Introduction And Definition Of Issues

Human individuals and societies have been identifying risks and managing them since ancient times (When you build a new house, you shall make a parapet for your roof, so that you shall not put blood in your house if [when] one falls from it. Deut. 22:8) by various procedures, including establishing codes of practice and formal laws. What appears to be a more modern concern is the quantitative nature of risk, that is, the precise calculation of probabilities of risk. Performing these calculations is complex and involves input from many areas of the society. In particular, hazards and the risks associated with them need to be identified, and society must value the knowledge that calculation of the risks provides. It is not surprising that in a well-informed, free society, risk analysis has become a serious and growing field. The complexity of the calculations and the political will to make the calculations have created the need to structure the process of risk analysis so that the calculations are performed in an efficient and understandable manner. This chapter is a short discussion of the managerial frameworks that have been adopted in risk analysis and some of the issues surrounding them.

A natural beginning point in a discussion of risk analysis is the definition of risk. Even among practitioners of risk analysis, developing a standard definition of risk has been problematic. A committee of professionals in the newly formed Society for Risk Analysis (SRA) convened in the early 1980s and was unable to reach a single, consensus definition for risk after 4 years of deliberations (Kaplan, 1997). The recommendation of the SRA at that time was that freedom be permitted for professionals to define risk in a manner best suiting the particular discipline or problem at hand.

A good operational definition of risk is important because from it one can determine how to structure the activities needed to perform the calculations of risk and to disseminate the meaning of the calculations. A general operational definition provided by Kaplan (1981, 1997) will serve, with some modification, as a starting point for our discussions of risk analysis frameworks. Risk was defined (Kaplan, 1981, 1997) with responses to three basic questions. 1) What can happen? 2) How likely is it? 3) What are the consequences? In the Kaplan papers, which use an engineering perspective, the first component, "What can happen?" seems to describe an event such as a fire. Kaplan terms this first component as a scenario, S, and defines So as the successful scenario of nothing happening or nothing going wrong. For risk analysis of foodborne illness, the causal event is always the ingestion of something that is hazardous. Thus, for risk in food, the only answer to the question "What can happen?" is a single event, ingestion of a hazardous chemical or pathogen. Consequently, for our purposes, we shall adapt the concept of "scenario" to mean an event or a process that can produce the specified potential hazard and consequence for a given population. Thus, for food risk analysis, the scenario represents a conditional event or process, for which the associated risk must be evaluated. For example, a scenario might be the production of a certain food for which the presence of a certain hazard cannot be excluded. This hazard could result in fetal complications for pregnant women consuming the food. Three aspects of a scenario must be defined for a risk assessment: 1) the process, 2) a potential consequence, and 3) the target population. The "How likely is it?" question represents the conditional likelihood for the given scenario that the hazardous agent will be ingested, for example, the number of times that a pregnant woman would consume a serving of the food. The "What are the consequences?" question represents the probability of the adverse consequence, given the ingestion of the hazard agent.

Our adaptation of Kaplan's definition emphasizes that the risk analysis must specify conditions (termed scenario) and that the results are dependent on these conditions. If one describes a scenario, then the likelihood of an adverse effect for that scenario is predicted with attendant uncertainty. The elements of the triplet (scenario, likelihood, consequences) do not impose limitations on the methodology used to estimate risk.

Societies can choose to control or manage risk by any number of alternative, mitigating strategies. The above definition of risk allows for hypothetical scenarios to be compared, thus allowing a society to determine the benefits of alternative, mitigating strategies. Societies can choose not to control risks or to leave to the individual the decisions of how to manage risks. An individual might be permitted to engage in or avoid a certain risk voluntarily, such as smoking or driving a car. Management of risks that are involuntarily imposed on members of a society, such as risks of foodborne illness, might cause public outrage if not handled in a consistent, open public process. Risk analysis thus is the field that provides the public with the information needed to make informed decisions about risks and how to manage them.

Risk analysis is simply the analysis of scenarios that result in adverse consequences. The overarching term "risk analysis" has come to include, in addition to the above, the control and communication of risk. The management of a risk analysis has become a large undertaking, and many strategies of managing it have been proposed. A common risk analysis framework encompasses three components: 1) risk assessment, 2) risk management, and 3) risk communication, all of which are briefly described in this introductory section. The remaining sections of this chapter discuss managerial frameworks for the risk assessment and risk management components, along with identification of some of the tensions between these frameworks.

Risk Assessment

Risk assessment is the estimation of the probability of the occurrence of adverse events with attendant uncertainty [National Research Council (NRC), 1983]. Sound science is the underpinning of a good risk assessment, which is viewed as a link between research or science and policy (NRC, 1983). A structured process is essential to risk assessment because risk rarely involves the certainty of direct, measurable observations relevant to human health but does involve inference, prediction, and uncertainty. Thus the probability of adverse consequences is formally estimated with derived models that describe mathematically the processes thought to produce adverse consequences.

The earliest publication that dealt specifically with the structure of risk assessment applicable to foodborne human health effects was the "red book" of the NRC (1983). The basic structure or managerial framework of risk assessment was initially described by four elements: hazard identification, exposure assessment, dose-response assessment, and risk characterization (NRC, 1983). A list of 11 principles for risk assessment for microbiological hazards is provided in Table 3.1 (CCFH, 1998).

Risk Management

In managing risk, the risk manager considers the results of risk assessment and other factors, including economic, political, social, and technological inputs or limitations, to develop policies to manage the risk. The decisions made by risk managers also often reflect the priorities of a society. Neither risk management nor risk assessment is conducted in a vacuum. Establishing regulatory standards is a risk management activity that reflects the level of safety deemed appropriate for a given hazard. Policy strategies to control one foodborne hazard may well create new hazards. For example, air bag performance in U.S. automobiles was initially determined to minimize risks of death in severe accidents. Because of these performance standards, a new risk was created to young children and others when air bags deployed. Risk-risk trade-offs and cost-benefit analyses are essential analytical activities for fully documenting the risk management options and their consequences. A list of eight principles for

TABLE 3.1. General Principles of Microbiological Risk Assessment from "Principles and Guidelines for the Conduct of Microbiological Risk Assessment" Document of the Codex Committee on Food Hygiene (CCFH; 1998; www.fao.orgl WAICENT/FAOINFOI ECONOMICIESNIcodexlReports.htm)

1. Microbiological Risk Assessment must be soundly based upon science.

2. There should be a functional separation between Risk Assessment and Risk Management.

3. Microbiological Risk Assessment should be conducted according to a structured approach that includes Hazard Identification. Hazard Characterization, Exposure Assessment, and Risk Characterization.

4. A Microbiological Risk Assessment should clearly state the purpose of the exercise, including the form of Risk Estimate that will be the output.

5. A Microbiological Risk Assessment should be transparent.

6. Any constraints that impact on the Risk Assessment such as cost, resources or time, should be identified and their possible consequences described.

7. The Risk Estimate should contain a description of uncertainty and where the uncertainty arose during the Risk Assessment process.

8. Data should be such that uncertainty in the Risk Estimate can be determined; data and data collection systems should, as far as possible, be of sufficient quality and precision that uncertainty in the Risk Estimate is minimized.

9. A Microbiological Risk Assessment should explicitly consider the dynamics of microbiological growth, survival, and death in foods and the complexity of the interaction (including sequellae) between human and agent following consumption as well as the potential for further spread.

10. Wherever possible, Risk Estimates should be compared over time with independent human illness data.

11. A Microbiological Risk Assessment may need réévaluation as new relevant information becomes available.

risk management is presented in Table 3.2 from the 1996 FAO/WHO consultation on risk management (ww\\es\esn\risk\riskcont.htm).

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