ABSTRACT
Current methods used in ecological risk assessments for pesticides are largely “deterministic.” These methods generally produce simple measures of risk (e.g., risk quotients) and do not quantify the influence of variability and uncertainty in exposure and effects. “Probabilistic” methods do quantify and analyze variability and uncertainty. They can also provide more meaningful measures of risk (e.g., the frequency and magnitude of impacts). Consequently, probabilistic methods are attracting growing interest from both industry and government, especially in North America (USEPA 2000), but also in Europe (e.g., Hart 2001), and elsewhere.
