• Title/Summary/Keyword: Cumulative risk assessment

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Cost-Benefit Analysis Method for Ageing Equipment of Chemical Plants Using Risk Assessment (위험성평가를 이용한 노후설비에 대한 비용 편익분석 방법)

  • Jung, Soomin;Jung, Changmo;Kang, Seok-Min;Chae, Seungbeen;Kang, Seung-Gyun;Ko, Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.24 no.4
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    • pp.84-92
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    • 2020
  • Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.

Certification Criteria and Safety Assessment for High Altitude Long Endurance Unmanned Aerial Vehicle (장기체공 무인항공기 기술기준 및 안전성 평가 연구)

  • Ko, Joon Soo;Kim, Kyungmok
    • Journal of Aerospace System Engineering
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    • v.10 no.2
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    • pp.7-13
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    • 2016
  • Multi disciplinary approach for aerodynamics, structure, propulsion, and flight control system is necessary to develop High Altitude Long Endurance Unmanned Aerial Vehicles (HALE UAV). Various HALE UAV development trends are surveyed to understand their operational requirements. Separating the UAV Take Off Weight by 150kg, Airworthiness implementation direction for HALE UAV is studied under the current Airworthiness regulations. NATO STANAG 4671 and STANAG 4703 Airworthiness certification criteria are analyzed, and their applicability was proposed for future HALE UAV development. In addition, minimization of the risk for UAV is studied by considering probability of cumulative catastrophic failure for HALE UAV. This Hazard Risk Index can support the future UAV Airworthiness Certification Criteria.

Acute and Chronic Exposure Assessment of Organophosphate Pesticides through the Consumption of Fruit Vegetables (과채류 섭취를 통한 유기인계 농약의 급성 및 만성노출평가)

  • Park, Byung-Jun;Gil, Keun-Hwan;Son, Kyeong-Ae;Im, Geon-Jae;Yoon, Hyunjoo;Park, Kyung-Hun;Kim, Doo-Ho;Ihm, Yangbin;Paik, Min-Kyoung
    • The Korean Journal of Pesticide Science
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    • v.18 no.2
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    • pp.95-103
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    • 2014
  • In this study, we monitored the residues of organophosphate pesticides (OP) in eight fruit vegetables grown in Korea, and assessed risk levels of acute and chronic exposure of OP through the consumption of fruit vegetables. Chlorpyrifos, EPN, methidathion and phosphamidon in eight fruit vegetables were detected in this study. The results of cumulative assessment of national estimated short term intake for acute exposure of OP were due to the following order; eggplant, tomato, squash and cucumber. Total theoretical maximum daily intake calculated at first step of chronic exposure assessment for registered OP in Korea was 76.14%, compared with acceptable daily intake ADI) based on chlorpyrifos. In addition, total national estimated maximum daily intake calculated at second step of chronic exposure assessment was 13.949%, compared with ADI. Third chronic assessment was conducted by probabilistic approach using OP residues detected in eight fruit vegetables and showed that total exposure risk was very low, corresponding to 0.0001% compared to ADI. Based on those finding, the risk of organophosphate pesticides in fruit vegetables was considered quantitatively negligible. In future, further investigation to expand the target should be followed to do more accurate and detailed risk assessment.

Short-term Effects of Ambient Air Pollution on Emergency Department Visits for Asthma: An Assessment of Effect Modification by Prior Allergic Disease History

  • Noh, Juhwan;Sohn, Jungwoo;Cho, Jaelim;Cho, Seong-Kyung;Choi, Yoon Jung;Kim, Changsoo;Shin, Dong Chun
    • Journal of Preventive Medicine and Public Health
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    • v.49 no.5
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    • pp.329-341
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    • 2016
  • Objectives: The goal of this study was to investigate the short-term effect of ambient air pollution on emergency department (ED) visits in Seoul for asthma according to patients' prior history of allergic diseases. Methods: Data on ED visits from 2005 to 2009 were obtained from the Health Insurance Review and Assessment Service. To evaluate the risk of ED visits for asthma related to ambient air pollutants (carbon monoxide [CO], nitrogen dioxide [$NO_2$], ozone [$O_3$], sulfur dioxide [$SO_2$], and particulate matter with an aerodynamic diameter <$10{\mu}m$ [$PM_{10}$]), a generalized additive model with a Poisson distribution was used; a single-lag model and a cumulative-effect model (average concentration over the previous 1-7 days) were also explored. The percent increase and 95% confidence interval (CI) were calculated for each interquartile range (IQR) increment in the concentration of each air pollutant. Subgroup analyses were done by age, gender, the presence of allergic disease, and season. Results: A total of 33 751 asthma attack cases were observed during the study period. The strongest association was a 9.6% increase (95% CI, 6.9% to 12.3%) in the risk of ED visits for asthma per IQR increase in $O_3$ concentration. IQR changes in $NO_2$ and $PM_{10}$ concentrations were also significantly associated with ED visits in the cumulative lag 7 model. Among patients with a prior history of allergic rhinitis or atopic dermatitis, the risk of ED visits for asthma per IQR increase in $PM_{10}$ concentration was higher (3.9%; 95% CI, 1.2% to 6.7%) than in patients with no such history. Conclusions: Ambient air pollutants were positively associated with ED visits for asthma, especially among subjects with a prior history of allergic rhinitis or atopic dermatitis.

Semi-Quantitative Exposure Assessment of Occupational Exposure to Wood Dust and Nasopharyngeal Cancer Risk

  • Ekpanyaskul, Chatchai;Sangrajrang, Suleeporn;Ekburanawat, Wiwat;Brennan, Paul;Mannetje, Andrea;Thetkathuek, Anamai;Saejiw, Nutjaree;Ruangsuwan, Tassanu;Boffetta, Paolo
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4339-4345
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    • 2015
  • Occupational exposure to wood dust is one cause of nasopharyngeal cancer (NPC); however, assessing this exposure remains problematic. Therefore, the objective of this study was to develop a semi-quantitative exposure assessment method and then utilize it to evaluate the association between occupational exposure to wood dust and the development of NPC. In addition, variations in risk by histology were examined. A case-control study was conducted with 327 newly diagnosed cases of NPC at the National Cancer Institute and regional cancer centers in Thailand with 1:1 controls matched for age, gender and geographical residence. Occupational information was obtained through personal interviews. The potential probability, frequency and intensity of exposure to wood dust were assessed on a job-by-job basis by experienced experts. Analysis was performed by conditional logistic regression and presented in odds ratio (ORs) estimates and 95% confidence intervals (CI). Overall, a non significant relationship between occupational wood dust exposure and NPC risk for all subjects was observed (ORs=1.61, 95%CI 0.99-2.59); however, the risk became significant when analyses focused on types 2 and 3 of NPC (ORs=1.62, 95%CI 1.03-2.74). The significant association was stronger for those exposed to wood dust for > 10 year (ORs=2.26, 95%CI 1.10-4.63), for those with first-time exposure at age > 25 year (ORs=2.07, 95%CI 1.08-3.94), and for those who had a high cumulative exposure (ORs=2.17, 95%CI 1.03-4.58) when compared with those considered unexposed. In conclusion, wood dust is likely to be associated with an increased risk of type 2 or 3 NPC in the Thai population. The results of this study show that semi-quantitative exposure assessment is suitable for occupational exposure assessment in a case control study and complements the information from self-reporting.

Worker Health Hazard and Risk Assessment of Formamide using in Workplaces in South Korea (작업장에서 사용하는 포름아미드(Formamide)의 근로자 건강 유해성과 위험성 평가)

  • Kim, Hyeon-Yeong
    • Journal of the Korean Institute of Gas
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    • v.20 no.2
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    • pp.35-42
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    • 2016
  • Formamide is a colorless fluid with ammonia odor, and irritable when inhaled. It has $LD_{50}$ value of > 5,577 mg/kg in rats for acute oral toxicity and NOAEL of 113 mg/kg/day for target organ (liver) of whole body toxicity. It is also known as reproductive toxicant (1B) and TWA(Time Weighted Average) for it is 10 ppm. Workplace measurements of work places dealing with formamide showed the ppm of all 25 samples was very lower than WEL. However, the exposure concentration can change, depending on workplace condition such as the intensity of work, operating local ventilation system, and wearing protection equipment (Respirators). Therefore, considering it with the risk of whole body toxicity and reproductive toxicity, exposure quantity of each imaginary scenario was calculated at 5.16, 1.72, and $0.43mg/m^3$. The average value was calculated at 0.02-0.58, 0.02-0.66 at 90 percent of cumulative distribution, 0.02-0.69 at 95 percent of cumulative distribution. Therefore, it was generally evaluated to be safe because all values were below 1. However, caution is required to prevent health hazard because it has hepatotoxicity and reproductive toxicity and risk of a high level momentary exposure, depending on the condition of workplace.

A Study on the Determination of Indicators for the Risk Assessment of Ground Depression Using SAR Imageson (SAR 영상을 활용한 지반침하의 위험평가를 위한 지표결정에 대한 연구)

  • Lee, Hyojin;Yoon, Hongsic;Han, Hak
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.7
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    • pp.13-20
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    • 2021
  • The problem of subsidence of the roadbed near the Honam High Speed Railway, which opened in April 2015, continues to be raised, and the ground stability of the area near the Honam High Speed Railway may also be problematic. It is very important to select the factors that determine the indicators and indicators in producing the risk maps. Existing risk indicators are calculated as the final displacement volume based on the last observed date of the observed period, and time-series indicator displacement must be identified to analyze the cause of subsidence and the behavior of the indicator. Furthermore, for a wide range of regions, it is economically inefficient to conduct direct level measurements, so we wanted to observe surface displacement using SAR images. In this paper, time series indicator displacement was observed using PS-InSAR techniques, and risk was compared by rating each factor using the difference between final indicator displacement, cumulative indicator displacement, minimum displacement and maximum displacement as factors for determining risk indicators. As a result, the risk rating of the final displacement is different from that of each factor, and we propose adding factors from different perspectives in determining risk indicators. It is expected to be an important study in finding the cause of ground subsidence and finding solutions.

Seismic assessment and retrofitting of Pombalino buildings by pushover analyses

  • Meireles, Helena;Bento, Rita;Cattari, Serena;Lagomarsino, Sergio
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.57-82
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    • 2014
  • The heritage value of the mixed wood-masonry 18th century Pombalino buildings of downtown Lisbon is recognized both nationally and internationally. The present paper focuses on the seismic assessment of global response and retrofitting of a typical Pombalino building by nonlinear static analyses, performed by the research software Tremuri, which is able to model 3D configurations. The structure is modelled using nonlinear beams for masonry panels, while in case of the internal walls (frontal walls) an original formulation has been developed in order to take into account their specific seismic behaviour. Floors are modelled as orthotropic membrane finite elements: this feature allows to simulate the presence of both flexible and rigid diaphragms, being the first ones more representative of the original state while the second ones of retrofitted configurations. Seismic assessment has been evaluated by applying nonlinear static procedure and comparing the performance of different configurations (by considering various retrofitting strategies). Finally, assuming a lognormal cumulative distribution, fragility curves are obtained to be representative of Pombalino buildings: the most important application of such curves is for seismic risk and loss estimation analyses.

Meta-Analysis of the Association between the rs8034191 Polymorphism in AGPHD1 and Lung Cancer Risk

  • Zhang, Le;Jin, Tian-Bo;Gao, Ya;Wang, Hui-Juan;Yang, Hua;Feng, Tian;Chen, Chen;Kang, Long-Li;Chen, Chao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2713-2717
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    • 2015
  • Background: Possible associations between the single nucleotide polymorphism (SNP) rs8034191 in the aminoglycosidephosphotransferase domain containing 1 (AGPHD1) gene and lung cancer risk have been studied by many researchers but the results have been contradictory. Materials and Methods: A computerized search for publications on rs8034191 and lung cancer risk was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between rs8034191 and lung cancer risk with 13 selected case-control studies. Sensitivity analysis, test of heterogeneity, cumulative meta-analysis, and assessment of bias were also performed. Results: A significant association between rs8034191 and lung cancer susceptibility was found using the dominant genetic model (OR=1.344, 95% CI: 1.285-1.406), the additive genetic model (OR=1.613, 95% CI: 1.503-1.730), and the recessive genetic model (OR=1.408, 95% CI: 1.319-1.503). Moreover, an increased lung cancer risk was found with all genetic models after stratification of ethnicity. Conclusions: The association between rs8034191 and lung cancer risk was significant using multiple genetic models, suggesting that rs8034191 is a risk factor for lung cancer. Further functional studies of this polymorphism and lung cancer risk are warranted.

Determination of Target Clean-up Level and Risk-Based Remediation Strategy (위해성에 근거한 정화목표 산정 및 복원전략 수립)

  • Ryu, Hye-Rim;Han, Joon-Kyoung;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.12 no.1
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    • pp.73-86
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    • 2007
  • Risk-based remediation strategy (RBRS) is a consistent decision-making process for the assessment and response to chemical release based on protecting human health and the environment. The decision-making process described integrates exposure and risk assessment practices with site assessment activities and remedial action selection to ensure that the chosen actions are protective of human health and the environment. The general sequences of events in Tier 1 is as follows: initial site assessment, development of conceptual site model with all exposure pathways, data collection on pollutants and receptors, and identification of risk-based screening level (RBSL). If site conditions do not meet RBSL, it needs further site-specific tier evaluation, Tier 2. In most cases, only limited number of exposure pathways, exposure scenarios, and chemicals of concern are considered the Tier 2 evaluation since many are eliminated from consideration during the Tier 1 evaluation. In spite of uncertainties due to the conservatism applied to risk calculations, limitation in site-specific data collections, and variables affecting the selection of target risk levels and exposure factors, RBRS provides us time- and cost-effectiveness of the remedial action. To ensure reliance of the results, the development team should consider land and resource use, cumulative risks, and additive effects. In addition, it is necessary to develop appropriate site assessment guideline and reliable toxicity assessment method, and to study on site-specific parameters and exposure parameters in Korea.