• 한국환경보건학회지
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• 제23권2호
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• pp.57-63
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• 1997

This study was carried out to find the adverse health effects of ozone by papers, the potential indoor sources of ozone by papers, and then the removal mechanism of ozone by experiments. The exposure of individuals to excessive levels of ozone both in the industrial and ambient environment is a continuing public health concern. Ozone indoors may play a role in generating secondary pollutants that may have adverse health effects. The removal efficiency of ozone was studied by (1) the effect of concentration on breakthrough time, (2) the effect of flow rate on breakthrough time, (3) the effect of adsorbent's weight on breakthrough time, (4) the effect of temperature on breakthrough time, (5) the application of Langmuir's isotherm equation in using activated carbon. The followings are the conclusions that were derived from this study. 1. In the effect of concentration on breakthrough time, the adsorption capacity of activated carbon was inversely proportional to ozone concentratuion (0.1, 0.2, 0.3 ppm). 2. In the effect of flow rate on breakthrough time, the service life of activated carbon was inversely proportional to flow rate (2, 8, 14l/min). 3. The difference in removal efficiency of ozone between weights(100 mg and 150 mg) was seen. And when weight of activated carbon was 100 mg and 150 mg, pressure loss was 4-5mmHg and 6-7mmHg, respectively. It is required to study relations among flow rate and adsorbent's weight and ventilation quantity, too. 4. Generally, Langmuir's equation, one of the oldest and most used frequently isotherm equation, applies to chemisorption. In case of ozone, when the weight of activated carbon was 70 mg and temperature 40, slope(1/a) was $6.25\times 10^{-1}$ and intercept(1/ab) was $1.9\times 10^{-4}$ (average r=0.94).

• 한국환경과학회지
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• 제4권5호
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• pp.61-61
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• 한국환경과학회지
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• 제4권5호
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• pp.447-459
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• Journal of Preventive Medicine and Public Health
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• 제39권1호
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• pp.81-86
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• 2006

Background: A number of studies have reported associations between the ambient air pollution concentrations and various health outcomes. Especially, ozone is well known for primary risk factor of asthma attacks. The results of a recent study indicate that the size of the effect on health outcomes due to air pollution varied according to several conditions, including age, gender, race and the socioeconomic status. Therefore, this study was conducted to examine the associations of ozone with the childhood asthma hospitalizations as stratified by the socioeconomic status (SES) at the community level in Seoul, Korea, 2002. Methods: SES at aggregated levels was measured on the basis of average regional health-insurance rate per citizen in the area. We applied the generalized additive model to analyze the effect of ozone on asthma after controlling for the potential confounding variables that were capable of influencing the results. Results: Our analysis showed that the number of children who were hospitalized for asthma increased as the SES of the residence area decreased. The estimated relative risks of hospitalization for asthma, as stratified by the SES of the community level, were 1.12 (95% confidence interval 1.00-1.25) in districts with the highest SES levels, 1.24 (95% CI=1.08-1.43) within the moderate SES levels, and 1.32 (95% CI=1.11-1.58) in the districts with the lowest SES levels. Conclusions: Our analysis showed that exposure to air pollution did not equally affect the health status of individuals. This suggests that not only the biological-sensitivity markers, but also the SES of the subjects should be considered as potentially confounding factors.

• 한국환경농학회지
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• 제19권2호
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• pp.154-159
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• 2000

대기환경오염원인 오존을 벼와 콩에 처리하여 오존피해증상, 품종간 저항성 차이 및 유전양상을 밝히고자 가시피해, 피해엽율, 엽록소함량, 임실율 등을 조사한 결과를 요약하면 다음과 같다. 벼의 오존피해증상은 피해정도에 따라 잎에 작고 붉은 반점이 형성되거나 잎전체가 적갈색 또는 황백색으로 변색되며 잎끝부터 말리면서 고사하였다. 콩은 피해엽이 황백색 또는 흑갈색으로 변색되었으며 벼와 콩 모두 잎의 표면보다는 이면이, 신엽보다는 하위엽에서 뚜렷하게 나타났다. 벼의 오존저항성 정도는 밀양 23호와 농안벼가 저항성을, 추청벼가 감수성으로 조사되었다. 오존처리시간이 2시간에서 8시간으로 길어짐에 따라 벼의 피해엽율은 증가하였고 엽록소함량은 감소하는 경향이었지만 그 정도는 품종에 따라 다르게 나타났다. 콩의 품종별 오존저항성정도는 큰올콩과 단엽콩이 저항성을, 두유콩, 무한콩, 은하콩 및 푸른콩 등이 감수성으로 나타났다. 콩의 생육시기별 피해엽율은 품종에 따라 다소 다른 경향이었으나 대체로 파종후 45일 처리에서 피해엽율이 가장 높았다.

• 한국환경과학회지
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• 제10권1호
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• pp.73-77
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• 2001

This study examined blends of styrene butadiene rubber(SBR) and chloroprene rubber(CR) prepared from an open 2-roll mill following the conventional polymer blend method for a wide range of the blend composition. Rubber vulcanizates were manufactured by hot press and then mechanical properties, heat and ozone resistance of the specimens were examined. Due to the post cure during the aging test, hardness of vulcanizates was increased. It was found that the undesirable characteristics of heat and ozone resistance of pure SBR was significantly improved through the blending of SBR with CR.

• 한국작물학회지
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• 제51권2호
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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.

• 상하수도학회지
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• 제27권1호
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• pp.39-47
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• 2013

This study demonstrates the oxidative degradation of pharmaceutical compounds during ozonation of surface waters in Ulsan. Diclofenac, carbamazepine, bezafibrate, and ibuprofen were selected as surrogate pharmaceutical compounds, and ozonation experiments were performed using raw waters collected from the Sayeon Dam and the Hoeya Dam in Ulsan. Diclofenac and carbamazepine which have high reactivity with molecular ozone showed higher removal efficiencies than bezafibrate and ibuprofen during ozonation. The addition of tert-butanol, a hydroxyl radical scavenger, increased the removal efficiencies of diclofenac and carbamazepine by increasing the ozone exposure. However, the oxidation of bezafibrate and ibuprofen was inhibited by the presence of tert-butanol due to the suppression of the exposure to hydroxyl radical. The elimination of the selected pharmaceuticals could be successfully predicted by the kinetic model base on the $R_{ct}$ concept. Depending on the experimental condition, $R_{ct}$ values were determined to be $(1.54{\sim}3.32){\times}10^{-7}$ and $(1.19{\sim}3.04){\times}10^{-7}$ for the Sayeon Dam and the Hoeya Dam waters, respectively. Relatively high $R_{ct}$ values indicate that the conversion of $O_3$ into $^{\cdot}OH$ is more pronounced for surface waters in Ulsan compared to other water sources.

• 한국산림과학회지
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• 제87권1호
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• pp.50-56
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• 1998

오존에 약(弱)하거나 저항성(抵抗性)을 가지는 포플러 개체(個體)를 선발(選拔)하기 위해서 36개의 잡종(雜種)포플러 클론을 오존에 노출(露出)시켰다. Open-top chamber를 이용(利用)하여 하루에 6-8시간, 3개월 동안 90-115ppb의 농도(濃度)로 오존을 노출시켰다. 수고(樹高), 직경(直徑), 엽수(葉數), 물질생산량(物質生産量), root/shoot비율(比率), 낙엽률(落葉率), 기공반응(氣孔反應) 조사(調査)하였다. 수고, 직경, 엽수, 물질생산량, root/shoot비율, 기공 conductance는 오존 때문에 감소(減少)하였고, 낙엽률은 증가(增加)하였다. 이 연구에서는 기공 conductance와 물질생산량과의 관계(關係)는 아주 낮게 나타났다. 오존환경(環境)에 대해서 저항성을 갖는 것은 기공(氣孔)의 개폐(開閉)와 항상(恒常) 관계(關係)가 있는 것은 아니라고 사료(思料)되며, 아마도 생화학적(生化學的)이고 생리적(生理的)인 다른 요인(要因)에 대(對)한 연구(硏究)가 포플러 클론이 갖는 저항성을 이해(理解)하는데 도움이 될 것이다.

• 한국대기환경학회지
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• 제24권3호
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• pp.310-320
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• 2008

Concentration of tropospheric ozone ($O_3$) was investigated for the South Korea. And then the critical ozone levels, expressed as AOT40 (Accumulated exposure over a threshold of 40 ppb) to vegetation have been used in this region within the UNECE (United Nations Economic Commission for Europe) Convention on Long-Range Trans-boundary Air Pollution (CLRTAP). Hourly ozone concentration data from 1996 to 2001 at 26 air monitoring stations was used to estimate the exceedance of the critical levels. It was calculated for daylight hours for each station, and mapped using surface interpolation over the South Korea. The critical levels of ozone have shown the highly exceeded value in the Gyeonggi region, southern coastal region and central inland of the South Korea. It was some different from the typical ozone distribution which represented highly in the western inland and coastal regions. The area exceeding the critical level for crops was founded to be more than 40% of the whole South Korean territory. While that for trees was to be about 17% of the South Korea. The critical ozone critical level was based upon data from experiments on specific species, and thus may not be fully representative for all types of vegetation. Nevertheless, the critical level and its exceedance of the ozone concentration would be one of the useful tools for international agreements on abatement strategies to prevent ecosystem damage.