Summaries Published in the October 2019 Issue
Kirsten Schannong Jørgensen, Finnish Environment Institute SYKE; Diane M. Orihel, Queens University Canada; and Thomas-Benjamin Seiler, Institute for Environmental Research RWTH Aachen University
The effects of oil spills on aquatic and marine environments are of global concern. The damage caused by oil spills to local ecosystems may depend on factors, such as the type and volume of the spill, the substances released, the location, the time of year, the organisms affected, along with other factors that may affect the extent and level of this damage. The types of oils drilled, refined and transported vary greatly in their characteristics, making both environmental risk assessments and selection of oil response strategies highly complex. This session examined new developments in tracking the fate and transport of chemicals from oil spills as well as applying new approaches to assessing their biological and ecological effects in ecosystems. Emphasis was given to new developments in toxicological screening methods, developments in monitoring techniques of chemical constituents and biological systems, and tracking toxic effects at the population and ecosystem level (e.g., adverse outcome pathways). The session covered presentations that advance our understanding of the impacts of oil spills on freshwater and marine ecosystems, as well as presentations that discussed mitigation strategies to reduce these impacts.
The session was attended by around 100 experts. It featured several novel studies focusing on the exposure of biota to the water accommodated fractions (WAF) of crude oil and dilutions of these in order to represent realistic concentrations of in situ concentrations of spilled oil in the water column. The impact of chemical dispersants as a means of oil spill response was assessed in a number of poster presentations. In situ exposure to diluted bitumen was assessed in freshwater systems by using large-scale limnocorrals, which is a large, submerged mesocosm. Diluted bitumen is a large Canadian problem due to the large use and transport of this natural resource.
First, Diane Orihel (Queens University, Canada) presented the results from a large limnocorral experiment in a Canadian lake. In this experiment, permission was obtained to release diluted bitumen into the IISD-ELA (International Institute for Sustainable Development) Experimental Lakes Area, a unique freshwater facility situated on the Boreal Shield in northwestern Ontario, Canada. They studied the effect of diluted bitumen at different trophic levels, such as prokaryotes, zooplankton, amphibians and fish. Orihel concluded that the community structure of planktonic organisms was changed due to exposure. Data are still being produced on the effect on the higher trophic levels.
Next, Tomasz Ciesielski (Norwegian Technical University) presented data obtained in the EU-H2020 project GRACE (Integrated oil spill response actions and environmental effects) on effects of North Sea Crude Oil WAF on copepods. This exciting presentation showed that effects can be observed not only in conventional biomarkers, but also in the metabolome of the organisms, e.g., in amino acids and in malonate.
The third presentation by Sarah Johann (RWTH Aachen University), also from the GRACE project, went one step further and presented effects on zebrafish of oil in the water phase (WAF) on the expression of genes encoding for enzymes using transcriptomics. These impacts correlated well with the effects on the enzyme activity, the mobility on the zebrafish embryos and effect on the eye development in zebrafish. This novel analysis provides an initial understanding of the underlying processes leading to the disruption of biological functions.
Another very important feature to take into account when assessing impact of oil in the environment after a spill is that the baseline level and the variation of the biological parameters must be known. This was nicely assessed by Dennis Benito (University of the Basque Country), also from the GRACE project. Benito showed that mussels from two different salinities in two different seasons in the Baltic Sea had a different level of a number of biomarkers. This is important when assessing pollution scenarios in the Baltic Sea.
Katherina Softcheck (Smithers) showed that different algae exhibit different sensitivity to WAF of weathered CTC oil from the Deepwater Horizon spill. Therefore, further algal toxicity testing beyond standard species like Skeletonema sp. may be needed to better evaluate oil toxicity to algae.
Three poster spots gave a fresh presentation of interesting news on the effects of three different oil types in the presence of dispersants and the effects of sub-lethal concentrations of crude oil on cod embryos. The last poster presentation made recommendations for a more standardized way of analyzing effects of difficult chemicals, such as oils and dispersed oils, which are not very soluble in water.
Conclusions of the Session
Novel methods like metabolomics and transcriptomics are new, very sensitive methods to observe effects of oil compounds at sub-lethal concentrations. These methods were also found to correspond to observed enzymatic and apical effects.
Low concentrations of oil are more relevant for the assessment of the likely concentrations in the environment after a spill. The use of water accommodated fraction (WAF) and dilutions hereof has shown to produce relevant concentrations and help to reveal effects at sub-lethal concentrations.
However, the chemical analysis of WAF and its dilutions using more standardized analytical methods is needed also in toxicity studies to measure the actual concentrations of total petroleum hydrocarbons and of single compounds and different relevant groups of oil hydrocarbons. The actual concentrations are also needed when comparing the effects of dispersed oil to non-dispersed.
The natural variation in biomarker levels in mussels in the Baltic Sea depends on the season and salinity, and this must be taken into account when collecting baseline information on these parameters.
More toxicity background data from a larger number of species and trophic levels is needed in data bases to broader assess impacts of oils.
Juliska Princz, Environment and Climate Change Canada; Mark Maboeta, North-West University, South Africa; Bettina Hitzfeld, Swiss Federal Office for the Environment; Janine Wong, Centre Ecotox, EPFL ENAC IIE-GE; and Silvia Pieper, German Federal Environment Agency
Recently, the United Nations Environment Assembly (UNEA) adopted a resolution to address soil pollution within the global environmental, agriculture and food security, and health agendas; the resolution acknowledges that soil is one of our largest reservoirs of biodiversity, and forms the basis to which ecosystem services are anchored (UNEA 3 resolution 6). Therefore, an integrated approach across science and policy research and development is required to prevent, control and manage soil pollution. To this end, we must constantly assess whether current ecotoxicity and risk assessment and management regimes offer sufficient soil protection to sustain biodiversity and ecosystem services (e.g., nutrient cycling, water purification, climate regulation, etc.), as well as responsible resource development.
The session gathered soil ecotoxicologists and risk assessors, and brought forth 18 platform presenters, six poster-corner presentations and 35 posters, spanning two days. All contributors recognized the heterogeneous nature of soils, and the complexity involved when trying to incorporate these unique elements, balanced against biodiversity, structure and function, into a coherent toolbox of ecotoxicological and risk assessment tools. The sessions were divided into three major categories for discussion: new and emerging issues to soil pollution, new methodological advances to soil ecotoxicological testing, and the evaluation of current and new risk assessment approaches.
New and emerging issues included:
- Climate change acts as a stressor to soil biodiversity, including function and chemical-soil-organism interactions. Maria Gonzalez-Acaraz (University of Aveiro) presented an integrated research approach to examine how current global trends (e.g., changes to soil moisture content, temperature, UV radiation and atmospheric CO2) affect biotic and abiotic components of metal-contaminated soils. Carla Sofia Pereira (University of Coimbra) demonstrated that changes in salinity, moisture and temperature (individually and combined) influenced life-cycle parameters of earthworms in soil. Catarina Malheiro (University of Coimbra) also observed changes in avoidance behavior when soil organisms were exposed to metal-contaminated soils under various climate stressors.
- Land-spreading of organic materials (e.g., biosolids, biochar, manure) as a method of amending soils, but also minimizing waste was further discussed in this session. Edward Stutt (WCA Environment Limited) presented a risk assessment of land-spreading, highlighting the need for a broad initiative to compile and generate data for multiple contaminants (e.g., pharmaceutical, veterinary medicines, industrial chemical) to derive robust predicted no-effect concentrations (PNEC) applicable across Europe and beyond. This sentiment is echoed by the UNEA’s resolution for the promotion of coordinated data collection and management, and information-sharing (UNEA 3 resolution 6). Marta Jaskulak (Czetochowa University of Technology) introduced plant biomarkers beneficial to the assessment of toxic phyto-metals in sludges, and Marija Prodana (University of Aveiro) demonstrated the integration of ecotoxicological tools (laboratory and field-based assessments) to optimize biochar amendment to soil, ensuring low-risk to soil organisms.
New soil ecotoxicological methods were also presented:
- Clemence Thiour Maauprivez (University of Perpignan) developed a toolbox to monitor the abundance, composition, diversity and activity of soil bacterial communities in response to herbicide application; micro-organisms are often considered as non-target organisms but have a critical influence on soil function through nutrient cycling. Non-target effects also played a significant role in the development of a new bionematicide delivery system to agriculture plants, as explained by Tiago Natal-de-Luz (University of Coimbra), wherein impacts on soil diversity of non-target arthropods and microbial function will be integrated into field evaluations. Sebastien Höss (Ecossa) linked standard laboratory tests with the nematode Caenorhabditis elegans to field-based microcosms, demonstrating the suitability of this standard test for the protection of in-situ communities. The development of a new Canadian and International Organization for Standardization (ISO) standard was introduced by Juliska Princz (Environment and Climate Change Canada) to expand the suite of available test species to include oribatid mites, an under-represented species in soil testing. Maria Kovacevic (University of Osijek) introduced a new biomarker for efflux pump activity in enchytraeids, and Tamara Djerdj (University of Osijek) demonstrated the use of artificial intelligence as an innovative way to map earthworm avoidance and activity in contaminated soils.
The evaluation of approaches to risk assessment focused on plant protection products (PPP) were also discussed. Within the scope of the European Plant Protection Regulation, the European Food Safety Authority (EFSA) published a scientific opinion on the state of science aiming at improving risk assessment for in-soil organisms. The scientific opinion takes into account regulatory frameworks and scientific development, with in-soil organisms serving as the drivers of ecosystems services within soil. Highlights included:
- The need for multi-species test systems and the inclusion of alternate exposure routes. Leticia Camargo (University of Coimbra) presented the incorporation of contaminated prey in predator-prey soil tests to reflect realistic exposure scenarios. Furthermore, she, and another presenter, Claudia Lima (Vrije Universiteit), stressed the importance of Species Sensitivity Distributions to capture the breadth of response across different types of organisms.
- Inclusion of off-field soil exposure and risk assessment. Gregor Ernst (Bayer Ag) presented an innovative approach to the design and modeling of off-field exposure, taking into consideration runoff, erosion and drift, but also spatial-temporal exposure scenarios. Vanessa Roeben (Research Institute gaiac) also stressed the importance of spatial-temporal exposures, in particular for earthworms, wherein movement and burrowing activity are affected by different exposure scenarios. This brought forth the need to consider ecological aspects of different species to bridge the gap between exposure and effect assessments in soil.
- Consideration of non-target species within the risk assessment approach. This was discussed as part of new methodological approaches to soil ecotoxicological testing (e.g., new test species, the inclusion of non-target impacts)
It is clear from the session that soils play an integral part to our global research community, and although we have come a long way in the evolution of ecotoxicological and risk assessment, the scope of research and emerging issues presented suggests our work is far from complete. We must continue to contribute more data across more substances, characterize and integrate ecological and functional aspects, improve our characterization of exposure, and embrace the collective integration of data and approaches globally to ensure remediation and risk assessment and management goals are indeed protective. We thank all contributors to the poster and platform sessions and encourage consultation with the abstracts for further information.
Joop de Knecht, Dutch Institute for Public Health and the Environment; Vaiopoulou Eleni, Concawe; and Lepper Peter and Tissier Chrystele, European Chemical Agency
A special session was organized on “Unknown or Variable Compositions, Complex Reaction Products and Biological Materials (UVCBs).” Presenters in this session discussed the challenges and approaches in testing and regulating UVCBs, which can contain a large amount of constituents that could be (partly) unknown or variable. Consequently, it is not easy to characterize, test or assess the environmental risks of these substances to make regulatory risk management action.
The first part of the session started with presentations on the challenges in testing UVCBs from a regulatory and industry perspective. Presentations on performing hazard assessments for petroleum substances and natural complex substances, taking into account the variability in composition, followed. The key points of the presentations included:
- Chris Tissier (European Chemical Agency) presented a perspective from regulatory authorities on how to regulate multi-constituents and UVCBs in an effective and proportionate manner. Tissier highlighted a different test strategy, based on the challenges mentioned above, and suggested that a weight-of-evidence approach for UVCBs might be needed. Tissier emphasized that it needs to be recognized that testing the whole substance does often not provide information of the properties of individual constituents and that the composition in the environment might be different from the test solution. It is important that the uncertainties associated with various approaches are understood by regulators to ensure appropriate actions can be taken.
- Delina Lyon (Shell) highlighted that from industry’s perspective there is still limited guidance on how to assess UVCBs. She presented a brief overview of UVCB hazard assessment approaches that are fit-for-purpose and pragmatic, including adaptation of existing methodology for persistent, bioaccumulative and toxic (PBT) testing, grouping substances into categories, and in silico approaches.
- The ongoing program of Concawe was presented by Louise Camenzuli (ExxonMobil), who addressed PBT assessment, including how to capture the variability of different potential isomers across petroleum substances.
- Karen Jenner (Givaudan) gave a presentation on the environmental risk assessment (ERA) of natural complex substances (NCS) based on a guidance document developed by the International Fragrance Association. The guidance document considers assessment based on specific constituents, block of constituents and information of the NCS itself. Case studies from the guidance document were presented to demonstrate the challenges in performing ERAs of NCS.
In the second half of the session, several presentations were given on recent developments of new approaches and learnings in testing and assessment of UVCBs, including reflection on dealing with remaining uncertainties:
- Aaron Redman (ExxonMobil) addressed how, with different models (PETROTOX and PETRORISK), the variability and uncertainty in the PBT and ERA of petroleum substances could be addressed. To improve transparency and predictability in the decision-making process, he advocated that in the PBT assessment the uncertainty should be addressed with a weight-of-evidence approach using different lines of evidence, especially higher-tier evaluation data.
- Paul Thomas (CEHTRA SAS) presented a method to determine the environmental risk of complex substances, based on a combination of an in silico generated whole-substance approach to determine the toxicity for pelagic organisms with the equilibrium partitioning method to extrapolate effects on benthic organisms. An activity-based approach was proposed to normalize the relationship between the toxicity and exposure by each constituent in order to determine a homogenous Risk Characterization Ratio (RCR) for mixtures.
- Philipp Mayer (Technical University of Denmark) gave an outline of his research project, UVCB-FATETOX, focusing on the toxicity and bioaccumulation of persistent UVCB constituents. An important objective of this project is to develop approaches for fate-directed assessment based on new analytical methods, dosing methods, fate directed fractionation, toxicity testing and models. He presented information from the first work package focusing on combining state of the art dosing and analytical techniques.
- Violaine Verougstraete (Eurometaux) presented the methodology developed by Eurometaux for the assessment of inorganic UVCBs based on constituents-based approach that can be used, including substance identification to risk assessment and risk management measures (RMMs) designation.
After the presentations, the panel discussed the instrumentation that needs to be developed to best support industry in ensuring safe use of UVCBs and multi-constituent substances (MCSs) and authorities in regulating them appropriately.
The panel highlighted that a testing strategy needs to be developed in close cooperation with all stakeholders, including academia, industry and regulators, which should also help to create a common understanding on what is technically feasible in characterizing and testing the constituents in an UVCB.
Depending on the regulatory target and the complexity or type of UVCB, different approaches, parameters and testing methods could be followed from whole substance testing to fractionation or testing representative structures, using techniques such as water accommodated fraction (WAF) or passive dosing. Approaches have to be defined that are fit-for-purpose where classification and labeling may require a different approach than risk or PBT assessment. Though, these approaches could also complement each other. Lessons can be learned on what has been developed for whole effluent testing. A weight-of-evidence approach can be used depending on the data that are available.
It was noted that a lack of knowledge of the full composition of an UVCB increases the concern of regulators. Therefore, maximizing efforts to characterize the full composition of the UVCB is key. However, for a number of UVCBs a fraction of the constituents may remain unknown, and there is a need to find a pragmatic way in accepting the remaining uncertainties. With respect to the PBT assessment, the threshold of 0.1% may also be challenging with respect to isolation and testing the constituents in question.
Anna Barra Caracciolo and Vera Terekhova, Moscow State University; José Julio Ortega-Calvo, IRNAS-CSIC; and Kamila Kydralieva, Moscow Aviation Institute
Green technologies, such as bioremediation and phytoremediation, can be an effective, cost-competitive and environmentally friendly alternative to the thermal and physico-chemical technologies more traditionally used for remediating soil and water ecosystems and removing organic and inorganic pollutants, emerging contaminants and chemical mixtures. This session comprised case studies from French, Russian, Italian, Spanish and Germany research groups. Presentations detailed example applications of compost, biochar, humic products, bio-surfactants, microbial fuel cells both at lab and field scale. Following the presentations, discussions focused on the effectiveness of different treatments in biostimulating contaminant degradation and the selection of bacterial strains from environment for bioaugmentation purposes.
A high interest for the session was expressed through the lively and interactive discussion among all the participants.
The key points for the 12 presentations included:
- Loic Yung from Université De Bourgogne Franchecomté showed the potential source of tree biomass from phytomangaed sites for bioenergy and energy-recovery techniques (e.g., combustion, gasification, pyrolis).
- Jose Julio Ortega-Calvo from IRNAS-CSIC presented innovative strategies for a controlled enhancement of pollutant availability for biodegradation with the aim of reducing execution periods and costs of bioremediation.
- Elisa Terzaghi from University of Insubria reported greenhouse experiment data on PCB rhizoremediation of an aged contaminated soil from a National Relevance Site (SIN) in Northern Italy.
- Anna Barra Caracciolo from IRSA-CNR showed the role of natural microbial communities in promoting PCB biodegradation in a poplar-assisted bioremediation strategy applied in a field study in Southern Italy.
- Yuan LI, University of the Highlands and Islands, evaluated the potential use of various low-cost natural waste (biosorbents) for the removal of pharmaceuticals from water.
- Galina Vasileva, Institute of physicochemical and biological problems in soil science RAS, proposed the use of adsorbents for accelerated bioremediation of petroleum-contaminated soils.
- Erika Berenice Martinez-Ruiz, Technical University of Berlin, presented the results of cyanotoxin biodegradation using manganese oxidixing bacteria.
- Vera Terekhova, Moscow State University – Soil Science Faculty, showed the potential of humic products in decreasing the content of available species of heavy metals in contaminated soils.
- Nadezhda Kudryasheva, Institute of Biophysics SB RAS, illustrated the antioxidant and toxic properties of humic substances with a bioluminescent enzymatic assay.
- Elena Fedoseeva, Russian National Research Medical University, Moscow, described the structure and dynamics of microfungal communities in soils with different humus content and metal pollution.
- Oleg Trubetskoj, Russian Academy of Sciences, showed the use of the electrophoretic approach for characterizing soil humic acids.
- Fabienne Battaglia-Brunet, Universitie d’Orleans and BRGM, reported the selection of amendments to decrease the mobility and toxicity of inorganic pollutants (Pb, As, Ba, Zn) in a mine tailing in order to develop a phytoremediation process.
The session made clear a couple key aspects to take into consideration for the success of bioremediation strategies such as organic contaminant bioavailability for biodegradation or sorption and phytoconcentration for heavy metals. Finally, the potential combination of bioremediation (e.g., phytoremediation) with providing valuable sources of renewable biomass is in line with the sustainability criteria of the Renewable Energy Directive (RED). The biomass cultivated for plant based remediation purposes in metal polluted soils can be thermally treated (combustion, gasification, torrefaction and pyrolysis) and used as potential fuel (biofuel, bioliquids) for obtaining bioenergy. In this context, it is necessary to develop common best practice guidelines at a European level and to establish contaminant concentration threshold limits for the use of biomass for energy production.
Summaries Published in the September 2019 Issue
Denis Mottet, European Chemicals Agency; Joel Tickner and Molly Jacobs, University of Massachusetts-Lowell
The progressive substitution of hazardous chemicals with safer alternatives contributes to the overarching EU objectives for a non-toxic environment and promotes a circular economy wherein innovation and sustainable production and consumption are key elements. However, the need to rethink conventional substitution approaches—typically the search for a “drop in” replacement from the same chemical group—has become apparent in recent years. Concepts such as functional substitution and safe-by-design are increasingly recognized, and advances in the methodologies and tools to support analyses of alternatives are improving informed substitution initiatives.
Despite the progress made, the scientific expertise in and the practical experience with the analysis of alternatives, substitution and sustainable chemistry innovations are not widespread yet. In this context, in January 2018 the European Chemicals Agency (ECHA) published a strategy to promote substitution to safer chemicals through innovation. The strategy focuses on four areas of action:
- Capacity building on analysis of alternatives and substitution
- Facilitation of access to research funding and technical support for substitution projects
- Facilitation of access to relevant data to avoid regrettable substitution
To support ECHA’s substitution strategy and encourage further discussion on informed substitution in the scientific community in Europe, ECHA co-organized this special session together with the University of Massachusetts-Lowell, a thought leader in the science of alternatives assessment and in engaging stakeholder dialogues on the topic of informed substitution.
The special session aimed at providing an overall perspective of the context in which substitution of chemicals of concern takes place and the tools to support the transition to safer chemicals, from analysis of alternatives as a response to regulatory requirements to sustainable chemistry and safe-by-design approaches. Participants were invited to discuss the needs and opportunities for better integrating the substitution of hazardous chemicals with innovations in sustainable chemistry and the role of the different stakeholders in this process.
The meeting attracted significant interest among the 200 participants and led to lively discussions.
The key points of the presentations of the first part of the session included:
- Molly Jacobs, University of Massachusetts-Lowell, talked about the current landscape of the science of alternatives assessment and pointed out new elements that are included in some alternatives assessment frameworks, such as considerations of the broader life cycle, new resources and tools for addressing data gaps in hazard assessments, as well as insights from recent decision-analysis and decision-making research.
- Elke Van Asbroeck, Apeiron-Team NV, presented an example of a recent analysis of alternatives conducted in the regulatory framework of the REACH Authorisation process. The team adopted a two-step approach, starting with the consideration of a broad range of potential alternatives, followed by a more in-depth assessment of the alternatives identified to have the highest potential for success. A key lesson was that assessments are context dependent. In some cases it makes sense to invest in long-term innovations, while in other cases incremental changes in technologies may be most effective.
- Considering the ever-tightening regulatory scrutiny on biocidal antifouling, Julian Hunter, Akzo Nobel N.V., described a particularly innovative approach for the development of an alternative to conventional products that embeds UV-LEDs in a protective film. He described the challenges in assessing chemical to non-chemical alternatives, as well as in adopting fundamentally new technologies.
- In addition to the responsibility of industrial stakeholders in considering substitution of hazardous substances, David Santillo, Greenpeace, highlighted the role of civil societies in promoting substitution. Santillo described how non-governmental organizations were able to collaborate with industry and policy makers to advance the replacement of hazardous chemicals.
The second part of the session built on the first one and focused on the design of new chemistries, addressing the following issues:
- Fergal Byrne, University of York, gave a presentation on the efforts of the Green Chemistry Centre of Excellence and provided the example of the design of two new solvents derived from non-food carbohydrates to replace toluene and n-methyl-2-pyrrolidone (NMP). He outlined an approach that can pave the way for the selection of alternatives to other hazardous substances.
- A broader perspective on the challenges and opportunities in relation to sustainability aspects of chemicals and products was presented by Peter Fantke, Technical University of Denmark. Fantke described how the use of spatial models and data per product type, the combination of chemical and product life cycles, and the setting of sustainability targets could help in this field.
- To approach hazardous substances already at the chemicals and product design stage, Jochem van der Waals, Dutch Ministry of Infrastructure and Water Management, presented the Dutch Government’s initiative to move from substitution to safe-by-design approaches through the Horizon Europe funding program, including examples of selected thematic research and development topics.
- Joel Tickner, University of Massachusetts-Lowell, talked about the connections between analysis of alternatives and safe-by-design innovation using the Preservatives Collaborative Innovation Challenge program of the Green Chemistry & Commerce Council as an example. He noted that when existing options may not represent great improvements over the chemical of concern, using the tools of analysis of alternatives can help carve out design needs for new options.
Conclusions From the Session
The session confirmed the growing interest of the academic community, regulatory agencies and industry in the field of assessment of alternatives to hazardous substances, safe-by-design approaches and the development of the underlying methodologies. Participants emphasized the need for adopting a broader sustainability perspective in chemical, material and product design and called for better integration of methods and tools to enable their application in concrete cases.
When it comes to the design of new products, ensuring from the start that the production and use will be safe along the life cycle, the so-called safe-by-design approach is certainly one way forward.
Several priority research themes have been proposed; it is up now to the relevant stakeholders to collaboratively address the various challenges, aiming at a more sustainable way of manufacturing and using products. New interdisciplinary professional collaborations, such as the Association for the Advancement of Alternatives Assessment (A4), provide an important venue for discussion of methodological gaps, best practices and training needs that will help advance the field in the future.
The importance of the role for agencies in better linking research and development resources to regulatory and market needs for safer chemicals has also been highlighted. This is key to support the transition to safer, more sustainable chemicals and products and to build an effective circular economy.
This session, organized at the initiative of ECHA, showed the benefit of bringing together experts from different disciplines to discuss the various elements necessary to move towards sustainable chemistry. It also demonstrated how the agency’s strategy on substitution could be a catalyst for initiating and interconnecting actions in this field of growing importance.
John Elliott, Kim Fernie, Environment and Climate Change Canada; Veerle L. B. Jaspers, Norwegian University of Science and Technology; and Nico van den Brink, Wageningen University
Wildlife, including birds, mammals, reptiles and amphibians, have provided many of the most compelling examples of the effects of environmental contaminants on populations and even whole ecosystems. Increasingly, research on vertebrate wildlife, particularly sampling of top predators, must be non-destructive and ideally non-intrusive due to concerns with animal welfare. Thus, exploration of effects mainly entails use of tools such as fecal, hair, feather and blood sampling with a focus on measurement of sub-lethal responses at, for example, molecular, biochemical and behavioral endpoints. This session organized by SETAC members from Europe and North America included five platform sessions, three poster spotlight mini-talks (with 60 to 125 attendees) and 20 posters. Presentations covered the range of biological levels of organization, from examination of molecular immune responses in small mammals to field behavioral ecology in gull species.
The session began with a talk by Diego Garcia-Mendoza, Wageningen University, on immune system effects of trace metals in small mammals. His presentation provided insights in mechanistic dose–response relationships between exposure to cadmium (Cd) and modulation of cell types of the innate and acquired parts of the immune system. It showed that effects of Cd were different in the different cell types. For instance in macrophages, Cd exposure resulted in an increase of pro-inflammatory TNFα, while in mast cells the production of TNFα decreased. This indicates that contaminants may have differential effects on specific parts of the immune system, which hampers generalization of effects and indicates the need for in vivo validation.
This presentation was followed by a broad-scale assessment of a range of emerging pollutants, persistent organic pollutants, metals and rodenticides in the urban terrestrial environment of Oslo, Norway, by Dorte Herzke, Norwegian Institute for Air Research. Generally, a large variety of the compounds were found in the investigated matrices (including air, soil, earthworms, birds and mammals) and the authors were able to identify some previously unknown point sources within the city. Levels of organic pollutants, especially polychlorinated biphenyls, were much higher in the top predators (sparrowhawk eggs), while metals were much higher in earthworms than other species. Per- and polyfluoroalkyl substances (PFAS) were present in most of the investigated sample types, and emerging PFAS were also detected. Biota near ski-trails contained more PFAS. Short-chain chlorinated paraffins (SCCPs) were present in all air, soil, fox, sparrowhawk and tawny owl samples, indicating a ubiquitous distribution in Oslo.
The subsequent presentation by one of the co-chairs, John Elliott, Environment and Climate Change Canada, expanded on the topic of rodenticide exposure of predatory and scavenging birds and focused on how to assess the effects of such exposure on survival and particularly recovery from trauma injuries caused by sublethal effects on blood clotting capacity (complementing Poster TU-240).
The fourth talk of the morning was presented by Åsa Berglund, Umea University, and examined multiple stress responses caused by exposure to heavy metals in a population of small insectivorous birds (Ficedula hypoleuca), breeding in an area of Finland impacted by lead contamination from mining and smelting. They used hemoglobin (Hb) levels as an indicator of bird health and examined interactions between metal accumulation (both essential and non-essential), habitat type and food availability to assess direct and indirect effects of mining. A key finding was that availability of terrestrial flying insects, connection to water and distance to the mine were more important than variation in Hb levels, indicating that the indirect effects of mining activities and specific food items, in addition to habitat, played important roles in the overall health of the birds.
The final full talk of the session was by Catia Santos, Ghent University, who investigated the possible effects of mercury exposure on parental foraging strategies and offspring quality in a population of a coastal gull species. They conducted a series of field studies as well as an experimental aviary study (dietary exposure). Significant effects of Hg were found on DNA damage and body condition of the chicks while increased input of Hg during post-hatch development was associated with a decrease in early development and physiological condition of the chicks. Thus, the use of marine sources by the birds increased maternal and parental input of Hg, which may have negative effects on offspring quality.
The session closed with five-minute speed talks from three posters:
- The in vitro modulation of transcriptional activity of nuclear receptors of Baleen whales by environmental pollutants was investigated by Katherina Luhmann, Norwegian Polar Institute. Baleen whales, such as fin whales (Balaenoptera physalus) and blue whales (musculus), were reported to be affected by multiple stressors, including exposure to pollutant mixtures.
- A field study in apple orchards to assess exposure and effects of a fungicide on the European Rabbit (Oryctolagus cuniculus) by Olaf Fuelling, Tier3 Solutions GmbH. They found no indication that rabbit reproduction was affected by the test item application.
- Validation of dynamic energy budget physiological models for small mammals was examined by Andre Gergs of Bayer AG – Crop Science Division. They determined that their models were particularly suitable to analyze chemical effects on life-history traits related to growth and reproduction.
The session was complemented by 20 posters. Poster topics were diverse and included several interesting studies on top predatory birds and mammals from both northern and southern European locations. Other studies were of pest control products in orchards and of a variety of endocrine endpoints in diverse species. Several posters detailed mechanisms of toxicity using in vitro approaches, for example, on immunomodulation in white-tailed sea eagles and waterfowl and effects of contaminants on cell proliferation. Results from large-scale monitoring of PFAS in birds of prey, as well as essential and non-essential metals in marine harbor porpoises, and rare metals from e-waste in eagle owls were presented. The posters showed not only the broad range of topics within wildlife toxicology in general but also the applicability of results of wildlife toxicity studies for environmental risk characterization and assessment of chemicals. This session continued the now long tradition of diverse and interesting work on vertebrate wildlife being conducted by researchers in Europe and elsewhere, and in particular how the science of wildlife ecotoxicology has been widely used in risk assessments, and in assessments and monitoring of success of remediation activities at the local, national and international levels. Presentations were high quality and intellectually stimulating and provided a broad overview of the field of wildlife toxicology to the audience.
Ondrej Adamovsky, Masaryk University, and Marie Simonin, Duke University
Microbiomes are not only keystones of soil fertility, water quality and performance of engineered ecosystems but also major drivers of plant and animal health. Due to a recent decrease of sequencing cost, there are an increasing number of a broad spectrum of toxicologists that study the effects of stressors on microbiomes.
In this session, researchers presented new experimental results on the response of microbial communities to a great diversity of chemicals (e.g., nanomaterials, pesticides, phthalates, triclosan, copper) and toxins (e.g., cyanobacteria). The session gathered scientists from aquatic, terrestrial and wildlife ecotoxicology who presented results on fish, soil, sediment, biofilm, invertebrates or bird microbiomes. Though many studies still focus on the common model organisms (e.g., zebrafish, medaka or gammarus), there is increasing tendency to cover non-model species or communities such as fish, benthic, river and periphytic communities. The session clearly showed that the various environmental chemicals have a potency to significantly modify microbial communities and thus their functions for ecosystem or host health.
To connect the chemical dependent microbial shift with the physiological outcomes of the host or ecosystem, the scientists presented latest bioinformatics approaches that help predict metagenome functional content from 16s rRNA gene (e.g., PICRUSt, Tax4fun). In addition, a study on the effect of phthalate of zebrafish gut microbiome successfully adopted and presented a new bioinformatics approach that can predict the effect of tested chemicals on levels of microbial bioactive metabolites. However, 16s RNA amplification or sequencing and metagenomics are currently the standard technologies for microbiome studies, a very innovative proof of concept study suggested that mass spectrometry (MS) can be used to determine taxonomic and functional characterization of the microbiota. Advances in MS instrumentation and bioinformatics provide the ability to detect thousands of taxon-specific proteins and peptides, which can be used for deep characterization of organisms present in a sample. The functionality of microbial communities can then be directly assessed by inferring the functions of the corresponding proteins. New bioinformatic approaches were presented in the session, and these methods open new possibilities in microbiome research. Specifically, the prediction of the changes in microbial metabolic capacity can help link microbial shifts in community structure with an adverse effect on the host health or ecosystem functioning. As discussed, such approaches would be crucial for an Adverse Outcome Pathway (AOP) concept, where a shift in microbial community composition would be one of the key events.
The session also stressed the need to adopt better data-sharing practices that would allow the scientific community to conclusively assess the effects of various natural and anthropogenic stressors on microbiota in all types of environments. A newly introduced project, The Microbiome Stress Project, was developed to identify how consistent microbiome responses are to the same stressor within the same environment, if there are there common microbiome responses to different stressors within the same environment, and if a stressor imposes consistent effects on microbiomes across multiple environments. The presented approach is a unique example of meta-analysis that would benefit both scientists and regulators. A large spectrum of collected data would be useful to determine the healthy or most common microbiome for a specific organism, but this information is not currently available.
Generally, the session and discussions emphasized the role of microbiomes in environmental health and introduced microbiomes as key endpoints or ecological indicators in environmental monitoring. Researchers working in environmental and microbial ecotoxicology suggest using latest approaches to understand the functional outcomes of the change of the microbial community and to link the microbial shift to ecosystem functions and the adverse outcomes of the ecosystem or the host. Last, but not the least, there is an apparent lack of data sharing, which we need to overcome as this would help put the pieces of the puzzle together to support the evidence about the toxicity of chemicals on complex microbial communities and to understand the principles behind the toxic effects.
Jessica Legradi,VU Amsterdam; Riccardo Massei, UFZ – Helmholtz Centre for Environmental Research; and Jorke Kamstra, Utrecht University
It is well known that fish species present several advantages compared with other model organisms, especially when it comes to ecotoxicological studies. In fact, the biological and ecological variability existing among fish species allows their use in many different research fields from human medicine up to environmental monitoring. Additional advantages of fish are the applicability of different life stages (from embryo to the adult) with unique characteristics and sensitivities. In this context, it was our intention to present in the session “Fish model species in human and environmental toxicology” a heterogeneous selection of presentations and posters covering many aspects of the ongoing research with fish model species. In particular, we aimed for a comprehensive overview on the state-of-art in the fields of -omics, behavior and molecular analyses. Despite a clear dominance of classical species (i.e., Danio rerio and Oryzias latipes), attention was also given to novel upcoming species that are currently used mostly in local studies but with great potential for future ecotoxicological studies. As in the last years, the session had an outstanding participation characterized by a great interest along all three presentation blocks, the poster sessions and the poster corner.
The first part of the session had a major emphasis on the growing field of -omics, focused on the application of modern toxicogenomic and target metabolomics techniques to gain deeper insights into complex toxicological mechanisms. We were pleased to discover that there is a growing attention for the application of molecular techniques in environmental monitoring and risk assessment.
-Omics techniques can now potentially help the determination of sex in juvenile Danio rerio before the main sexual traits appears. Despite specific set of genes (i.e., dmrt1, nr0b1, igf3, and cyp17a1) can be routinely monitored by qRT-PCR, new sex differentiation genes were discovered by using next generation sequencing (NGS) techniques. Such technology could help to understand how the gender could influence specific compound sensitivity. It was shown that toxicogenomic and bioinformatic techniques are powerful tools to understand the link between adverse outcome pathways (AOP) and transcriptomics. The new technologies help us get a deeper insight into the fish toxicogenomic universe and how transcriptomic changes are influenced by uptake and elimination processes. Additionally, researchers are trying to improve classical chemical risk assessments by using modern -omics approaches. Fish lipidomics profiles are useful tools as biomarker of exposure as demonstrated by the change of several lipid pathways in a compound-specific manner. Non-targeted GC-HRMS approaches were used to explore new metabolomic patterns in Oryzias latipes embryos helping to understand the toxic effect of polychlorinated (PCBs) compounds. Target metabolomics data were presented for native individuals of the marine species Salmo salar. The results confirmed that different POPs may affect the transcriptome and proteome more than the origin of the fishes. This outcome opens countless possibilities for the routine application of -omics techniques for environmental monitoring.
The second part of the session was focused on the analyses of behavioral patterns in different fish species. Attention was given on the application of new endpoints applicable for the detection of specific compound classes (i.e., neuroactive chemicals). Most presentations focused on novel behavioral tools for Danio rerio embryos, such as the assessment of potential damages of the lateral line by measuring rheotaxis using a multi-flow system, but behavioral tests with other fish species were also presented. For example, Nothobranchius furzeri (killifish) is an upcoming model organism for behavior ecotoxicological studies that can produce reproducible and relevant results in a short time.
Scientists are also trying to clarify the link between molecular mechanisms, morphology and changes in behavior. It was shown that thyroid disruptors (i.e., polybrominated diphenyl ethers or BDE) can inhibit the developmental larval vision system starting from the transcriptional level and, consequently, induce changes in larval behavior and morphology. In this particular study, an optokinetic test was able to assess the capacity of Danio rerio larvae to distinguish colors (blue, red and green). Danio rerio larvae were also used to assess the neurotoxicity of imidacloprid, a common neonicotinoid widely used in agriculture. The main goal of the study was to understand the link from molecular mechanism and organ toxicity and to build an AOP. The main advantage of such an approach is the possibility to predict toxicity for different exposures and in different species, which is a clear step from classical toxicology to system toxicology. However, not only chemicals can be neurotoxic. One presentation was studying the effect of ionizing radiation on the central nervous system for the development of new biomarkers for the exposure to physical stressors.
Besides novel behavioral assays, work was also presented on the improvement of widely used and existing assays. It was demonstrated that the use of single assays might not be enough to distinguish between neurotoxic mechanisms. A combination of different behavioral tests might improve this. Although analyzing such data is difficult, results from several tests can be combined in a 3Rs (replacement, reduction, refinement) assessment. Interestingly, nearly all presentations showed an increased sensitivity of the applied behavioral test compared with more standard apical endpoints (e.g., dead or malformations), which clearly highlights the importance of those test methods.
In the third and last session, we selected studies made with a wide variety of different fish species. A particularly interesting study showed the possible comparisons of the OECD 240 for Oryzias latipes with other fish species aiming for an extension of the guideline to additional fish species. New insights into different exposure scenarios were also presented. Results confirmed changes in effect according to the exposure scenario, mostly related to the different uptake and elimination kinetics. This would mean that the application of different exposure scenarios (i.e., media versus yolk microinjection) would help get a better understanding of the compounds’ absorption, distribution, metabolism and excretion (ADME). New imaging technologies were shown to be able to make 3D reconstructions of melanomacrophage in Myoxocephalus scorpius.
A poster session followed the oral presentations, with nearly 50 posters about a variety of different toxicological studies using different fish models and touching upon the main topics that were presented earlier. Finally, a poster corner reflected again the wide scope of the session with presentations covering topics as varied as bioaccumulation studies in zebrafish embryos at different pHs, metabolics of environmental extracts and local assessments of Salmon health in the Baltic Sea.
With respect to the years before, the session “Fish model species in human and environmental toxicology” in Helsinki showed again an increase in participation. This year’s SETAC Europe meeting had 363 abstracts containing “fish,” which is almost 20% out of a total of 1,924 poster and platform presentations, many of which were presented at other sessions. This substantiates the interest in using fish in ecotoxicology and as a model for human health. Moreover, fish early life stages are still widely used in ecotoxicological studies due to their unique characteristics. In parallel, we assisted to a progressive evolution of the approaches used to deal with unknown mechanistic processes taking place in the organisms. In fact, many research groups are now working on several levels of organization to achieve a full understanding of the toxicological mechanism behind the effects. Scientists are using more and more state-of-the-art methods and showing a deeper interest in technologies available in other scientific fields (i.e., microscopy, informatics, analytical chemistry). There is an increase in studies trying to find a link between gene expression and behavioral patterns, and multivariate statistic approaches are now common to link chemical pollution to effect data. As we already stated last year, the times of simple dose–response lethality curves, identifying only at what concentrations toxicity is caused, have clearly passed. Several steps forward were made, but there is still a long way to go to make these techniques accepted in toxicological risk assessment.
Based on the great success of this session, we are looking forward to the contributions for the SETAC Europe 30th Annual Meeting, which will be held from 3–7 May 2020 in Dublin, Ireland.
Summaries Published in the August 2019 Issue
Farhan R. Khan, Roskilde University; Dorte Herzke, Norwegian Institute for Water Research; Louise Lynn Halle, Roskilde University; and Zhanyun Wang, ETH Zürich
Plastics and synthetic rubbers pervade almost every single aspect of our life. They offer many benefits. However, the current linear make–use–dispose economic model and a lack of proper holistic management have resulted in serious environmental and societal issues. New developments in occurrence and exposure routes, ecotoxicological impacts and risk assessment were the focus of this session. At the SETAC Europe 29th Annual Meeting in Helsinki, we discussed these topics and engaged in constructive debates regarding the future direction of microplastic and tire rubber research with regard to chemical release. The session comprised five platform presentations and 13 posters, including three poster spotlights.
A major theme of this session was the release of chemicals from food packaging; how best to identify them and classify their hazard. Although plastic food packaging is used for protecting food and extending shelf-life, it contains a suite of known and unknown chemicals that may potentially migrate into the food and present a risk to consumers. The work of classifying this potential risk has been undertaken by ECHA in combination with industry as shown by Andreas Ahrens (ECHA). Their approach was to produce a substance list of additives (419), which were then modeled for release potential by way of ranking the potential risk of the additive. Different classes of release potential (low-, medium- and high-release potential) were set. An alternative approach was outlined during the session by Ksenia Groh of the Food Packaging Forum Foundation, who presented a database of Chemicals (in CPPdb) associated with plastic packaging compiled using publicly available sources. Hazard ranking of the included chemicals was based on existing classifications such as a persistent, bioaccumulative and toxic (PBT), very persistent and very bioaccumulative (vPvB), or as an endocrine disrupting (ED) substance. Based on this analysis, phthalates are considered a candidate for substitution in plastic packaging. An analytical approach was offered by Yelena Sapozhnikova of the U.S. Department of Agriculture with particular focus on the chemicals found in plastic stretch film (cling film). A non-targeted analysis using LECO Pegasus 4D GC×GC/TOF-MS to identify extracted compounds revealed a number of chemicals that could potentially move into food from packaging. Quantitative tools to estimate the amounts of migrating chemicals into food simulants and real foods are very helpful to provide data for risk assessment.
The emerging research area of car tire rubber emissions and related leached chemicals was an important theme of this session. Although recognized as a major contributor to the environmental microplastic burden, Merel Kool of Wageningan University presented that tire rubber has received comparatively little attention and addressed both the presence of tire particles in the environment and the potential ecotoxicological impacts on terrestrial and aquatic organisms. Pieter Jan Kole of the Open University of the Netherlands described a detailed study accounting for tire particles entering the environment from road wear and tear. Nuno Ratola of the University of Porto described environmental issues with a focus on crumb rubber used on synthetic football pitches. Research regarding toxicological effects is still in its infancy, but studies evaluating aquatic systems (Louise Lynn Hallee, Roskilde University) and terrestrial systems (Salla Selonen, Vrije University) highlighted the challenges of assessing the impacts of tires and their related chemicals.
This was a well-attended session, which reflects the concerns surrounding the exposure of chemicals via plastics and rubbers. Only by appreciating the challenges that still lie ahead in prioritizing, detecting and understanding realistic emissions of plastic and tire rubber particles into the environment can solutions be found. These solutions will be critical to accurately assess environmental impacts and risks, and to answer the growing concerns of both the public and policymakers.
Jaana Laitinen, European Chemicals Agency (ECHA); Ricardo Carapeto García, Spanish Medicines Agency AEMPS; Silvio Knäbe, Eurofins Agroscience Services Ecotox GmbH; and Robin Sur, Bayer AG
The session covered 12 talks on the environmental risk assessment (ERA) and risk management of pesticides, biocides and veterinary medicines (VM) by representatives from academia, authorities and industry.
The first half of the session focussed on higher–tier hazard assessment methods such as mesocosm studies, field studies and monitoring studies with a specific view on improving their reliability and meeting regulatory requirements. Higher-tier studies are an integral part of the assessment of pesticides in the context of registration of plant protection products (PPP) with the aim to better understand what happens in the real environment. They are also used in the regulatory assessment of biocides and veterinary medicines, though to a lower extent.
It is widely accepted that higher–tier studies provide an increased level of realism into the risk assessments as they cover, for example, different routes of exposure and environmental–species interactions. However, at the same time questions emerge with regard to extrapolation of higher–tier study results to other environmental conditions.
The session started with a talk by Aoife Parsons, Institute of Marine Research, presenting predicted environmental concentration of two VM active substances used in salmon farming in the marine environment and linking the exposure levels to the lethal and sub-lethal effects on the European lobster (Homarus gammarus). Melissa Staggs, Smithers Viscient, presented another example related to aquatic toxicity testing by describing practical experiences and challenges with copepods as test species. Based on this project, Staggs made recommendations for an alternative test species for the purpose of developing a species sensitivity distribution (SSD).
In regulatory assessments, among the most important aspects are reproducibility and coverage over time. The importance of a good dialogue between test facilities, risk assessment and risk management was highlighted in the study design of a mesocosm study in order to increase the statistical power and to derive robust community–level endpoints. In her presentation, Marie Allen, Cambridge Environmental Assessments, illustrated how to improve the reliability of mesocosm studies through higher subsampling or generally increasing the sampling effort. By improving the methodology, the acceptability in the regulatory assessments can be increased as well.
In addition, evidence was provided on terrestrial field studies as a valuable tool by the example of non-target arthropod field studies. In the presentation by Frank Bakker, FB Consultant, pesticides higher-tier off- crop test data of old studies was analyzed to check if the field test is reliable. Furthermore, some new work was showing that there is action at a distance at least for the springtails that were tested in a small field study.
Another example from terrestrial environment was provided by Anja Russ, tier3 solutions GmbH, on birds in the agricultural landscape. Russ proposed that this higher–tier test design could be included in the upcoming revision of the EFSA guidance on the risk assessment of birds and mammals. This example suggested that monitoring studies can provide information from exposure and effects in realistic circumstances and in ecologically relevant species. In addition, comparison of the results from standard and higher-tier studies was possible due to the aligned study endpoints. Russ also gave an example of a possibility to provide guidance and standardization for monitoring studies, which is a requirement for regulatory acceptance.
Maria Blázquez, Inkoa Sistemas, demonstrated that further work is needed for addressing the knowledge gap between the environmentally relevant metabolite and the regulated substances in question with an example from biocides. While in most cases the metabolite is less toxic, there are cases where the metabolite is showing higher toxicity. Blázquez suggested that one possible way to improve understanding of relative toxicity of the metabolite compared to the parent substance was to build up a database (LIFE-COMBASE project) on the observed hazards of the different substance.
The first half of the session showed that improved higher–tier study designs could be an essential corner stone in risk assessment, which is becoming more comprehensive. Based on the presentations, it was shown that there are agreements as well as mismatches between expectations and reality. It was highlighted that field studies and monitoring studies could provide realism into the regulatory assessment in comparison to lower–tier, laboratory–based standard tests.
Risk Assessment and Risk Management
In the second half of the session, the focus was on risk assessment and risk management under chemical regulations. Related to the exposure assessment of biocides, Heike Schimmelpfennig, ECHA, presented the latest guidance developments together with an introduction to the risk assessment tool EUSES 2.2.0. The presentation illustrated the constant development and improvement of guidance for regulatory exposure and risk assessment.
Regarding pesticides, it became clear that risk mitigation measures play a critical role in reducing emissions from agricultural fields. As shown in the presentation by Anne Alix (Corteva Agrisciences), a vast variety of measures is available (MAgPIE toolbox), but the regulatory implementation is in some areas lagging behind. In addition, new ideas to regionalize and adapt mitigation strategies to local conditions were highlighted by Gertje Czub, German Federal Office for Consumer Protection and Food Safety, as a promising strategy to pursue, rather than prescribing inflexible measures on the product label.
Regarding pharmaceuticals, all the presentations focused on VMs, specifically on novel methodologies for the exposure calculations and on the refinement of the risk characterization. In relation to the exposure calculations, the audience benefited from the gained experience of Competent Authorities (USFDA, Center for VM). The active substances and risks to the environment are to some extent the same regardless the legal framework in operation, but the approaches followed can be different in Europe and the US. Regarding the refinement of the risk characterization, the speakers gave interesting views and proposals for supplementing the current ERA in those cases where a risk is identified. The works presented might be very useful tools for better characterizing the risks for the environment when the current predicted effect or no-effect concentration (PEC–PNEC) methodology is surpassed. The local and spatial scale of the impacts were analyzed in the models proposed. These approaches might be implemented to reinforce the grounds of the decision-making process of the VM.
With regard to the relationships of regulatory assessment of biocides, pesticides and VM, the session was helpful for finding synergies between the different frameworks. For instance, the environmental exposure estimation for certain product types of biocides or risk mitigation measures for pesticides have relevance to the VM area as well. Therefore, it is anticipated that the lessons learned in the different frameworks can be shared across the sectors. Consequently, there is potential to make the assessments more efficient by exchanging experiences between biocides, pesticides and VM both from industry and the perspective of authorities. To this aim, it is important to keep following and be aware of developments in all the three areas as efforts could be reduced and alignment between the approaches can be achieved where relevant, for example, related to the development of testing methods and risk mitigation measures. For this purpose, SETAC Europe provides an opportunity for the represented sectors to continue the communication.
Furthermore, the session illustrated and reminded us about the importance of the link and dialogue between risk assessment methods (and their development) and risk management in order to address the correct protection goals in a meaningful way. The balance between continuous development of ever more complex risk assessment methods and guidance, and risk management was warranted.
Silke Gabbert, Wageningen University & Research; Monika Nendza, Analytic Laboratory; and Oliver Warwick, Peter Fisk Associates Ltd
The objective of this special session was to increase the visibility of socio-economic analysis (SEA) within the environmental science community and to foster an open and constructive dialogue between environmental chemists, toxicologists and economists on:
- Examples and experiences of SEA applications
- Methodological, empirical and policy challenges regarding the application and implementation of SEA
- Opportunities for improving SEA as decision-support tool in a regulatory context
Several key speakers were invited to discuss different aspects related to the application of SEA. Christoph Rheinberger, ECHA, presented “SEA under REACH: State-of-play and areas for improvement.” He presented the European Chemicals regulator’s experience of SEA to date and reflected on some learning points as well as specific areas for improvement. Daniel Slunge, Gothenburg University, elaborated on estimating impacts in his presentation “Incentives for truthful reporting in seeking authorization for using substances of very high concern.” Slunge discussed mechanisms such as taxing the continued use of otherwise banned substances and reductions to the tax based on a proportion of the estimated benefits. Jessica Coria, Gothenburg University, discussed the bias in regulatory action in her talk on “Political economy of inclusion on the REACH candidate list of substances of very high concern.” This theme was considered further by Isabel Hilber, Agroscope, who reviewed 24 restriction dossiers using principal component analysis to identify the main drivers for bans on specific uses of substances. Hilber recommended a more structured approaches, including “decision rules” for selecting risk management options and an application of “SMART” criteria. The wider impacts of risk management on circular economy were considered by Hugo Waeterschoot, Eurometaux, from the metals industry perspective, and Arianne de Blaeij, RIVM, from the regulators’ perspective. Possible bans to control the risks of substances can also lead to limitations on the recycling of materials and thus act as a barrier to recycling (conflicting policy goals). Approaches to consideration of wider human welfare and tiered approaches were exemplified by Hilber and de Blaeij.
The session concluded with a panel discussion in which the speakers and chairs engaged with the audience to focus on the main issues in socio-economic analysis and to gauge if the session was of value and continued interest. The auditorium was packed, with standing room only at the back, which the chairs considered a good indication of interest for this session at SETAC. Discussion points raised at the panel session included the effectiveness of SEA, potential biases in the assessment, the challenge to quantify (environmental) risks, and the use and integration of qualitative and quantitative methods. Finally, different options for valuing impacts were discussed, with the example of the sale value of sunscreen products versus the health value in terms of disease prevention. Overall, the session provided a good overview of the current status of SEA in chemicals regulation. At the same time, challenges for future research were pointed out. For the further exchange, the formation of a SETAC Interest Group was suggested, and possible participants are welcome to contact the session chairs.
Summaries Published in the July 2019 Issue
Mikko Nikinmaa, University of Turku
As there was standing room only in the 100-seat meeting room, the session must have been timely. The outset of the session was that we always discuss changes in the mean value of our measurements when evaluating environmental effects, hardly ever attaching any significance to variation. However, sexual reproduction maximizes the variability of offspring to parents. Variability is the basis for natural selection and consequently evolution. These statements are generally accepted. In view of this, it is amazing that individual variability is relegated to noise or error in much of experimental biology – we traditionally talk about “standard error of the mean” and “confidence interval.” Notably, the error component, which relates to inaccuracies in measurements, represents only a small percentage of variation in biological measurements.
Although variability is not thought to be an important endpoint, it is actually assessed in most publications. The homogeneity of variance is tested in order to evaluate if parametric statistical testing of the mean can be done, if data transformation (e.g., logarithmic transformation) must be performed before parametric testing is possible, or if one must resort to non-parametric statistical testing. When reading toxicological and physiological publications, one starts to get the feeling that many if not most of them showed that data were heterogeneous. Therefore, Mikko Juhani Nikinmaa and Katja Anttila, University of Turku and session chairs, conducted a literature review and found that heterogeneity was reported more than 80% of the time where heterogeneity or homogeneity was reported at all. Thus, the original gut feeling that the different experimental groups had different variances and further, that changes in variances could be an important component of environmental responses, appeared correct.
With the above premise at the outset of the session, the talks further explored the reasons for the individual variation and its changes. All the talks were focused on aquatic animals; the importance of individual variability in ecotoxicology is clearly recognized there. When thinking of the natural environment, the uptake and transfer of toxicants (across the placenta in mammals) can be time- and condition-dependent, as shown by Rosie Williams, Zoological Society of London, on porpoises. This means that even when one thinks that the exposures to toxicants are similar, they can be different. When animals are experiencing environmental exposure, a marked confounding factor is the existence of cryptic species. These may differ markedly in their responses to toxicants as discussed by Mirco Bundschuh, University of Koblenz-Landau. Individual variation both in invertebrates and fish can also result from genetic variation and adaptations, as discussed for corals and molluscs by Silvia Franzellitti, University of Bologna, and for fish by Eduarda Santos, University of Exeter. The effect may depend on the life stage of the exposure, whereby individual differences can be epigenetic in origin. Quite often the responses are repeatable (i.e., one individual consistently responds in a constant manner). Methodology for studying such individual differences on small crustaceans was introduced by Jan Heuschele, University of Oslo; however, even after accommodating the possible cryptic species, genetic and epigenetic effects, individual variability remains, as indicated by our studies on Daphnia, which are clonal (i.e., genetically identical). The results unequivocally showed that water-soluble fraction of crude oil decreased the variability of oxygen consumption rate of Daphnia without affecting its mean value.
As a conclusion from the session, it is quite clear that changes in individual variability can constitute an important component of environmental responses. The factors behind individual variation can be many. The available literature does not enable us to evaluate the role played by variation in environmental responses, since the data have invariably concentrated on the mean. It could be very valuable for environmental biology if scientists re-explored their datasets concentrating on changes in variability instead of the mean. This would give us information about the role of changes in variability in environmental responses very rapidly.
Author’s contact information: email@example.com
Neus Escobar, University of Bonn; Daniel Garrain, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (Ciemat); Diego Marazza, University of Bologna; and Tarmo Räty, Natural Resources Institute Finland
Bioeconomy constitutes a priority area in the transition towards resource-efficient and low-carbon economies. According to the definition given by the European Commission, bioeconomy refers to “the production of renewable biological resources and the conversion of these resources and waste streams into value added products, such as food, feed, bio-based products and bioenergy;” hence, sharing a common ground and similar objectives with the circular economy strategy. Indeed, the European Commission has recently put forward an action plan “to develop a sustainable and circular bioeconomy” by strengthening and scaling up the bio-based sectors while understanding the underlying environmental constraints.
This paves the way to the development of new processes while taking advantage of synergies at both technological and policy levels. In practice, it is about implementing cascading uses of biomass to minimize the loss of both material and value across life cycles, traditionally linear. But is this really viable and, most importantly, sustainable for bio-based industries? Concerns arise among stakeholders on actual recyclability potentials of waste streams and marketability of new products.
Life cycle assessment (LCA) can provide science-based answers to these questions. The general aim of the session was to assess the sustainability benefits brought about by technological innovation and circularity in key bio-based sectors from an LCA perspective while exploring the associated methodological challenges. Contributions covered a wide range of products, such as biopolymers and soil products, and multiple system configurations, such as biorefineries and industrial symbiosis. A special focus was put on forest products, which play a big role in Nordic economies. The relevance of these topics was underpinned by the lively discussion among the participants, which included representatives from academia, industry and consulting firms.
Most of the presented case studies pointed out the influence of modeling assumptions in the environmental performance of systems that involve recovery and recycling. This is especially the case for industrial symbiosis networks, which entail the exchange of by-products, wastes and energy between several firms to generate a portfolio of products. As highlighted by Michael Martin, Swedish Environmental Research Institute, the so-called “system expansion approach” allows for comparative assessments although uncertainties arise in the products being replaced, which can only be tackled by means of scenario analysis. This hinders assessments vis-à-vis a counterfactual scenario since there is no such process delivering the same functions.
The growing interest in biopolymers and their applications was also reflected in the session. Mathilde Vlieg, VliegLCA Consultants, showed that recycled plastics can be more environmentally friendly than bioplastics such as polylactic acid (PLA) plastics, depending on the impact category. The audience then discussed additional limitations of both recycled plastics and bioplastics for specific uses due to their mechanical properties.
There is a lack of suitable indicators capturing the impacts of marine litter, and Almudena Hospido, Universidad de Santiago de Compostela, pointed out that this may lead to the underestimation of the environmental advantages of bio-based and biodegradable polymers.
The session also drew attention to the need for indicators that better capture flows of carbon and other biological materials along the product lifetime, which prove crucial in the assessment of biomass- and wood-based value chains.
Two of the contributions explored the application of LCA for bio-product certification. Kari-Anne Lyng, Ostfold Research, discussed the modeling choices to enhance LCA for policy development and environmental certification, respectively. While policy support requires applying the “system expansion approach” for prospective assessments, environmental product declarations (EPDs) require partitioning to avoid double-counting and ensure the additive nature of the results. In the context of bio-waste recycling, the latter implies that waste generates zero environmental burdens upstream, which was contested by the audience. Finally, Tarmo Räty, Natural Resources Institute Finland (Luke), highlighted the shortcomings of EPDs based on average data, which assume uniformity of production. Although EPDs constitute a powerful tool to communicate on the environmental performance of products, these can be misleading in the case of wooden materials since the inherent properties of wood are neglected.
In conclusion, the session showed that there is still a long way to go for the standardization of the LCA methodology for the systematic assessment of circular life cycles and biorefineries. Further harmonization is needed, especially for the cut-off criteria in defining the system boundaries in order to enhance the applicability of LCA for bio-product certification and labeling. Work should be carried out with the objective to provide a reliable tool to strengthen the market position of the most sustainable products while informing consumers and public procurers. The session encourages further dialogue between practitioners and stakeholders, and the session chairs will explore the possibility of organizing further meetings in this regard.
Miguel Gonzalez Pleiter and Francisca Fernandez-Piñas, Universidad Autónoma de Madrid
The use of plastics has increased over the last five decades. In fact, 348 million tons of plastics were produced around the world in 2017. As a consequence of their widespread use, many plastics end up in the ecosystems causing harm to marine and terrestrial life. In this context, the importance of the smaller fractions, nanoplastics, has only been documented in recent times. Despite the fact that the presence of nanoplastics in the environment is poorly known due to the difficulty to detect them in real samples with the current methods, indirect evidence of their presence has been previously shown, and it is likely that nanoplastics are being produced and accumulated in the environment right now.
Nanoplastics, like other nanomaterials, have unique properties due to their size, shape and capacity to interact with other substances because of their large surface area. Nanoplastics can cause physical damage and may also be transported across cell membranes. In this regard, mechanistic approaches are needed in order to understand their risk for the environment at different levels of biological organization (whole organism, population and communities) and human health. The chemical composition of plastics makes them conveyors for non-polar anthropogenic pollutants, supposing an additional risk factor for which very little is known.
This session aimed at:
- Gathering the information required to evaluate the risk posed by nanoplastics to the environment and human health in real-world scenarios
- Identifying the components of potential outcome pathways at different levels of biological organization from molecules and whole organisms and ecological responses. For this, special attention was paid to the mechanisms of nanoplastic internalization and to their toxic action by using suitable biomarkers as indicators of cytotoxicity, cell viability, oxidative and genotoxic damages. The use of high-throughput techniques (RNA-Seq and proteomics) may allow the generation of biomarkers (genes and proteins) of global importance in the elucidation of the biological effects of micro and nanoplastics. At the higher levels of biological organization, it is important to consider structural changes at the level of population and communities
- Discussing the role of nanoplastics as vectors for other pollutants
The session attracted high interest, initially 27 abstracts were submitted resulting in the delivery of five platform presentations and two poster spotlights. These were selected in order to cover as many of the main goals of the session as possible.
The second platform by Paride Manecca, University of Milano, presented biointeractions and toxicity of microparticles from waste plastics in in vitro and in vivo systems. The effects on human alveolar A549 cells were size-dependent, with the smaller microplastics inducing a decrease in cell viability and an increase in proinflammatory cytokine release. For aquatic environments, Xenopus laevis embryos were exposed to the microplastics, finding that they accumulated into the gut, where lesions at the intestinal mucosa level were evident, together with microplastics in contact or internalized into epithelial cells.
In the third presentation, Yooeun Chae, Konkuk University, reported on the trophic transfer of nanoplastics and the dietary effect, using plant and snail in terrestrial ecosystems. Chae confirmed the adverse effect of nanoplastics on soil organisms and their transfer via food exposure in soil.
The fourth presentation by Marco Vighi, IMDEA Water Institute, dealt with polystyrene microbeads’ uptake, tissue distribution and toxicity on zebrafish embryos. It also covered their sorption capability for triclosan. Adsorption analysis showed that triclosan can adhere to microplastics’ surface, and this outcome underlined a potential synergistic effect of microplastics and other pollutants on aquatic organisms.
Carolin Schultz, Centre for Ecology and Hydrology Wallingford, presented the last platform, which was titled “What’s on the outside matters – surface charge and transformations affect toxicity of polystyrene nanoparticles to Caenorhabditis elegans.” The bio-nano interface appeared as an important parameter to understand the effect of nanoplastics on organisms.
Sixteen posters were selected for the session. Among these, two were also presented as poster spotlights. The first spotlight, by Alicia Mateos Cardenas, University College Cork, dealt with the impacts of polyethylene microplastics on freshwater duckweed and reported no negative effects. The second spotlight, by Miguel Pleiter, Universidad Autónoma de Madrid, reported on the release of secondary nanoplastics from biodegradable microplastics, which were found to be toxic to aquatic primary producers and consumers.
The session was very successful; the congress room was completely full. The discussion was fruitful and dynamic with lots of questions and comments.
In conclusion, the presented works tried to address the question of whether the smallest fraction of plastics may pose a threat to environmental and human health:
- Some works demonstrated that this kind of materials may be harmful for some organisms of ecological relevance, while in other studies it was not so clear that they could be considered as toxic.
- The fact that secondary nanoplastics derived from the degradation of biodegradable plastics are toxic to the aquatic biota highlights that biodegradable plastics may not be as harmless as considered right now. Much more research is needed in this area.
- Plastic may behave as vectors of adsorbed pollutants, but more studies are needed in order to understand the toxicological consequences.
- Trophic transfer has been demonstrated both in aquatic and terrestrial environments, which poses a serious risk for the environment and human health.
Svetlana Patsaeva, Lomonosov Moscow State University; Elena Krasnova, White Sea Biological Station; Artem Poromov, Lomonosov Moscow State University; and Tatiana Kuznetsova, Scientific Research Center for Ecological Safety at the Russian Academy of Sciences
Costal aquatic ecosystems formed through the interaction of marine and terrestrial environment need special approaches and methodologies to evaluate their functioning and require special attention in the terms of their evolutionary development and anthropogenic impact. Ecological monitoring of sub-Arctic meromictic water bodies is essential for studying their evolution under the action of global climate change and other natural processes; it becomes extremely important when solving such practical problems as construction of tidal power plants, seawalls, bridges and other hydraulic structures leading to the separation of water areas from the sea.
This session was targeted to give an overview of the current physical methods, biomonitoring tools and strategies used towards ecological monitoring of aquatic environments mainly in the regions of the White and Baltic Seas. These unique ecosystems are the focus of attention of scientists like biologists, physicists, geologists, chemists as well as scientists from other disciplines. Trans-disciplinary collaboration is necessary to study coastal ecosystems in Northern Europe with the aim to improve environmental quality and predict environmental challenges for sustainable development of this region.
The platform and poster presentations covered two main topics: (1) evolution and environmental status of coastal ecosystems and (2) the application of bioindication methods for coastal ecosystems in the Northern Europe.
Topic Area 1: The evolution of coastal ecosystems can be driven by artificial or natural isolation of the marine areas from the sea when they often transfer into meromictic reservoirs and the ecosystem of a saline water body undergoes irreversible changes. The surface water layer gradually becomes fresh, and the near-bottom water stagnates with the formation of oxygen deficiency and hydrogen sulfide contamination. This leads not only to changes in the physicochemical characteristics of the water bodies but also implies sharp changes in the microbial community whose distribution can be monitored using optical spectroscopy. Microorganisms, including anaerobic phototrophs representing the oldest communities on our planet, are especially important for the ecosystems in meromictic lakes. The first talk, given by Elena Krasnova from the White Sea Biological Station, described the diversity and typical structures of salt stratified lakes on the White Sea coast.
Relic reservoirs of this type are rare in nature and fragile; they need to be studied using novel optical and physical techniques and preserved. Two poster presentations described the research performed on relic meromictic lakes of the White Sea region. They were prepared by young scientists and aroused keen interest and discussion. The first poster, presented by Tatiana Repkina from the Moscow State University, demonstrated integrated geomorphological mapping (tachometric, bathymetric and geomorphological surveys and aerial photography from an unmanned aerial vehicle). A survey was purposed to identify the mechanisms of the seabed transformation in the coastal zone of the Kindo Peninsula.
Along the coastline of the Kandalaksha Bay of the White Sea, several lakes are known to be at different stage of separating from the Sea. The second poster, presented by Anna Zhiltsova from Faculty of Physics, Moscow State University, summarized the results of complex inspection of five meromictic lakes and lagoons in the Kandalaksha Bay performed in different seasons in 2014–2018 and presented depth distribution of phototrophic bacteria, redox potential and hydrogen sulfide concentration.
Svetlana Patsaeva (Faculty of Physics at Lomonosov Moscow State University) talked about optical methods to study chromophoric dissolved organic matter (CDOM) naturally occurring in waters of the White Sea isolated lakes. The CDOM may be characterized by its absorbance and fluorescence spectra. The main CDOM optical characteristics are absorbance spectral slope and its second derivative; the wavelength of fluorescence emission maximum and the value of fluorescence quantum yield, as well as and their dependence on excitation wavelength.
Olga Isaeva-Lunina (Winogradsky Institute of Microbiology, Russian Academy of Sciences) moved from physico-chemical parameters in meromictic lakes to biological and presented information on phototrophic bacteria inhabiting the meromictic lakes in the White Sea region. The presentation was titled “Unlike relatives and unrelated doubles in the world of microbes by the example of anoxygenic phototrophic bacteria from the lakes of Kandalaksha Bay, White Sea, Russia.” The data obtained for studied species confirm that the horizontal gene transfer by viruses is common for green sulfur bacteria, and it may cause the appearance of new species and be a factor of bacteria evolution.
Scientists from Finland (Aura Nousiainen, Pöyry Finland Oy, Environmental Consultancy and Anna Reunamo, Finnish Environment Institute, Marine Research Centre) studied degradation of oil by oil-degrading bacterial communities of the Baltic Sea in experiments. This case study demonstrates the reclamation of an oil storage cave in Helsinki, Finland by utilizing the oil degrading bacteria naturally present in the sea water, which could be utilized as the sole bioremediation agent. The results show that the residual oil is degraded naturally in the storage cave, but the addition of seawater enhances and accelerates the process.
Topic Area 2: This topic area provided a wide spectrum of different methods and species used for biomonitoring strategies in the Northern Europe. Marine invertebrates have been traditionally taken into account when assessing risks of chemicals and environmental conditions released to the environment. In spite of this, Artem Poromov (Lomonosov Moscow State University) presented novel toxicity data of copper retrieved using starfish Asterias rubens. This benthic predator could be used as a relevant bioindicator of seawater quality at different levels of biological organization. Survival, behavioral response of starfish, changes in cellular elements of coelomic fluid and protein level change in response to copper. The results show dose and time response development that could be predicted at the lowest levels of the organization.
Tatiana Kuznetsova (Scientific Research Center for Ecological Safety, Russian Academy of Sciences) reported on the experience in ecological status assessments in different sub-regions of the Baltic Sea using an approach with functional load testing and non-invasive cardiac activity monitoring in mussels and crustaceans as bioindicators of environmental quality. The presentation focused on achievements and prospects in the development of automated biologically early warning systems for environmental biomonitoring and a real-time water quality control in water supply stations of the cities, as well as in the wastewater assessment, using cardiac activity and behavior of the selected indigenous species of the invertebrates.
Daria Todorenko (Lomonosov Moscow State University) presented information on chlorophyll fluorescence measurements to estimate the functional state of the photosynthetic apparatus of phytoplankton during biomonitoring of five water bodies separated from the White Sea. Photosynthetic activity of phytoplankton was found to be the highest in the chemocline zone despite the low light and the presence of hydrogen sulfide.
In conclusion, the participants agreed that coastal ecosystems play an important role in the transformation of substances entering the sea from the catchment area along with freshwater runoff and, therefore, in the formation of water quality at the sea-terrestrial interface. With an excellent turnout, the session had attendees from Russia, Finland, Germany and Norway, fostering further discussion among the participants. Transdisciplinary approaches were recognized as very important tools not only to understand the dynamics and response of the ecosystems, but also as an indirect way to potentiate wide monitoring and legislation enforcement regarding priority contaminants.In Northern Europe, ecosystems are dynamic and sensitive to anthropogenic pressure and climate changes. Therefore, there is a need to integrate the efforts of various sciences to study such multicomponent systems.
The necessity to involve participants at SETAC focused on ecological biomonitoring studies was considered essential to raise awareness of both the problems that need addressing in Northern Europe and the tools available to address these problems, especially, in the White Sea and the Baltic Region. Transboundary coastal complexes can be studied and maintained only by joining international efforts and transdisciplinary collaboration.
Ana Marta Gonçalves, University of Coimbra and University of Aveiro; Nelson Abrantes and Isabel Campos, University of Aveiro
Aquatic ecosystems are complex and dynamic adaptive systems driven by multiple biotic and abiotic factors. These factors encompass an intricate range of biological interactions and environmental pressures, and they all influence each another. Under global changes, the interaction between these factors may be disturbed and can impair the normal functioning of the aquatic ecosystem. A set of parameters and mechanisms may be affected with repercussions at several biological levels. Hence, it is of crucial importance to understand how abiotic and biotic factors interact with one another in a changing world and how species respond to this disruption, as well as the implications along the trophic web. Additionally, to establish early warning indicators and implement prevention or even mitigation measures, it is of high importance to comprehend the action mechanisms and adequately quantify the impacts resulting from global changes.
This session focused on the combined effects of biotic and abiotic factors in aquatic ecosystems facing global changes, as well as on integrative tools to analyze these impacts from molecular to high levels of biological organization.
Six platform presentations plus 14 posters were made as part of this session. It attracted a high attendance with standing room only at a number of the presentations. The presentations focused on several abiotic and biotic stressors with particular emphasis on water flow, light, temperature, predation, nutrients and contaminants (pharmaceuticals, metals and pesticides). The effects were assessed at different complex levels of organization including molecular, biochemical, individual and population.
The first talk, presented by Carmen Espinosa, University of Vic-Central University of Catalonia, focused on evaluating the effect of light availability and water velocity in the appearance of geosmin-producing organisms. Her main conclusions were: 1) light and water velocity influence the biofilm structure-function and 2) the geosmin formation in the biofilm was favored by the interaction between low light and low water velocity. Vienna Delnat, KU Leuven, presented information to assess the reciprocal impact of sensitivities of the mosquito Culex pipiens to a pesticide exposure and to climate change by integrating the effects of daily temperature variation and life stages. The main conclusion was that the reciprocal interactions are interdependent. Delnat also highlighted the importance of integrating daily temperature variation and life-stage specificity to improve risk assessment of pollutants under global climate change. The third presentation by Alba Sanchez, IMDEA Water Institute, focused on 1) assessing the effect of pollution and drought on the taxonomic and functional composition of invertebrate communities in a Mediterranean semi-arid basin and 2) how traits mirror tolerance of community response to pollution and drought. It highlighted that taxonomic and functional composition were influenced by pollution and that polluted sites with pronounced drought showed enhanced negative effects on richness overall and, specifically, richness in the summer. Irene Gutiérrez, University of Coimbra, presented information aimed to determine the potential changes on the biochemical profile of Scrobicularia plana after single exposure to S-metolachlor and terbuthylazine. The main conclusions were: 1) fatty acids and carbohydrates are suitable tools to detect the presence of the contaminants in tissues of the species and 2) muscle revealed to be the best tissue to determine the presence of pollutants. The presentation by Torben Lode, University of Oslo, examined the potential mechanism for biotic and anthropogenic stressor interaction using the copepods Calanus finmarchicus and Tigriopus brevicornis. The main conclusions were that T. brevicornis respond more strongly towards predation risk and copper exposure than C. finmarchicus, and respiratory effects of predation risk and copper varies with gender composition in groups. The last platform presentation, which was held by Quentin Petitjean University of Toulouse, addressed 1) how the exposure to trace metal elements, combined with an immune challenge, could affect fish responses across biological levels (moleculer to individual) and 2) how the past history of exposure to metal pollution of wild populations would affect their plastic responses to a realistic experimental contamination. This study highlighted that 1) both stressors affected fish responses but at different levels of organization; 2) interactions between stressors occurred but only at high levels of organization; 3) high interpopulation variability occurred in stress responses suggesting different sensitivity to stressors; and 4) past history of exposure in the wild might affect stress responses.
Overall, this session highlighted the importance to study the effects of distinct stressors acting alone or combined on aquatic environments as a way to better understand the complexity of natural systems.