Risk management quantitative assessment

In essence, the earlier components of this overall assessment process are mainly deterministic in character (albeit with some probabilistic elements), whereas the later stages are mainly probabilistic. Not all elements of the process are quantifiable (with any degree of confidence), however and the socicii-political-cultural context of any downstream decision-making process may be intensely uncertain. Such uncertainties make the process of risk communication and debate a complex and sometimes unpredictable undertaking. It is essential therefore that those elements of the risk management process that cein be objectively einalysed and evaluated (either qualitatively or quantitatively, as appropriate) are so assessed. 

Exposure assessments have become an essential element of contemporary risk assessment (NAS/NRC, 1983). The primary purpose of exposure assessment is to qualitatively and/or quantitatively determine exposure and absorbed dose associated with a particular use practice or human activity. Contemporary exposure assessors and risk managers place a high premium on accurate data obtained by monitoring chemical exposure scenarios and critical human activities or work tasks. 

The link between the ecological/ecotoxicological risk assessment and the risk management frameworks is demonstrated. The ecological risk assessment consists of seven interactive elements (Fig. 17). The quantitative and descriptive science used to conduct ERA (Table 5) does not answer, in a direct way, the question of what should be done to manage the risk. Science determines adversity, but the public determines acceptability (Fig. 18). But acceptable risk is a highly subjective and relative term. It is time and space-specific and depends upon definitions of quality of life and robustness of the environment. 

Qualitative findings of ecosystem risk assessments are of low utility for risk management. They cannot be compared with quantitative estimates of other risks this compromises the ability of risk ranking to provide insights to setting priorities. It is particularly difficult to convert them into a format applicable for cost-benefit analysis, which is a key tool that any proponent uses in decision-making on a proposed project. 

William R. Rhyne received a B.S. in nuclear engineering from the University of Tennessee and M.S. and D.Sc. degrees in nuclear engineering from the University of Virginia. Dr. Rhyne is currently an independent consultant and earlier cofounded H R Technical Associates, Inc., where he remains a member of the board of directors. He has extensive experience in risk and safety analyses associated with nuclear and chemical processes and with the transport of hazardous nuclear materials and chemicals. From 1984 to 1987, he was the project manager and principal investigator for a probabilistic accident analysis of transporting obsolete chemical munitions. Dr. Rhyne has authored or coauthored numerous publications and reports in nuclear and chemical safety and risk analysis areas and is author of the book Hazardous Materials Transportation Risk Analysis Quantitative Approaches for Truck and Train. He is a former member of the NRC Transportation Research Board Hazardous Materials Committee, the Society for Risk Assessment, the American Nuclear... 

The aim of the guidance value is to provide quantitative information from risk assessment to the risk managers to enable them to make decisions. (See also reference dose.)... 

Risk assessment is quantitative and differs from risk management, which involves weighing options to reduce the risk. The risk assessment process begins with identifying the potential hazards and their occurrence in a specihc environment (i.e., exposure assessment), their toxicity (i.e., dose-response), and a characterization of the risk (NRC, 1994). Risk assessment determines the probability of realizing harm as a result of exposure to a given hazard. 

In the case of biological contamination, the identification of risk became obvious by experience, the risk assessment was made unambiguous by epidemiology, and the immediate and obvious effectiveness of the risk management decisions demonstrated their wisdom in the absence of elegant quantitative risk extrapolation models and projections of costs per case averted. Costs of water treatment and distribution became trivial relative to almost all other essential commodities, and in the public expectation the biological safety of drinking water became axiomatic. 

It is important that both the qualitative and quantitative characterization be clearly communicated to the risk manager. The qualitative characterization includes the quality of the database, along with strengths and weaknesses, for both health and exposure evaluations the relevance of the database to humans the assumptions and judgements that were made in the evaluation and the level of confidence in the overall characterization. The quantitative characterization also includes information on the range of effective exposure levels, dose-response estimates (including the uncertainty factors applied), and the population exposure estimates. Kimmel et al. (2006) reviewed many of the components of the risk characterization for reproductive and developmental effects and provided a comprehensive list of issues to be considered for each of the components of the risk assessment. 

Through the review of approaches to explicit qualitative consideration of contributing sources, this section offers a framework to facilitate and promote a qualitative consideration of the impact of uncertainties on exposure assessment where data are very limited and/or as a prelude to more quantitative characterization of uncertainties. Transparency to address uncertainties and specification of those uncertainties that impact most on outcome are essential to effective decision-making in risk management. 

The product of the exposure assessment process should provide the scientific basis for risk management and communication, which are often initiated by identifying possible hazards. As a measurement, the result is complete only when accompanied by a quantitative statement of its uncertainty (Taylor Kuyatt, 1994), which is required in order to decide whether the result is adequate for its intended purpose and to ascertain whether it is consistent with other similar results. In 2002, the European Commission s Health and Consumer Protection Directorate-General published a scheme in a report on animal health that highlights the role played by exposure assessment in risk assessment and emphasizes the need for risk communication in all steps of risk assessment (EC, 2002). 

Goldstein BD. 1985. Risk assessment and risk management of benzene by the Environmental Protection Agency. In Risk quantitation and regulatory policy, Banbury Report 19 293-304. 

A product lifecycle ranges from resource extraction through manufacture to use and final waste disposal or processing. Under the current EU chemical risk assessment procedure, lifecycle thinking considers the risks at each stage of a substance s lifecycle, with the possible summation of multiple sources of exposures to a single substance [144], LCA that quantitatively evaluate the overall environmental and health impacts of processes, services or products can complement risk assessment as a useful decision-support tool for chemical risk management [183, 188, 536]. 

ASSESSMENT OF RISKS TO HUMANS EXPOSED TO PESTICIDES 2 The Four Steps in Risk Assessment 2 Hazard Identification 2 Dose-Response Assessment 3 Margin of Safety Approach 3 Quantitative Risk Assessment 3 Exposure Assessment 4 Risk Characterization 4 RISK MANAGEMENT 5 ADVANCES IN DATA INTERPRETATION 5 Probabilistic Approaches 5 Recognition of the Tier Approach 5 Aggregate Exposure 6 Cumulative Exposure 6 Impact of New Scientific Advances 7 Post-Registration Monitoring 7 HARMONIZATION OF REGULATORY APPROACHES SUMMARY 9... 

Hie quantitative estimate of the risk is tlie principal interest to tlie regulatory agency or risk manager making a decision. The risk manager must consider tlie results of tlie risk cliaracterization when evaluating tlie economics, societal aspects, and various benefits of the assessment. Factors such as societal pressure, technical uncertainties, and severity of tlie potential hazard influence how the decision makers respond to the risk assessment. As one iniglit suppose, there is room for improvement in this step of tlie risk assessment. ... 

It is one of the aims of the lUPAC project to qualitatively and quantitatively assess the impact of altered pesticide use on GM crops. Furthermore, otho impacts will also be taken into account, which may include weed eeology and soil conservation. Finally a risk-benefit analysis of these impacts will be made by evaluating the various outcomes of our research, which may provide a tool for further polieies in the area of GM crop cultivation and pest management. This is an important endeavour given the public concerns regarding large scale cultivation of GM crops and its environmental consequences. 

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