Risk assessment, improved

Process Hazards Analysis. Analysis of processes for unrecogni2ed or inadequately controUed ha2ards (see Hazard analysis and risk assessment) is required by OSHA (36). The principal methods of analysis, in an approximate ascending order of intensity, are what-if checklist failure modes and effects ha2ard and operabiHty (HAZOP) and fault-tree analysis. Other complementary methods include human error prediction and cost/benefit analysis. The HAZOP method is the most popular as of 1995 because it can be used to identify ha2ards, pinpoint their causes and consequences, and disclose the need for protective systems. Fault-tree analysis is the method to be used if a quantitative evaluation of operational safety is needed to justify the implementation of process improvements. 

The physical condition and characteristics of the material shipped should be considered in transportation risk assessments on a case-by-case basis. There may be options available to reduce transportation risk by reducing the potential for releases or the severity of the effects of releases. A few possible ways of improving safety by modifying conditions are ... 

Interpreting PSA as any risk assessment using accident probabilities and consequences, government and industry have prepared many examples. These are discussed as Public Risk, Specialized Analyses, and Performance Improvement. 

The severe accident research program improved public risk assessment, reduced uncertainties, and the reliance on subjective expert opinion. To close two severe accident issues in NRC s Severe Accident Research Plan (NUREG-1365) Mark I Liner Attack and Direct Containment Heating (DCH) were addressed with a new approach using the Risk Oriented Accident Analysis Method (ROAAM) (Theofanous, 1994, 1989). The resolution of the Mark-I Liner Attack issue constitutes the first full demonstration of ROAAM. It emphasizes the determinism and provides a basis for synergistic collaboration among experts through a common communication frame. 

It is important to remember that unexpected benefits may arise from integration. You should actively look for these benefits and document them. It may be possible to improve some of these benefits by small modifications to the plan or integration framework. Such additional work should be undertaken only with the appropriate approvals. Never the less, if any benefits would only be achieved with the integration project, you should include them in your overall statement of benefits. An example of this might be the better allocation of capital to risk reduction efforts when an integrated risk assessment is done-addressing several different types of risk. 

PBPK models improve the pharmacokinetic extrapolations used in risk assessments that identify the maximal (i.e., the safe) levels for human exposure to chemical substances (Andersen and Krishnan 1994). PBPK models provide a scientifically sound means to predict the target tissue dose of chemicals in humans who are exposed to environmental levels (for example, levels that might occur at hazardous waste sites) based on the results of studies where doses were higher or were administered in different species. Figure 3-4 shows a conceptualized representation of a PBPK model. 

The concept of risk assessment requires a profound understanding of food dynamics and technological conditions that may impact the risk levels of certain hazardous compounds. It requires that scientific information and data are collected to underpin conclusions about risk levels. Risk assessment can be used to scientifically underpin the selection of hazards that must be covered by a quality or safety assurance system (e.g., HACCP) that will improve the reliability of the system. 

The activities of enforcement laboratories should not be focused on irrelevant problems. Therefore, a clear definition of the relevant residue is needed. In the crops and food sector, procedures are well established to derive the two residue definitions, one for risk assessment and one for monitoring, from metabolism studies. As far as environmental samples are concerned, there is much potential for improvement. There are no clear criteria as to which metabolites should be included in monitoring and control programs. Additionally, the development of criteria for nonpriority pesticides, e.g., naturally occurring compounds or low-risk products, which can be excluded from monitoring exercises would be helpful for laboratories and evaluators. 

The survival of patients with leukemia has improved markedly in the last 30 years. This is a result of intensive classification and risk assessment that is a prerequisite in the selection of treatment aimed at ensuring that patients are... 

Where possible, it is preferable to demonstrate safety without the application of advanced risk assessment techniques such as QRA, which can be resource intensive, time consuming, and costly. The decision to proceed with QRA should be based on an estimate of the benefits to be derived from such a study. Management should evaluate the expected cost of improving safety against the cost of conducting a detailed QRA to determine if there is potential benefit to performing QRA. If the expected benefits of perform-... 

There is a growing need to better characterize the health risk related to occupational and environmental exposure to pesticides. Risk characterization is a basic step in the assessment and management of the health risks related to chemicals (Tordoir and Maroni, 1994). Evaluation of exposure, which may be performed through environmental and biological monitoring, is a fundamental component of risk assessment. Biomarkers are useful tools that may be used in risk assessment to confirm exposure or to quantify it by estimating the internal dose. Besides their use in risk assessment, biomarkers also represent a fundamental tool to improve the effectiveness of medical and epidemiological surveillance. 

As it has been shown in this chapter knowing the concentrations of chemicals in the environment is a key aspect in order to carry out meaningful hazard and risk assessment studies. Predicting concentrations of chemicals can serve as a quick and robust way to produce an acceptable screening level assessment however if further precision is desired, the complexity of real environmental scenarios can make it a cumbersome and unaffordable task. Models improvement requires not only refining their computation algorithms but also and more important, implementing new inputs and processes in order to better describe real scenarios. 

However, as a general observation, this study demonstrated the feasibility of the integrated modeling approach to couple an environmental multimedia and a PBPK models, considering multi-exposure pathways, and thus the potential applicability of the 2-FUN tool for health risk assessment. The global sensitivity analysis effectively discovered which input parameters and exposure pathways were the key drivers of Pb concentrations in the arterial blood of adults and children. This information allows us to focus on predominant input parameters and exposure pathways, and then to improve more efficiently the performance of the modeling tool for the risk assessment. 

The US Congress funded the Pesticide Data Program (PDP) in order to improve the accuracy of pesticide dietary risk assessments carried out by the US EPA. The USDA s Agricultural Marketing Service carries out the program. As recommended in the 1993 NAS/NRC report, the PDP focuses on the foods consumed most heavily by children and food is tested, to the extent possible, as eaten (Agricultural Market Service, 2004 National Research Council, 1987). For example, banana and orange samples are tested without the peel processed foods are tested as they come out of a can, jar or freezer bag. 

NOMIRACLE (2004-2009, http //viso.jrc.it/nomiracle/) provided support to the development and improvement of a coherent series of methodologies underpinned by mechanistic understanding, while integrating the risk analysis approaches of environmental and human health. The project delivered understanding of and tools for sound risk assessment, developing a research framework for the description and interpretation of combined stressor effects that leads to the identification of biomarkers and other indicators of cumulative impacts. 

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