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: firstname.lastname@example.org
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.
Summaries Published in the June 2019 Issue
Maria Vila-Costa, IDAEA-CSIC and Rainer Lohmann, University of Rhode Island
This session, divided into two parts, covered different experimental approaches to determine the physicochemical and biological factors driving the transport and fate of organic pollutants in aquatic systems. The platform presentations and posters studied a wide range of aquatic settings, including lakes, streams, sediment-water interfaces and seawater. The organic pollutants of interest ranged from polar micropollutants (pharmaceutical and personal care products, pesticides, etc.), (methyl)mercury, antimicrobial peptides, some persistent organic pollutants (POPs) and other apolar organic pollutants, such as polycyclic aromatic hydrocarbons. The main subjects covered included: (1) quantification of transformation rates in the field and in laboratory-based incubations, (2) spatial and temporal variation of concentrations and rates in the environment, and (3) internal concentration of pollutants in organisms (mostly in fish but also plankton and turtles, etc). Additionally, methodological innovations to analyze organic pollutants were presented. Of note for the authors presenting, 20% of the participants were candidates for student awards and 60% were female scientists. The session was composed of two presentation blocks that included a total of 11 platform presentations and a large poster session. The first part of the session, mostly devoted to the determination of biotransformation rates in different habitats, included measurements in:
- Lakes Ecosystems. Annie Chalifour from Eawag presented a mass balance study of micropollutants concentrations in Lake Griefensee with biotransformation rates measured in complementary batch-lab experiments. She observed that for the less recalcitrant micropollutants, faster transformation rates occurred under the higher in situ microbial (mainly phytoplanktonic) biomasses, suggesting a more important role of biotransformation versus photodegradation for a large number of compounds. Anna-Lena Rehrl from the Swedish University of Agricultural Sciences measured concentrations of micropollutants along a seasonal and spatial (vertical and horizontal) gradient in the Swedish lake Mälaren. Concentrations of some compounds were closely correlated, indicating a similar source and transport, and some deep samples showed higher concentrations than surface waters, suggesting that the physicochemistry of the lake (stratification), along with biological activity, plays a key role determining MP fate. Heleen de Wit from NIVA presented a study of the dynamics of airborne mercury (Hg) in a northern humic lake with special focus on the role played by the size of dissolved organic matter (DOM) on Hg fate. Differences in the lability of Hg-associated DOM were observed between inlet and outlet streams of the lake, which seems to accumulate in food webs more based on the microbial loop.
- Freshwater Water Column-Sediment Interfaces. Carolin Seller from Eawag analyzed in laboratory-based time-series tests the biotransformation kinetics of micropollutants across different water sediment systems. Results were used to create a mathematical model to estimate biotransformation rates in these systems, correcting the rates by bioavailability and microbial biomass parameters among others. The role of protozoans in degradation was highlighted. Karolina Nowak from TU Berlin used stable isotope approaches to track the microbial turnover of pesticides. Their fate diverged among compounds and included mineralization to CO2, incorporation into biomass with distinction between the different amino acids, and transformation products clearly different depending on whether they underwent an abiotic or biotic transformation.
- Streams. Werner Desiante from Eawag compared the micropollutant biodegradation capacity of river biofilms upstream and downstream from a wastewater treatment plant. Desiante concluded that downstream communities had a higher biodegradation capacity although other factors need to be taken into account, such as bacterial abundance, which are positively correlated to degradation rates. Caroline Davis from ETH Zurich tracked the fate of three antimicrobial peptides (AMPs) in riverine system and distinguished between different types of photochemical transformations, biological (mainly by riverine biofilm bacteria) and sorption. The study concluded that although some transformation rates are really fast, some AMPs persist in the environment.
- Seawater. Belen Gonzalez-Gaya, PIE, University of Basque Country, showed that biodegradation of atmospheric aromatic hydrocarbons into the oligotrophic ocean is a widespread process that plays a key role determining PAHs fate in the water column.
The second block of oral presentations included the determination of concentrations in fish. Georg Radermacher from Fraunhofer IME quantified concentrations of cyclic volatile methylsiloxanes in German wild fish via GC-ICP-MS/MS method. Lijun Han from the China Agricultural University quantified organophosphate esters in fish using a robotic ITSP mini-SPE cleaning step followed by a comparison of three different methods: GC-MS/MS, LC-MS/MS and LC-Flow injection-MS/MS, which was the one giving the highest resolution and lowest contamination. Finally, Terry Bidleman from Umea University was the only speaker on natural (not anthropogenic) but potentially toxic compounds: the concentration of bromophenolic compounds in Nordic macroalgae that are consumed by humans. They play important ecological (positive and negative) roles in the ecosystem. Concentrations of these compounds and their transformation products present a large variability between them as well as addressing potential seasonal variability.
The session finished with two poster highlights. Sean McLaughlin, Smithers Viscient, discussed the use of two different OECD guidelines (301 and 307) to determine the biodegradability of acetaminophen as a model compound. Johannes Schwobel, COSMOlogic, showed how to best predict the bioaccumulation potential of ionizable organic chemicals and suggested that COSMOS-RS could be a useful modeling tool in that regard.
In general, many studies aimed to distinguish the different transformation products, and differentiate between biotic and abiotic process and determine their drivers. A general conclusion in many studies was that there is a current need to open the black box of microorganisms, key degraders of organic pollutants in aquatic systems, to have a better understanding of biodegradation rates. The incorporation of taxonomical and functional information of the microbial communities is underway and calls for more interdisciplinary approaches.
Peter Fantke, Technical University of Denmark
Why Does Substituting Harmful Chemicals Matter?
A worldwide, growing diversity of consumer goods puts more and more pressure on a variety of chemicals that can be used in these goods, including flame-retardants, pesticides, plasticizers, solvents, cleaning agents and the list goes on and on. During the life cycle of consumer goods – from manufacturing to waste handling – chemical exposure can cause negative effects on human and environmental health.
There is a growing need to use safer and more sustainable chemicals in our goods and materials across all sectors. In 2018, the European Chemicals Agency (ECHA) issued a “Strategy to promote substitution to safer chemicals through innovation,” indicating challenges to transition towards safer chemicals, and the European 7th EU Environmental Action Programme has called for a strategy for a non-toxic environment. In addition, the “Sustainable Development Goals” defined by the United Nations call for a broad reduction of chemical pollution and minimization of human and ecological exposure to harmful chemicals as clear targets.
How can chemical pressure on human and environmental health be best linked to advances in producing consumer goods? This question is addressed in the emerging field of “alternatives assessment,” which gains more and more interest as a framework for identifying and evaluating chemicals, materials, processes or behavioral changes that may serve as viable alternatives to using hazardous substances. At the same time, high-throughput screening and prioritization approaches are increasingly becoming available to support the broader phase-out and substitution of harmful chemicals across goods and industry sectors.
However, the multitude of relevant substitution components along with the need for easy-to-use and operational assessment tools currently render it difficult to achieve consistency across data requirements, assessment methods and resulting indicators. This often leads to “regrettable substitutions” in substitution practice, leaving relevant trade-offs between assessment components unaddressed.
What can we learn from advances in green and sustainable chemistry, alternatives assessment and substitution to successfully replace harmful chemicals in goods and materials? The purpose of this session was to discuss challenges and opportunities in substitution methods, to look beyond current practices and build synergies with adjacent fields, such as life cycle assessment, exposure analysis and decision science.
A high relevance of this session was noted through its alignment with an adjacent session on “Substitution of Chemicals of Concern” and a lively and interactive discussion among the more-than-100 session participants.
The session had six presentations that covered the views from different experts and stakeholders from the International Chemical Secretariat (ChemSec); universities in Denmark, Lithuana, Norway, Sweden, Switzerland and the United States; the Environmental Genome Initiative; and European and U.S. environmental and public health agencies. Presentations were accompanied by posters discussing views on advancing substitution practice from the Finnish Environment Institute; Peter Fisk Associates LTD; a Portuguese, a Swiss and two Italian universities; the German Federal Environment Agency; and the European Commission’s Joint Research Centre.
Key points from the six presentations included:
- Anna Lennquist, ChemSec, introduced the session by presenting open access databases and knowledge exchange platforms in support of progressing substitution practice. The use of such databases and platforms was encouraged to overcome challenges related to the introduction of lesser known alternatives to harmful chemicals in various applications.
- Peter Fantke, Denmark Technical University, and his U.S. collaborators proposed how to integrate life cycle impacts into alternatives assessment. They highlighted that indicators for impacts along chemical and product life cycles are essential to uncover relevant tradeoffs. Yet, they noted that simply applying existing life cycle assessment methods is not straightforward, but instead, streamlined and focused identification of relevant impact categories and exposure contexts is needed.
- Semih Oguzcan, Kaunas University of Technology, presented a method for testing an approach combining precautionary risk estimates for workers, consumers and general public in substitution with the aim to encourage substitution practice in Small and Medium Enterprises (SMEs). Concerns were raised that a broader set of indicators is needed to avoid burden shifting across impacts and exposed population groups.
- Ian Cousins, Stockholm University, and his team of international researchers and public stakeholders presented an approach for identifying when the use of various per- and polyfluoroalkyl substances (PFAS) can be phased out. It was highlighted that it is not practical to ban all uses but to evaluate if a use is essential for the functioning of society and to focus substitution efforts systematically on essential uses.
- Katerina Stylianou, University of Michigan, her team and collaborators from the U.S. EPA and the Technical University of Denmark proposed a quantitative screening framework for coupling consumers with environmental exposure for thousands of chemical-product combinations. The need for a consistent mass balance across exposure pathways was emphasized, rendering such a framework suitable for chemical substitution, but also in life cycle impact assessment and high-throughput risk screening and chemical prioritization.
- Ziye Zheng, Umeå University, together with a team from other Swedish and Norwegian research institutions closed this session with a presentation of an assessment framework that includes in silico data across multiple endpoints and that evaluates different multi-criteria decision analysis (MCDA) methods. They highlighted that current hazard data gaps should not prevent us from evaluating alternatives but to close these gaps using in silico based approaches, also including mobility as relevant hazard endpoint.
Main Conclusions From the Session
The session made it very clear that several novel methodological improvements are required to advance and further operationalize alternatives assessment and substitution across sectors.
Life cycle impacts need to be considered using a broader set of environmental and human health indicators to address possible tradeoffs between alternatives. This should, however, be done in a streamlined and focused approach that is consistent with the requirements of a rapid screening substitution, while being quantitative and based on a complete chemical mass balance where possible, in-line with a comparative context of substitution.
Tools and data for assessing hazard are more advanced, while approaches that consider various exposure contexts, thereby making use of high-throughput modeling and in silico-based approaches for filling in data gaps, are becoming more available on both sides.
There are several challenges related to the introduction of lesser known alternatives in substitution, which should be addressed by starting from readily available databases and platforms promoting known and lesser known alternatives. Finally, any substitution effort should be systematically focused on essential uses before committing capacity to assess and introduce any alternative.
Overall, there is an urgent need to look beyond hazard and qualitative assessments in alternatives assessment and chemical substitution in order to address a wider range of impacts and avoid regrettable substitutions. Yet, substitution tools should be easy to use and operational for a broad application in decision support around replacing and phasing out harmful substances across sectors.
Authors’ contact information: email@example.com
Carla Caldeira, European Commission – Joint Research Center (EC-JRC)
The main goal of the session was to present recent methodological developments and applications of stand-alone or integrated life cycle approaches used to assess the sustainability of circular economy. Presentations covered key areas identified in the EU Action Plan for circular economy, namely production, consumption, waste management and market for secondary raw materials.
The session included five platform presentations and three poster spotlights. The main points covered in the five presentations included:
- Elias De Valk, National Institute for Public Health and the Environment suggested that impact assessments can be used to evaluate circular procurement sustainability to: 1) determine for which products or services circular procurement is most beneficial; 2) choose between optional products and services; 3) evaluate the actual effects of the sustainable and circular procurement during and after contract management to strive for further improvement. Life Cycle Analysis (LCA) plays a role in all three aspects but differs with regards to scope, requirements for the inventory and quality assessment.
- The application of the Life Cycle Gap-Analysis was demonstrated by Michael Dieterle, Fraunhofer Institute for Chemical Technology, based on a virtual case study of a lithium-ion battery for e-mobility. This technique analyzes the consequences of product innovations and new technologies regarding both the vision of circular economies and the actual consequences for current life cycle systems.
- Dieuwertje Schrijvers, University of Bordeaux, presented an approach to evaluate the environmental performance of circular strategies, using the market–price ratio between a recycled and a primary product to: 1) identify the functional equivalence of the two product systems and 2) identify the substituted products and processes due to the use or the supply of a recycled product. This approach enables the comparison of two product systems by considering specific market segments and downstream effects of using a recycled product.
- Carla Caldeira, EC-JRC, presented a tool developed for non-LCA expert users to evaluate the effectiveness of food waste prevention actions based on LCA and cost–benefit analysis. The adoption of a life cycle approach minimizes the risk of burden shifting and can support the design of effective food waste prevention actions.
- Preliminary results presented by Francesca Rosa, University of Milano Bicocca, showed that the use of plastic waste in asphalt mixtures improves the asphalt’s structural and environmental performance. The analysis covered the system up to the production plant and included the road construction, maintenance and end of life phases to provide a more comprehensive assessment.
The poster spotlights included:
- Xiaoyu Yan, University of Exeter, presented the Life Cycle Assessment of an alternative method that involves the use of acid mine drainage generating coal waste in a way that produces a leaching solution (lixiviant). This lixiviant can be used to solubilize metals from printed circuit boards taken from electronic waste.
- Carla Rodrigues, University of Coimbra, showed an environmental assessment of an improved foam glass using alternative waste glass streams as raw material and compared these materials with alternative thermal insulation materials available in the market (insulation cork board, EPS, XPS and stone wool). Foam glass has a great potential for improvement in terms of environmental performance as it presents lower impacts than most of the conventional insulation materials.
- Donald Chapman, KU Leuven, presented a life cycle analysis of car-sharing, including both user and provider responses, to estimate the impacts on both resources and the environment. The complex interaction of different effects means that, under certain circumstances, car-sharing may not lead to lower resource use or environmental benefits.
The session illustrated that LCA is a relevant tool in the assessment of the sustainability of circular economy strategies, such as new materials and processes using secondary materials, or in the assessment of food waste prevention actions. Additionally, new methodological approaches were presented to ensure that the assessment is carried out in the most comprehensive manner.
Author’s contact information: firstname.lastname@example.org
Miguel Oliveira, University of Aveiro & CESAM; James Cizdziel, University of Mississippi; Amy Lusher, NIVA Norwegian Institute of Water Research; and Jane Muncke, Food Packaging Forum Foundation
Plastics are used in a wide range of applications and everyday products. As a result of their usage and environmental release, they may undergo multiple degradation processes and form increasingly smaller-sized particles, often ranging down to the nano-size. This session had a total of 58 abstract submissions, including 22 platform presentations, six poster spotlight presentations, five poster corner presentations and 47 posters. Four blocks, containing five to six platform presentations each, were respectively dedicated to the following subjects: Micro(nano)plastics Source and Occurrence, Micro(nano)plastics Sorption and Toxicology, Micro(nano)plastics Determination and Analytical Developments, and Micro(nano)plastics Fate and Approaches to Tackle the Plastics Problem.
These topics attracted considerable attention from the audience with most people staying for the entire session. On average, around 200 people participated in the platform sessions and approximately 30 joined the poster spotlight session. Furthermore, the session was visible through the SETAC Twitter feed under #SETAC_Microplastics.
Conclusions and Key Points
Plastic materials are being released to the environment as a result of their use. Items like fabrics release sizable numbers of particles, which vary according to the type of fabric material and its production processes. Different sizes, shapes, density and polymers may be found in environmental samples of water, sediments and biota. Fibers are among the most commonly reported shapes and polymers, including polyethylene, polystyrene, polypropylene and polyvinyl chloride, which are the chemical constituents most frequently detected. Terrestrial sources, such as wastewater treatment plants discharges and overland and road runoffs, are recognized as important sources for aquatic contamination. New methodologies to increase the efficiency of representative sampling of microplastics in water samples, analysis (e.g., use of high throughput techniques) and resolution were presented as methods that allow a more efficient detection of microplastics in environmental samples (e.g., metal doping, 14C radiotagging). Several studies showed the degradation of microplastics, short-term and generational effects, and species-specific ability to depurate small plastic particles. Presenters discussed the need to standardize information in terms of exposure conditions and method development to isolate, identify and quantify nanoplastics, especially in environmental samples. Relevant biological models and matrices samples (e.g., sea salt) that may provide information on the levels of waterborne microplastics were discussed.
Overall, several keywords summarize the content of the presentations, including microplastics, nanoplastics, adsorption, size, shape, polymer, density, vector, contaminants, depuration, quantification, methodologies, protocols, monitoring and biological effects.
The take-home messages from this session were:
- Time course analysis show that plastic levels have increased in the last years.
- New techniques for quantification and analysis of microplastics are being developed, but their efficiency in real scenarios needs further validation.
- Detection, quantification and analysis of nanoplastics in environmental media remains an unsolved challenge, but first laboratory studies investigating the behavior of nanoplastics in the environment are needed. This further suggests the likely accumulation of nanoplastics in soil.
- Polyethylene terephthalate (PET) microplastics may be a feedstock for syngas production, from which fuels may be produced. This finding promises generation of carbon-neutral fuels if PET is made from renewable sources.
- Improvements and harmonization are still needed with further validation on different complex environmental matrices.
- Bio-based and biodegradable plastics present toxicity similar to convention polymers in in vitro.