The components of risk

Risk can be subdivided into many elements. The major components are considered below. 

The definition of hazard presented above has two elements. The first is that a hazard has within it the ability to harm a person. The second is that the existence of a hazard does not mean that harm will arise - a hazard only has to have the potential to harm. Identifying hazards is an ongoing process. There are everyday hazards associated with living - e.g. using gas as a fuel to cook food. There are unusual hazards that most people encoxmter only rarely - e.g. undergoing surgery. 

There are hazards that will cause immediate harm if they are encountered. These are termed acute hazards and are usually recognisable to most people so there is rarely a need for them to be explained. For example, most people will understand that being struck by a moving vehicle will result in immediate harm. Other hazards may affect us but we do not experience immediate harm. An example is exposme to asbestos fibres which may be inhaled many times over many years before harm is caused to the body. These are termed chronic hazards. Some hazards can be both acute and chronic. Radiation in small repeated doses can cause chronic harm in the form of cancers. However, a large single dose can cause acute harm in the form of bums and poisoning. 

Some hazards are caused by workplace exposure. Other hazards arise from a combination of workplace exposure and personal lifestyle. Two examples illustrate this point. Stress may arise at work (and usually does to some extent) and be quite tolerable to an individual. However, combine that with stress from the individual s personal life (such as undergoing a divorce or a bereavement) and harm to health can easily arise. The other example is musculo-skeletal injury, such as carpal tunnel syndrome, which may be experienced by a VDU operator using a keyboard all day. Combine the workplace activity with a hobby of surfing the net and it easy to see that this additional exposure increases the risk of wrist injury. In both these examples it is not easy to determine which of these activities are the causative factors and what their contributions are to the resulting harm. An activity that is not a hazard because it does not cause harm can become one under different circumstances. 

Consequently, recognising hazards is not always straightforward or easy. If a check list of hazards is used, it should be reviewed periodically, preferably by different people so that there is a chance that what one reviewer misses another will identify. 

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Special regulatory provisions. European Economic Area (EEA). The components of risk management programs in Europe have been similar to those listed above. However, it is probably fair to say that, overall, there has been less experience with these programs in Europe than in the United States. 

Once we have the formula and definition of risk, one needs to consider how that can be used in the context of an SMS to evaluate risk. To allow us to combine the components of risk we need to develop ... 

Inspection of the risk matrix reveals a series of diagonal stripes within which the clinical risk remains the same. Different combinations of severity and likelihood typically result in the same clinical risk. If individuals disagree on the components of risk they may well agree on the derived clinical risk. One person s Moderate-Remote might be another person s Minor-Occasional ultimately both concluding on the same degree of risk. 

The components of risk involve acceptance of its existence understanding the hazard, the consequences, the likelihood of a hazard causing injury or damage the perception of the risk and the tolerance of the risk by individuals or by a group. 

Definition of Terms Following are some definitions that are useful in understanding the components of hazards and risk (CPQRA, 1989, pp. 3, 4). 

The components of a risk analysis involve the estimation of the frequency of an event, an estimation of the consequences (the extent of the material or energy release and its impact on population, property, or environment), and the selection and generation of the estimate of risk itself. 

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. 

This brings us to the issue of risk assessment methodologies. Risk assessment is an interactive process that addresses (using risk assessment jargon) the Source, the Source-term, the Dispersion, the Dc, and the Impact a process in which there are many common components, including ... 

The method must be capable of determining all components (a.i. and relevant/major metabolites) that are included in the residue definitions used in the assessment of risk to nontarget organisms. For ground (drinking) water and air, the risk to con-sumers/operators or bystanders must also be considered. 

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. 

Obtaining a good quality QSAR model depends on many factors, such as the quality of biological data and the choice of descriptors and statistical methods. As a consequence, the uncertainty of the QSAR predictions is a combination of experimental uncertainties and model uncertainties. QSAR methods have to be applied to individual chemicals, not on mixtures. If the QSAR demands it, the components of the mixture have to be addressed separately and individually - in case of unknown compounds, QSAR cannot identify the toxicity risk and is therefore not useful. 

By decoupling risk response behavior into the separate components of risk perception and risk attitude, a more robust conceptualization and prediction of consumer reactions are possible. The insights that result from decoupling risk perceptions and risk attitudes can yield important implications. Consider the two following outcomes from a program of research by Pennings et al. (2002) ... 

Thus two components, exposure and hazard, must be evaluated together in determining the level of risk posed by a given colorant or other chemical. Risk management may therefore be regarded as a series of interdependent steps ... 

Ecosystem characterization Long-term monitoring should continue in order to enable estimation of natural variability, as well as to establish a baseline against which to evaluate the effects of disturbances. Standard environmental risk assessment approaches may not be useful if the components of the ecosystem in question have not been determined. Further research on... 

The science policy components of risk assessment have led to what have come to be called default assumptions. A default is a specific, automatically applied choice, from among several that are available (in this case it might be, for example, a model for extrapolating animal dose-response data to humans), when such a choice is needed to complete some undertaking (e.g., a risk assessment). We turn in the next chapter to the conduct of risk assessment and the ways in which default assumptions are used under current regulatory guidelines. We might say we have arrived at the central subject of this book. 

The upper bound on lifetime risk can easily be estimated by multiplying the cancer potency by the number of dose units individuals are, or could be exposed to each day. This multiplication constitutes the quantitative component of risk characterization (Step 4) for carcinogens. That is, if potency has units of upper bound on lifetime risk per unit of dose, and we multiply it by number of dose units, the result is upper bound on lifetime risk. This is the mathematical form of what we are doing when we are reading the risk directly from Figure 8.1. 

Effects assessment, by, as in the case of risk assessment for chemicals and pesticides, determining a set of marker organisms (including algae, zebrafish, insect larvae, benthic worm, water flea, etc.) that represent ecosystem components and food networks and are used to indicate acute and chronic effects. This step is also used to define the predicted no-effect concentrations (PNECs). 

If yes, further evaluation of additivity and interactions is necessary for the components of concern (having risk estimates equal to or greater than 1 X 10 ). Go to step 4. 

Apart from changing the definition of a medicinal product, the definition of risks related to use of the medicinal product has also been changed. The definition now has four components - in addition to the current definition which defines risk to public health in terms of the quality, safety and efficacy of the product, the revised legislation requires an assessment of any undesirable effects on the environment from use of the product. 

Article l(28)a of Directive 2004/27/EC defines the risk-benefit balance as an evaluation of the positive therapeutic effects of the product in relation to the risks to patients or public health. The environmental component of the definition of risks is excluded from the risk-benefit balance. Under the new legislation, the risk-benefit balance is considered as part of Article 23 (which enables the competent authority to continuously assess the risk-benefit balance by requesting relevant data from MAH), and Article 104 (relating to the submission by MAH of PSURs). 

Risk analysis and risk management play an important role in public policy. These debates range from the development of environmental impact statements for the location of buildings to debates on household lead abatement and what chemicals can be allowed in the food supply. Quality of life issues such as asthma and/or loss of mental function are now recognized as important components of risk assessment. 

Contraindications Serum calcium above normal level, those at increased risk for osteosarcoma (Paget s disease, unexplained elevations of alkaline phosphatase, open epiphyses, prior radiation therapy that included the skeleton), hypercalcemic disorder (e.g., hyperparathyroidism), hypersensitivity to teriparatide or any of the components of the formulation... 

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