Probabilistic Ecological Risk Assessment Framework for Chemical Substances

The goal of probabilistic ecological risk assessment (PERA) is to estimate the likelihood and the extent of adverse effects occurring to ecological systems due to exposure(s) to substances. It is based on the comparison of an exposure concentration distribution (ECD) with a species sensitivity distribution (SSD) derived from chronic toxicity data. A PERA framework was proposed and illustrated with a case study on the pesticide atrazine in the surface waters of Flanders. The risk and its uncertainty or confidence interval can be visualised in a pie chart. A probabilistic approach results in a more realistic environmental risk assessment and therefore improves decision support of handling impact of individual chemicals.