0.098mg/m^3$ of 'heavy construction(KSIC 412)' and $0.062mg/m^3$ of 'cast of metals(KSIC 243)'. In terms of crystalline silica contents in airborne dust, 'manufacture of other non-metallic mineral products(KSIC 239)' showed the highest value of 7.3%(wt/wt), followed by 6.8% of 'manufacture of ceramic ware(KSIC 232)', 5.8% of 'mining of iron ores(KSIC 061)', 4.9% of 'cast of metals(KSIC 243)' and 4.5% of 'heavy construction(KSIC 412)'. WAM concentrations of RCS had no consistent trends over time from 1994 ($0.26mg/m^3$) to 2012 ($0.12mg/m^3$). Conclusion: The data set related RCS exposure level by industries can be used to determine not only the possibility of retrospective exposure to RCS, but also to evaluate the level of quantitative retrospective exposure to RCS.

• Resources Recycling
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• v.30 no.6
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• pp.68-75
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• 2021

This study aims to investigate the manufacturing process of calcium chloride-based special cement, i.e., CCA (calcium chloro aluminate, C₁₁A₇·CaCl₂), which uses limestone, by using one type of random industrial by-product, domestic coal ash, cement kiln dust. The manufacturing process of was examined in detail, and the results suggested that the amount of CCA synthesized increased with an increase in the firing temperature. The manufacturing process of CCA was investigated at 1200℃, which was determined as the optimum firing temperature. The results showed that in general, the amount of CCA synthesized tended to increase with an increase in the firing time; however, the clinker melted when the firing time was more than 30 min, thereby suggesting that a firing time of less than 20 min would be suitable for the clinkering process. The optimal firing conditions for manufacturing CCA were obtained as follows: heating rate of 10 ℃/min, firing temperature of 1200 ℃, and holding time of 20 min. The results also suggest that manufacturing CCA will be easier when high chlorine-containing cement kiln dust is used.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.32-43
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• 2008

Source samples were collected to construct source profiles for 9 different source types, including soil, road dust, gasoline/diesel-powered vehicles, a municipal incinerator, industrial sources, agricultural/biomass burning, marine aerosol, and a coal-fired power plant. Seasonal profiles for 'Chinese aerosol', aerosols derived from the urban area of China, were reconstructed from seasonal $PM_{2.5}$ compositions reported in Beijing, China. Ambient $PM_{2.5}$ at a receptor site was also measured during each of the four seasons, from April 2001 to February 2002, in Seoul. The Chemical Mass Balance receptor model was applied to quantify source contributions during the study period using the estimated source profiles. Consequently, motor vehicle exhaust (33.0%), in particular 23.9% for diesel-powered vehicles, was the largest contributor affecting the $PM_{2.5}$ levels in Seoul, followed by agricultural/biomass burning (21.5%) and 'Chinese aerosol' (13.1%), indicating contributions from long-range transport. The largest contributors by season were: for spring, 'Chinese aerosol' (31.7%); for summer, motor vehicle exhaust (66.9%); and for fall and winter, agricultural/biomass burning (31.1% and 40.1%, respectively). These results show different seasonal patterns and sources affecting the $PM_{2.5}$ level in Seoul, than those previously reported for other cities in the world.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.304-309
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• 1992

Background: The alveolar macrophage may metabolize arachidonic acid through cyclooxygenase- and lipoxygenase- catalyzed pathways to produce a variety of metabolites of arachidonic acid. The production of these metabolites of arachidonic acid may enhance the defensive ability of the challenged lung. However, continued stimulation with the consequent production of proinflammtory metabolites of arachidonic acid, may ultimately enhance the disease process by contributing to chronic bronchoconstriction, fibrosis, and the persistent release of toxic oxygen species. Silicosis is an example of a disease process resulting from chronic exposure of the lung to foreign particles. This study was carried out to evaluate the changes of arachidonic acid metabolites from macrophages in experimental silicosis. Methods: We measured $PGE_2$, and $LTB_4$ in cultured macrophages taken from rats by radioimmunoassay at 24 and 48 hours after stimulation by silica dust, natural carbon dust, lipopolysaccharide, calcium ionophore (A23187) and medium (RPMI) as a control. For the experimental silicosis, 50 mg silica in 0.5 ml saline was administered intratracheally into the rat and grown to 20 weeks and measured $PGE_2$, and $LTB_4$ in the cultured macrophages lavaged from that rat. The used stimulants were the same as above. Results: 1) The amount of $PGE_2$ in the cultred macrophages from normal rat was significantly decreased in the group which was stimulated with silica dust for 48 hours compare with control non-stimulated group. 2) In the experimental silicosis group, $PGE_2$, release in cultured macrophages after 48 hours incubation with silica and natural carbon dust tended to be lower than those of non-stimulated group. 3) There were marked changes of $LTB_4$ in the groups of normal rats which were incubated with silica for 24, 48 hours and natural carbon for 48 hours compared with non-stimulated group. 4) In the experimental silicosis group, the release of $LTB_4$ was significantly increased macrophages cultured with silica and natural carbon dust after 24 and 48 hours incubation compared with non-stimulated group. Conclusion: The results of these studies suggest that the in vitro exposure of rat alveolar macrophge to silica and coal dust results in an alteration in alveolar macrophage metabolism of arachidonic acid that may promote an inflammatory reaction in lung tissue.

• Tuberculosis and Respiratory Diseases
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• v.52 no.3
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• pp.241-250
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• 2002

Background : Coal-worker's pneumoconiosis(CWP) is characterized by a chronic inflammatory lung reaction associated with macrophage accumulation in the alveolar spaces. CWP is usually divided into two stage : simple pneumoconiosis(SP) where there are a limited number of fibrotic lesions remain limited, with radiological opacities smaller than 1cm and progressive massive fibrosis(PMF), which is characterized by the development of a perifocal extensive fibrotic response of the lung and severe alterations in pulmonary function. In this study, the lymphocyte compartment and cytokine were evaluated by measuring the serum levels in the control, SP and PMF groups. Materials and Methods : The coal workers selected for this study were employees(patients?) of the Tae-Baek and Dong-Hae hospital. All were men, 45-76 years old and the mean duration of their exposure to coal dust was 23.2 years in the lymphocyte compartment and 24.3 years in the cytokine checked group. According to X-ray examination results, the patients were classified into either one of the SP, PMF categories. The normal controls examined were 26-70 years old men. The serum cytokine levels were estimated by using an end point enzyme immunoassay technique. Results : T lymphocyte, helper and suppressor T cells were highly related to pneumoconiosis in this study. A statistically significant decrease in the number of suppressor T lymphocytes was observed in the simple pneumoconiosis patients and at the same time, there was an increase in the lymphocyte index. Howevere, there was no statistically difference in the serum cytokines levels among the SP, PMF and control groups. Conclusion : T lymphocyte, helper T, and suppressor T cells may be highly related to the development of CWP compared to the control group particularly in the early stage of pneumoconiosis. The changes observed in the immunological system in patients with pneumoconiosis may lie at the bottom of the pathogenesis of fibrosis. Further study is needed to evaluate the lymphocyte compartment as a marker for pneumoconiosis development in the early stage.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.338-345
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• 2002

Background : Coal workers' pneumoconiosis(CWP) is a fibrotic lung disease resulting from the chronic inhalation of coal dust. Various cytokines and growth factors secreted from macrophages and monocytes play a key role in the pathogenesis of pneumoconiosis. The platelet-derived growth factor (PDGF)-BB and the insulin-like growth factor(IGF)-1 secreated from the macrophages and monocytes are believed to stimulate the accumulation of mesenchymal cells and fibrosis of the lower respiratory tract that is observed in fibrotic lung disease. The serum concentraion of PDGF-BB and IGF-1 in 30 CWP patients and 10 healthy controls were measured in order to determine if PDGF-BB and IGF-1 can be used as sensitive biomarkers in CWP. Method : Serum was collected from 30 patients with CWP(13 with simple CWP and 17 with complicated CWP) and 10 healthy controls. The serum concentrations of PDGF-BB and IGF-1 were measured using ELISA (R&D system, Minneapolis, MN). Results : The serum PDGF-BB concentration in patients with complicated CWP($10083.76{\pm}639.07pg/mL$) was significantly higher than in the patients with simple CWP ($8493.88{\pm}848.51pg/mL$) and the healthy controls ($3726.17{\pm}292.20pg/mL$) (p<0.05). Compared to the healthy controls ($413.40{\pm}1.94ng/mL$), there was no significant difference in the serum IGF-1 concentration in patients with simple ($366.77{\pm}183.67ng/mL$) and complicated CWP ($403.18{\pm}15.39ng/mL$) (p>0.05). Conclusion : These results show the important role of the PDGF-BB mediated pathways in the pathogenesis of CWP. These data suggests that the PDGF-BB serum concentration is a useful biomarkers of the fibrotic extent in CWP patients.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.668-675
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• 2019

Fine dust in air pollutants is recognized as one of the most serious social environmental problems. Most of the NOx is generated in a combustion process such as that of a coal-fired power plant, and therefore efficient elimination of the NOx from the coal-fired power plants is needed. This study investigates the removal efficiency of using $TiO_2$, a photocatalyst, to remove NOx by Selective Catalytic Reduction (SCR). To evaluate the NOx removal efficiency, $TiO_2$ catalyst and phosphate binder were mixed on the surface of the $Al_2O_3$ substrate with the exothermic agent, and the substrate was heat-treated. The NOx removal efficiency of the catalysts was evaluated according to the temperature, and XRD, SEM, TG-DTA and BET analyzes were performed to investigate the physicochemical properties of the catalysts. NOx removal efficiency was 58.7%~65.9% at 20min, 63.7~66.0% at 30min with temperature change according to time($250^{\circ}C{\sim}500^{\circ}C$). The $TiO_2$ used in the SCR for NOx removal is judged to have the most efficient removal efficiency at $300^{\circ}C$.

• Resources Recycling
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• v.31 no.4
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• pp.12-18
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• 2022

Korea depends on the import of raw materials such as iron ore and coal for the steel industry. These raw materials have a major impact on the cost, productivity, and quality competitiveness in the global steel industry. To secure the competitiveness of steel companies, it is necessary to reduce the country's dependence on raw materials. This can be achieved using byproducts with a high Fe content, which are primarily generated by the steel industry. These byproducts are available in the form of a very fine powder, which can disperse as dust when used directly in plant processes. Dust dispersion has a negative impact on the environment and can lead to the loss of raw materials. To enable the use of a wide range of Fe-containing byproducts, it is necessary to pretreat them in the form of larger aggregates such as pellets and briquettes. There are several methods to achieve such aggregates. There are two ways to produce briquettes: using a hot briquette, which supplies additional heat to produce briquettes, or using a cold briquette, which does not use heat. A method for producing cold briquettes using Fe-containing byproducts was investigated in this study. The yield ratio and briquette strength were examined under various manufacturing conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.5
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• pp.411-429
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• 2015

The Korea Ministry of Environment has established an air quality standard for $PM_{2.5}$ in 2012 and it is effective from January 2015. In this study, we review various aspects of $PM_{2.5}$ in China, including its measurement, modeling, source apportionment, and health effect, and suggest future research directions for $PM_{2.5}$ studies in Korea. Measurements studies for $PM_{2.5}$ have examined organic marker compounds and $^{14}C$ as well as inorganic aerosols for distinguishing sources. Modeling results supported that the control of $PM_{2.5}$ pollution in big city needs effective cooperation between city and its surrounding regions. The major $PM_{2.5}$ sources in China have been identified to be secondary sulfur, motor vehicle emissions, coal combustion, dust, biomass burning, and industrial sources, however, they have seasonal dependency. Especially, the severe haze pollution event during January 2013 over eastern and northern China was driven to a large extent by secondary aerosol formation. Short-term exposure to $PM_{2.5}$ is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases, as well as total non-accidental mortality. Considered previous $PM_{2.5}$ studies in China, analysis of specific organic species using online measurement, chamber experiment for secondary aerosol formation mechanism, and development of parameterizing this process in the model are needed to elucidate factors governing the abundance and composition of $PM_{2.5}$ in Korea.