• Korean Journal of Bronchoesophagology
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• v.6 no.1
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• pp.44-61
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• 2000

Objectives : This study was designed to compare the morphological changes in the nasal, tracheal and main bronchial mucosa in rats exposed to 0, 0.3, 0.6, 0.9 and 1.2 ppm ozone for 7 days, 6 hours per day. Materials and Methods : We observed the nasal, tracheal and main bronchial mucosa in rats exposed to 0, 0.3, 0.6, 0.9 and 1.2 ppm ozone for 7days, 6hours per day with LM, SEM and TEM. Results : In light microscopy, influx of inflammatory cells, epithelial hyperplasia, loss of cilia and increased goblet cells were observed in all rats except those exposed to 0.3 ppm. these findings increased with the increase of ozone concentration, but there were no significant differences among the nasal, tracheal and main bronchial mucosa in rats exposed to the same ozone concentration. In scanning electron microscopy, a loss of cilia was observed in rats exposed to 0.3 ppm in some sections and 0.6 ppm and 1.2 ppm in all sections. In transmission electron microscopy, vacuolization of epithelial cells was observed in rats exposed to 0.3 ppm in some sections and 0.6 ppm in all sections. These results suggest that electron microscopic observation is necessary to study morphology of airway mucosa in rats exposed to ozone below 0.3 ppm. And also the morphological changes in nasal septal epithelium may reflect those of tracheal and bronchial epithelium after high concentration ozone-exposure.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.63-70
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• 1995

Continuous measurements of ground-level ozone (O3) were made in five minutes intervals in the rural area of Korea from July 1993 to June 1994. This site is located in Chongwon, near latitude 36.4$^{\circ}$N, longitude 127.6$^{\circ}$E. The results show that the one-year mean value was 17 ppb, and monthly mean ranged from 6 to 47 ppb. A pronounced maximum in summer and a minimum in winter were found, and these were related to anthropogenic emission and photochemical reaction. Diurnal variations of ozone minimum at 07:00 - 08:00. During the period when ozone concentration was very high (> 80 ppb), the stable winds were from N and UW; on the other hand, when ozone concentration was very low, air movement in the large scale was from the North Pacific Ocean. This suggests that in the rural area the long range transport of anthropogenic pollutants from distant sources can contribute to the larger contribution than the generation of ozone from local sources in the rural area.

• Asian Journal of Atmospheric Environment
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• v.9 no.4
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• pp.247-258
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• 2015

Exposure of high concentration of ground-level ozone (GLO) can trigger a variety of health problems including chest pain, coughing, throat irritation, asthma, bronchitis and congestion. There are substantial human and animal toxicological data that support health effects associated with exposure to ozone and associations have been observed with a wide range of outcomes in epidemiological studies. The aim of the present study is to estimate the spatial distributions of GLO using geostatistical method (ordinary kriging) for assessing the exposure level of ozone in the eastern part of Texas, U.S.A. GLO data were obtained from 63 U.S. EPA's monitoring stations distributed in the region of study during the period January, 2012 to December, 2012. The descriptive statistics indicate that the spatial monthly mean of daily maximum 8 hour ozone concentrations ranged from 30.33 ppb (in January) to 48.05 (in June). The monthly mean of daily maximum 8 hour ozone concentrations was relatively low during the winter months (December, January, and February) and the higher values observed during the summer months (April, May, and June). The higher level of spatial variations observed in the months of July (Standard Deviation: 10.33) and August (Standard Deviation: 10.02). This indicates the existence of regional variations in climatic conditions in the study area. The range of the semivariogram models varied from 0.372 (in November) to 15.59 (in April). The value of the range represents the spatial patterns of ozone concentrations. Kriging maps revealed that the spatial patterns of ozone concentration were not uniform in each month. This may be due to uneven fluctuation in the local climatic conditions from one region to another. Thus, the formation and dispersion processes of ozone also change unevenly from one region to another. The ozone maps clearly indicate that the concentration values found maximum in the north-east region of the study area in most of the months. Part of the coastal area also showed maximum concentrations during the months of October, November, December, and January.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.339-349
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• 2012

In order to clarify the impact of emissions reductions on the air quality over Metropolitan area of Korean Peninsula, several numerical experiment and analysis of integrated process rate(IPR) of ozone were carried out. Numerical models used in this study are WRF for the estimate the meteorological elements and CMAQ for assessment of ozone concentration. As result in the sensitive test of VOC/NOx reduction experiments, although VOC reduction tends to induce the different impact on the advection and photochemical reaction rate of ozone in urban area and rural area, the mechanism of ozone appeared to be more sensitive to the reduction of VOC than that of NOx over the metropolitan and its surround area. So the control of VOC emission inventories is an effective means to decrease the ozone concentrations around this area.

• Fisheries and Aquatic Sciences
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• v.25 no.8
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• pp.429-440
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• 2022

This study assessed the effects of oxygen and ozone nanobubbles on gill morphology, weight gain, and mortality of Pacific white shrimp (Penaeus vannamei), as well as the level of Vibrio parahaemolyticus and water quality of shrimp culture tanks under lab conditions. Two experiments were carried out with oxygen macrobubble, ozone macrobubble, oxygen nanobubble, ozone nanobubble, and control treatments (air-stone macrobubble). Experiments were done in triplicate in 100 L tanks with 15‰ saline water, and 20 shrimp per tank. Tanks in Experiment 1 were not inoculated with bacteria; tanks in Experiment 2 were inoculated with V. parahaemolyticus at a concentration of 10⁶ CFU/mL. The results revealed that short treatments with ozone nanobubbles had minimal impact on shrimp gills, mortality, and growth rates, reduced V. parahaemolyticus concentration in water compared to the other groups, and improve water quality. These laboratory results indicate that ozone nanobubble treatment may be useful for controlling V. parahaemolyticus. More work is needed to find the best protocol to apply the technology on a commercial scale.

• Food Science and Preservation
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• v.5 no.2
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• pp.177-185
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• 1998

For the purpose of enhanceing soybean-sprouts quality, the optimum conditions for ozone treatment of soybean during soaking before cultivation at 18~2$0^{\circ}C$ were evaluated with ozone concentration, treatment time and treatment frequency by response surface methodology. Germination rates of cleaned soybean by ozone water in the conditions of solubilized-ozone concentrations of 0.15 to 0.35ppm, ozone-treatment frequency of 1.5 to 2.3 times and ozone-treatment time of 30 to 36min. increased 18.8 to 24.0% for the control products. And, length of hypocotyl in conditions of 0.12 to 0.33ppm, 1.7 to 2.7 times and 45 to 90min. were also increased by 69.36 to 79.40%. On the other hand, weight of roots with ozone treatment were decreased in the conditions of solubilized ozone concentrations of 0.1 to 0.2ppm and ozone-treatment time of 30 to 57min. But, ozone-treatment frequency did not affected root growth. Putrefaction rates of the control were 5 to 15%, but those of ozone-treated samples during cultivation did not show. The overall optimum conditions for above 16% germination rates, above 9% hypocotyl yields compared to the control samples and below 98% of the control root weight were solubilized-ozone concentrations of 0.25 to 0.30ppm, ozone-treatment time of 43 to 49min. and ozone-treatment frequency of one time.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.267-280
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• 1999

To investigate the characteristics of high-ozone occurrences in the Greater Seoul Area(GSA), three high-ozone episodes were selected, for which the ozone warning for concentration above 120 ppb might be issued. The selection was on the basis of morning wind directions and speeds, and daily maximum ozone concentrations measured between 1990 and 1997. The episodes chosen to meet selection criteria were seven days in July 1992, nine days in July 1994, and three days in August 1994, as respectively characterized by southwesterly, easterly, and calm winds in the morning. However, more than 80% of high-ozone days in the GSA were associated with calm winds and the concomitant accumulation of local emission in the morning, rather than being due to transport of ozone or its precursors. This is believed to be the primary reason why ozone concentrations in the GSA varied in a completely different manner even between adjacent monitoring stations. Several premises for initiating research studies for resolving these local variations of ozone concentrations in the GSA are also discussed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.125-129
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• 2001

ln this paper, a ozone generator using superimposition of silent discharge has been designed and manufactured. This type ozone generator is equipped with three electrodes and two gaps. Ozone is generated by superimposition of silent discharge, which is respectively come from two gaps. The maximum values of ozone concentration, ozone generation flow and ozone energy field were obtained 4,750[ppm], 2.37[g/h], 102.3[g/kWh]. Also, the result of reaction of 1,8921ppm] ozone and the sampling water from the lake, the water quality was improved from IV grade to In grade, and obtained 100[%] sterilization rate of Escherichia coli within 5.0(min).

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.438-441
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• 2000

Ozone has the advantages for the strong oxidant agents. Ozone is widely used as a disinfectant and deodorant in water treatment and biosafety cabinets. We attempted deodorization and disinfection in the piggery using ozone treatment. It was found that ozone affects deodorization of ammonia and decrease of microbial organism in the air. Concentration of ammonia decreased 50 percents and microbial organisms in the air were decreased below 10 percents. It will be useful for the application of the ozone to environmental treatment in the piggery.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.417-426
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• 2004

We investigate changing characteristics and concentration distribution of ambient air quality using data from which obtained local ambient air monitoring network and local meterological measuring sites in Gwangju area from January to December in 2003. Sulfur dioxide ($SO_2$) showed that increase from 8 AM and decrease in 6 PM but, it was not drastically changed concentration. it also 0.010 ppm in 1995 from at this time it's decrease step by step and than some constant in year 2001 to 2003. Nitrogen dioxide ($NO_2$) concentration was showed highest peak in 10 AM and increase again at 6 PM. And also it showed peak concentration (0.026 ppm) in 2001 and decreased from after that times. Ozone was showed peak concentration in 1 PM and Nitrogen dioxide was ditto in 10 AM from this data, we can conclude that this two article ws showed chemical reaction by 3 to 5 hours. There was no case of Ozone alarm in Gwangju area since 1995, but it showed highest ozone concentration (over 0.070 ppm) in May and June of the year and 2 to 4 PM of the day and sometimes it showed increase at the dawn. Ozone product optimum condition was that air temperature is over $25^{\circ}C$, no rain and increase solar radiation (over $20MJ/m^2$) and no wind or below 2.0 m/s wind speed.