• Title/Summary/Keyword: Contamination evaluation

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Studies on the Evaluation Method of Heavy Metal Contamination Degree in the Han River (한강 저질중의 중금속 오염도 평가 방법에 관한 연구)

  • 어수미;박성배
    • Journal of Environmental Health Sciences
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    • v.18 no.1
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    • pp.47-57
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    • 1992
  • This study was performed to evaluate contamination degree of heavy metals in sediments of Han River, compared with other nation's evaluation method. The results were as follows 1. The contamination Ratio calculation method by heavy metal concentration in differnt fraction size has a limitation to apply to all of the areas of Han river because of its characteristics of sediment. As a result, this method applied to only 4 areas of Pal Dang, Wang Sook Chon, Uk Chon, and Bul Kwang Chon, and Contmination Ratio of heavy metals in those areas were relatively low of below 3. So it's considered that those areas have less contaminated from anthropogenic contaminants. 2. The Contamination Ratio calculation method by heavy metal concentration in different areasthat of upper area to be background level-has a limitation also to apply to Han river. But it is considered that this method was relatively suitable to apply, so it should be prepared evaluation standand method for them. Contamination ratio from background level as Pal Dang area were most high in An Yang Chon. So it must be prepared purification and control measure at An Yang Chon.

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Six-years' Experience of Pseudomosaicism and Maternal Cell Contamination in Cultured Amniocytes

  • Moon, Shin-Yong;Jee, Byung-Chul;Kim, Seok-Hyun;Oh, Sun-Kyung;Park, Joong-Shin;Choi, Young-Min
    • Journal of Genetic Medicine
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    • v.3 no.1
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    • pp.25-27
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    • 1999
  • Purpose: To present our experiences in pseudomosaicism or maternal cell contamination in genetic mid-trimester amniocentesis confirmed through percutaneous umbilical blood sampling. Methods: From 1992 to 1997, repeated cytogenetic evaluation with fetal cord blood was carried out in 14 cases showing mosaic patterns. Results: We confirmed pseudomosaicism in 12 cases (85.7%) by repeated cytogenetic evaluation, and also maternal cell contamination in 2 cases. Conclusion: Repeated cytogenetic evaluation via percutaneous umbilical blood sampling was a rapid and useful method for the confirmation of mosaicism resulted from genetic mid-trimester amniocentesis.

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Virtual Contamination Lane Image and Video Generation Method for the Performance Evaluation of the Lane Departure Warning System (차선 이탈 경고 시스템의 성능 검증을 위한 가상의 오염 차선 이미지 및 비디오 생성 방법)

  • Kwak, Jae-Ho;Kim, Whoi-Yul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.6
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    • pp.627-634
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    • 2016
  • In this paper, an augmented video generation method to evaluate the performance of lane departure warning system is proposed. In our system, the input is a video which have road scene with general clean lane, and the content of output video is the same but the lane is synthesized with contamination image. In order to synthesize the contamination lane image, two approaches were used. One is example-based image synthesis, and the other is background-based image synthesis. Example-based image synthesis is generated in the assumption of the situation that contamination is applied to the lane, and background-based image synthesis is for the situation that the lane is erased due to aging. In this paper, a new contamination pattern generation method using Gaussian function is also proposed in order to produce contamination with various shape and size. The contamination lane video can be generated by shifting synthesized image as lane movement amount obtained empirically. Our experiment showed that the similarity between the generated contamination lane image and real lane image is over 90 %. Futhermore, we can verify the reliability of the video generated from the proposed method through the analysis of the change of lane recognition rate. In other words, the recognition rate based on the video generated from the proposed method is very similar to that of the real contamination lane video.

Evaluation of Nitrate Nitrogen Contamination Degree in Groundwater Wells, Jeju Island (제주도 지하수 관정 내 질산성질소 오염도 평가)

  • Song, Sung-Ho;Hwangbo, Dongjun;Jang, Ki-Young;Kim, Jin-Sung;Seo, Sang-Ki;Yang, Won-Seok
    • Journal of Soil and Groundwater Environment
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    • v.26 no.4
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    • pp.8-19
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    • 2021
  • In this study, the evaluation standard for nitrate nitrogen contamination degree (WELCUP) was established using six factors that influence the groundwater quality in Jeju Island. To do this, weightings, ranges, and ratings were assigned for each factor and the relative possibility of nitrate nitrogen contamination degree was evaluated using WELCUP index for each well. As a result of calculating the WELCUP index using groundwater quality data of 5,112 wells in Jeju Island for 27 years (1993-2019), all 61 wells with the WELCUP index value higher than 100 are distributed in Daejung and Hangyung watershed with relatively large area of farmland in Jeju Island. In particular, as the ratio of private wells is more than 64%, it is necessary that systematic management is needed for private wells in terms of nitrate nitrogen contamination. Consequently, based on the results of applying the WELCUP evaluation standard, it is necessary to select the prioritization of nitrate nitrogen contamination pathways project for groundwater wells in Jeju Island.

Co-contamination of Aflatoxins with Ochratoxin A and Zearalenone in Thuja orientalis Semen

  • Cho, So-Yean;Kang, Shin-Jung;Jung, Joo-Hee;Jeong, Byeong-Ok;Jeong, Choon-Sik
    • Toxicological Research
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    • v.25 no.3
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    • pp.125-131
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    • 2009
  • Korea is representative of a country that consumes herbal medicines; most of the herbal medicines circulating in South Korea have been imported from developing countries in Southeast Asia, such as China and Indonesia. Recently, domestic hygiene and safety are issues that have come to the forefront, because herbal medicines currently in circulation could possibly contain contaminants or residues. Furthermore, the appearance or discovery of harmful new species due to environmental and industrial developments is becoming a social problem. Therefore, it may be necessary to consider and investigate these matters on a continual basis. Recently, mycotoxin contaminations in such foods as cereals, nuts, and powdered red pepper have been reported. They have become a problematic issue; the possibility of contamination in herbal medicines has also been considered. Nevertheless, recognition of and research into mycotoxin contamination in herbal medicines has been scarce because herbal medicine is used in only a few nations. In this research, we identified contamination by aflatoxin which is known to be the most potent mutagenic, carcinogenic, and teratogenic mycotoxin in Thujae Semen, a herbal medicine. We also found co-contaminations involving other mycotoxins, including ochratoxin A and zeraleanone.

Contamination and Detoxification of Aflatoxins (아플라톡신 오염 및 저감화 방안)

  • Cho, So-Yean;Kang, In-Ho;Shim, Young-Hoon;Yang, Dong-Hyug;Oh, Seh-Wook;Lee, Byung-Hee;Hyeon, Seong-Ye;Chang, Seung-Yeup;Jeong, Choon-Sik;Lee, Yong-Soo;Kim, Young-Shik;Kang, Shin-Jung
    • Korean Journal of Pharmacognosy
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    • v.38 no.3 s.150
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    • pp.205-216
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    • 2007
  • South Korea is the representative consumption country of herbal medicines and most of herbal medicines circulating in Korea have been importing from the developing countries of Southeast Asia such as China, Vietnam, Indonesia and so forth. Domestic hygiene and safety are continuously proposed because herbal medicines which are circulating have the possibility could remain contaminants or residues. Physicochemical contaminants such as heavy metals, persistent organic pollutants, radionucleosides, microbial toxins, biological contaminants such as microorganisms and animals, agrochemical residues such as pesticides, substances used for fumigation, antiviral agents, and solvent residues are classified as major contaminants and residues in herbal medicines from 2005 September WHO.$^{1)}$ Currently our administration have established a permission standard and the inspection criteria against the heavy metal, the residual pesticides and a residual sulfur dioxide. Furthermore our administration is continuously monitoring and conducting researches for the policies and their scientific ground against herbal medicines. But the appearances or discoveries of the harmful new species due to environmental and industrial developments are becoming social problems. Therefore it may be necessary to continuously consider and investigate regarding hereupon. Recently, the contamination of the mycotoxins against foods such as cereals, nuts and the powdered red pepper have developed and started became problematic issue, and possibility of contamination against the herbal medicine is proposed. And since populations who are using the herbal medicines very limited to several nations, recognition and researches about contamination of mycotoxins in herbal medicines are very insufficient. Therefore it will be need to more focus on the international regulation of quality control and safety for herbal medicines. Now on, we are going to introduce the importance, occurrence, characteristic properties, World-wide research trends and detoxification of aflatoxins, which is known as the most potent mutagen, carcinogen and teratogen mycotoxins.

The Microbiological Safety Evaluation of Foodservice Facilities and Side Dishes in Elementary Schools and Universities in the Jeolla-do Region

  • Lee, Byung-Doo;Kim, Du-Woon;Kim, Jang-Ho;Kim, Jeong-Mok;Rhee, Chong-Ouk;Eun, Jong-Bang
    • Food Science and Biotechnology
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    • v.15 no.6
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    • pp.920-924
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    • 2006
  • The microbiological safety of foodservice facilities and side dishes in 6 elementary schools and 6 universities in the Jeolla-do region was evaluated. The micro-aerosol evaluation of foodservice facilities including the kitchen, refrigerators, and freezers showed a comparatively high level of microbial contamination. In the microbial safety evaluation of cooking utensils and appliances, the total plate counts of serving tables, cutting boards, and food plates were comparatively high, but did not reveal significant counts of coliforms, Staphylococcus aureus, and Escherichia coli were both below the general limit of microbial contamination. The microbiological safety of the cooking utensils and appliances were satisfactory. In the microbiological safety evaluation of side dishes served at these foodservice facilities, microbial counts were generally below the limit of microbial contamination.

Evaluation of Salmonella cross contamination at retail chicken meat outlets in Kandy, Sri Lanka

  • Alwis, Upeksha S.;Mudannayake, Deshani C.;Jayasena, Dinesh D.;Ubeyarathna, Kamalika J.H.
    • Korean Journal of Agricultural Science
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    • v.41 no.1
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    • pp.35-40
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    • 2014
  • This study was carried out to evaluate the Salmonella cross contamination at retail chicken meat outlets in Kandy, Sri Lanka and to identify the risk factors for Salmonella contamination at retail chicken meat outlets. Fifteen retail chicken meat outlets in Kandy area were randomly selected. Pre-tested questionnaires were used to collect data for identifying risk factors of Salmonella cross contamination at retail outlets and swab samples from meat contact surfaces/utensils were obtained. Out of 57 swab samples collected from meat contact surfaces/utensils, the overall prevalence of Salmonella cross contamination was 21%. Weighing scale (33%), meat containing trays/buckets (27%) and cutting board (25%) showed the highest percentage of Salmonella prevalence whereas knife and showcase showed relatively low percentages, 14% and 9%, respectively. Retail chicken outlets with slaughtering facilities had a significantly higher prevalence of Salmonella cross contamination than those without slaughtering facilities. This higher rate of Salmonella cross contamination at retail chicken meat outlets could be attributed to lack of proper cold chains and minimal facilities, and poor level of hygiene in those outlets.

Evaluation of Artificially Contaminated Suspension Insulators for Transmission (송전용 현수애자의 인공오손 평가)

  • Kim, Chan Young;Choi, In-Hyuk;Hong, Dong-Suk;Kim, Beom-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.08a
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    • pp.123-127
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    • 2002
  • This paper presented the results of evaluation of artificially contaminated suspension insulators for transmission lines. The suspension insulators were contaminated with kaolin and clay which were included various amount of natural salt. The degree of contamination were evaluated by measuring equivalent salt deposit density(ESDD). Then, the leakage currents were measured as a function of applied voltage, degree of contamination, humidity.

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