• Title/Summary/Keyword: Identify contamination

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A Study on the Selection of Optimal Counting Geometry for Whole Body Counter (WBC) (인체 내부방사능 측정용 전신계측기의 최적 검출 모드 선정에 관한 연구)

  • Ko, Jong Hyun;Kim, Hee Geun;Kong, Tae Young;Lee, Goung Jin
    • Journal of Radiation Protection and Research
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    • v.39 no.1
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    • pp.1-6
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    • 2014
  • A whole body counter (WBC) is used in nuclear power plants (NPP) to identify and measure internal radioactivity of workers who is likely to ingest or inhale radionuclides. WBC has several counting geometry, i.e. the thyroid, lung, whole body and gastrointestinal tract, considered with the location where radionuclides are deposited in the body. But only whole body geometry is used to detect internal radioactivity during whole body counting at NPPs. It is overestimated internal exposure dose because this measured values are indicated as the most conservative radioactivity values among the them of others geometry. In this study, experiments to measure radioactivity depending on the counting geometry of WBC were carried out using a WBC, a phantom, and standard radiation sources in order to improve overestimated internal exposure dose. Quantitative criteria, could be selected counting geometry according to ratio of count rates of the upper and lower detectors of the WBC, are provided through statistical analysis method.

Defining Area of Damage of 2012 Hydrofluoric Acid Spill Accident in Gumi, Korea (구미 불산 누출사고로 인한 주변지역 환경영향권 설정에 관한 연구)

  • Koh, Dohyun;Kim, Jeongsoo;Choi, Kyungho
    • Journal of Environmental Health Sciences
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    • v.40 no.1
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    • pp.27-37
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    • 2014
  • Objectives: On September 27, 2012, leakage of anhydrous hydrofluoric acid occurred in a chemical plant in the Gumi National Industrial Complex. Following the accident, local factory workers and residents complained of abnormal health conditions. In addition, visual discolorations were widely observed in crops and trees in surrounding areas. The main objectives of the present study were to identify the area that was affected by the spill using data obtained from plants, soil, and water samples after the accident. Methods: Fluoride concentrations were analyzed in pine tree needles, soil, nearby streams, ponds and reservoirs collected from an area within a radius of three kilometers from the plant where the leak occurred. Fluoride concentrations in the air at the time of leakage were then estimated from fluoride concentrations that were measured in the pine tree needles. A Kriged map was developed to describe the spatial distribution of hydrofluoric acid at the time of the leakage and was compared with the area designated as a Special Disaster Zone by the government. Results: The Special Disaster Zone did not include all the affected area that was estimated by the Kriged map. Analytical results of the environmental samples also supported this discrepancy. Conclusion: Using plants, atmospheric concentrations of fluoride at the time of the leakage could be estimated. For the area that was identified as affected, further public health risk assessment and environmental risk assessment should be considered. Also, in the absence of air monitoring at the time of leakage, studies employing plants may be conducted in order to better understand the spatial extent and severity of the contamination.

Environmental Investigation of a Long-term Care Hospital with Respect to COVID-19

  • Park, Min Woo;Shin, Seung Hwan;Cha, Jeong Ok;Lim, Hyeon Jeong;Kim, Jun Nyun
    • Journal of Environmental Health Sciences
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    • v.46 no.5
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    • pp.599-609
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    • 2020
  • Objectives: Coronavirus disease 2019 (COVID-19) first emerged in December 2019 in Wuhan, China, and has rapidly become a global pandemic with over 26.4 million confirmed cases and approximately 871,000 fatalities worldwide as of this writing. In the Republic of Korea, disease clusters frequently occurred in long-term care hospitals where the majority of residents are elderly with underlying medical conditions. Despite the fact that public health authorities and local community health centers have put tremendous efforts into preventing the spread of disease, positive cases have continued to occur. Thus, the Korea Centers for Disease Control & Prevention rapid response team decided to conduct an environmental investigation of a long-term care hospital to identify whether environmental contamination has remained and contributed to the spread of COVID-19. Methods: An environmental investigation was conducted at Hospital A. The characteristics of the facility and its HVAC system were assessed by checking the layout and interviewing the people in charge. A total of 64 surface samples were collected from areas of concern, including patient rooms, toilets, elevators, and nurses' station. These samples were tested by a regional health and environmental research institute using real-time reverse transcription polymerase chain reaction. Results: All samples from Hospital A were confirmed to be negative. Through interviews with high-level personnel at the regional community health center, we found that extensive disinfection is frequently performed on potentially contaminated areas in Hospital A in accordance with government guidelines. Conclusion: The environmental control measures implemented in Hospital A had been sufficient for mitigating the risk of further infection, suggesting that such measures may also be effective for other long-term health care facilities.

Isolation and Characterization of Novel Denitrifying Bacterium Geobacillus sp. SG-01 Strain from Wood Chips Composted with Swine Manure

  • Yang, Seung-Hak;Cho, Jin-Kook;Lee, Soon-Youl;Abanto, Oliver D.;Kim, Soo-Ki;Ghosh, Chiranjit;Lim, Joung-Soo;Hwang, Seong-Gu
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.11
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    • pp.1651-1658
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    • 2013
  • Nitrate contamination in ground and surface water is an increasingly serious environmental problem and only a few bacterial strains have been identified that have the ability to remove nitrogen pollutants from wastewater under thermophilic conditions. We therefore isolated thermophilic facultative bacterial strains from wood chips that had been composted with swine manure under aerated high temperature conditions so as to identify strains with denitrifying ability. Nine different colonies were screened and 3 long rod-shaped bacterial strains designated as SG-01, SG-02, and SG-03 were selected. The strain SG-01 could be differentiated from SG-02 and SG-03 on the basis of the method that it used for sugar utilization. The 16S rRNA genes of this strain also had high sequence similarity with Geobacillus thermodenitrificans $465^T$ (99.6%). The optimal growth temperatures ($55^{\circ}C$), pH values (pH 7.0), and NaCl concentrations (1%) required for the growth of strain SG-01 were established. This strain reduced 1.18 mM nitrate and 1.45 mM nitrite in LB broth after 48 h of incubation. These results suggest that the G. thermodenitrificans SG-01 strain may be useful in the removal of nitrates and nitrites from wastewater generated as a result of livestock farming.

Characterization of Bacteria and Their Antibiotic Sensitivities in Porcine Liquid Semen (돼지 액상정액 내 세균오염과 항생제 감수성에 관한 연구)

  • Ryu, Jae-Weon;Cho, Kyu-Ho;Hong, Joon-Ki;Kim, Myung-Jick;Park, Jun-Chul;Jung, Il-Byung;Kim, In-Cheul
    • Journal of Animal Science and Technology
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    • v.50 no.6
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    • pp.793-798
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    • 2008
  • The semen collection process in the porcine is far from being a sterile procedure. Consequently, porcine ejaculates commonly contain bacterial contaminants. The aim of this study is to identify the bacteria in porcine semen and to find the antibiotics resistance of bacteria. Twelve porcine originating from four AI center were used to collect semen. Bacteria were identified by automated instrument for rapid organism identification system and bacterial sensitivities of 8 antibiotics were tested. The Bacterial contaminants of Staphylococcus genus(37.8%), Proteus genus(7.0%), Bacillus genus (6.1%), Pasteulla genus(5.7%), Acinetobacte genus(5.2%), Serratia genus(4.3%) and others(33.9%) were frequently isolated. However, amikacin showed higher antibiotic sensitivity than other antibiotics. General sanitation protocols can contribute partly to inhibit the bacterial contamination, with monitoring boar housing, semen collection areas and the extended semen. But, proper selection of preservative antibiotics by microbial sensitivities can minimize the influence of bacteria.

Performance Comparison of Bed-type and Stand-type Commercial Whole Body Counter Made by Canberra for Internal Exposure Monitoring (Bed-type과 Stand-type 상용 전신계수기(Whole Body Counter)의 성능 비교)

  • Kim, Bong-Gi;Ha, Wi-ho;Kwon, Tae-Eun;Park, Min-Seok;Lee, Jun-Ho;Kim, Jong-Min;Lee, Sang-Gyung;Jung, Kyu-Hwan
    • Journal of radiological science and technology
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    • v.41 no.5
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    • pp.437-444
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    • 2018
  • Whole-Body counters have been used to evaluate the internal contamination of gamma emitting radionuclides. Among the whole-body counters used in domestic nuclear facilities, Fastscan made by CANBERRA contains 2 NaI(Tl) detectors and is generally used to monitor the primary internal exposure. It has the advantage of achieving MDA even with short time measurements. Accuscan is a bed type, and has good energy resolution because it is composed of HPGe detector. Since the Accuscan with better energy resolution than Fastscan has better able to identify radionuclides, it is used to monitor secondary internal exposure. Some nuclear facilities have only Fastscan. We analyzed statistically whether Fastscan is enough to ensure accuracy and precision comparing with Accuscan. To do this, we prepared a CRM created by the Korea Research Institute of Standards and Science. We also obtained the data of 6 Fastscans and 5 Accuscans in domestic nuclear facilities. As a result of the study, although Fastscan compared with Accuscan is not as accurate as the Accuscan, the precision is statistically same. However, accuracy of Fastscan is in compliance with international standards except low energy range. In terms of accuracy and precision except radionuclides emitting low energy, it is possible to measure radioactivity inside workers even in nuclear facilities where only Fastscan is used.

A Study on the Management and Utilization of Sub-Health Center in Rural area, Paraguay [1] - Focused on Limpio, Paraguay (파라과이 농촌지역 보건지소의 시설 관리 및 이용실태에 관한 연구[1] - 파라과이 림삐오시를 중심으로)

  • Kim, Ji Eon;Kim, Min Kyu;Nam, Eun Woo
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.26 no.2
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    • pp.7-17
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    • 2020
  • Purpose: The purpose of this study is to identify the operational status and current management of Sub-Health Centers in Limpio, Paraguay. Second, understanding the use of Sub-Health Centers and Perceptions of Sub-Health Centers in Limpio, Paraguay. Third, Providing policy implications for strengthening the Health Delivery System in Paraguay. Methods: The survey of the current status of sub-health centers in Limpio was conducted with observation and interview. Utilization of Sub-Health centers was analyzed in the 2018 Paraguay Community Health Survey. A face to face interview was conducted to complete a questionnaire and 831 samples were collected for the study. Results: In order to perform the normal function of the sub-health center, it will be necessary to allocate manpower that meets the standard. A common problem with sub-health centers in Limpio is that they have an environment vulnerable to rain. Currently, there are no health promotion and communicable disease management programs in sub-health center. Satisfaction of users about treatment, equipment, medicines and cleanleness of rooms. Implications: First, it is necessary to allocate human resources and organize spaces according to the standard. Second, there was a problem caused by moisture, and continuous maintenance and repair are required. Third, water and sewage related facilities must be safely improved to prevent contamination of groundwater. Forth, it is necessary to implement a program that fits the role of the sub-health center. Fifth, it is necessary to form a health delivery system considering the accessibility of residents. Finally, it is necessary to discuss the location of sub-health center considering travel time of Limpio residents.

Identification of Transition Characteristics and Bio-concentration Factors of Heavy Metal (loid)s in the Selected Perennial Root Medicinal Plants

  • Kim, Won-Il;Noh, Hyun Myung;Hong, Chang-Oh;Kim, Da-Young;Kim, Kwon-Rae;Oh, Kyeong-Seok;Moon, Byeong-Churl;Kim, Ji-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.4
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    • pp.251-258
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    • 2017
  • This study was conducted to identify transition characteristics of arsenic (As), cadmium (Cd), and lead (Pb) and to calculate bio-concentration factors (BCF) in the three perennial root medicinal plants, namely Codonopsis lanceolata (Deoduck), Platycodon grandiflorum (Balloon flower) and Panax ginseng (Korean ginseng) grown in major medicinal plant producing districts in Korea. Average BCF values ranged from 0.009~0.029 in As, 0.334~1.453 in Cd, and 0.021~0.023 in Pb in three perennial root medicinal plants. The BCF values increased in the order of ginseng (0.029) > deodeok (0.012) > balloon flower (0.009) for As, balloon flower (1.453) > deodeok (0.685) > ginseng (0.334) for Cd, and ginseng (0.023) > deodeok (0.022) > balloon flower (0.021) for Pb. The BCF values calculated in this study will be useful for predicting the uptake of heavy metal (loid)s. Further study on uptake and accumulation mechanism of toxic metal (loid)s by agricultural products is required to assess the human health risk associated with soil contamination.

Residual properties of ethoprophos with treatment methods in sweet pepper under greenhouse condition (착색단고추 시설재배시 에토프 입제의 처리방법별 잔류특성)

  • Kim, Jin-Bae;Song, Byung-Hun;Lee, Soo-Hyung;Nam, Hong-Shik;Son, Kyung-Ae
    • The Korean Journal of Pesticide Science
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    • v.8 no.2
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    • pp.112-116
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    • 2004
  • Two experiments were carried out in greenhouse under hydrophilic culture facilities and simulation model to provide residual characteristics of ethoprophos treated in sweet pepper's growth. To identify the pattern of absorption-translocation through the plant roots, ethoph 5 % GR were diluted in hydrophilic culture solution and drenched at a time per day for three days. The residue in fruit came closed to 0.02 ppm of MRL at 10 days after treatment(DAT) and reached peaked 0.06 ppm at 30 DAT and remained excess MRL level until around 40 DAT. To confirm the pattern of contamination by volatilization of ethoprophos, ethoph 5%GR was scattered 2 g per cubic meter. At 72 hours after treatment, the residue in sweet pepper fruit was exceed the MRL and the maximum residual amount were 0.62 ppm by volatilization. Consequently the use of ethoprophos during the growth of sweet pepper would be strong possibility to exceed the MRL.

Using Design to Make Doffing of Personal Protective Equipment Safer for Healthcare Workers (의료종사자의 안전한 개인보호장비 탈의를 위한 공간 설계에 관한 연구)

  • Matic, Zorana;Oh, Yeinn;Lim, Lisa
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.26 no.3
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    • pp.17-26
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    • 2020
  • Purpose: This paper presents research evidence that the environmental design of the doffing area in a biocontainment unit (BCU) can have a measurable impact on increasing the safety of frontline healthcare workers (HCW) during doffing of high-level personal protective equipment (PPE), and proposes optimized biocontainment unit design. Methods: From 2016 to 2019, The SimTigrate Design Lab conducted 3 consecutive studies, focusing on ways in which the built environment may support or hinder safe doffing. In the first study, to identify the risky behaviors, we observed 56 simulation exercises with HCWs in 4 BCUs and 1 high-fidelity BCU mockup. In the second study, we tested the effectiveness of a redesigned doffing area on improving the HCWs performance and used simulation, observation, and rapid prototyping in 1 high-fidelity mockup of a doffing area. In a follow-up study, we used simulation and co-design with HCWs to optimize the design of a safer doffing area in a full-size pediatric BCU mock-up. Results: We identified 11 specific risky behaviors potentially leading to occupational injury, or contamination of the PPE, or of the environment. We developed design strategies to create a space for safer doffing. In the second study, in a redesigned doffing area, the overall performance of HCW improved, and we observed a significant decrease in the number of risky behaviors; some risky behaviors were eliminated. There was a significant decrease in physical and cognitive load for the HCWs. Finally, we propose an optimized layout of a BCU for a safer process of PPE doffing. Implications: The proposed BCU design supports better staff communication, efficiency, and automates safer behaviors. Our findings can be used to develop design guidelines for spaces where patients with other highly infectious diseases are treated when the safety of the patient-facing HCWs is of critical importance.