How to measure uncertainties in environmental risk assessment

Environmental risk assessment is an essential element in any decision-making process in order to minimize the effects of human activities on the environment. Unfortunately, often environmental data tends to be vague and imprecise, so uncertainty is associated with any study related with these kind of data. Essentially, uncertainty in risk assessment may have two origins - randomness and incompleteness. There are two main ways to deal with these uncertainties - probability theory and fuzzy logic. Probability theory is based on a stochastic approach, using probability functions to describe random variability in environmental parameters. Fuzzy logic uses membership functions and linguistic parameters to express vagueness in environmental issues. We discuss the best way to deal with uncertainties in the environmental field and give examples of probabilistic and fuzzy-logic approaches applied to environmental risk assessment. (C) 2008 Elsevier Ltd. All rights reserved.