ABSTRACT
Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under the abnormal conditions which we know as disease. While it is recommended to consider and evaluate variability and uncertainty separately, these two concepts are nevertheless frequently misunderstood or misused. A useful way to think about sources of variability is to consider these four broad categories: Variability is observed in each component of risk assessments for biological and chemical hazards in food. The variability in serving size or frequency of consumption is also an element that explains the exposure assessment variability. These approaches include useful elements to consider when constructing an appropriate generic uncertainty analysis framework. The result of a risk assessment that consider uncertainty is a single value integrating variability. In practice, some resources exist to conduct second-order Monte-Carlo simulations.
