• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.142-147
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• 2006

The present study describes carbohydrate metabolism, macro-element utilization and antioxidant defenses in response to an ozone dose (100 ppb, 8d) in two rice varieties. Tolerant (cv. Jinpumbyeo) and sensitive (cv. Chucheongbyeo) varieties of rice were grown in growth chamber for 30 days after sowing. Concentrations of chloroplast pigments and non-structural carbohydrates as well as activity of antioxidant enzymes were determined to evaluate the resistance against ozone stress. Ozone caused the decrease in chlorophyll a and carotenoid contents, and also resulted in faster decomposition of non-structural carbohydrate in leaf blade and leaf sheath. The contents of nitrogen and potassium in leaves were visibly decreased in cv. Chucheongbyeo with an increase in ozone exposure, but not in cv. Jinpumbyeo. Enzymatic antioxidants against ROS in both varieties responded in the order of POD, SOD and CAT, and their capacity was stronger in cv. Jinpumbyeo.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.55-66
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• 1996

One-hour average concentrations of ground-level ozone from around 80 monitoring stations in Korea during 1991 to 1993 were analyzed to examine characteristics of the ozone concentration variations. Two types of variations were observed: one was for the Capital area typified by Kwanghwmun, and the other was for the south and east seashore region typified by Tongkwangyang. In the Capital area including Seoul, Inchon, Kyonggi-do and Chunchon, mean daily 1-hout maximum was the highest in June following high monthly averages in spring. But frequent precipitation prevented further rise of daily maximum in July and August even though there were frequent episodes of high concentration exceeding 100ppb. In the south and east seashore region, average concentration was the highest throughout the year, and daily maximum and minimum simultaneously changed owing to small contributions from photochemical reactions. The typical annual variation was spring peak, summer down, and fall rise. Spring peak accompanied an usual observations of background variations at remote sites in the Northern Hemisphere. Riess of average and daily maximum with lower daily minimum in fall were attributable to photochemical reactions.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.165-172
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• 2003

The objectives of this study were to examine the physiological responses to ozone and to measure ozone uptake rates of Betula species exposed to relatively high concentration of pollutants. At the end of the growing season, photosynthesis, pigments contents, antioxidants (SOD and GR) and ozone uptake rates were measured or estimated at the leaves of five Betula species (Betula costata, B. davurica, B. platyphylla var. japonica, B. schmidtii and B. ermanii) exposed to 100ppb ozone concentration. On the termination of the experiment, growth effects were determined by measuring leaf area and dry weights of leaf, stem and root. Ozone treatment showed the significant reduction the leaf area and dry weight of four Betula species, except for B. ermanii. Shoot / root (SR) ratio of five species represented two different types. SR ratio of B. costata and B. davurica were lower than control, in contrast, SR ratio of B. platyphylla var. japonica, B. schimidtii and B. emani, were higher than that of control. The photosynthetic responses of five species were different in responses to ozone exposure. Four species, except for B. emanii, maintained or increased the stomatal conductance, but B. emanii decreased both stomatal conductance and photosynthesis. SOD activities of five species decreased by the ozone exposure, especially B. ermanii showed the largest reduction, GR activities of B. platyphylla var. japonica and B. schmidtii increased, B. costata and B. emanii decreased. Instantaneous ozone uptake rate was the highest at the leaves of B. ermanii and B. costata, ozone uptake per seedling was the highest at the leaf of B. schmidtii and B. emanii. It was concluded that B. costata, B. davurica and B. platyphylla var. japonica, appeared the growth reduction and visible ozone injury, were sensitive species to ozone, and B. schmidtii with the increased antioxidant activity and B. ermanii without the growth reduction were relatively resistant species to high ozone concentration at the early growing stage.

• Journal of Korean Society of Forest Science
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• v.94 no.3 s.160
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• pp.191-196
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• 2005

This studies were conducted to compare ozone sensitivity among half-sib families of Japanese red pine (Pinus densiflora S. et Z.). 90 families were exposed in walk-in type chambers to charcoal-filtered air and 100 ppb ozone for 8 hours daily, 5 consecutive months. We surveyed the foliar injury, Relative DRC (diameter at root collar) growth and relative dry weight after fumigation. After 5 months of exposure, foliar injury ranged from 1.9% at tolerant group to 15.2% at sensitive group. Relative DRC growth rates showed increased 12% at tolerant group, but reduced 23% at sensitive group. Total dry weight increased 17% at tolerant group, otherwise reduced by 33% at sensitive group, relative to the control. The root biomass showed more sensitive than the other part biomass. On the basis of the results of these screening studies, families Kangwon 04, 16, 26, 27 and 73 were determined to be tolerant; Kangwon 40, 52, 83, Gyeonggi 01 and Gyeongbuk 20 to be sensitive to ozone. Considerable genetic variation in ozone responses occurred, as shown by differences in sensitivities among families and among groups. These results indicate that tolerant groups of P. densiflora exhibited a high degree of resistance to ozone pollution injury.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.50-61
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• 2020

Street trees are very important to urban environments as they can alleviate air pollution. However, when ozone is absorbed through the stomata, it can induce the formation of free radicals inside the tree, negatively affecting the vegetation. The present study investigated the Air Pollution Tolerance Index (APTI) of four major street tree species: Prunus yedoensis, Zelkova serrata, Chionanthus retusus, and Pinus densiflora. Two-year-old seedlings were placed in a phytotron and fumigated with 100 nL·L^-1 (ppb) ozone for 4 weeks, following which the ascorbic acid contents, chlorophyll contents, leaf pHs, and relative water contents were measured. There was no significant difference in the APTI of Prunus yedoensis and Zelkova serrata between the ozone and control treatments. By contrast, the ozone treatment caused the APTI of Chionanthus retusus to increase and that of Pinus densiflora to decrease compared with the respective controls. These results suggest that the APTI of these tree species exhibit very different responses to ozone. Therefore, more detailed research should be conducted on a range of species in the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.6-10
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• 2003

This study was conducted to select the ozone tolerant individuals of Cornus controversa Hemsl., and to use malondialdehyde (MDA) content as an indicator of plant damage level for several oxidative stress levels. Seeds of C. controversa were collected at 9 provinces in Korea. One-year-old seedlings were grown in greenhouses and exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 10 weeks. At the termination of ozone exposure, heights of seedlings were measured and MDA contents in the leaves were analyzed. Tolerant, intermediate, and sensitive individuals were selected using the standardized indices of height and MDA content. Height and MDA content of C. controversa exposed to ozone were significantly different among individuals and provinces. MDA content showed negative correlation (r=-0.531, p$\leq$ 0.001) with height growth performance. Height and MDA content of tolerant individuals presented significant differences from those of sensitive individuals. As a result, MDA content may be suitable for the evaluation of the damage level of plants by oxidative stress.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.87-97
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• 2004

NMHC (non-methane hydrocarbons) and fine particles such as P $M_{10}$ and P $M_{2.5}$ were measured at KIST (Korea Institute of Science and Technology) in Seoul for a month from the end of May. At the beginning of June, peak ozones exceeded 100ppb both near KIST and in Seoul while ozone and fine particles decreased from the middle of June due to frequent precipitation. Because the measurement site was close to trees on a hill, isoprene concentration went up to 4.1ppb with an average of 0.76ppb. Toluene was the highest all day long, but particularly high concentration in the afternoon implied a contribution of emission from solvent use as well as vehicle exhaust. Eighty-five percent of P $M_{10}$ was P $M_{2.5}$ on an average since major ions except sea salt, including nitrate, were present within P $M_{2.5}$. Daily variations of pollutants were generally similar except for NMHC. One of major differences in NMHC variation was maintenance of a relative high concentration in rainy day, showing that NMHC were not effectively scavenged by precipitation.ion.ion.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.72-79
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• 2002

This study was conducted to compare the physiological and biochemical responses of four Betula species in response to ozone, and to find out the relationship between ozone uptake rate and photosynthesis or antioxidant activity. One-year-old seedlings of four Betula sp, B. costata, B. davurica, B. platyphylla var, japonica, and B. ermani, exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 5 weeks in fumigation chamber. Ozone uptake rate, photosynthesis, SOD and GR activity were measured in the leaves of four species once a week. Cumulative ozone uptake rate was largest in the loaves of B. costata(53.8 mmol m$^{-2}$ ), smallest in the leaves of B. davurica(35.5 mmol m$^{-2}$ ). Photosynthesis of four Betula sp. exposed to ozone reduced relative to control, but the photosynthetic responses with changing stomatal conductance were different among species. Ozone exposure increased SOD activities of four species at the early exposing period, but after a critical point SOD activity decreased gradually. GR activity of B. costata was similar to the change of SOD activity, but the others showed the different patterns from B. costata. In conclusion, decreasing both SOD and GR activity at the critical point, B. costata may be sensitive species in response to ozone. In contrast, the others may be resistant species, which gradually increase GR activity following ozone exposure. GR activity was not always in accord with the change of SOD activity against ozone uptake, and the different responses between species were supposed to be affected by the cumulative ozone uptake.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1169-1182
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• 2008

The chemical and meteorological effects on the concentration variations of air pollutants ($O_3$ and its precursors) were evaluated based on ground observation data in coastal and inland regions, Busan during springs and summers of 2005-2006. For the purpose of this study, study areas were classified into 5 categories: coastal area (CA), industrial area (IA), downtown area (DA), residential area (RA), and suburban area (SA). Two sites of Dongsam (DS) and Yeonsan (YS) were selected for the comparison purpose between the coastal and inland regions. $O_3$ concentrations in CA and SA were observed to be highest during spring (e.g., 40 ppb), whereas those in DA and RA were relatively low during summer (e.g., $22\sim24$ ppb). It was found that $O_3$ concentrations in IA were not significantly high although high VOCs (especially toluene of about 40 ppb) and $NO_x$ ($\geq$ 35 ppb) were observed. On the other hand, the concentration levels of $O_3$ and $PM_{10}$ at the DS site were significantly higher than those at the YS site, but $NO_x$ was slightly lower than that at the YS site. This might be caused by the photochemical activity and meteorological conditions (e.g., sea-land breeze and atmospheric stagnance). When maximum $O_3$ (an index of photochemical activity) exceeds 100 ppb, the contribution of secondary $PM_{10}\;((PM_{10})_{SEC})$ to total observed $PM_{10}$ concentrations was estimated up to 32% and 17% at the DS and YS sites, respectively. In addition, the diurnal variations of $(PM_{10})_{SEC}$ at the DS site were similar to those of $O_3$ regardless of season, which suggests that they are mostly secondary $PM_{10}$ produced from photochemical reactions.

• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.61-72
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• 2001

Objectives : To evaluate the hypothesis that increasing ambient levels of ozone or particulate matter are associated with increased emergency room visits for asthma and to quantify the strength of association, if any, between these. Methods : Daily counts of emergency room visits for asthma, air quality, and weather data were collected from hospitals with over 200 beds and from monitoring Stations in Seoul, Korea from 1994 through 1997. Daily counts of emergency mom visits for asthma attack were analyzed using a general additive Poisson model, with adjustment for the effects of secular trend, seasonal variation, Sunday and holiday, temperature, and humidly, according to levels of ozone and particulate matter. Results : The association between daily counts of emergency room visits for asthma attack and ozone levels was statistically significant in summer(from June to August), and the RR by unit inclement of 100 ppb ozone was 1.30(95% CI = $1.11\sim1.52$) without lag time. With restriction of the period from April to September in 1996, the RR was 1.37(95% CI = $1.06\sim1.76$), and from June to August in 1995, the RR was 1.62(95% CI = $1.12\sim2.35$). In the data for children$(5\sim14yr)$, the RR was 2.57(95% CI = $1.31\sim5.05$) with restriction of the period from April to September in 1997. There was no Significant association between TSP levels and asthma attacks, but a slight association was seen between PM10 levels and asthma attacks in a very restricted period. Conclusion : There was a statistically significant association between ambient levels of ozone and daily counts of emergency room visits for asthma attack. Therefore, we must make efforts to effectively minimize air pollution, in order to protect public health.