Unacceptable Risk (unacceptable + risk)

Distribution by Scientific Domains

Selected Abstracts

Environmental risk assessment of human pharmaceuticals in the European Union: A case study with the ,-blocker atenolol

Anette Küster
Abstract ,-Adrenergic receptor blockers (,-blockers) are applied to treat high blood pressure, ischemic heart disease, and heart rhythm disturbances. Due to their widespread use and limited human metabolism, ,-blockers are widely detected in sewage effluents and surface waters. ,-Adrenergic receptors have been characterized in fish and other aquatic animals, so it can be expected that physiological processes regulated by these receptors in wild animals may be affected by the presence of ,-blockers. Because ecotoxicological data on ,-blockers are scarce, it was decided to choose the ,-blocker atenolol as a case study pharmaceutical within the project ERAPharm. A starting point for the assessment of potential environmental risks was the European guideline on the environmental risk assessment of medicinal products for human use. In Phase I of the risk assessment, the initial predicted environmental concentration (PEC) of atenolol in surface water (500,ng L,1) exceeded the action limit of 10,ng L,1. Thus, a Phase II risk assessment was conducted showing acceptable risks for surface water, for groundwater, and for aquatic microorganisms. Furthermore, atenolol showed a low potential for bioaccumulation as indicated by its low lipophilicity (log KOW,=,0.16), a low potential for exposure of the terrestrial compartment via sludge (log KOC,=,2.17), and a low affinity for sorption to the sediment. Thus, the risk assessment according to Phase II-Tier A did not reveal any unacceptable risk for atenolol. Beyond the requirements of the guideline, additional data on effects and fate were generated within ERAPharm. A 2-generation reproduction test with the waterflea Daphnia magna resulted in the most sensitive no-observed-effect concentration (NOEC) of 1.8,mg L,1. However, even with this NOEC, a risk quotient of 0.003 was calculated, which is still well below the risk threshold limit of 1. Additional studies confirm the outcome of the environmental risk assessment according to EMEA/CHMP (2006). However, atenolol should not be considered as representative for other ,-blockers, such as metoprolol, oxprenolol, and propranolol, some of which show significantly different physicochemical characteristics and varying toxicological profiles in mammalian studies. Integr Environ Assess Manag 2010;6:514,523. © 2009 SETAC [source]

Comparative analysis of three user equilibrium models under stochastic demand

Zhong Zhou
Abstract Recent empirical studies on the value of time and reliability reveal that travel time variability plays an important role on travelers' route choice decision process. It can be considered as a risk to travelers making a trip. Therefore, travelers are not only interested in saving their travel time but also in reducing their risk. Typically, risk can be represented by two different aspects: acceptable risk and unacceptable risk. Acceptable risk refers to the reliability aspect of acceptable travel time, which is defined as the average travel time plus the acceptable additional time (or buffer time) needed to ensure more frequent on-time arrivals, while unacceptable risk refers to the unreliability aspect of unacceptable late arrivals (though infrequent) that have a travel time excessively higher than the acceptable travel time. Most research in the network equilibrium based approach to modeling travel time variability ignores the unreliability aspect of unacceptable late arrivals. This paper examines the effects of both reliability and unreliability aspects in a network equilibrium framework. Specifically, the traditional user equilibrium model, the demand driven travel time reliability-based user equilibrium model, and the ,-reliable mean-excess travel time user equilibrium model are considered in the investigation under an uncertain environment due to stochastic travel demand. Numerical results are presented to examine how these models handle risk under travel time variability. [source]

Is your IT structure obsolete?

Timothy Iijima
Today's big companies rely on their IT systems and networks in a huge way,and that concentrates a substantial portion of a company's risk in the IT organization. Virtually no activity within a company can now happen without major help from IT. So IT organization structure can no longer function as an afterthought,because a poorly performing IT organization creates unacceptable risk for the company. The author takes a close look at today's critical functions and roles for IT, the organization structures used, and why older IT organization models are no longer adequate. Is your firm's IT organization obsolete in today's world? © 2008 Wiley Periodicals, Inc. [source]

Managing chronic hepatitis C in the difficult-to-treat patient

Nyingi Kemmer
Abstract Patients with chronic hepatitis C virus (HCV) infection and disease-related complications , among them cirrhosis and liver failure , pose a particular management challenge. Some of these patients may fail to respond to current therapy (non-responders), and some are affected so severely that treatment puts them at an unacceptable risk for complications. Treatment with pegylated interferon (peg-IFN) plus ribavirin improves hepatic enzyme levels and eradicates the virus in ,50% of patients; however, a significant number of patients do not respond to therapy or relapse following treatment discontinuation. Several viral, hepatic and patient-related factors influence response to IFN therapy; many of these factors cannot be modified to improve long-term outcomes. Identifying risk factors and measuring viral load early in the treatment can help to predict response to IFN therapy and determine the need to modify or discontinue treatment. Retreatment options for patients who have failed therapy are limited. Retreatment with peg-IFN has been successful in some patients who exhibit an inadequate response to conventional IFN treatment, particularly those who have relapsed. Consensus IFN, another option in treatment-resistant patients, has demonstrated efficacy in the retreatment of non-responders and relapsers. Although the optimal duration of retreatment and the benefits and safety of maintenance therapy have not been determined, an extended duration is likely needed. This article reviews the risk factors for HCV treatment resistance and discusses the assessment and management of difficult-to-treat patients. [source]

LOPA misapplied: Common errors can lead to incorrect conclusions,,

Karen A. Study
Abstract Layer of Protection Analysis is a powerful tool for quantitative risk assessments. If applied correctly, it can provide quick and efficient guidance on what additional safeguards are needed, if any, to protect against a given scenario. If misapplied, an overly conservative calculation of risk may result in over-instrumentation, additional life-cycle costs, and spurious trips. A nonconservative calculation of risk could result in an under-protected system and unacceptable risk of an undesired consequence occurring. This article describes several categories of common errors, some overly conservative and some nonconservative. Case studies of actual plant scenarios are used to illustrate. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009 [source]

The development of risk criteria for high severity low frequency events,

Fred Henselwood
Abstract Quantitative risk assessments (QRAs) are used within the field of process safety to decide the allocation of resources and risk reduction investments. Typically risk assessments involve the evaluation of probabilistic measures that estimate the average expected value for the situation being considered across a range of potential outcomes. The resulting expected value is then used to determine if a situation represents an acceptable or unacceptable risk based on a threshold value allotted to the risk. This approach often gives guidance that is at odds with the thoughts and behaviors of some stakeholders as illustrated by the "but what if it does happen?" type of question. This inconsistency results from the inherent limitation associated with expected value approaches in that the methodology is based on whether or not a mean assessed risk represents an acceptable risk while overlooking the possibility that a single scenario could represent an intolerable event. This article looks at an adjustment to traditional QRAs so as to assess both the acceptability of risk and the tolerability of the associated consequences relative to risk criteria. These adjustments have been found to better represent stakeholder perceptions of risk, more closely relate risk tolerance to corporate values and resources, and to better justify the use of various risk transfer strategies. © 2008 American Institute of Chemical Engineers Process Saf Prog, 2009 [source]

Sedation by non-anaesthetists: an unacceptable risk?

ANAESTHESIA, Issue 10 2010
D. Hunter
No abstract is available for this article. [source]

Applying Human Systems Integration to the Rapid Acquisition Process

The rapidly changing complexity of the Global War on Terrorism has changed the approach to equipping forward-deployed military forces. Combatant Commanders conducting operations now require timely materiel solutions to enhance mission capabilities and reduce the risk for individual soldiers. To address this challenge, the US Army established the Rapid Equipping Force to assess emerging requirements, to propose solutions to those requirements, and to implement those solutions in an expedient time frame. Unfortunately, the REF lacks a consistent analytical methodology for assessing alternative materiel solutions. To address the need for a human systems integration (HSI) analysis method, the authors developed an Assessment-Based Rapid Acquisition HSI Analysis Method (ABRAHAM) capable of generating tailored surveys and evaluating these surveys for unacceptable risks to soldiers. To validate ABRAHAM's concept and content, ABRAHAM was showcased in three Department of Defense settings: the Human Factors Engineering Technical Advisory Group, the REF, and the US Marine Corps' Operational Test and Evaluation Activity. The ABRAHAM appears to fill a gap in the current library of HSI tools. Based on the feedback provided during the product showcases, there is sufficient interest and technological maturity to further develop ABRAHAM to serve both the traditional and rapid acquisition processes. [source]

Application of the operating window concept to remediation-option selection

REMEDIATION, Issue 3 2004
Duncan I. Scott
An Erratum has been published for this article in Remediation 14(4) 2004, 141. The selection of remediation options for the management of unacceptable risks at contaminated sites is hindered by insufficient information on their performance under different site conditions. Therefore, there is a need to define "operating windows" for individual remediation options to summarize their performance under a variety of site conditions. The concept of the "operating window" has been applied as both a performance optimization tool and decision support tool in a number of different industries. Remediation-option operating windows could be used as decision support tools during the "options appraisal" stage of the Model Procedures (CLR 11), proposed by the Environment Agency (EA) for England and Wales, to enhance the identification of "feasible remediation options" for "relevant pollutant linkages." The development of remediation-option operating windows involves: 1) the determination of relationships between site conditions ("critical variables") and option performance parameters (e.g., contaminant degradation or removal rates) and 2) the identification of upper- and lower-limit values ("operational limits") for these variables that define the ranges of site conditions over which option performance is likely to be sufficient (the "operating window") and insufficient (the "operating wall") for managing risk. Some research has used case study data to determine relationships between critical variables and subsurface natural attenuation (NA) process rates. Despite the various challenges associated with the approach, these studies suggest that available case study data can be used to develop operating windows for monitored natural attenuation (MNA) and, indeed, other remediation options. It is envisaged that the development of remediation-option operating windows will encourage the application of more innovative remediation options as opposed to excavation and disposal to landfill and/or on-site containment, which remain the most commonly employed options in many countries. © 2004 Wiley Periodicals, Inc. [source]

,Acceptable' and ,unacceptable' risks

No abstract is available for this article. [source]