Ecological Risk Assessment: From Book-Keeping to Chemical Stress Ecology

Abstract

To best address the effect of chemicals in the environment, extrapolation from single species to ecosystems must be understood and modeled.Ecotoxicology emerged in the 1970s as the environmental branch of the field of toxicology. As a consequence, its major focus was on investigating the impacts of chemicals on individuals, rather than populations, communities, or ecosystems. Typical ecotoxicity experiments involve testing the effects of a chemical under standard laboratory conditions on individuals of a standard test species. This has yielded a massive amount of historical data, compiled in databases (e.g., www.epa.gov/ecotox) that are used in the ecological risk assessment (ERA) to estimate the environmental consequences of anthropogenic use of chemicals. Because of its focus on standardization, singlespecies tests, prescribed risk assessment methodologies, and flowcharts, ERA often seems more based on bookkeeping than on science. Ecotoxicology, as the science underpinning ERA, should permit itself to grow out of its "single-species" shell because it should focus on the protection of populations and communities in the field (1, 2). The discrepancy between the question posed in ERA and the answer provided by single-species tests is concealed by the use of assessment factors (1).This historical background explains why only a very limited amount of ecological theory has become integrated into the field of ecotoxicology and ERA. As a result, sciencebased, ecosystem-level risk assessment methodologies have hardly been developed. To counteract this ecological deficiency in ERA, frameworks have been proposed to integrate some level of ecology into decision making (e.g., 3, 4). During the past decade, great progress toward this integration has been made on the experimental side (e.g., 5, 6) and some also on the modeling side (e.g., 7, 8). The understanding of how populations, communities, and ecosystems are affected by chemicals could be increased by integrating the fields of toxicology, chemistry, ecology, and bioinformatics at different levels of biological organization. The development of methods to extrapolate this improved understanding to untested situations would then greatly improve the ERA of chemicals (9); Figure 1).I designate this integrative field as the scientific area of "chemical stress ecology", which I regard as a subdomain of the recognized field of stress ecology. The term "stress ecology" was used occasionally in the 1970s and 1980s (10, 11) but became institutionalized in the field of ecotoxicology and ERA because of the 2003 paper by Van Straalen (12). Contemporary definitions of ecology and stress are combined in chemical stress ecology, which is the study of the consequences of chemically induced changes in a biological RHONDA SAUNDERS PAUL VAN DEN BRINK FIGURE 1. Conceptual framework for the propagation of effects across different levels of organization and spatiotemporal extrapolation. The vertical axis denotes the propagation of effects to higher levels of biological organization while expl...

Effects of time‐variable exposure regimes of the insecticide chlorpyrifos on freshwater invertebrate communities in microcosms

“…Consequently, these hazardous chemicals may affect the nontarget biotic communities of such freshwater ecosystems [2]. Protecting the biological integrity of these waters requires assessing the potential risks associated with the pesticide stress to aquatic ecosystems.…”

“…Freshwater model ecosystems such as microcosms and mesocosms have been widely recommended as surrogate tools for the (higher-tier) ecological risk assessment of pesticides [3]. Microcosms and mesocosms are most useful in the advanced phases of an ecological risk assessment, where they provide information that cannot be derived from laboratory studies, such as indirect effects and recovery of affected populations [2]. A major advantage of these experimental systems is their realistic simulation of both chemical exposure and ecological effects [4,5].…”

Urbanisation shapes behavioural responses to a pesticide

“…Despite increasing attention for spatially explicit ecological risk 22 assessment (Van den Brink, 2008;Clements et al, 2012) vulnerability to these contaminants (reviewed in Medina et al,35 2007; but see e.g. Crespi, 2000;Spitzer, 2006).…”

Macroinvertebrate responses to insecticide application between sprayed and adjacent nonsprayed ditch sections of different sizes

“…9, pp. 1994-2008 # 2010 SETAC Printed in the USA DOI: 10.1002/etc.238 * To whom correspondence may be addressed (theo.brock@wur.nl).…”