Importance of Variability and Uncertainty in Risk Assessment

Variability and uncertainty affect every element of every risk assessment. For example, participants in the European Workshop on Probabilistic Risk Assessment for the Environmental Impacts of Plant Protection Products (EUPR A) were asked to list sources of uncertainty affecting current procedures for assessing pesticide risks to aquatic 

Some key sources of uncertainty affecting current risk assessments for pesticides in Europe, as listed by the EUPRA workshop (Hart 2001) 

Extrapolation from individuals in single species tests to populations 

Extrapolation from individuals of single species to communities 

Discrepancy between exposure in laboratory studies and in the field 

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