SETAC Globe - Environmental Quality Through Science
  19 July 2012
Volume 13 Issue 7

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Berlin Special Session—New Challenges for Ecological Risk Assessment

Marco Vighi, University of Milano

The Need for Challenges in Ecological Risk Assessment
The need for environmental protection was recognised around the middle of the last century. In particular, the emissions of chemicals produced by human activities in ecosystems, especially in surface water, were likely to produce effects at the sub-acute and acute level on natural populations. Therefore ecotoxicology was initially developed with the aim to provide answers to growing and pushing problems, even using relatively scarce information.

In the last few decades, ecological risk assessment (ERA) was based on simplified tools in order to provide methods suitable to be applied in support of chemical regulations. This pragmatic approach produced transparent and easy methods, applicable using the reduced information available, and allowed the development of many European directives and regulations, such as the pesticide and biocide directives, REACH, etc.

According to Van Straalen (2003), chemical control in the last few decades substantially changed environmental and pollution problems in developed countries. The quality of ecosystems improved and acute effects, likely to occur in the past, at least in surface water ecosystems, are now exceptional events, mainly related to accidental spills. Nevertheless, the problem of environmental pollution is far from being solved and the effects of anthropogenic stress factors are still capable of producing serious damages to ecosystems. One must be aware that the objective of environmental protection (and of ecological risk assessment) is protecting structure and functions of natural biological communities and ecosystems (CSTE, 1994).

In spite of their practical usefulness, the traditional tools generally used in ERA for assessing effects of chemical substances, mainly based on laboratory toxicological tests, suffer from a lack of ecological realism. Their capability to describe and predict the actual consequences on structure and functions of natural ecosystems is poor. The same comments may be made on exposure assessment, generally based on simple models applied to more or less standardised scenarios, poorly representative of the complexity and the variability of actual environmental conditions.

As a consequence, there is an increasing need for approaches capable of answering more complex questions than dose/concentration-response relationships can. To do this, it is essential to improve the predictive power of ecology and ecotoxicology for describing effects at the hierarchical level of communities and to increase the ecological realism of ecological risk assessment in order to better describe actual consequences for natural ecosystems.

Figure 1
Figure 1. The future development of ecotoxicology and ERA must be based on more complex tools than concentration-response relationships on a few selected species assumed as representatives of ecosystems.

These kinds of approaches are particularly relevant for some environment-oriented regulatory tools, such as the Water Framework Directive (WFD), the Marine Strategy Framework Directive and the forthcoming Soil Directive. In these directives, the approach is more holistic and the focus is on ecosystems and not on chemical substances (as for example in REACH). Therefore, these regulatory instruments require a site-specific or region-specific assessment, accounting for the vulnerability and the particular ecological values of the ecosystems.

In the frame of the activities of the scientific committees of the European Commission, DG SANCO (SCHER, SCENHIR, SCCS) a Working Group is focusing on “Addressing the New Challenges for Risk Assessment.” An opinion will be approved within the near future (September 2012). The environmental subgroup highlighted a number of relevant issues worth developing. Among them:

  • Increasing the ecological realism of exposure and effect assessment approaches
  • Assessing the effects of highly time-variable exposures
  • Covering the gap between effects at cellular- or individual-level and consequences to ecologically relevant endpoints
  • Assessing the vulnerability of natural biological communities and ecosystems
  • Assessing the role of indirect ecological effects of stressors
  • Assessing the interactions between combined stressors and environmental factors
  • Developing trait-based risk assessment
  • Improving ecological modelling
  • Improving the scientific bases for the statistical assessment of uncertainty and for the development of extrapolation approaches

The objective of the special session was to involve a wider audience in a discussion of the main issues highlighted by the Working Group, particularly to involve stakeholders from regulatory agencies and industry in the discussion. The opinion of these stakeholders is particularly relevant considering that new tools should be realistically applicable for regulatory purposes, in practical risk assessment procedures. Moreover, it perfectly fits with the SETAC mission of joining academic, industrial and regulatory points of view.

Special Session Program
The Special Session lasted for a whole day. After a series of planned invited presentations, much time was spent in a free, brainstorming, discussion.

The program of the invited presentations is described below.

  1. Introduction of the Chair:
    • Marco Vighi (University of Milano Bicocca, Italy): The need for more ecological realism in ecological risk assessment procedures
  2. The main topics developed by the European Working Group
    • Antonio Di Guardo (University of Insubria, Como, Italy): Exposure assessment in ERA: from current tools to new approaches
    • Colin Jannsen (University of Gent, Belgium): Environmental effect assessment and risk characterization of chemicals: What's wrong and how can we do it better?
    • Volker Grimm (UFZ, Leipzig, Germany): Mechanistic effect modeling for ecological risk assessment: state-of-the art, trends and challenges.
  3. The point of view of academia
    • Valerie Forbes (University of Nebraska, Lincoln, USA): Addressing complexity in ecological systems – ignore it or embrace it?
    • Theo Brock (Alterra, Wageningen, The Netherlands): Priorities to improve ecological risk assessment for chemicals
  4. The point of view of regulatory agencies
    • Liisi Vakra (ECHA, Helsinki, Finland): Regulatory point of view (focused on the implementation of REACH) on the new scientific challenges for ecological risk assessment on hazardous substances
    • Henning Clausen (Danish EPA, Copenhagen, Denmark): An opinion of a regulator on the possibilities for applying more ecologically relevant effect assessments
  5. The point of view of scientist working in industry
    • Peter Campbell (Syngenta, Bracknell, UK): Addressing the new challenges for risk assessment: An industry perspective
    • Peter Dohmen (BASF, Limburgerhof, Germany): Environmental risk assessment-Basic principles, future trends - View from an industry employed environmental scientist on “Addressing the new challenges for ecological risk assessment”

The open discussion highlighted the huge interest in the issues. Even if, as expected, different points of view were expressed by the three components of the SETAC community (academia, industry and regulators), there was a general consensus on the need for substantial improvements in ecological risk assessment for the 21st Century.

Main Message
Some important messages, arising from the presentations and from the open discussion in the Special Session, may be synthesized as follows.

  1. There is the need for more ecology in ecotoxicology. For the future development of ecotoxicology and ERA approaches, a change in the scientific paradigm is necessary, moving from simplified approaches toward more complex tools capable to explain the complex interactions among all the components of an ecosystem and between these components and the multi-stress factors potentially present.
  2. Relevant research efforts must be developed in the near future. The progress of ecotoxicological science in the last few years allowed a substantial improvement in ERA, producing tools and information for improving ecological realism (SSD, higher-tier testing, etc.). However, a big research effort is needed for the development of new tools as sound as necessary for a practical regulatory application.
  3. Different approaches may be needed for different regulatory tools. Chemical-based regulations (e.g., REACH) must provide the basis for placing chemical substances on the European market. In these cases simple tools applicable to a “general” European environment are needed. Therefore, currently used ERA approaches may be improved but a conceptual change is not expected in the short or medium timeframe. On the contrary, environment-based regulations (e.g., WFD) require site-specific assessment that must consider the complex characteristics of ecosystems. In these cases, ecosystem assessment becomes an essential component of ERA (Figure 2).
  4. Ecological modeling is a fundamental tool. The need for describing, understanding and predicting the behavior of communities and ecosystems subject to multiple stress factors cannot be based only on experimental work. For the future development of ecotoxicology and ERA ecological modeling is the most promising tool. At present, ecological modeling it not yet developed enough for regulatory purposes. Therefore it must be considered as an important priority for future research.

Figure 2
Figure 2. Simplified scheme of the traditional ERA approach (above) compared with a more ecologically based approach (below) where the assessment of specific characteristics of ecosystems represents an essential component of risk characterisation


  • CSTE/EEC - Ecotoxicity section (F. Bro-Rasmussen, P.Calow, J.H.Canton, P.L.Chambers, A.Silva-Fernandes, L.Hoffmann, J.M.Jouany, W.Klein, G.Persoone, M.Scoullos, J.V.Tarrazona, M.Vighi) (1994): EEC water quality objectives for chemicals dangerous to aquatic environments. Rev. Environ. Contam. Toxicol. 137: 83-110.
  • Van Straalen NM 2003. Ecotoxicology becomes stress ecology. Environ. Sci. Technol. 37:325-330

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