• Title, Summary, Keyword: Contamination

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A Study of Radioactive Contamination in Hospital Toilet (병원 화장실의 방사성 오염에 관한 연구)

  • Kim, Ki-Jin;Kim, Gha-Jung
    • Journal of the Korea Safety Management and Science
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    • v.17 no.4
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    • pp.241-246
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    • 2015
  • Generally a patient who was injected radiopharmaceuticals for nuclear medicine examination is not an object of isolation. Therefore, when the patient uses toilet, we expect surface contamination of a toilet by radioisotope. The measured value is $25.69Bq/cm^2$(a restroom near admission and administration), $19.39Bq/cm^2$(a toilet near department of radiology). The study shows that 9 of 24 locations in controlled area exceed over surface contamination limit. From now on, we should find source of contamination through measurement radioactive nuclide to apply radiation safety management.

Harmonics Analysis of Leakage Current due to Artificial Contamination of Distribution Arresters (배전용 피뢰기의 인공오손에 의한 누설전류의 고조파 분석)

  • Park, Jae-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.9
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    • pp.1306-1313
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    • 2012
  • This paper reports the contamination performance of two distribution arresters (new and used ones) tested under three different contaminant conditions - clean fog, ESDD (equivalent salt deposit density) level (A, B, C, and D), and kaolin contamination conditions, and their leakage current, total leakage current, and component of the resistive leakage current were measured in order to diagnose arrester deterioration. The 3rd harmonics was larger than 5th and 7th ones for the arrester under the clean fog, and as the ESDD contamination level was applied, 5th one became relatively larger than 3rd one. Therefore, these results indicated that the resistive leakage current could be used for the diagnosis of the arresters.

Analysis of Microbial Contamination in Poultry Slaughtering Operations for the Application of HACCP (HACCP 적용을 위한 도계처리 공정내 미생물 오염의 분석)

  • 홍종해;권혁무;고주언
    • Journal of Environmental Health Sciences
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    • v.22 no.1
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    • pp.45-50
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    • 1996
  • The application of HACCP system, which was adopted by Codex Alimentarius Committee for the safe meat and poultry production, is one of the urgent task for competing in the world trade markets. But there have been no useful analytical studies to identify the causes of contamination in the poultry meat processing plants in Korea. This study was conducted to investigate the potential hazards during the operations by the microbiological examination for the poultry meat processing plant (20,000 birds capacity a day) located in Kangwon province. In spite of air contamination of work places, it may not directly affect the surface contamination of poultry meats. But the risk of Campylobacter jejuni/coli contamination was high. The number of total count was decreased about ten times, but remarkable changes of microbial contamination could not be recognized in each procedure during the operations. The washing water was already contaminated as much as $10^{3-6}CFU/ml$ in SPC before the operations. It means that to keep water tanks hygienic is a primary step to prevent the occurrences of microbial contamination. The overflow and recirculation of water in scalding, washing, and chilling was aslo an important factor for a hygienic control. Based on this study, the followings could be regarded as an important factors for hygenic control in the poultry slaughtering plants on a small scale. The temperature of water used for scalding should be constantly maintained on a required temperature, and the overflow rate of 1~1.5 liter per bird. The carcass surface and the body cavity should be washed thoroughly and the cross-contamination due to facilities, workers, and tools should be prevented. The chilling water sholud be maintained under 5$\circ$C of temperature with ice and overflow, and residual chlorine level of 50 ppm.

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A Study on Soil Contamination Investigation of Farmland Around Industrial Areas in Northern Gyeonggi Province (경기북부 산업단지 주변 농지의 토양오염도 조사연구)

  • Park, Jin-Ho;Kwon, Kyung-Ahn;Jung, Eun-Hee;Kim, Jae-Kwang;Kim, Ji-Young;Oh, Jo-Kyo
    • Journal of Environmental Health Sciences
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    • v.43 no.5
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    • pp.393-400
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    • 2017
  • This study was investigated on pH, heavy metals, oils and solvents in 34 surface soil samples and the samples are collected at two times for 17 farmland sites around 7 industrial areas in Northern Gyeonggi Province. As a result of pH for soil contamination monitoring network, the range of pH showed 4.4~8.4 and average was 6.3. The range of pH for Agricultural land around industrial area was 6.7~7.5 and average indicated 7.1 that mostly showed neutral condition in this area. he average concentrations of Cu, Pb, Ni, As and $Cr^{6+}$ are lower than Korea soil contamination worrisome levels at region 1 and the mean levels of farmland from the soil quality monitoring network. The average concentrations of Zn, Cd and Hg didn't exceed the soil contamination worrisome levels at region 1 but slightly higher than the mean levels of farmland from the soil quality monitoring network. The heavy metal levels of all samples are within Korea soil contamination worrisome levels at region 1. The results showed that the detected heavy metal concentrations ranged from N.D. to ~32.7% of Korea soil contamination worrisome levels at region 1. BTEX, TPH, TCE and PCE were not detected in all samples and thus the farmland around the industrial areas were free from oils and solvents contamination.

Contamination measurement, Analysis & Control for Satellite (인공위성의 오염 측정, 분석 및 관리)

  • Lee, Sang-Hoon;Hong, Seok-Jong;Cho, Hyok-Jin;Seo, Hee-Jun;Moon, Guee-Won
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.116-122
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    • 2010
  • It is necessary to be careful about contamination control to minimize the accumulation of the contamination material on satellite surface during the I&T phase. In the space environment which characterized by high vacuum, high and very low temperature, contamination material causes satellite to lose its own performance. Especially, contamination material can accumulate on critical surfaces such as lenses, mirrors, and sensors. KARI(Korea Aerospace Research Institute) conducts the clean room to control and minimize the contamination effect. This paper introduces the principle of contamination and the method of measure and analysis for the contamination.

Food Safety Perceptions on Pesticide Contamination among Koreans -Based on the 2008 Social Survey- (한국인의 농산물 농약 오염 불안도 연구 -2008년도 사회조사를 바탕으로-)

  • Nam, Eun-Kyung;Cha, Eun-Shil;Choi, Yeong-Chull;Lee, Won-Jin
    • Journal of Environmental Health Sciences
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    • v.37 no.4
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    • pp.323-331
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    • 2011
  • Objective: This study aimed to examine the level of risk perception related to pesticide contamination of food products and associated sociodemographic factors, as well as investigate the association with environmental pollution preventive behaviors. Methods: Based on data from Social Survey conducted in 2008 among a nationally representative sample of the population 15 years or older, we estimated proportions and 95% confidence intervals of the risk perception of pesticide contamination of food products. Logistic regression analyses were used to analyze the effects of sociodemographic status on risk perception. Results: Among respondents, those who feel anxious about the risks of pesticide contamination of domestic food products accounted for 40.4%, whereas the proportion rose to 87.0% with imported food products. These numbers showed that levels of anxiety about the pesticide contamination of imported food products were ranked at the top, and those for domestic products were at the bottom of the list of all environmental pollutants examined in the survey. Significantly related factors to anxiety about pesticide contamination of food products included women, the 40-50 age group, university graduates, married, non-manual employment, having school-aged children, and owning one's own home. The population attempting to prevent environmental pollution showed higher levels of anxiety about pesticide contamination of food products than did those who were not taking such steps. Conclusion: Compared to other forms of environmental pollution, Koreans show the highest levels of anxiety about pesticide contamination of imported food products. Therefore, it is necessary to establish appropriate regulations and transparent risk communication with the public about the safety of imported food.

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.

Polychaete Taxocenes Variability Associated with Sediment Pollution Loading in the Peter the Great Bay (the East Sea/Japan Sea)

  • Belan Tatyana A.;Moschenko Alexander A.
    • Ocean Science Journal
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    • v.40 no.1
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    • pp.1-10
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    • 2005
  • Variations in species diversity and abundance of polychaete taxocenes that occurred in 1980-1989 under different contamination levels of bottom sediments were studied in three areas of Peter the Great Bay. The most polluted area was shown to be the Golden Horn Inlet where contaminant contents in the bottom sediments exceed the threshold values of negative biota alterations. Amursky Bay is characterized by a moderate level of contamination, while Ussuriysky Bay has the lowest level of contamination. Pollutant contents vary considerably within the same areas and their separate patches are polluted differently. An integral index characterizing the contamination of bottom sediments is proposed. This index is an average grade of the rank value of contaminant contents in sediments. The index was used to compare the contamination level and data on polychaete species diversity and abundance. The highest species diversity of polychaetes is found in the least affected zones. Monotonous decrease of the species number, as well as decrease in the indices of diversity and evenness, is correlated with pollution level increases. Significant growth of the average polychaete biomass and polychaete density is observed in the case of an increase of contamination from low to moderate levels. Conversely, the biomass and abundance of polychaetes decline following an increase in contamination.

The prediction of contamination degree through the relationship analysis between the climatic factor and ESDD (기후인자와 ESDD간의 상관관계 분석통한 오손도 예측)

  • Lee, W.Y.;Kim, D.Y.;Park, H.S.;Han, S.O.;Park, K.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.440-443
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    • 2003
  • Recently, with the rapid growth of industry, environmental condition became worse. With the mix of the various contaminants, such as, salts, dust and industrial pollutants, synergy effect could be happened. So, many researches have been focused on the issue. The cause of natural accident could be classified as, lightning, rainstorm and contamination. However, the accident by contamination influences on the larger area than that by lightning, and, in the case of rapid contamination, it takes a shorter time than rainstorm. The salt contaminant is one of the most representative pollutants, and known as the main source of the accident by contamination. So, in this investigation we make a research on the prediction of contamination degree through the relationship analysis between the climatic factor and ESDD.

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A Study on Yeast and Mold Contamination of Fermented Milk Products in Korea (우리나라 유산균 제품의 Yeast, Mold 오염에 관한 조사연구)

  • 홍종해
    • Journal of Environmental Health Sciences
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    • v.7 no.1
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    • pp.51-57
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    • 1981
  • This Study was carried out to investigate yeast and mold contamination in fermented milk products produced by 9 different domestic manufacturers from October 20. to December 5. 1980 The results obtained in the study were as follows 1) pH values of the products were ranged from pH 3.14 to pH 4.20 and average of sour milk drinks was pH $3.66\pm 0.19$ and fermented milks pH $3.74\pm 0.11$. Therefore the difference of pH average among sour milk drinks and fermented milks was statistically significant. (p<0.01) 2) In case of yeast contamination, yeast was found on all the four producted at the same date. From this result, it seemed that yeast contamination occured during the manufacturing progress. 3) Degree of contamination by the indicator organisms was E. coli positive, 3.7%: over 1,000 yeasts/ml, 14.8% over 10 molds/ml, 0.9%. 4) In the range of over 1,000 yeasts/ml, degree of contamination by yeast was 8.4% in fermented milk and 16.7% in sour milk drink. 5) Yeasts in product C increased to the spoilage number within 5 days and in H increased within 10 days at 5C. At 15$\circ$C, yeast increased to the spoilage number within 15 days in product A.D. 6) It seems that the yeast number of initial contamination should be important than the increase rate as criteria on the fermented Milk products.

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