Risk Assessment: A Quantitative Approach
A risk can be defined as a function of the probability of an adverse health effect and the severity of that effect, consequential to a hazard in food (Codex Alimentarius, 1999) . During a risk assessment, an estimate of the risk is obtained. The goal is to estimate the likelihood and the extent of adverse effects occurring to humans due to possible exposure(s) to hazards. Risk assessment is a scientifically based process consisting of the following steps: (1) hazard identification, (2) hazard characterization, (3) exposure assessment and (4) and risk characterization (Codex Alimentarius, 1999) .
During the hazard identification , biological, chemical and physical agents that are capable of causing adverse health effects and which may be present in a particular food or group of foods are identified (Codex Alimentarius, 1999). In the second step, the hazard characterization , the nature of the adverse health effects associated with the hazards is evaluated in a qualitative and/or quantitative way (Codex Alimentarius, 1999); therefore, a dose—response assessment should be performed. The dose—response assessment is the determination of the relationship between the magnitude of exposure (dose) to a chemical, biological or physical agent and the severity and/or frequency of associated adverse health effects (response). The overall aim is to estimate the nature, severity and duration of the adverse effects resulting from ingestion of the agent in question (Benford, 2001). Exposure assessment is defined as the qualitative and/or quantitative evaluation of the likely intake of the hazard via food as well as exposure from other sources, if relevant (Codex Alimentarius, 1999) . For food, the level ingested will be determined by the levels of the agent in the food and the amount consumed. The last step, risk characterization, integrates the information collected in the preceding three steps. It interprets the qualitative and quantitative information on the toxicological properties of a chemical with the extent to which individuals (parts of the population, or the population at large) are exposed to it (Kroes et al., 2002). In other words, estimating how likely it is that harm will be done and how severe the effects will be. The outcome may be referred to as a risk estimate, or the probability of harm at given or expected exposure levels (Benford, 2001).
KeywordsAdverse Health Effect Exposure Assessment Markov Chain Monte Carlo Method Quantitative Risk Assessment Probabilistic Risk Assessment
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