• Journal of Plant Biology
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• 제19권4호
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• pp.107-110
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• 1976

This study was carried out to investigate lead contamination in the leaves of roadside trees and the cause of yellow-brown symptom of leaves in Jinju and Daegu city. After the leaves were collected and dried in 105$^{\circ}C$ drying oven from September to October in 1974, the samples were used for analysis of the lead contents in 1976. The roadside trees in the two cities were mostly the four kinds of Ginkgo biloba L., Thuja orientalis L., Platanus orientalis L. var. acerifolia AIT. and Prunus pseudo-cerasus $LINDL{\times}Prunus$ subhirtella MIQ. The lead contents in the leaves of roadside trees in Daegu city was higher than that of Jinju city. The lead contamination of the evergreen trees of roadside was higher than that of the deciduous trees. In Jinju city the site of the highest contents of lead in the leaves was revealed with Jinju station(0.73ppm), the next site was revealed with the road(0.16ppm) between Namgang bridge and Jinju middle school, and the lowest site was generally beside the roads of suburbs (0.07ppm). Because of the low contents of lead in the leaves, it was found that the yellow-brown symptoms of leaves were not caused by the lead toxicity.

• 한국환경보건학회지
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• 제48권4호
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• pp.227-235
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• 2022

Background: Abandoned metal mines are classified as vulnerable areas with the highest level of soil contamination among risk regions. People living near abandoned metal mines are at increased risk of exposure to toxic metals. Objectives: This study aimed to evaluate the correlation between soil contamination levels in areas around abandoned metal mine and the blood lead levels of local residents. Moreover, we assess the possibility of using soil contamination levels as a predictive indicator for human exposure level. Methods: Data from the Survey of Residents around Abandoned Metal Mines (2013~2017, n=4,421) and Investigation of Soil Pollution in Abandoned Metal Mines (2000~2011) were used. A random coefficient model was conducted for estimation of the lower level (micro data) of the local resident unit and the upper level (macro data) of the abandoned metal mine unit. Through a fitted model, the variation of blood lead levels among abandoned metal mines was confirmed and the effect of the operationally defined soil contamination level was estimated. Results: Among the total variation in blood lead levels, the variation between abandoned mines was 18.6%, and the variation determined by the upper-level factors such as soil contamination and water contamination was 8.1%, which was statistically significant respectively. There was also a statistically significant difference in the least square mean of blood lead concentration according to the level of soil contamination (p=0.047, low: 2.32 ㎍/dL, middle: 2.38 ㎍/dL, high: 2.59 ㎍/dL). Conclusions: The blood lead concentration of residents living near abandoned metal mines was significantly correlated with the level of soil contamination. Therefore, in biomonitoring for vulnerable areas, operationally defined soil contamination can be used as a predictor for human exposure level to hazardous substances and discrimination of high-risk abandoned metal mines.

• Ecology and Resilient Infrastructure
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• 제2권3호
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• pp.237-246
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• 2015

대한민국은 도시화 과정과 인접 국가에서부터 대기를 통한 유입 등으로 납과 같은 중금속의 토양 오염 문제가 관심을 받고 있다. 이에 가로수 수종으로 많이 쓰이고 있는 자생종 4종을 대상으로 토양 내 납 오염에 대한 엽록소 함량, 항산화 효소, 광합성량, 생물량과 같은 생리-생태적인 반응과 흡수능력을 연구하여 납 오염에 대응하는 가로수로 적합한 수종을 제시하고자 하였다. 연구 대상종인 은행나무, 왕벚나무, 느티나무, 이팝나무는 200 mg Pb/kg 이상의 처리구에서 엽록소 함량, 항산화 효소에서 납 독성에 대한 반응을 보였다. 반면에 생물량이나 광합성량의 경우 고농도 (5,000 mg/kg)를 제외하고는 큰 차이를 나타내지 않았다. 특히 은행나무는 항산화 효소, 광합성 및 생물량에서 고농도에서도 납의 부정적인 영향이 나타내지 않았다. 실제 환경에서 나타날 수 있는 저농도 처리구에서 은행나무와 벚나무의 경우 연구 대상종 중 높은 납 흡수율을 보였다. 이처럼 은행나무와 같이 납에 대한 저항력과 흡수능력을 가진 수종을 선발하여 가로수로 식재하여 도로 주변 납 오염에 대응하는 방안이 필요할 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.758-760
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• 1998

This paper provides the results of performance investigation of gas insulated switches(G/S) for distribution power system. In order to investigate anti-contamination capability of G/S we carried out electrical tests and material analysis on the body of G/S and it's accessories. Through this experiment we found out the lead cable of G/S had not anti-contamination capability and G/S had insufficient interval between each phase. In order to improve the performance of G/S for heavy contamination area it is indispensable to replace the lead cable to the new cable which has anti-contamination ability.

• Environmental Engineering Research
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• 제14권1호
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• pp.53-60
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• 2009

The main objective was to develop and assess a dynamic fate and transport model for lead in air, soil, sediment, water and vegetation. Daejeon was chosen as the study area for its relatively high contamination and emission levels. The model was assessed by comparing model predictions with measured concentrations in multi-media and atmospheric deposition flux. Given a lead concentration in air, the model could predict the concentrations in water and soil within a factor of five. Sensitivity analysis indicated that effective compartment volumes, rain intensity, scavenging ratio, run off, and foliar uptake were critical to accurate model prediction. Important implications include that restriction of air emission may be necessary in the future to protect the soil quality objective as the contamination level in soil is predicted to steadily increase at the present emission level and that direct discharge of lead into the water body was insignificant as compared to atmospheric deposition fluxes. The results strongly indicated that atmospheric emission governs the quality of the whole environment. Use of the model developed in this study would provide quantitative and integrated understanding of the cross-media characteristics and assessment of the relationships of the contamination levels among the multi-media environment.

• Journal of Plant Biology
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• 제15권3호
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• pp.9-13
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• 1972

This report deals with lead and zinc contamination of roadside soil and plants caused by motor vehicles as a function of distance from the road edge. The concentrations of Pb and Zn in roadside soil and plant samples from several locations decrease regularly with increasing distance from traffic. Soil samples up to 24m distance from the road edge are contaminated with more than 12.99ppm lead, and 13.40ppm zinc. The decrease in Pb and Zn contamination with increasing distance from the road is characteristically curvilinear; the relative coefficiency of Pb and Zn with distance is -0.69, -0.48, respectively. The average contents of Pb and Zn in plants are 21.5ppm and 30.00ppm. It is suggested that the contamination is related to the composition of gasoline, motor oil and to roadside of the residues of this metals.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2005년도 춘계 학술발표회 논문집
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• pp.7-10
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• 2005

• 한국환경보건학회지
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• 제8권1호
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• pp.31-43
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• 1982

Seventy-seven Mugil cephalus of spinal deformation, living in Hanam, Nogsan, and Myeongji area, the downstreams of the Nagdong River, were collected in order to determine their forms and the levels of heavy metal contamination between March and October, 1981. The specimens were examined by X-ray and content of cadmium, lead, copper, and zinc by atomic absorption spectrophotometer. The results were summarized as follows: 1. The rate of appearance of deformational fish to the total Mugil cephflus were 4.3% (13 fish), 5.7% (17 fish), relatively high in May and June (dry season). Meanwhile during March and October they were low by 1.0% (3 fish), 2.0% (6 fish). As far as the research areas are concerned, they appeared in larger numbers in downstreams than in upper streams Myeongji (39), Nogsan (25), and Hanam (13). 2. Concerning with fractured parts of vertebraes,86 percent (66 out of 77) had their caudal regions fractured and 72 percent (55) their first to seventh caudal regions fractured. 3. The average levels of cadmium, lead, copper, zinc detected from flesh were 0.26ppm, 2.06ppm, 6.35ppm, 0.85ppm on the other hand, they were 0.22ppm, 1.84ppm, 5.03ppm, 0.93ppm in normal fish. 4. The average levels of cadmium, lead, copper, zinc measured in the bones were 0.39ppm, 2.55ppm, 8.97ppm, 2.73ppm. Meanwhile, from normal fish they were 0.33ppm, 2.25ppm, 7.24ppm, 2.42ppm. 5. Compared with regional heavy metal contamination such as cadium, lead, zinc, Myeongji area had higher contamination content than Nogsan area Nogsan area than Hanam area. 6. Compared with heavy metal contamination level in their tissues, cadmium was highly found in bones Lead and copper were highly detected in viscera. Particularly in skeleton cadmium was 560 times, zinc 160 times in proportion to those in the downstreams of the Nagdong River.

• 한국환경보건학회지
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• 제19권3호
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• pp.46-51
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• 1993

In order to survery the risk of air-borne lead to human, the relation between air-borne lead level and blood lead level was examined by using of the kinetic model and statistical model. The results of this survey were as follows: 1. The pathways of lead intake were food and water, mainly. 2. Though blood lead level of Korean urbanire was higher than that of American or Japanese, it was not so severe as to influence human health. 3. The lead content in food and water was high, and so it is needed to confirm the cause of high content was whether second contamination by air pollution or not.

• International Journal of Precision Engineering and Manufacturing
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• 제5권2호
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• pp.46-52
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• 2004

Numerous connectors are used in automobiles for transmission of electrical signals across various electro-mechanical components. The connectors must operate with high reliability in order to minimize failures due to signal degradation. In this work, the effects of contamination at the contact interface of connectors used fur automobile crankshaft position sensor on the impedance change were investigated. An experimental set-up was built to simulate the electrical signal transmitted from the sensor to the engine control unit through a connector. Output from the connector was investigated using connectors contaminated with engine block residues and water droplets. It was found that slight contamination of the connectors could lead to significant signal degradation which can lead to engine failure. Also, the effect of water in the connector altered the signal severely. However, the signal gradually regained the original state as the water evaporated from the interface.