Past and ongoing production and use of legacy and alternative poly- and perfluoroalkyl substances (PFASs) has been recognized as one of the biggest challenges in chemical management. With the development of advanced chemical analytical methods, hundreds of highly fluorinated compounds have been detected in humans and the environment. However, considerable gaps exist in linking the vast amount of data to actionable strategies for reducing wildlife and human exposures and associated adverse health effects. This is due to the limited understanding of physical–chemical properties of alternative PFASs, relative importance of environmental and human exposure routes, and variable mechanisms of toxicity across compounds and across species. This session provided a forum to share advances in monitoring and modeling efforts that help to better quantify exposure to PFASs and associated health impacts.

Strong interest for the session was expressed through 28 high-quality presentations and more than 70 participants. Principal investigators, postdoctoral scientists and three graduate students gave six platform presentations, which were organized in the order of advancements in analytical chemistry, evaluation of physical chemical properties, environmental fate and exposure modeling, and remediation.

Gabriel Munoz from the University of Montreal, Canada, kicked off the session with a talk on development of a method for measuring a wide range of PFASs in soil samples at aqueous film-forming foam (AFFF)-impacted sites. Current methods for analysis of perfluoroalkyl acid (PFAA) could seriously underperform for certain newly identified PFASs. His talk proposed a suitable preparation procedure for the multi-residue analysis of PFASs that improved the method recovery for many PFASs, such as betaines (improved from 30–50 % to 70–105%). Ongoing work involves method development for PFASs in biota to support better evaluation of PFAS bioaccumulation. Munoz presented a companion poster titled “Assessment of persulfate oxidation liquid chromatography tandem mass spectrometry for the analysis of perfluoroalkyl and polyfluoroalkyl substances in water.”

Raphael Janousek from the University of Applied Sciences, Germany, presented his work on PFASs in products used in the building industry and industrial textiles. A total of 23 samples from products used in the building industry and 28 industrial textiles were investigated. Monitoring covered 29 PFASs with chain lengths from C4 to C14, including carboxylic acids, sulfonic acids, sulfonamides and fluorotelomer alcohols (FTOHs). FTOHs accounted for more than 80% of the sum of PFASs detected. In addition, he a worst-case scenario calculation was presented to estimate the emission potential from the entire building industry in Germany.

Clifton Dassuncao from Harvard University, USA, presented findings from a longitudinal cohort study among a seafood-consuming population in Faroe Island. A variety of novel tools were used, including advanced statistical analysis and toxicokinetic modeling. Despite the global efforts to reduce production and emission for long-chain legacy PFASs, work done by Dassuncao and colleagues suggested PFAS concentrations in seafood have not decreased as rapidly due to their extreme persistence in the marine environment. Over the study period of 1993 to 2012, PFAS exposures from consumer products have become increasingly important.

Steven Droge from University of Amsterdam, The Netherlands, presented his work that filled an important data gap in understanding the physical–chemical properties of a wide variety of PFASs. A model based on quantum chemistry, COSMOtherm, was able to predict both the membrane-water partitioning (Kmw) and pKa of emerging ionic PFASs. However, experimental data using solid supported lipid membranes highlighted that COSMOtherm misinterpreted the membrane affinity of anionic perfluorinated surfactants. This work has important implications for environmental fate modeling and risk assessment of PFASs.

Charlotte Wagner from Harvard University, USA, presented a large-scale modeling exercise on the burden of perfluorooctane sulfonate (PFOS) in the global oceans. Using a global marine circulation model, MITgcm, and an updated spatially resolved emission inventory from Europe, North America and China, this work estimated that historical total discharge into the ocean from Europe was to a similar amount as that from North America. The contribution of Chinese emissions to the PFOS concentration in the surface ocean currently is small but may increase over time.

The session ended on a positive note with a talk focusing on solutions, given by Gijs Breedveld from the Norwegian Geotechnical Institute. He presented two case studies on identification of point and diffusive source of PFAS inputs, environmental behavior in multiple environmental media as well as suitable remediation methods for different sites. The first case study was at Oslo airport, where AFFF was used for firefighting purposes. Two remediation methods using sorbent amendment and in situ soil washing showed promises to reduce leaching and improve ground water quality. The second case study was in Tyrifjorden, where PFAS profiles were identified in different sources to determine their distinct chemical signatures.

The talks and posters presented at this session highlighted the scientific challenges faced by society in managing the entire class of PFASs. Due to their unique surfactant properties and deviation from traditional persistent organic pollutants, innovative methods are needed to effectively assess and manage PFASs. By integrating up-to-date knowledge, highlighting state-of-the-art research tools and identifying critical gaps for decision-making, this session aimed at advancing efforts to reduce ubiquitous exposure to PFASs, avoiding regrettable substitution and reducing risks to public health.

Authors’ contact information: xhu@mail.harvard.edu, rlohmann@uri.edu and Jon.Benskin@aces.su.se

While the Water Framework Directive defines a holistic ecological status to monitor and assess the quality of aquatic ecosystems, chemical status is defined in a very traditional way focusing on 45 so-called priority substances. This approach ignores non-regulated and unknown (emerging) pollutants as well as the effects of mixtures. A recent study in the process towards a non-toxic environment led by the European Commission highlights several environmental management issues and recommendations including:

1. Improved identification and tracking of all substances meeting the criteria for substances of very high concern (SVHCs) and including very persistent substances as well as substances of concern meeting other endpoints not yet adequately addressed (e.g., endocrine disrupters, neurotoxins, immunotoxins and developmental toxins)
2. Additional hazard identification and risk assessment processes that allow for more rapid screening and identification of potential chemicals of concern and that can cope more efficiently with the large numbers of existing chemicals as well as the ever increasing numbers of new chemicals being invented and placed on the market

Scientific and technological progress in effect-based and multi- and non-target chemical screening opens new horizons for holistic monitoring as demonstrated for example in the large EU project SOLUTIONS. Moreover, high-throughput integrated modeling is becoming capable to predict emissions, fate and transport, and exposure from and risks to aquatic ecosystems and human health for thousands of chemicals to rivers in Europe. Increasing knowledge about the efficiency of abatement options and packages, through the use of integrated modeling, helps to find tailor-made solutions to minimize chemical footprints and estimate toxic risks. This special session demonstrated how the integration and mutual validation of such approaches could open new opportunities to achieve a non-toxic environment. The session brought together experts in effect-based monitoring, analytical chemistry, mixture assessment, exposure and effect modeling, abatement measures and science-policy interfacing from academia, European and national regulation, industry and non-governmental organizations to maximize the impact of these new ideas.

The session included 18 presentations starting with the perspective of non-governmental organizations, industry and regulation represented by Manfred Santen, Greenpeace; Milou Dingemans, KWR; and Manuela Helmecke, German Environment Agency, UBA. Santen highlighted that wastewater treatment is not able to deal effectively with hazardous substances so that the problem also needs to be tackled at the source, for example the elimination of perfluorinated compounds from textiles manufacturing, and the needs to involve large international retail brands. He challenged scientists to identify hazardous chemicals in a timely manner. Dingemans stressed the need for and the promise of effect-based monitoring and the necessary trigger values to safeguard water resources. According to Helmecke, the review and possible revision of the Water Framework Directive provides a suitable window of opportunity for implementation of such new approaches. The feasibility of a proposed revision for all member states is a pre-requisite, and therefore UBA intends to evaluate several new monitoring tools and methods during the upcoming 4th Joint Danube Survey.

In the subsequent block, these general perspectives were supported by presentations on novel monitoring tools that have been successfully demonstrated in comprehensive case studies. Emma Schymanski, University of Luxemborg, fascinated the audience with the combination of non-target screening for “real-time” monitoring as well as retrospectively via “digital freezing” platforms. Her contribution highlighted the strength of open science and world-wide (big) data sharing practices. This chemical analytical approach was complemented by Beate Escher, Helmholtz Centre for Environmental Research - UFZ, highlighting the capabilities of toxicological profiling with cell-based and low-complexity whole organism assays. Escher completed her presentation with a generic approach to define effect-based trigger values, which serve a goal similar to the well-known concentration-based quality standards. She distinguished between specific endpoints where a large share of the observed effect can often be explained from known chemicals and apical endpoints where effects may be caused by the complex mixture of many compounds. Anthony Schroeder, University of Minnesota, highlighted chemical–gene interactions networks to develop knowledge assembly models, again building on shared data from existing sources. Using the mapping of transcriptome data from fathead minnows exposed to wastewater treatment plant effluents, he could evaluate the likelihood of a chemical to contribute to the detected effects. Werner Brack, Helmholtz Centre for Environmental Research - UFZ, demonstrated integrated chemical and biological tools for the identification of drivers of effects detected by effect-based monitoring. Using the example of the fluorescent dye coumarin 47, which was found as an endocrine disruptor in the environment for the first time, he demonstrated that this approach often unravels unexpected toxicity drivers that remain ignored in chemical monitoring. He also showed to the packed meeting room how fractionation and mixture toxicity experiments can reveal synergistic effects in complex environmental mixtures.

Since contamination with chemical mixtures is the normal case rather than an exception, the session put a strong emphasis on risk assessment of mixtures. Roman Ashauer, University of York, pointed out that aquatic organisms are not only exposed to mixtures at the same time but also in sequence and stressed that not only the dose makes the poison but also the sequence. Rolf Altenburger, Helmholtz Centre for Environmental Research - UFZ, presented the conceptual framework used in the SOLUTIONS project to deal with mixtures of pollutants in water resources management, coming back to the specific uses of apical assays for monitoring purposes and specific assays for diagnosis. Andreas Kortenkamp, Brunel University, explained the human-health–related mixture risk assessment for pollutants via the uptake of fish contaminated by polychlorinated dioxins and polybrominated diphenyl ethers. Based on data from the Joint 3rd Danube Survey, he showed that according to state-of-the-art human risk assessment practices the analyzed fish should not be eaten. Michael Faust, F+B, then moved back to water pollution and addressed the prioritization of pollutants and mixtures based on different lines of evidence including ecological, effect-based and chemical monitoring as well as modelling. Faust argued that his recommendations would not be able to find their way into standing Water Framework Directive legislation unless certain aspects would be addressed in the upcoming revision.  A convincing application of Faust’s approach was presented by Thomas Backhaus, University of Gothenburg. He described the impact of complex mixtures from wastewater treatment plant effluents and the recovery of the biofilm community after the upgrade of the wastewater treatment plant.

Monitoring-based approaches can be strongly supported by high-throughput exposure and risk modelling. This was demonstrated by Jos van Gils, Deltares, using the SOLUTIONS “model train” for the spatially explicit prediction of the concentrations of about 1,800 chemicals validated in the rivers Danube and Rhine as well as several Spanish and Swedish rivers. He subsequently presented work by Andreas Focks, Alterra, who used Individual Based Models to translate predicted concentrations into simulated inhibition of population growth rates and hence the chemical impact on population viability on the European scale. He also demonstrated the application of widely used msPAF modelling, on a larger spatial scale and for more chemicals than ever before. The meaning of such results was discussed by Leo Posthuma, RIVM, using eco-epidemiology as a strong tool to liaise ecological status to mixture toxic pressure, based on large sets of surveillance monitoring data. This is also an important step towards unravelling mixtures in the context of multiple stress, as presented by Sebastian Birk, University of Duisburg-Essen, who highlighted the conclusions of the EU project MARS and the implications of toxic stress as assessed in the SOLUTIONS project.

In a final block of presentations, Annemarie van Wezel, KWR Watercycle Research Institute, and John Munthe, IVL Svenska Miljöinstitutet, closed the loop back to the stakeholder perspectives from the beginning of the session, addressing mitigation options for emerging chemicals and future perspectives. She presented the current knowledge of removal efficiencies of advanced water treatment technologies, while also highlighting the power of measures earlier in the chemicals’ life cycle. Munthe briefly discussed the different existing legislative frameworks and emphasized the need for dialogue, transparency and exchange of knowledge, and co-presenter Dirk Bunke, Öko-Institut, explained the implications of developments in public health, food production, urbanization and technologies for the identification of future pollution challenges.

Conclusions

Complex mixtures give distinction to water quality rather than individual (priority) pollutants. Powerful monitoring approaches are available to detect contamination and toxic stress and the associated links to both. Modelling may strongly support these approaches and help to evaluate best abatement options. A solutions-focused approach rather than status assessment alone is of key importance for approaching the goal of a non-toxic environment. This requires transparency and openness of information as well as increased international cooperation in science and regulation. Integrated European projects on applied research themes with strong stakeholder involvement such as MARS and SOLUTIONS are milestones in this process, and their results embody a strong plea for European research.

Authors’ contact information: werner.brack@ufz.de, rolf.altenburger@ufz.de, Jos.vanGils@deltares.nl and john.munthe@ivl.se

This session aimed at giving an overview of the current biomonitoring tools and strategies used towards the protection of the environment. Besides unintentionally produced contaminants, hundreds of high production volume chemicals on the market cannot be properly assessed for risk without bioaccumulation data in registered dossiers. Certain ecological groups, sensitive to contaminants, can be used as sentinels of emerging contaminant problems.

The session hosted contributions regarding environmental monitoring of inorganic and organic contaminants using terrestrial ecological biomonitors (plants and animals) and covered a wide range of contaminants, being specifically focused on bioaccumulative, toxic and persistent compounds.

The key points for the six presentations included:

1. The session started with Annekatrin Dreyer, Eurofins, who presented results of the evaluation of 123 selected persistent organic pollutants (POPs) in mosses within the 2015 European moss survey. The findings were further compared with results derived for deciduous tree leaves and coniferous shoots (needles) collected from the German Environment Specimen Bank (ESB).
2. Stefan Nickel, University of Vechta, provided the audience with an example of how mosses can be used to monitor heavy metal and nitrogen concentrations at a national scale over time. By mapping percentile statistics of element concentrations in moss collected from 1990–2015 in forests throughout Germany, the authors could observe temporal and spatial trends for some priority pollutants according to the Convention on Long-range Transboundary Air Pollution (CLRTAP). 
3. Fabrizio Monaci, University of Siena, presented the results of a biomonitoring study using holm oak leaves and pine needles from Southern Tuscany, known for its long mining history. The author focused on sources of variability (e.g., different age classes) when using these plants to monitor heavy metals and nutrient concentrations and how these can be overcome for a better interpretation of long-term environmental monitoring results.
4. The use of bat guano to assess the historical exposure to inorganic contaminants was introduced by Lauren Gallant, University of Ottawa. Gallant and her colleagues, examining two bat guano deposits from Jamaica dated over 3,000-years-old, were able to reconstruct the agricultural and industrial revolution history of the country, the introduction of leaded gasoline as well as the peak of nuclear weapon testing.
5. Velesia Lesch, North-West University, explored for the first time the use of dragonflies as potential biomonitors of environmental metallic elements and perfluoralkyl substances (PFAS). Results indicated that farming areas had significant lower PFAS concentrations than industrial areas and that the presence of mining and wastewater treatment plants showed an impact in terms of metal contamination.
6. In the last presentation of the session, Lakmini Egodawatta, University of Wollongong, focused on the impacts the ageing of agricultural lands has on the co-contamination of arsenic and antimony on edible plants. The author concluded that antimony contamination in agricultural soils poses a greater human health risk and hazard when in presence of arsenic, as antimony accumulates in edible crops with no observed phytotoxicity or reduction in vegetable productivity.

Conclusions

The successful session featured six platforms from four different continents, balanced between young researchers and more experienced scientists, and provided a wide spectrum of uses for biomonitoring strategies. With an excellent turnout, the session had a strong audience participation, fostering further discussion among the participants.

Biomonitoring was again recognized as a very important tool 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.

Lastly, the need to involve the general population on ecological biomonitoring studies (as direct participants or through informational meetings) was considered essential to raise awareness of both the tools and the problems to tackle.

Authors’ contact information: s.augusto@fc.ul.pt, nrneto@fe.up.pt and mira.anicic@ipb.ac.rs

Adequate interpretation of life cycle assessment (LCA) results is important to ensure that the related information is correctly used to inform interested stakeholders and decision-makers. However, LCA remains in all cases a modelled system that only reflects key elements of the real life system. A description and assessment of this model system requires simplifications, streamlining, assumptions, filling data gaps, cross reading from other sources of information or the application of further models (e.g., for impact assessment), just to name a few. Decisions made in relation to the assessment of such modeled systems will in turn affect the results, their representativeness, scope of validity and ability to answer the research questions set out in the goal and scope of a study.

Although this topic has been in discussion since the early 1990s, uncertainty seems to be one of the most unsolved problems within LCA. Only when we know how reliable the outcomes of LCA results are, then we can use them in an effective way as part of decision-making. This requires information as to what extent the outcome of an LCA is affected by various types of uncertainty such as parameter, scenario and model uncertainty. Currently, a best practice is still missing, and uncertainties are often not considered or addressed in LCA result presentation. These limitations might even lead to wrong decisions.

Therefore, this specific session was held to address this topic. A high interest for the session was expressed through a large attendance of approximately 200 people. This session not only dealt with the final interpretation representing the last stage of an LCA, but it also included the other stages of LCA studies where uncertainties can occur. Currently the majority of LCA studies do not include data uncertainty and uncertainty analysis. Due to the high variability, LCA results should be interpreted as a distribution of values rather than a single “true value.”

Presentations during this session included:

1. Reinout Heijungs, Vrije University, summarized recently published work on how to treat uncertainty in LCA. Previous works did not account for correlation. Heijungs described two types of correlations: correlated samplings and correlated results. Dependent sampling implies that process data for the product alternatives being compared are sampled based upon one and the same random drawing of parameter values, resulting in identical data sets for this shared process. As an example for correlated results, Heijungs used transport processes as the process input of diesel is always related to the process output of CO2 (emission); if the process consumes more diesel for the same amount of transport, the CO2 emission will also increase. An analysis of the uncertainty propagation and correlation should, therefore, always be provided.
2. Mélanie Douziech, Radbound University, presented on the variability and uncertainty using personal care products as a case study, which were based on the chemical footprint. The calculated chemical footprints spanned nearly four orders of magnitude. This wide span could be attributable to fragrances (61%), surfactants (20%) and the amount of product used (16%). The significant contribution from fragrances and surfactants can largely be explained by the uncertainty in their environmental impacts.
3. A combined uncertainty and scenario analysis within LCA of waste management systems was introduced by Valentina Bisinella, Technical University of Denmark – DTU Environment. Bisinella presented a novel method for combining uncertainty and scenario analysis, illustrated by a case study with three hypothetical waste management options for treatment of residual household waste in the municipality of Copenhagen extending through 2025.
4. Antoine Esnouf, French National Institute for Agricultural Research (INRA) Laboratory of Environmental Biotechnology, focussed on the relevance of specific impact categories for LCA results interpretation to avoid uncertain conclusions because of challenges caused by the wide range of environmental impacts results. Esnouf proposed a novel methodology as to how practitioners could benefit by selecting impact categories to focus the interpretation of the results with regards to relevant environmental issues.
5. One major reason for uncertainty is spatial variability. Regionalization of life cycle inventories can therefore help increase the geographic representativeness of the model, but this is connected with huge efforts for data collection. Laure Patouillard, CIRAIG, proposed in his presentation of a procedure to prioritize regionalization efforts based on global sensitivity analysis (GSA) to reduce the spatial uncertainty of LCA.

All of the presenters gave insightful views as to the range of uncertainty topics within LCA modelling, starting with data quality, providing solutions concerning modelling assumptions but also focusing on characterization factors and impact category selection. Once more the importance of including uncertainty assessment for reliable LCA results was pointed out in these presentations. One should always to be aware that results of an LCA are uncertain due to lack of knowledge about the true value of its model parameters. Therefore, presenting one single value as output of an LCA could be misleading, and in the worst case, may lead to wrong decisions.

Authors’ contact information: gudrun.obersteiner@boku.ac.at and michele.derosa@lca-net.com

Nanomaterials have turned into ecological and public health problems of great importance due to their extensive uses and broad applications. During the last few years, considerable research has been performed related to nanomaterials and their possible biological impact on the biota and human health. However, the knowledge of their distribution, transformations and abundance is far from complete and requires further evaluation. The knowledge of the accumulation potential, sources, sinks and real environmental impacts of nanomaterials is also currently limited. The published studies to date are only focused on pristine or manufactured nanomaterials where modifications of the materials or experiments mimicking real scenarios have not been fully assessed. Another research topic currently receiving a lot of attention is related to plastic pollution. Plastic particles (micro- and nanoplastics and nanopolymers) represent environmental contaminants of high importance due to their low degradation rate and their high persistence in the environment. The growing amount of plastics which are being used in many industrial fields derived for their excellent material properties, such as low weight, easy processing and high stability against various chemical degradation, may also increase their undesirable presence in the environment. It is worth noting that much of the recent concern has been focusing only on microplastics, but almost no data has reported the impact of nanoplastics or nanopolymers.

This session was focused on experimental studies that highlight the importance of assessing the distribution and, also, the biological effects of nanomaterials and plastics under more relevant environmental conditions. After reviewing all the high-quality contributions received, six platform presentations and twenty-six posters were delivered in the session.

There is a lack of knowledge regarding the abundance of microplastics in the environment. The first presentation by Mark Hartl, Heriot-Watt University, addressed this problem and aimed to contribute to the development of a previously lacking, quantitative long-term marine microplastic database. The results of a three-year pilot project in the Firth of Forth, United Kingdom, was presented. It was shown there are high numbers of plastic particles and fibers along both shores of the estuary. The microplastic concentration remained stable along the sampling time, and no apparent pattern of spatial distribution of neither particles nor fibers was observed. This study has established a significant baseline set of information and will help future research better track the contamination by microplastics.

The second platform presentation focused on understanding the effect induced by nanoparticles (gold and polystyrene nanoparticles) towards a model freshwater microalga and discriminate the responses of the microalga in comparison with known stress mechanisms, such as nutriment deficiency, light deficiency and metallic stress, using infrared spectroscopy. Maureen Déniel, University of Le Mans, showed that the different stresses involved chemical modification of the microalgae leading to variations in the infrared spectra and that this technique, coupled to a multivariate analysis promises to be a useful tool to rapidly discriminate different stress effects on the model microalgae Chlamydomonas reinhardtii.

During the third presentation, Gerardo Pulido-Reyes, Autonomous University of Madrid, showed the biological effects of two nanopolymers, high­generation cationic poly(amidoamine) dendrimers of generation 5 and 7. After using a wide panel of techniques, it was clearly demonstrated that these polymers can induce a severe toxicity to Anabaena sp. PCC7120 and provoke several physiological, morphological, photosynthetic and genetic alterations. This study provided relevant information for the environmental risk assessment of this nanomaterial.

Due to their multiple applications, there is a great concern over the potential impact of nanomaterials on environmental health, either alone or in combination with other anthropogenic contaminants. The presentation given by Awadhesh Jha, University of Plymouth, focused on testing the hypothesis that environmentally relevant carbon-based nanoparticles, C60 fullerenes and multi-walled carbon nanotubes, and polycyclic aromatic hydrocarbons as benzo(a)pyrene can interact with each other to differentially modify their potential toxicity. The biological response of marine mussels showed variable sensitivity with respect to exposures and co-exposures with the different nanomaterials and the organic compound. This study underlined the complexity of the environment, regarding the potential effects of nanomaterials along with other environmental toxicants.

The last two platform presentations assessed the effects of copper oxide nanoparticles (CuONPs) under more relevant environmental conditions. Tobias Lammel, University of Gothenburg, addressed the transfer of CuONPs and dissolved copper, administered as CuCl2, from sediment to worms (Tubifex tubifex) and further from worms to fish (Gasterosteus aculeatus). This bioaccumulation study concluded that the transfer of CuONPs along the food chain may be limited compared to dissolved copper. Moreover, the work presented by Laure Giamberini, Université de Lorraine, was focused on the fate and effects of different CuONPs on a widespread endobenthic freshwater bivalve within a mesocosm study. It was shown that CuONPs affected some biological biomarkers and also the bivalve behavior by increasing burrowing, suggesting an avoidance reaction. Both works dealt with setting up a more complex design of exposure, which may help gain more environmental realism.

All talks were well received and the attendees, more than a hundred people for most presentations, engaged in a lively discussion. After this stimulating session, it is necessary to highlight the importance of addressing eco(nano)toxicity from a more realistic point of view and to develop robust methods and techniques to help monitor the presence of anthropogenic particles, nanomaterials and micro- and nanoplastics in the environment. All this information will be useful to reduce the uncertainties which surround nanotechnology and to shed light regarding the current problem of the high amount of plastics in the environment.

Authors’ contact information: gerardo.pulido@uam.es and roberto.rosal@uah.es

The accidental spills of contaminants such as hydrocarbons and chlorinated solvents can contaminate soil and water, raising concern because they are recalcitrant compounds and toxic for ecosystems and human health. In situ remediation techniques, in particular those involving microbial communities, represent an economically and environmentally sustainable strategy for reducing the contamination and understanding the responses of biological targets to these pollutants. The development of new tools and technologies for monitoring in situ and enhancing microbial activity is crucial for advancing the remediation of contaminated sites. In order to make this technology more profitable and successful, it is important to include an interdisciplinary involvement of scientists of different discipline (e.g. hydrogeologists, microbiologists, chemists and ecotoxicologists).

This session, incorporated several research applications, embracing soil, sediments and groundwater matrices, including six oral presentations and 22 posters. The use of innovative methods for both monitoring and enhancing the bioremediation strategy were presented. Several presentations focused on the stimulation of biodegradation processes, others on advances in the exploitation of plant-bacteria interactions, moreover the use of colloidal activated carbons and bio-electrochemical approaches were also presented.

Sara Borin, University of Milan, described the biostimulation performed by different plant species in a soil polluted by polychlorinated biphenyls (PCBs). Marco Petrangeli Papini, Rome La Sapienza University, reportedon the reductive dechlorination process and its ability to restoretwo aquifers contaminated by chlorinated aliphatic hydrocarbons. Federico Aulenta, Italian National Research Council’s Water Research Institute of Rome, illustrated microbial electrochemical technologies and its application for in situ treatment of a petroleum-contaminated groundwater. Other oral presentations addressed the application of novel monitoring methods, reporting new insight into biomolecular and microscope analyses. The other three oral presentations addressed the application of novel monitoring methods, reporting new insight into biomolecular and microscope analyses. Joaquim Vila, Spanish Institute of Natural Resources and Agrobiology, described microbial processes linked to polycyclic aromatic hydrocarbons (PAH) biodegradation during the laboratory assessmentof a creosote-contaminated soil using the next generation sequencing technology on both DNA and RNA transcripts. Natalia P. Ivleva, Munich Technical University, presented on the use of Raman microspectroscopy in combination with a stable isotope approach for the characterization of the molecular and isotopic composition of microorganisms at the single cell level. Finally, Renato Baciocchi, Rome Tor Vergata University, demonstrated that the calculation of the natural attenuation rates for petroleum hydrocarbons using the flux of contaminants by assessing the effective emission rate of the contaminants measured with the flux chambers.

The poster session was extensive with 22 presentations, and topics included recent applications for restoring ecosystems affected by various contaminants such as PCBs, dichlorodiphenyldichloroethene (DDE), hexavalent chromium and various other hydrocarbons, including polycyclic aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, polyfluorinated alkyl substances and monochlorobenzenes. Several approaches for monitoring and evaluating bioremediation processes, such as the use of biomolecular tools, compound specific isotope analysis and software, were presented. Both senior researchers and students actively participated in the session.

In both the poster and platform presentations, microbes were in the spotlight, due to their great versatility in contaminant degradation and the many efforts that have been made to promote them, in particular in addressing persistent organic contaminants. The importance of this session was due to the fact that it used a multidisciplinary approach to discuss techniques in onsite applications to enhance microbial activity using in situ rather than laboratory only experiments.

In summary, while there are several organic pollutants no longer in production, such as PCBs, they still constitute an environmental problem due to their persistence in the environment. Many studies have been performed to restore sites from the effects of contamination, but additional research is still necessary, in particular site-specific interdisciplinary research to widen the range of pollutants treated by biological methods and to increase the efficiency of in situ applications.

Authors’ contact information: grenni@irsa.cnr.it, barracaracciolo@irsa.cnr.it, andrea.franzetti@unimib.it and luca.alberti@polimi.it

Session Summary

The accumulation of plastics in freshwater and terrestrial systems constitutes an emerging scientific and societal issue due to their ubiquity, high persistence and potential to cause ecological effects. As a modern, populous society, we rely heavily on the preservation of these environments as resources for both agriculture and drinking water. The factors influencing fate, behavior and effects of particles are complex and can rely on a combination of environmental and biological interactions. The form in which plastics enter the environment will have a significant influence on their behavior.

In most cases, the results of several studies are not comparable due to the application of different methods of sampling, processing and analysis. This session covered distinct aspects of extraction and methodological approaches, fate, monitoring and effects of microplastics in freshwater and terrestrial systems.

Morning Slot 1

This first slot was focused mainly on novel methodologies and analytical tools for detection and quantification of micro- and nanoplastics within the environment. The presentations detailed spectroscopic and chemical analytical tools to detect, identify the types of polymers and quantify microplastics in samples, including a new metal-doping technique for particle tracing. The presentations included extraction techniques for complex media such as soil, sludge and wastewater. The presentations provided data on microplastic distributions within terrestrial environments such as sludge-treated land. The final presentation considered how particle properties may influence their behavior within aquatic systems.

Morning Slot 2

The second slot was predominantly focused on data from environmental surveys of rivers and storm water ponds, which may both accumulate microplastics from various sources, influenced by environmental factors. The presentations also considered modeling as a tool for predicting particle interactions with other pollutants. As part of this session, we also had a poster spotlight session where three poster presenters gave a brief overview of their work.

Afternoon Slot

The afternoon focused on modeling tools for predicting the transport, fate and behavior of microplastics, in addition to predicting how particle properties can affect their interactions and biological effects to organisms. Varied presentations studied bioaccumulation, biochemical and molecular effects. This session also included three poster spotlights, which were selected to represent the breadth of the research presented in the session.

Overall, this session highlighted the wide range of research that is currently being carried out in the field of microplastics, with several novel techniques being developed and implemented, and a rapidly increasing amount of data. However, land systems are still underrepresented when it comes to environmental studies due to methodological difficulties when working with complex samples. There is still a need for standardization of methods to allow for comparability between studies, which the ongoing research will address.

Authors’ contact information: anamartagoncalves@ua.pt, njabrantes@ua.pt, alihort@eeh.ac.uk and csv@ceh.ac.uk

Session Summary

A major challenge for ecotoxicologists is to understand the complex real-world situation in which terrestrial and aquatic organisms are dynamically exposed to multiple chemical and environmental stressors. There is increasing interest from stakeholders to develop mechanistic models for risk assessment that focus on the underlying processes governing environmental or physiological changes to extrapolate across levels and make predictions for untested scenarios. Integrated approaches utilizing the vast “toolbox” in ecotoxicology are needed to better understand the links between exposure and biological effects of contaminants and other stressors. At the SETAC Europe 28th Annual Meeting in Rome, we chaired a session to broaden our understanding of how process-based modeling can be used to advance the interpretation of and predictions from laboratory and environmental toxicology studies.

The use of ecological and process-based modeling has advanced considerably in recent years, as evidenced by the broad array of contaminant types, toxicity endpoints, modeling approaches and species covered during the session talks and discussions. The oral and poster presentations centered around three main themes: toxicokinetic-toxicodynamic (TKTD) models of contaminants, full life cycle risk assessment using Dynamic Energy Budgets (DEB) and extrapolating effects across biological levels. Here we briefly summarize the major themes discussed within this session.

1. DEB theory emerged as an especially useful framework to evaluate the effects of multiple stressors on organisms, considering various health and toxicity endpoints, timescales and life history traits. Sylvain Bart, INRA France, experimentally exposed earthworms to a copper fungicide and used DEB to model effects on growth and reproduction throughout ontogeny. Erik Muller, University of California, modeled bioaccumulation and sub-lethal and lethal effects of nano-particles in amphipods. A framework was also presented by Louise Stevenson, University of California–Santa Barbara, to combine molecular information (AOPs) in DEB models of organisms. Such an approach opens the door for future collaborations between ecological modelers and molecular toxicologists. Finally, several posters presented interesting DEB applications in copepods, fish and marine mammals.
2. The importance of TKTD models in risk assessments was highlighted in several talks and posters. Sandrine Charles, Université de Lyon, started the session with an overview of TKTD models and their use in risk assessment and presented a new R package “morse” that simplifies user implementation of TKTD models. The application of TKTD modeling in multiple stressor situations was explored by Yen Le (University of Duisburg-Essen, Germany) in her talk about metal accumulation in fish infected with acanthocephalan parasites. Several posters focused on this issue, presenting new initiatives for the General Unified Threshold model for Survival (GUTS) and metal uptake and partitioning within cells.
3. There is increasing interest in ecotoxicology to understand how contaminant effects extrapolate between biological levels and complexity. Irv Schultz, U.S. National Oceanic and Atmospheric Administration, showed how biologically based mathematical models can be used to extrapolate in vitro data for endocrine active contaminants in rainbow trout, linking molecular data to reproductive performance. We also had several posters examining quantitative AOP models, including endpoints for lung cancer, embryotoxicity and recruitment, and acetylcholinesterase.   

In summary, the session addressed a diverse array of modeling approaches in the study of laboratory and environmental toxicology. It was clear from the session talks and discussions that process-based models are of interest to a broad group of research areas. We can expect much future development and implementation of mechanistic models in risk assessment of various stressors, especially linking sub-lethal effects to relevant biologically meaningful organism endpoints.

Authors’ contact information: jpd@bios.au.dk, elke.zimmer@ibacon.com and andre.gergs@bayer.com  

There is growing recognition for the role of informed substitution as part of the risk management of chemicals, particularly for those substances considered to be of greatest concern, such as those that are carcinogenic, mutagenic or reprotoxic (CMR); have endocrine disrupting (ED) properties; or are persistent, bioaccumulative and toxic (PBT). This recognition is driven by international conventions, such as the Stockholm Convention, as well as regional regulatory systems (e.g., the REACH authorization and restriction scheme), national legislation, non-government organizations or, in some cases, by consumers themselves. There is also a growing interest and motivation to substitute hazardous chemicals within industry. All are seeking guidance on the selection of appropriate methods and tools for chemical substitution.

A number of case studies were presented during the oral and poster sessions, including focus on the alternatives review process for perfluorooctanesulfonate (PFOS) at international levels under the Stockholm Convention; alternatives assessment for regional regulatory risk-based assessment, such as lead in gunshot in wetlands; practical programs on the assessment of alternatives for certain per- and polyfluoroalkyl substances (PFAS) used in durable water repellent (DWR) fabrics; recycling practices of textile materials and non-ferrous metals; and substitution of flame retardants, PFAS in fire-fighting foams and chemicals in food packaging. Some overarching themes from these contributions were:

1. A proper understanding of the functionality of the substance is key to assess the relevancy for substitution and the starting base.
2. Alternatives should be defined, recognizing the technical performance for each of the functional uses. This may result in alternatives for some functionalities while not for others.
3. Regrettable substitution should be prevented, which requires a balanced view on the toxicity or risks of the alternatives. It also requires taking a holistic perspective covering the impact of the product during its entire life cycle and recycling after “End of Life” when considering circular economy perspectives. 
4. Life Cycle Impact Assessment (LCIA) models and approaches could help in this respect but may not always be adapted to the type of chemicals being assessed. Therefore, their application requires careful consideration. Science will play an important role in ensuring that appropriate models are available in time.
5. LCIA, hazard and risk assessment provide complementary information that should be considered in a balanced way. 
6. The drivers in market versus regulatory substitution may not be equal, but both require scientific evidence.
7. The road to developing alternatives between investigation and commercialization may be difficult and long, but it can be facilitated if supported by the market and if the appropriate science is available.

There was support for continuing this theme at next year’s SETAC Europe meeting in Helsinki, potentially building on the themes introduced during this session, and further development in the areas of benign-by-design and green chemistry.

Authors’ contact information: Peter.Simpson@echa.europa.eu, ian.cousins@itm.su.se, patrik.andersson@chem.umu.se and waeterschoot@eurometaux.be

In recent years, the vision of a circular economy has rapidly gained a key role in the international political and business agendas on how to decouple economic growth from resource constraints. According to the EU Action Plan for the circular economy (2015), “The transition to a more circular economy, where the value of products, materials and resources is maintained in the economy for as long as possible, and the generation of waste minimized, is an essential contribution to the EU’s efforts to develop a sustainable, low carbon, resource efficient and competitive economy.”

To this end, material producers and downstream users are being asked to provide ever greater and more sophisticated information to authorities and consumers on the environmental footprints of the materials it produces and markets. For a circular economy to be sustainable, circularity strategies (i.e., strategies aiming at keeping products, components and materials at their highest utility at all times), need to also consider economic, social and normative aspects beyond the environmental considerations.

In such an articulated context, what is the role for life cycle approaches in the definition of a sustainable circular economy? As life cycle approaches are very powerful methodologies to address trade-offs, both between life cycle stages and different sustainability aspects, the purpose of this session was to facilitate information exchange on methodological developments and applications of stand-alone or integrated life cycle approaches (environmental footprint, life cycle sustainability assessment), present challenges associated with cultural barriers for data collection, and illustrate the need for a collective response from all stakeholders. Presentations covered aspects of the transition to a sustainable circular economy, from both methodological and applicative perspectives, and provided case studies in different areas focusing on the following themes:

The Role of Indicators to Measure Circularity

Hanna Helander, University of Freiburg, presented a framework to compare and assess circular economy performance indicators at a product level based on the life cycle phase (production, use phase, end-of-life), and Monia Niero, Aalborg University, discussed a case in the packaging sector where multicriteria decision analysis is used in combination with different material circularity and life cycle based indicators.

Methodological Challenges for Life Cycle Assessment (LCA)

Dieuwertje Schrijvers, University of Bordeaux, addressed the importance of defining the proper research question and derived archetypes of LCA goal and scope definition based on several criteria (perspective, reason to conduct the study, allocation procedure).

David Turner, EMPA, emphasized the crucial role of introducing region-specific life cycle inventory for tailings disposal in order to provide a more comprehensive and adequate integration of primary metals in LCA studies.

Markus Berger, TU Berlin, and Thomas Sonderegger, ETH Zurich, presented the outcomes of the task force on primary material resources in life cycle impact assessment (LCIA) and the range of LCIA methods which are more suited according to the goal and scope of a particular study.

Circular Economy Strategies Other Than Recycling

Ellen Bracquené, KU Leuven, focused on the reuse strategy and addressed the potential benefits of repair and reuse of products and components in the case of laptops, highlighting the key role of durability. Meanwhile Martí Rufí, Universitat Autònoma de Barcelona, addressed the challenge of closing loops in the biological cycle, namely in the case of integrated rooftop greenhouses.

End-of-Life Recycling

Raoul Meys, RWTH Aachen, discussed under which conditions chemical recycling of polyethylene terephthalate (PET) bottles is favorable from an environmental point of view, in comparison with mechanical recycling. Meanwhile Luca Ciacci, University of Bologna, presented a scenario analysis with material flow analysis of copper in Europe, highlighting the potentials for greenhouse gases emissions reduction.

Coupling of Environmental and Economic Methods

Changgun Lee, University College London, presented a multi-objective, mixed-integer, linear programming optimization problem considering different reverse supply chain network configurations to close the loop in the case of fluorescent lamps. Benoit Timmermans and Wouter Achten, Université Libre de Bruxelles, discussed how LCA could be used to adjust consumption taxes, introducing the Damage and Value Added Tax (DaVAT) concept.

Conclusions

The session made clear that life cycle approaches are essential to move towards a sustainable circular economy, although most of the contribution focused on the environmental and, to a limited extent, economic aspects, disregarding the social aspects.

More efforts are needed to adapt the LCA methodology as a decision support tool to assess circularity strategies in all phases (goal and scope definition, life cycle inventory, LCIA and interpretation).

Authors’ contact information: monian@plan.aau.dk and evangenderen@zinc.org

With a total of 13 poster presentations by authors from academia, industry and regulatory authorities, this session highlighted the continuing interest and relevance of biopesticides to the ecotoxicology community.

The poster corner session focused on microbial biopesticides, regulated in Europe under Regulation (EC) 1107/2009. Through dialogue with the presenters and the wider audience, we aimed to identify the key challenges currently faced by applicants, study directors or evaluators during the evaluation process of microbial active substances and products. This proved to be a valuable discussion as a common theme emerged. The consensus among the 20 or so participants was that a particular ecotoxicological test type or non-target organism group was not of key concern, but rather across test types a more structured approach is needed for microbials to account for the different requirements in test design and interpretation compared with conventional chemical substances. Those participating in the poster corner session felt that this was where most of the experience currently, and understandably, lies. After carefully designing their study program, notifiers need reassurance that their approaches will be accepted by all concerned authorities, and the current guidelines are not yet sufficient for this purpose and are often open to interpretation with no clear goal around study acceptance criteria. It was noted that the end solution should not just be a set of test guidelines fit for purpose for microbials but a better understanding of how endpoints and data generated are used in the risk assessment process. Concerns raised included how to measure and interpret potential effects of infectivity and pathogenicity on non-target organisms, what application rates and test item doses can be practically tested, and how to verify exposure and dosing concentrations. Further discussions included whether we are currently assessing appropriate organism groups and whether a qualitative approach based on the characteristics of the microorganism might be more suitable than quantitative risk assessments.

We hope this first SETAC session on the topic highlighted that there are shared challenges to overcome, with an acknowledgement that all stakeholders (industry notifiers, study directors, regulators and researchers) can contribute to developing appropriate solutions. SETAC provides a valuable platform for these discussions, and we consider that this session brought an interested network together and formed a valuable starting point for a continuation of the dialogue at future meetings.

Authors’ contact information:elizabeth.collison@apc.eu.com, jacobijn.van.etten@ctgb.nl and alison.hamer@erm.com

Analytical methods utilizing luminescence have been developed in many areas of biology, medicine and ecology. Luminescence is a highly useful tool since it can be detected with simple physics devices. This type of analysis is not time consuming, it provides a lot of experimental information under comparable conditions, which is essential for further evaluation using statistical tools.
 
Excited states in luminescent systems can be obtained in many different ways, such as chemical reactions (chemiluminescence), biochemical reactions (bioluminescence) and photoexcitation (photoluminescence). Bioluminescence provides an opportunity in using the assay systems in ecotoxicology.  Chemiluminescene methods reveals a role of reactive oxygen species, and photoluminescence provides a study of physico-chemical processes taking place in complex systems, including living organisms.

This session presented reports from researchers working with luminous organisms (bacteria) using enzyme reactions and fluorescent proteins, chemiluminescent reactions for study peroxide content, and fluorescence of intracellular components of fungi spores and fluorescence of surface of nanoparticles. Fundamental and applied aspects were encouraged, including ecological monitoring of waste and fresh waters, soils and air; application of luminescent bioassays in remediation procedures; and the luminescent ecological biosensors including instrumentation.

The key points for the five presentations included:

1. Valentina Kratasyuk, Siberian Federal University, discussed a development of bacterial bioluminescent enzymatic biosensors and their application as toxicity bioassays. New enzymatic reagents and portable devices (bioluminometers) were presented.
2. Nadezhda Kudryasheva, Institute of Biophysics Russian Academy of Sciences, Siberian Federal University, presented an investigation of toxic and adaptive effects using luminescent assay systems of different complexity: bacterial cells, enzyme reactions and fluorescent proteins.
3. Aleksei Trofimov, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, presented a new application of chemiluminescent method for a comparative study on oxidant and antioxidant activity of two types of nicotine-containing aerosols, namely tobacco (cigarette) smoke and emissions derived from electronic cigarettes. It was concluded that electronic cigarettes and tobacco cigarettes exert different oxidative impacts on humans.
4. Investigation of fluorescence spectra of filamentous fungi cultivated under different concentrations of source of bioavailable and not readily bioavailable carbon in the growth medium was presented by Fedoseeva Elena, Pirogov Russian National Research Medical University, Russia. Fluorescence characteristics were found to correlate with saturation of growth medium by sources of carbon. This research is promising for using fungal fluorophores to assess responses to external stimuli.
5. New fluorescence method to investigate the surface characteristics of nanoparticles was presented by Lyubov Kulyabko, Moscow Aviation Institute. Relations of the surface characteristics with bioactivity of the nanoparticles Fe3O4 was demonstrated. Kulyabko hypothesized that, along with the size of nanoparticles, coordination of ligands on their surface is a major factor contributing to the toxicity of nanoparticles.

The session included three poster spotlights by Marie-Claire Lot, CEHTRA; Anna Sachkova, Tomsk Polytechnic University; and Alena Petrova, Krasnoyarsk State Agrarian University. They presented a comparison between results of LumiMARA and Microtox tests, an application of bioluminescent assays for studying antioxidant activity and toxicity of bioactive compounds (humic substances and carbon nanoparticles), and the effect of low-dose gamma-radiation on luminous marine bacteria.

Conclusions

The ability to emit light by several organisms is widely used by researchers in toxicological investigations. Luminescence is assumed here as a physiological function, and it is sensitive to the presence of exogenous compounds. Luminescence can be used to evaluate quantitatively a toxicity of media or monitor adaptive response of organisms.

Luminescent assay systems can be based on living systems of different complexity, ranging from higher organisms to cells and specific proteins. Within the last decades, there has been substantial development of new bioassays that are based on enzymatic reactions (enzymatic bioassays). Enzymatic bioassays can be used to estimate rates of biochemical reactions under toxicant influence and provide a better understanding of the toxicity mechanisms at both the molecular and macromolecular levels. These new type of bioassays are based on fluorescent coelenteramide-containing proteins, which can reveal the effects of toxic compounds on protein structures. These bioassays lead to a more complete understanding of the physicochemical processes in biological responses to toxicants. Chemiluminescence methods have proven to be highly prospective for the evaluation of the role which reactive oxygen species have in responses to toxic effects and the resulting protective responses of organisms. Photoluminescence methods have also proven to be very useful for monitoring of intracellular processes and the properties of toxic compounds.

Authors’ contact information: n_qdr@yahoo.com and valkrat@mail.ru