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In order to provide a better knowledge of visibility degradation during the PM2.5 event day (episodic high PM2.5 level, hereafter called as "event day"), the relationship between visibility and the chemical species of PM2.5 measured in Gwangju, Korea was estimated. Moreover, a visibility forecasting model was constructed by a statistical approach. The diurnal variation of visibility and PM2.5 concentration on the event day indicated that as the concentration of PM2.5 increased, more light was absorbed and scattered, resulting in visibility deterioration. The averaged visibility during the event day was 7.9 km, which was almost three times lower than that observed during a non-event day. Although the hygroscopic growth of aerosol was not considered in this study, it has been proved that NH4NO3 and organics dominantly contributed to the light scattering during the PM2.5 event day in Gwangju, Korea. The visibility determined in this study had also a negative correlation with PM10, nitrate, relative humidity, EC, OC, and sulfate. Meanwhile, visibility was positively linked with wind speed and temperature. The results of interrelationship and a multiple regression model suggest that among the meteorological variables, temperature was the main variable that influenced visibility. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19), first reported in Wuhan, China, became pandemic in less than two months, and Korea was no exception. Daegu Metropolitan City, in particular, has become the center of the explosive outbreak in Korea. In this study, we evaluated how the air quality of Daegu Metropolitan City varied when people were fighting the spread of COVID-19. In concretely, we tried to estimate the air quality variation with the trend of COVID-19 in Daegu Metropolitan City based on the measured data at hourly intervals from two air quality monitoring stations (AQMSs) (see Fig. 2). In addition, we quantitatively assessed the positive health effects of improved air quality from fighting against COVID-19. Compared to the concentration in the same period of 2019, the PM2.5 measured at the ambient AQMS decreased by 36.7, 22.5, and 37.6% respectively in January, February, and March. Meanwhile, those at the road side AQMS were 39.9, 23.7, and 40.3% in January, February, and March, respectively. The decreasing trend was not shown in April. Along with the floating population, the concentration of NO2 at the road side AQMS decreased from 49.9 ppb to 32.7 ppb, indicating that the reduction rate was 34.5%. The summed concentration of seven hazardous metals decreased by 27.4% in February 2020 compared to 2019. Among them, lead showed the biggest drop to 43.4% in 2002 compared to 2019. The exposure of PM2.5, DosePM2.5 (µg), during 60 days of self-reflection for 10-year-old children has decreased by 29.6% compared to that in the same period of 2019. The results of adult females and males also show 27, 8% and 29.5% decrease, respectively. [ABSTRACT FROM AUTHOR]

It is crucial for understanding the characteristics of fly ash, emitted from the incinerator of municipal solid waste, to properly diagnose its impact on air quality and human health. In this study, to precisely describe the chemical property of the fly ash and its effects on near ambient particles, an intensive measurement was conducted. Fly ash was collected in dry condition from the downstream of a bag filter dust collector which is installed at an incinerator located in Iksan City, Korea. Sampling of ambient particles was carried out at both near and far away sites from an incinerator. Elemental analyses of the pretreated samples were subsequently performed by a Particle Induced X-ray Emission (PIXE) and a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive X-ray Detector (EDX). Moreover, in order to estimate the residents' exposure to the fly ash and the effect of fly ash on the near ambient particles, Gaussian plume model was carried out. The high content of soluble S, Cl, K, and Ca in fly ash were detected. Small quantities of heavy elements including Zn, Br, and Pb were also detected in the water-soluble fraction. The scattering plots drawn by the ratios of Z/Zn (i.e., the ratio of mass concentration of each element (Z) to that of zinc) of ambient PM2.5 and that of fly ash reveal a good relationship regardless of the distance from an incinerator. A ternary plot drawn by the wt% concentrations of Na, K, and Cl in the individual ambient particles and fly ash powders indicates that a small portion of the fine and coarse ambient particles was directly influenced by the fly ashes. Modeling evaluation of fly ash diffusion suggests that the air quality at the incinerator nearby areas, especially 1.5 km points, was strongly influenced by the air pollution materials emitted from an incinerator. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate differences in self-concepts and their influence on decision-making styles in apparel shopping across two cultures; namely, Korea and the United States. Data is obtained from university students in both countries (3 universities in Korea and 2 universities in the United States), generating a sample size of 1,166. The questionnaire consists of three parts: decision-making styles for apparel shopping, self- concepts, and demographic information. The results indicate that Korean respondents have higher interdependent self-concepts than the American respondents. Moreover, the self-concepts of young consumers have significant effects on their decision-making styles. This study also finds that the self-concepts of young consumers from both countries has a significantly different impact on decision-making styles for apparel shopping. The similarities and/or differences of the relationships between self-concepts and decision-making styles of young Korean and American consumers are also found when such relationships are examined within each country. This study makes a unique contribution to enhancing the understanding of contemporary global consumer behavior by exploring relationships in culture, self-concepts, and decision-making styles of young consumers. [ABSTRACT FROM AUTHOR]

The article presents a study on the environmental behavior and long-term trends of airborne toxic metals in Seoul and Busan, South Korea from 1991 to 2004. It reveals that the long-term trends of metals are likely to decrease their concentrations regardless of the city. It recommends that the rate of long-term monitoring data for toxic metals permits the assessment of factors involved in the effort of regulating target pollutants.