• Journal of Environmental Science International
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• v.12 no.9
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• pp.977-986
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• 2003

In this study, the scenario for a numerical modeling of the fine grid scale air dispersion phenomena was proposed and an analysis of the special event which was occurred on September 3, 2002 was performed using by a coarse grid prognostic meteorological model, a fine grid diagnostic meteorological model and a fine grid air dispersion model. Based on the results, we found that the local circulations, like as land-sea breeze, should be seriously considered for evaluating the high PM10 concentration event and for making the reduction policy of the major air pollutant emissions in Ansan area.

• Toxicological Research
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• v.28 no.4
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• pp.209-216
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• 2012

The biological activity of particles is largely dependent on their size in biological systems. Dispersion in the aqueous phase has been both a critical impediment to and a prerequisite for particle studies. Carbon black has been used as a surrogate to investigate the biological effects of carbonaceous particles. Here, biocompatible methods were established to disperse carbon black into ultrafine and fine particles which are generally distinguished by the small size of 100 nm. Carbon black with a distinct particle size, N330 and N990 were suspended in blood plasma, cell culture media, Krebs-Ringer's solution (KR), or physiological salt solution (PSS). Large clumps were observed in all dispersion preparations; however, sonication improved dispersion - averaged particle sizes for N330 and N990 were $85.0{\pm}42.9$ and $112.4{\pm}67.9$ nm, respectively, in plasma; the corresponding sizes in culture media were $84.8{\pm}38.4$ and $164.1{\pm}77.8$ nm. However, sonication was not enough to disperse N330 less than 100 nm in either KR or PSS. Application of Tween 80 along with sonication reduced the size of N330 to less than 100 nm, and dispersed N990 larger than 100 nm ($73.6{\pm}28.8$ and $80.1{\pm}30.0$ nm for N330 and $349.5{\pm}161.8$ and $399.8{\pm}181.1$ nm for N990 in KR and PSS, respectively). In contrast, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) exhibited little effect. Electron microscopy confirmed the typical aciniform structure of the carbon arrays; however, zeta potential measurement failed to explain the dispersibility of carbon black. The methods established in this study could disperse carbon black into ultrafine and fine particles, and may serve as a useful model for the study of particle toxicity, particularly size-related effects.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.789-803
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• 2003

The purpose of this study is to compare the usefulness between Gaussian dispersion model and receptor model with the experimental result of the dispersion tracing of the particulate pollutants from Taean coal-fired power plants. For this purpose, the component analysis of the collected PM 10 samples was performed. In order to trace the pollution sources, factor analysis was done with the result of the component analysis. As a result of the correlativity analysis of the fifteen power plants' profiles offered by US EPA, the correlativity of No.11202 source profile showed highest rate up to 84.5%. Thus it was adopted as proper one and the contribution rate by each pollution source was calculated by Chemical Mass Balance (CMB)-8 model. The contribution rate, which was the effect rate of the power plants on each measuring point, were calculated with a range of 24∼52％ and the standard error was below 0.9 $\mu\textrm{g}$/㎥. This indicates the selection of the source profile was appropriate. Also, the concentrations of each point were calculated by the ISCST3 which is suggested by US EPA as one of the regulatory Gaussian dispersion model. The calculation result showed that the predicted concentration was 50∼58 $\mu\textrm{g}$/㎥, comparing with the measured result of 9∼65 $\mu\textrm{g}$/㎥. It was found that the concentration calculated by ISCST3 was underpredicted. It was thought that the receptor model was more favorable than the Gaussian dispersion model in estimating the effect of the particulate matter on a certain receptive point.

• Journal of Environmental Impact Assessment
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• v.14 no.6
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• pp.427-441
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• 2005

In order to choose proper dispersion model and emission factors suitable in Korea in evaluating the effect of pollutants emitted by the vehicles in highway on nearby area, various road dispersion models and vehicle emission factors were reviewed. With theoretical inter-comparisons of the exiting models for line source, CALINE 3 and CALINE 4 models which were suggested by US EPA were selected as the road dispersion models for further evaluation with the measurement. The emission factors suggested by Korean Ministry of Environment was turned out to be appropriate since the classification of vehicle kinds was simple and easy to apply in Korea. The comparisons of predicted concentrations by CALINE 3 and 4 models with the measurements in flat, fill and bridge road types showed that CO and PM-10 were in good agreements with experiments and the differences between CALINE 3 and 4 models are negligible. The model concentrations of $NO_2$ by CALINE 4 were also in good agreement with the measurement but those by CALINE 3 were over-predicted. The discrepancies in CALINE 3 model were due to rapid decay reaction of $NO_2$ near the highway, which was not included in CALINE 3 model. For the road type with one & two side cutting grounds, the similar patterns as the flat & fill road type for CO, PM10, & $NO_2$ were observed but the number of data for comparison in these cases were not enough to draw the conclusion. These results lead to the conclusion that CALINE4 model is proper in road environmental impact assessment near the highway in flat, fill and bridge road types.

• 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.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.267-278
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• 2021

Objectives: Using atmospheric dispersion representative models (AERMOD and CALPUFF), the emissions characteristics of each model were compared and analyzed in ready-mixed concrete manufacturing facilities that generate a large amount of particulate matter (PM-10, PM-2.5). Methods: The target facilities were the ready-mixed concrete manufacturing facilities (Siheung RMC, Goyang RMC, Ganggin RMC) and modeling for each facility was performed by dividing it into construction and operation times. The predicted points for each target facility were selected as 8-12ea (Siheung RMC 10, Goyang RMC 8, and Gangjin RMC 12ea) based on an area within a two-kilometer radius of each project district. The terrain input data was SRTM-3 (January-December 2019). The meteorological input data was divided into surface weather and upper layer weather data, and weather data near the same facility as the target facility was used. The predicted results were presented as a 24-hour average concentration and an annual average concentration. Results: First, overall, CALPUFF showed a tendency to predict higher concentrations than AERMOD. Second, there was almost no difference in the concentration between the two models in non-complex terrain such as in mountainous areas, but in complex terrain, CALPUFF predicted higher concentrations than AERMOD. This is believed to be because CALPUFF better reflected topographic characteristics. Third, both CALPUFF and AERMOD predicted lower concentrations during operation (85.2-99.7%) than during construction, and annual average concentrations (76.4-99.9%) lower than those at 24 hours. Fourth, in the ready-mixed concrete manufacturing facility, PM-10 concentration (about 40 ㎍/m³) was predicted to be higher than PM-2.5 (about 24 ㎍/m³). Conclusions: In complex terrain such as mountainous areas, CALPUFF predicted higher concentrations than AERMOD, which is thought to be because CALPUFF better reflected topographic characteristics. In the future, it is recommended that CALPUFF be used in complex terrain and AERMOD be used in other areas to save modeling time. In a ready-mixed concrete facility, PM-10, which has a relatively large particle size, is generated more than PM-2.5 due to the raw materials used and manufacturing characteristics.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.2
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• pp.19-30
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• 1986

This study was performed to develop a long-term air pollution dispersion model based on CDM program for use in the personal computer. The model CDM.PC, developmented for use of this study, simplified the plum equation of point pollution source in a windy state and sindless state. We used the classified 8 class stability, 16 wind direction and 4 class wind speed for the computer input climatological data. The plum rise equation is applied for CONCAWE's equation above 2,000 Kcal/sec of the exhaust calorie and Moses-Carson's equation below 2,000Kcal/sec at windy state, and Brigg's equation at calm. The time required is 200 minutes for drawing the air pollution contour for treating ten stacks under the above-stated conditions. It is the weakness of using personal computer that the operation time is longer than a large-size computer. But it strength is that the personal computer is used widely. To compare the treatment results of CDM.PC with TCM, we comfirmed that the shape of $SO_2$ pollution contour is similar but the concentration distribution is quite different because of characteristics of each models. Estimated and measured $SO_2$ concentration were similar, namely, Cest/Cob ratio of CDM.PC and TCM were respectively $0.96 \pm 0.25 (mean\pmS.D)$ and $1.08\pm0.26$.

• Ocean and Polar Research
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• v.36 no.3
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• pp.289-302
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• 2014

This paper aims to evaluate the indirect economic damages to anglers of the marine recreational charter caused by marine pollution associated with the Herbei Spirit vessel, which spilled 12,547 kl of crude oil in Taean coastal areas in December 2007. In order to evaluate the indirect cost to anglers of the charter fishing, consumer surplus for charter fishing is estimated using a Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM), which account for the characteristics of count data (non-negative discrete data), for individual travel cost method (ITCM). Because of over-dispersion problem in PM and TPM, NBM and TNBM are considered to be more appropriate statistically. All parameters such as income, fishing careers, travel cost and catch that are estimated are statistically significant and theoretically valid. Based on TNBM results, consumer surplus per trip and per person was estimated to be 277 thousand won, total consumer surplus per person and per year about 2.3 million won, and the marginal effect of consumer surplus on % changes in catch rate is about 33 thousand won. The consumer surplus was converted into total indirect economic damages for aggregation which are evaluated to be 125 billion won, reflecting the number of anglers and damage rate.

• Ocean and Polar Research
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• v.30 no.2
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• pp.141-148
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• 2008

This paper aims at estimating consumer surplus for recreational sea fishing in Tongyeong coastal area using individual travel cost method. A Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM) are applied for individual travel cost method in order to account characteristics of count data (non-negative discrete data.) The survey was conducted for 462 inshore anglers using personal interview method in Tongyeong during July and October 2007. Respondents were asked about how often they do fishing, travel costs, catch, income, and so on. Because of over-dispersion problem in PM and TPM, NBM and TNBM were considered to be more appropriate statistically. All parameters estimated are statistically significant and theoretically valid. As the results based on TNBM, consumer surplus per trip was estimated to be 183,486 won, total consumer surplus per person and per year 3,399,658 won, and the marginal effect of consumer surplus on % changes in catch rate is 185,372 won.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.21-33
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• 2014

PURPOSES : This study presents a specific methodology for air dispersion analysis of urban areas methodology in accordance with urban planning and transport policy. METHODS : This study performed three alternatives including development density and public transit applying integrated urban model for the Delft city on Netherlands. Based on this result, the two types of air pollutant emissions($PM_{10}$, NOx) were calculated and analyzed the emission dispersion on that City. RESULTS : As a result, the quality of air near the City is better than that of current conditions showed that approximately from 2.1 to 7.9% according to alternatives. CONCLUSIONS : Air quality assessment in urban areas can be reasonably performed by applying a methodology when urban development and transport policy are considered.