PRINCIPLES OF ENVIRONMENTAL TOXICOLOGY AND CONTAMINATION (PART III)

Table of Contents

1. Index
2. UNIT 9 - Environmental risk assessment
   1. Introduction
   2. Problem formulation
   3. Analysis Phase
   4. Risk characterization
   5. Risk management and assessment
   6. Human health risk assessment
3. UNIT 10 - Environmental risk communication
4. UNIT 11 - Modelling in Ecotoxicology
5. UNIT 12 - Legislation
6. Glossary of key terms associated with environmental toxicology

Risk characterization

During this step, risks are estimated and interpreted, and the limitations, strengths, assumptions, and major uncertainties are summarized. Risks are estimated - which determines the probability of adverse environmental effects to assessment endpoints - by integrating exposure and stressor-response profiles using a wide range of techniques (e.g.: empirical approaches such as field observational data, process models, comparisons of point estimates or distributions of exposure and effects data). Risks are described during this final phase by evaluating the lines of evidence supporting or refuting the risk estimate(s) and interpreting the adverse effects on the assessment endpoint (fig. 1). Criteria for evaluating adversity include the nature and intensity of effects, spatial and temporal scales, and the potential for recovery. Agreement among different lines of evidence of risk increases confidence in the conclusions of a risk assessment. Risk description is a step that partially serves to identify ways to remedy effects at a particular site (e.g. no human intervention/action in some cases or removal of a contaminant from sediments).