||19 July 2012
Volume 13 Issue 7
More from Berlin
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- Session EM02C—Fate and Exposure Modeling
—Chaired by: Michael Matthies, Tom McKone, Bernhard Gottesbüren
Fate and exposure modeling of general chemicals and pesticides have been integrated into one joint session for the first time. It is recommended to continue it in future SETAC conferences. Between 100 and 200 participants attended the 24 platform presentations. Some overarching issues could be taken away from the session.
Persistence has been and continues to be reported as a strong indicator of potential for cumulative exposure—from humans to ecosystems and to biological receptors. Several papers revealed that persistent pollutants are important for addressing food-web exposures. Other talks revealed the importance of local environmental fate/distribution (indoor environments, local watersheds, etc.). Another theme that came across in many of the papers is the essential role that chemical properties play in defining exposures (to humans, to ecosystems, to any biological receptor, ) and exposure indicators (LRTP, persistence, bioaccumulation). Almost all of the papers addressed variability (the variation of inputs, observations, and measurements) and how this variability impacts the interpretation of results. Some of the papers also confronted the more difficult issue of uncertainty—particularly how the level of model detail or data gaps give rise to lack of confidence in results and conclusions.
The session gave us important insights on how scale is related to chemical properties and the unique exposure question. Fate models are increasingly coupled with GIS to take spatial variability of exposures into account.
Guidance for pesticide registration in the EU on exposure from covered crops and terrestrial soil exposure had been developed recently by the European Food Safety Authority (EFSA). It was found that emissions from covered crops may be substantial and might have been underestimated in the risk assessment in the past.
Soil exposure scenarios were developed by EFSA aiming at a 90th percentile of the PEC in space and time considering all fields in the North, Centre and South regulatory zones grown with the target crop where this active substance is applied. The types of ecotoxicologically relevant concentrations considered were both the concentration in total soil and the concentration in pore water averaged over different ecotoxicologically relevant depths (down to 0-1 cm). Scenarios were developed for the 3 regulatory zones (North, Centre, South) in the EU.
The ecotoxicological impact of the dramatic increase of the exposure concentrations in soil on the terrestrial risk assessment for earthworms was questioned and a method for adjustment of the relevant depth under real world conditions was proposed based on standard laboratory and higher tier field studies.
Applications of a process-based metamodel for pesticide leaching according to pertinent FOCUS guidance were presented for different geographic scales. Case studies for different EU countries were shown on how to determine the coverage of agricultural use areas by EU FOCUS scenarios and to develop, if necessary, national groundwater scenario.
For the case of nano-pesticides, the need was identified to substantiate the validity of current fate and exposure assumptions and where a differentiated assessment may be required.
Predicting herbicide leaching to field drains in a clay-dominated headwater catchment using MACRO model showed the significant value of combining modeling tools and experimental data in complex hydrological catchments.
- Session EP02—Endocrine Disrupting Chemicals: Recent Developments
—Chaired by: Jana Weiss and Åke Bergman
Almost 100 abstracts were received for this session, out of which 17 were selected for oral presentation. The platform presentations covered the topics about new bioassay developments in vivo and in vitro, measured EDC potency and EDC occurrence in the environment and risk assessments strategies. In addition, 4 posters were included the poster spotlight and 8 poster in the poster corner session to highlight interesting topics.
Raldua, D. IDAEA-CSIC, Spain. “Zebrafish eleuthero-embryos provides a suitable vertebrate model for screening thyroid gland disrupting chemicals.” A new promising in vivo assay (thyroxine-immunofluorescence quantitative disruption test [TIQDT]) was presented screening thyroid gland disrupting chemicals in zebrafish embryos. This method is fast, simple and a sensitive alternative method for assessing thyroid gland function disruptors and it was shown to have high concordance with published mammal studies.
Teta, C. National University of Science and Technology, Zimbabwe. “Detection of estrogenic and androgenic chemicals in waste waters and peri-urban water bodies in Bulawayo, Zimbabwe”. Estrogenic and androgenic potency were measured in water bodies in Zimbabwe for the first time. This study is important since this kind of data is lacking from several countries. High potency was measured in a dam in the vicinity of Bulawayo.
Orton, F. Brunel University, UK. “Mixtures of the most commmon antiandrogenic pesticides act additively in vitro: implications for risk assessment”. She investigated the mixture toxicity and mode of action of 37 pesticides. It was shown that compounds with the same mode of action (all agonists or antagonists) followed the concentration addition model, but when the mode of actions were mixed the model did not work. She also separated compounds with dual actions (both agonists and antagonists).
Brandsma, S. Institute for Environmental Studies, The Netherlands. “Endocrine and anti-androgenic potency of by-products in flame retardants”. Alternatives to the brominated flame retardants were tested for their endocrine-disrupting potency. One technical product was suspected to contain impurities that caused the toxic effect but it was shown to be the product itself. This study design is important for a correct evaluation of suspected EDC.
- Session EP06—Perfluorinated Compounds: From Emission Sources to the Place of Impact
—-Chaired by A. Dreyer
The aim of this session was to discuss new results and developments in the field of perfluorinated compounds with emphasis on emission data, environmental fate and transport as well as ecotoxicological findings. A wide range of abstracts covering all of these topics was submitted for poster and platform presentations. Interesting data of high quality about environmental processes were presented, particularly for soil and sediments, uptake into food and dietary exposure. For example, lysimeter studies and uptake experiments showed that PFCs move through solid matrices and are taken up by plants dependent upon the perfluorinated chain length. Interestingly, it was observed that food processing did not seem to increase PFC contamination. Although attempts were made to estimate emission strength on the basis of measured and modeled, it was concluded that knowledge about specific sources or emission rates as well as more of such studies combining field and model data are urgently needed. Several state and federal agencies shared their tremendously large amount of data in this session. This also showed the scientific potential of such data that is often not reported to the 'pure' scientific community.
- Session ET02—Advanced Statistical Methods in Ecotoxicology
—Chaired by David Fox, Elise Billoir and Wayne Landis
This session was extremely well attended. It brought together both researchers and practitioners who spoke on a range of statistical topics and issues relevant to the practice of ecotoxicology. David Fox and Wayne Landis spoke to the issue of “banning” NOECs/NOELs wile Elke Zimmer and Sandrine Charles convinced us of the need to devote equal time to the specification of an error model. Carol Forfeit highlighted the importance of proper statistical design in C-R experiments while Ross Smith emphasized the need to consider the variance of a response and not just the mean. Overall, a highly successful session that opens the way for a continuing dialogue on important statistical issues for ecotoxicologists.
- Session ET04—Bioavailability and Bioaccumulation—Impact of Environmental, Biological and Ecological Variation
—-Chaired by H. Selck
- Session ET05—Ecotoxicology and Ecosystem Services: A Southern Perspective
—Chaired by D. Nugegoda. A Weichman, V. Wepener
The aim of the session was to provide an opportunity for scientists from the southern hemisphere to present research results that explore interrelationship between the assessment and measurement endpoints of ecotoxicological studies that can be related to ecosystem services. In addition, presenters were encouraged to highlight different cultural valuations of ecosystem services. Six platform presentations addressed issues such as the use of risk assessment techniques to evaluate influences of climate change and multiple stressors on ecosystem services in the Murray (Australia) and Vaal (South Africa) River systems. Standard ecotoxicological endpoints were applied to evaluate pesticide effects in laboratory bioassays and field studies using economically important indigenous fish species in Argentina, Australia and South Africa. The session was closed with a presentation on risks associated with release of mercury from end-of-life main tailings. During the poster session, 17 posters were displayed related to application of ecotoxicological methods to assess exposure to environmental hypoxia, metals pesticides, PBDEs and bacteria. The application of models and indices to evaluate wetlands and river basins were also presented.
- Session ET06—Ecotoxicology of Amphibian and Reptiles: Novel Approaches for Linking Contaminant Effects with Population Declines
—Chaired by M.E. Ortiz-Santaliestra
- Session ET14—Bringing Ecological Processes into Ecotoxicological Risk Assessment
—Chaired by F. Pomati
Current procedures for ecotoxicological risk assessment still present significant uncertainties, and despite safety factors being applied, protection of ecosystems as a whole (in their structure and functioning) is not certain. Many ecological processes and characteristics (e.g., ecosystem sensitivity and vulnerability) that may enhance, buffer or simply mask real effects of chemical exposure in the environment are not considered in the current ERA.
In this session, we assembled 6 presentations, each addressing the sensitivity of higher-level endpoints (population and ecosystem) towards chemical stress. The endpoints that were discussed included energy transfer, trophic level/niche, community structure and population size. Both experimental and modeling approaches were covered. All the talks demonstrated that there is a two-way relationship between how ecosystems function and the effects toxicants have on the constituting populations. In conclusion, the session demonstrates that a step forward in ERA could be the embracement of ecological complexity in (experimental and modeling) approaches and establish causal relationships between toxic stress and alterations of ecosystem endpoint.
- Session ET15—Pesticide Fate and Ecotoxicology
—Chaired by A. Terry and G. Mitchell
Twelve platform presentations were exploring how “fit for purpose” the current risk assessment approach for pesticides is. We are all aware that it is not possible to test everything, under all possible conditions likely to be found in the real world. Compromises have to be made, because pesticides are an important part of food production in the world (and we need more food), but we don’t want to accept the status quo – it is important to be continually asking “is this test system appropriate?”. And to constantly be seeking to better understand exposure, effects and ecology, and, hence, to move closer to a truly sustainable model. Each of the presentations pushed at those questions, whether in the area of aquatics, terrestrial, single-species tests, ecological fate and effects or huge Chinese dam ecosystems.
- Session LC01—Development in Life Cycle Inventory Analysis and Modeling
—Chaired by T. Ekvall
We received more than 40 abstracts for this session, ranging from advanced methodological developments to pure case studies. For platform presentations we selected interesting methodological contributions, this year giving priority to presentations on consequential life cycle assessment (LCA) and to the use of economic models in LCA.
We saw examples of the combination of LCA and different types of models. Some of these are largely unknown to many in the LCA community: optimizing energy systems models, and economic partial and general equilibrium models. We also had presentations on the combination of LCA and input-output tables. Such hybrid LCA can be carried out in different ways (tiered, integrated hybrid, etc.), and it is becoming more widespread. It is potentially powerful, and it is good to see that our experience and expertise in the use of hybrid LCA grows.
The session included several contributions on the modeling of accidents in LCA, which is a novel area. In addition, we had platform presentations on dynamic modeling of climate impacts, including changes in the albedo, on the modeling of water use and water trade, and on the modeling of electricity production under a system of electricity certificates trade.
The fact that we had such presentations at this conference is a sign that the boundaries between LCA, energy systems analysis, and economics are dissolving. This means that a broader range of tools and methods will be available to LCA practitioners. Decision-makers, in turn, can then be supported by a more flexible and versatile analysis.
- Session RA 11—Guidance Documents and Guidelines for Environmental Risk Assessment (ERA): Needs, Developments and Progress
—Chaired by Robert Luttik
Paul Neumann (Ecological risk assessment of pesticides: linking non-target Arthropods testing with protection goals) summarized the results of the ESCORT 3 workshop. He was followed by Peter Matthiessen followed with an open view within OECD and guidance on how to assess endocrine disrupting compounds, particularly on how to interpret the test result. The third talk by A. Weyers "Ecotoxicological Assessment of Endocrine Disrupting Chemicals" presented additional views from industry on the same topic. C. Heiss "Environmental Quality Criteria (EQC): A Comparison of Methods Under Different Regulatory Regimes" brought a regulator’s view on EQCs to the audience. M.A. Daam and colleagues's "Representativeness of Eisenia fetida for the Environmental Risk Assessments of Pesticides to Soil Organisms" presented a critical review about appropriate testing species for soil risk assessments. A poster spotlight on molluscs started with a presentation of V.P., Ducrot and colleagues requested joining a ring test for mollusc reproductive toxicity tests. The same working group particular circumstances of the testing regime were presented in the following poster presentations. Finally a special poster corner on bee risk assessment showed that many groups are trying to improve risk assessment of bees (e.g., SETAC workshop, ICPBR, EFSA, OECD, and different universities).
- Session RA12—Health and Environmental Risk Assessment of Pesticides and Biocidal Products
—Chaired by A. Paya Perez
This session gave special emphasis to regulatory aspects of the biocides and pesticides, such as the implications of new data requirements for active substances under the future biocides regulation in Europe as well as policy and scientific challenges for the assessment of chemical mixtures that are relevant to biocides, plant-protection products and industrial chemicals regulations. A tool was proposed for calculating concentrations of toxicants in human organs with potential applications for the calculation of bioconcentration factors (BCF) in aquatic or terrestrial species; a dynamic crop model was presented that relates residue concentrations and intake from food to predict health impact and its uncertainty; and new models were showcased for the prioritization of the monitoring of chemicals in environmental compartments as well as on humans and workers exposed through air or food. This session offered many good ideas to share among scientists, practitioners and decision makers from Europe, Asia and overseas, and across regulatory frameworks on chemicals.
- Session RA17—Multiple Stressors in a Changing World
—Chaired by: Jenny Stauber, Mechthild Schmitt-Jansen, Kenneth Leung and Helmut Segner
Twelve platform presentations and 23 posters in this session focused on the effects of multiple chemical, physical and biological stressors on biota from the individual through to the population and community level in freshwater and marine ecosystems. The session was very well attended with more than 130 people in the audience. Most notable was the recognition that we need to move on from simply collecting empirical data to better use modeling approaches to predict interactive effects of multiple stressors, particularly in response to the future challenges of climate change, urbanization and land use change.
- Session RA19—Plants and Chemicals in the Environment: Risk Assessment, Pest Management and Phytoremediation
—Chaired by Gertie Arts
During this session several topics in plant ecotoxicology, plant testing, risk assessment and phytoremediation were discussed. Plants are at the basis of aquatic and terrestrial food webs, however they are often ignored in risk assessment. The new trend is that sediment-rooted plants gain more and more attention. Several lower and higher tier plant studies were discussed and risk assessments were reviewed. Sublethal endpoints are important when addressing effects of chemicals on plants. This might result in less production in the long-term to and change competition in plant communities. Uptake, accumulation and elimination studies in relation to toxicity get more attention and the first modeling of these processes is underway. Applying the capability of plants to change their chemical environment is a promising approach to be studied for the phytoremediation of contaminated ecosystems.
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