Propagating Variability and Uncertainty

A 2nd critical addition when planning a probabilistic assessment is the choice of methods for propagating variability and nncertainty. The workshop reviewed a range of contrasting methods of analyzing uncertainty in risk assessments  

Second-order (hierarchical or 2-dimensional) Monte Carlo 

From the standpoint of practical regulatory assessment, it would be desirable to reach a consensus on the selection of methods for routine use for pesticide risk assessments while recognizing that there may be scientific reasons for preferring alternative methods in particnlar cases. Such a consensus does not yet exist. Further case studies are required, covering a range of contrasting pesticides and scenarios, to evaluate the available methods more fully. While a consensus is lacking, it is important that reports on probabilistic assessments clearly explain how their methods work and why they were selected. 

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