• Title/Summary/Keyword: quantitative risk assessment

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A Risk Assessment of Vibrio parahaemolyticus for Consumption of Shucked Raw Oyster in Korea

  • Lee, Jong-Kyung;Yoon, Ki-Sun;Lee, Hyang;Kim, Hyun-Jung
    • Journal of Food Hygiene and Safety
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    • v.33 no.4
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    • pp.248-254
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    • 2018
  • To assess the risk of V. parahaemolyticus infection caused by consumption of raw oysters in Korea, contamination levels during the retail-to-table route of oysters was modeled to predict V. parahaemolyticus growth based on temperature and time. The consumed amount data of the KNHANES and the standard recipe of RDA were applied. A consumption scenario for exposure assessment was developed and combined with a Beta-Poisson dose-response model. The estimated probability of illness from consumption of pathogenic V. parahaemolyticus in raw oysters during three separate months (April, October, and November) was $5.71{\times}10^{-5}$ (within the 5th and 95th percentile ranges of $2.71{\times}10^{-8}$ to $1.03{\times}10^{-4}$). The results of the quantitative microbial-risk assessment indicated that the major factors affecting the probability of illness were the initial contamination level at the retailer, the consumed amount, the prevalence of pathogenic strains [tdh or trh genes], and exposure temperature and time.

Risk-based Security Impact Evaluation of Bridges for Terrorism (Security and Risk를 기반으로 한 교량구조물의 재난 안전성 평가)

  • Kang, Sang-Hyeok;Choi, Hyun-Ho;Seo, Jong-Won
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.629-632
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    • 2008
  • Risk-based security impact evaluation may be affected by various factors according to numerous combinations of explosive devices, cutting devices, impact vehicles, and specific attack location to consider. Presently, in planning and design phases, designers are still often uncertain of their responsibility, lack of information and training of security. Therefore, designers are still failing to exploit the potential to reduce threats on site. In this study, the concept of security impact assessment is introduced in order to derive the performing design for safety in design phase. For this purpose, a framework for security impact assessment model using risk-based approach for bridge structures is suggested. The suggested model includes of information survey, classification of terror threats, and quantitative estimation of severity and occurrence.

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Quantitative microbial risk assessment indicates very low risk for Vibrio parahaemolyticus foodborne illness from Jeotgal in South Korea

  • Choi, Yukyung;Kang, Joohyun;Lee, Yewon;Seo, Yeongeun;Kim, Sejeong;Ha, Jimyeong;Oh, Hyemin;Kim, Yujin;Park, Eunyoung;Lee, Heeyoung;Lee, Soomin;Rhee, Min Suk;Yoon, Yohan
    • Fisheries and Aquatic Sciences
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    • v.25 no.9
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    • pp.463-472
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    • 2022
  • In this study, a microbial risk assessment was performed for the bacteria Vibrio parahaemolyticus, which causes a foodborne illness following the consumption of Jeotgal, a fermented seafood in South Korea. The assessment comprised of six stages: product, market, home, consumption, dose-response, and risk. The initial contamination level (IC) was calculated based on the prevalence of V. parahaemolyticus in 90 Jeotgal samples. The kinetic behavior of V. parahaemolyticus was described using predictive models. The data on transportation conditions from manufacturer to market and home were collected through personal communication and from previous studies. Data for the Jeotgal consumption status were obtained, and an appropriate probability distribution was established. The simulation models responding to the scenario were analyzed using the @RISK program. The IC of V. parahaemolyticus was estimated using beta distribution [Beta (1, 91)]. The cell counts during transportation were estimated using Weibull and polynomial models [δ = 1 / (0.0718 - 0.0097 × T + 0.0005 × T2)], while the probability distributions for time and temperature were estimated using Pert, Weibull, Uniform, and LogLogistic distributions. Daily average consumption amounts were assessed using the Pareto distribution [0.60284,1.32,Risk Truncate(0,155)]. The results indicated that the risk of V. parahaemolyticus infection through Jeotgal consumption is low in South Korea.

Study on the Methodology of the Microbial Risk Assessment in Food (식품중 미생물 위해성평가 방법론 연구)

  • 이효민;최시내;윤은경;한지연;김창민;김길생
    • Journal of Food Hygiene and Safety
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    • v.14 no.4
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    • pp.319-326
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    • 1999
  • Recently, it is continuously rising to concern about the health risk being induced by microorganisms in food such as Escherichia coli O157:H7 and Listeria monocytogenes. Various organizations and regulatory agencies including U.S.FPA, U.S.DA and FAO/WHO are preparing the methodology building to apply microbial quantitative risk assessment to risk-based food safety program. Microbial risks are primarily the result of single exposure and its health impacts are immediate and serious. Therefore, the methodology of risk assessment differs from that of chemical risk assessment. Microbial quantitative risk assessment consists of tow steps; hazard identification, exposure assessment, dose-response assessment and risk characterization. Hazard identification is accomplished by observing and defining the types of adverse health effects in humans associated with exposure to foodborne agents. Epidemiological evidence which links the various disease with the particular exposure route is an important component of this identification. Exposure assessment includes the quantification of microbial exposure regarding the dynamics of microbial growth in food processing, transport, packaging and specific time-temperature conditions at various points from animal production to consumption. Dose-response assessment is the process characterizing dose-response correlation between microbial exposure and disease incidence. Unlike chemical carcinogens, the dose-response assessment for microbial pathogens has not focused on animal models for extrapolation to humans. Risk characterization links the exposure assessment and dose-response assessment and involve uncertainty analysis. The methodology of microbial dose-response assessment is classified as nonthreshold and thresh-old approach. The nonthreshold model have assumption that one organism is capable of producing an infection if it arrives at an appropriate site and organism have independence. Recently, the Exponential, Beta-poission, Gompertz, and Gamma-weibull models are using as nonthreshold model. The Log-normal and Log-logistic models are using as threshold model. The threshold has the assumption that a toxicant is produce by interaction of organisms. In this study, it was reviewed detailed process including risk value using model parameter and microbial exposure dose. Also this study suggested model application methodology in field of exposure assessment using assumed food microbial data(NaCl, water activity, temperature, pH, etc.) and the commercially used Food MicroModel. We recognized that human volunteer data to the healthy man are preferred rather than epidemiological data fur obtaining exact dose-response data. But, the foreign agencies are studying the characterization of correlation between human and animal. For the comparison of differences to the population sensitivity: it must be executed domestic study such as the establishment of dose-response data to the Korean volunteer by each microbial and microbial exposure assessment in food.

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Risk Assessment of Petrochemical Equipments Using Enhanced RBI Technique (개선된 RBI 기법을 이용한 석유화학설비의 위험도평가)

  • Lee Sang-Min;Song Ki-Hun;Chang Yoon-Suk;Choi Jae-Boong;Kim Young-Jin;Han Sang-In;Choi Song-Chun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.10 s.241
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    • pp.1392-1398
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    • 2005
  • API 581 guideline provides a methodology for calculating the risks of equipments in refinery or petrochemical plant. However, especially in part of the consequence of failure, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk while the equipment is composed of numerous materials. The objectives of this paper are to propose an enhanced risk-based inspection (RBI) technique to resolve shortcomings inclusive of the above issue and to assess the risks of typical petrochemical equipments. In this respect, a program incorporating material database was developed to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison to those in the current guideline. It has been applied to assess the risks of equipments in ethylene facilities of petrochemical plants. Thereby, more realistic evaluation results were obtained and applicability of the proposed RBI program was proven.

Analysis of Damage Range and Impact of On-Site Hydrogen Fueling Station Using Quantitative Risk Assessment Program (Hy-KoRAM) (정량적 위험성평가 프로그램(Hy-KoRAM)을 이용한 제조식 수소충전소 피해범위 및 영향 분석)

  • KIM, HYELIM;KANG, SEUNGKYU
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.5
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    • pp.459-466
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    • 2020
  • As the hydrogen industry grows, expansion of infrastructure for hydrogen supply is required, but the safety of hydrogen facilities is concerned due to the recent accidents at the Gangneung hydrogen tank and the Norwegian hydrogen fueling station. In this study, the damage range and impact analysis on the on-site hydrogen fueling station was conducted using Hy-KoRAM. This is a domestically developed program that adds functions based on HyRAM. Through this risk assessment, it was evaluated whether the on-site hydrogen fueling station meets international standards and suggested ways to improve safety.

Probabilistic Risk Evaluation Method for Human-induced Disaster by Risk Curve Analysis (확률.통계적 리스크분석을 활용한 인적재난 위험평가 기법 제안)

  • Park, So-Soon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.6
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    • pp.57-68
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    • 2009
  • Recently, damage scale of human-induced disaster is sharply increased but its occurrences and damages are so uncertain that it is hard to construct a resonable response & mitigation plan for infrastructures. Therefore, the needs for a advanced risk management technique based on a probabilistic and stochastic risk evaluation theory is increased. In this study, these evaluation methods were investigated and a advanced disaster risk evaluation method, which is based on the probabilistic or stochastic risk assessment theory and also is a quantitative evaluation technique, was suggested. With this method, the safety changes as the result of fire damage management for recent 40 years was analyzed. And the result was compared with that of Japan. Through the consilience of the traditional risk assessment method and this method, a stochastical estimation technique for the uncertainty of future disaster's damage could support a cost-effective information for a resonable decision making on disaster mitigation.