Air quality modeling about coastal urban region such as Pusan shoud be consider shipping source emmited from ships anchoraging and running. It has been proved at our previous studies that the ratios of air pollutants emission amount in coastal area to inland are 12.2% for NO2 and 11.7% for SO2 and the air quality of coastal urban area consierably counts on ships. Also the dispersion pattern of the air pollutants followed local circulation system in this region. Therefore this study has been developed air quality model which can describe the formation, transport, transformation and deposition processes of air pollutants considering shipping source. Currently, restriction for emission amount of ships does not exist, so our study will be useful to set the emission standard and for devising air quality policy in coastal urban region.

The well-mixed room model has been traditionally used to predict the concentrations of contaminants in indoor environments. However, this is inappropriate because the flow fields in many indoor environments distribute contaminants non-uniformly, due to imperfect air mixing. Thus, some means used to describe an imperfectly mixed room are needed. The simplest model that accounts for imperfect air mixing is a two-zone model. Therefore, this study on development of computer program for the two-zone model is carried out to propose techniques of estimating the concentration of contaminants in the room. To do this, an important consideration is to divide a room into two-zone, i.e. the lower and upper zone assuming that the air and contaminants are well mixed within each zone. And between the zones the air recirculation is characterized through the air exchange parameter. By this basic assumption, the equations for the conservation of mass are derived for each zone. These equations are solved by using the computational technique. The language used to develope the program is a VISUAL BASIC. The value of air exchange coefficient(f_12) is the most difficult to forecast when the concentrations of contaminants in an imperfectly mixed room are estimated by the two-zone model. But, as the value of f_12 increases, the air exchange between each zone increases. When the value of f_l2, is approximately 15, the concentrations in both zone approach each other, and the entire room may be approximately treated as a single well-mixed room. Therefore, this study is available for designing of the ventilation to improve the air quality of indoor environments. Also, the two-zone model produces the theoretical base which may be extended to the theory for the multi-zone model, that will be contributed to estimate the air pollution in large enclosures, such as shopping malls, atria buildings, airport terminals, and covered sports stadia.

This study examined the carbon dioxide (CO_2) pollution inside vehicles under low ventilation condition and evaluated the Air Quality System (AQS) for in-vehicle air quality using two techniques. The low ventilation condition is not recommended in order to keep oxygen-rich condition inside vehicles. Under the low ventilation condition, the in-vehicle CO_2 concentrations exceeded 1,000 ppm, the air quality guidelines in the United States, Western Europe, and Japan, indicating more oxygen deficiency inside vehicles. On the contrary, with the AQS-on condition, the in-vehicle CO_2 concentrations were less than 1,000 ppm for most of the driving time, indicating that the AQS could solve the problem of CO_2 accumulation inside vehicles under the low ventilation condition. The AQS test conducted by comparing carbon monoxide (CO) and volatile organic compound (VOC) concentrations inside two vehicles indicated that the AQS effectively decreased the in-vehicle concentrations by 21 to 36%, as compared to medium ventilation condition with the windows closed, the vent opened, and air conditioning on. In addition, The AQS test conducted by comparing the interior and exterior concentrations indicated that the AQS effectively decreased the in-vehicle concentrations by 18 to 31%, as compared to medium ventilation condition.

The purpose of this study was to quantitatively determine the indoor infiltration of pollutants of outdoor origin. The relationship between indoor and outdoor air is dependent, to a large extent, on the rate of air exchange between these two environments. Mean indoor/outdoor ratios measured from this study were: 0.70 for HNO_3; 1.60 for HNO_2; 0.56 for SO_2; 1.30 for NH_3; 0.96 for PM_2.5(d_p<2.5μm); 0.89 for SO_4^2-; 0.87 for NO_3^- and 0.79 for NH_4^+. Mean indoor concentrations for PM_2.5, SO_4^2-, HNO_3, NO_3^- and NH_4^+ were similar to outdoor levels. Indoor HNO_2 and NH_3 values were higher than outdoors. However, the indoor level of SO_2 was lower than ambient level.

Diurnal variations of air quality due to the characteristic features of local weather phenomena over Kunsan, Taegu, and Pohang are analyzed using various synoptic wind fields and the characteristics of local weather during the period of 1990 to 1992. The air pollutants analyzed are sulfur dioxide(SO_2), nitrogen dioxide(NO_2), and oxidants (O_3). The synoptic wind fields estimated at over the 850 hPa geopotential height are divided in terms of four wind directions and two wind speed categories for each season. The synoptic weather conditions are also classified into two categories depending on the total cloud amounts. The present study shows that the SO_2 concentration over Kunsan, and Taegu was maximum at the two or three hours after sunrise and second primary was three or four hours after sunset. On the other hand, its concentration over Kunsan was maximum at 1900 LST or 2000 LST. The O_3 concentration over the three cities shows its maximum in the afternoon when the solar radiation is strong. The NO_2 concentration over Kunsan shows in reverse proportion to the 0_3 concentration over the Kunsan.

Diurnal variations of air quality for each season over Taegu city were analyzed using the characteristic features of the various synoptic wind fields. The air quality data which were monitored by four stations are the hourly averaged sulfur dioxid(SO_2), total suspended particulate (TSP) and oxidants (O_3) during the period of 1989 to 1992. The various synoptic wind fields obtained from the 850 hPa geopotential height were divided into four geostrophic wind directions and two geostrophic wind speeds for each seasons. The synoptic weather conditions were again subdivided into two categories using the total cloud amounts. The results shows that diurnal and seasonal variations of the air quality over Taegu city, such as sulfur dioxide, total suspended particulate and oxidants reveal the various characteristics under the same synoptic weather conditions.

Two experiments were conducted to evaluate breathing zone air quality in Taegu, using automatic analyzers for four air quality standards(SO2, NO2, CO, and O3). First, air target compounds were measured for 8 to 12 hours in each of two commercial areas and five residential areas. Second, air target compounds were hourly measured for 24 hours in each of two commercial areas, two residential areas, and an industrial complex area. Based on the first experiment the breathing zone air was more polluted in the commercial area as compared to the residential area, while the second experiment showed that the breathing zone air was polluted rather in the residential area as compared to the commercial area. The second experiment also indicated that there was some variation of breathing zone air concentration with time and measuring sites. Diurnal variation of breathing zone air concentrations was consistent with previous studies which measured at building height. The highest breathing zone air concentration was shown in Seongseo industrial complex area. An unusual finding of this study was that SO2 concentration in the breathing zone air of Bisandong, a typical residential area of Taegu, was higher than that of other residential areas, even higher than that of Seongseo industrial complex area.

When we conduct environmental impact assessment, main contents consist of summary, project outline, environmental conditions, environmental impacts due to the project, mitigation devices, and alternative measures of harmful impact on environment. In this paper, to understand how they really conduct air quality impact assessment and prediction and examine their effectiveness, we considered the provisions and actual case of environmental impact assessment in Korea with that in Japan. As a result, we propose a method of improving air quality impact assessment and prediction, such as reflection of the result in environmental impact assessment, detailed assessment focused on relatively important environmental impact elements, field measurement investigation over four season and seven sucessive days, the uniformity of units, the proper model development to predict environmental concentration and a biennial environmental impact assessment for ex post management.