Identification and Prioritization of Emerging Contaminants Session Summaries from SETAC Barcelona
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- Challenges in Wastewater Treatment and Reuse and the Agricultural Use of Manures and Biosolids
Despo Fatta-Kassinos (University of Cyprus), Célia Manaia (Catholic University of Portugal), Dean Leverett (wca Environmental Ltd.) and Jason Snape (AstraZeneca)
In response to the increasing problem of water shortage, treated wastewater is widely reused and is generally considered a reliable alternative water source for irrigation and replenishment among other applications. Currently, sustainable and safe urban water cycles are a high priority on the policy agenda of many EU countries and elsewhere. Challenges include the assessment of environmental and human health hazards associated with regulated and unregulated chemical contaminants and transformation products present in wastewaters. Microbial contaminants such as antibiotic resistant bacteria and resistance genes are also a human health concern. The safe reuse of wastewater requires an understanding of the fate of chemical and microbial contaminants during treatment. Whether wastewater is discharged or reused, the potential for enrichment of antibiotic resistance and subsequent dissemination in the environment, the development and evaluation of treatment technologies that are able to reduce exposure to these contaminants, and the identification of technical and regulatory approaches and practices to address these problems are similar as well as being unique. Overall, in order to reach an informed risk assessment, regulation and control of wastewater, high-quality information is required on the composition of effluents, the sources of contaminants in the effluent, the effectiveness of advanced and conventional effluent treatments, the fate in terrestrial and aquatic ecosystems of contaminants, and the effects of the substances (both alone and in mixtures) on ecosystem (including terrestrial systems) and human health. Furthermore, the conditions and circumstances that determine, enrich and disseminate antibiotic resistance within the ecosystem and key exposure routes to humans need to be further defined. Key lessons, particularly with respect to environmental fate and impacts, may be learned from experience with land application of animal manures and sewage sludge.
In this well-attended session, that included four platform sessions, a poster corner and a regular poster session, many interesting and diverse presentations were provided. In total, 24 platform presentations, 61 posters and six poster corner presentations were delivered. The sessions included presentations on wastewater treatment plant designs and examples of efforts made to implement recently established policies. For example, there were presentations on the first results obtained by the implementation of the Swiss Water Protection Act, and on how England and Wales are preparing for the second phase of a chemical investigation program on trace substances, and also about the designs for wastewater recycling in Antarctica to tackle microcontaminants. Concerning technological treatments, recent findings on the capacity of ozonation, solar-driven biofiltration and antimicrobial membrane processes to remove micropollutants and antibiotic resistant bacteria were presented. New information concerning the fate of micropollutants, for example how is it possible to evaluate the potential biodegradation of sulfonamides to improve wastewater processing and how is it possible to tune the microbial function to transform such contaminants during managed aquifer recharge and engineered biofiltration, was discussed. Lots of innovative presentations on the new, “hot” issue of antibiotic resistance were delivered. We learned how resistance can be disseminated through the sewage systems, about the quantification and resistance genes in wastewater, and how exploring the plasmid-based dissemination of resistance is taking place in the water environment. Moreover, the potential impacts of metals on antibiotic resistance and information on the definition of limits of quantification on resistance in soils were further highlighted. Establishing causality in ecotoxicological risk assessment of micropollutants in wastewater and biosensors were also discussed. Aquatic impact assessment of sewage through the toolbox approach, ecotoxicity testing and crop uptake were some of the new approaches and concerns that have been raised through the presentations and discussions.
The major conclusions from the sessions included:
- The fate of chemical and microbial contaminants in wastewater, aquatic and terrestrial environments due to reuse applications still requires further investigation
- The uptake of microcontaminants and antibiotic resistant bacteria and resistance genes by crops is currently an unexplored field that requires intensive scientific effort
- Effect-based bioassays required for wastewater reuse assessments need to be developed
- Cost effective technologies to meet the current wastewater discharge and reuse regulations need to be developed and validated
- The human health risks associated with wastewater reuse must be evaluated thoroughly
- Recent insights that can be used to advance, support or challenge the regulatory processes that are applied to control wastewater effluents must be explored further by the scientific community
This session was co-organized by EU COST Action ES1403 – NEREUS: New and emerging challenges and opportunities in wastewater reuse.
Authors’ contact information: firstname.lastname@example.org, email@example.com, Dean.Leverett@wca-environment.com and Jason.firstname.lastname@example.org
- Developing End-points and Effect-based Methodologies for Characterization of Emerging Pollutants at Relevant Exposure Concentrations
Ismael Rodea-Palomares (Autonomous University of Madrid) and Roberto Rosal (University of Alcalá)
Identification and prioritization of pollutants classically relies on the paradigm of risk identification based on the straightforward characterization of exposure and effects. However, the way we approach complexity somehow determines the answers we get. Consequently, the assumptions and conditions we establish on the systems to approach and reduce complexity may influence the results obtained. The session was devoted to the characterization of the effect of emerging pollutants from non-standard perspectives, both in the selected end-points and in the ways of characterizing the effects of a given exposure in different complexity scales.
Many interesting works were received for the session and distributed among platform, poster spotlight and poster presentations. The session was well attended with an audience that nearly filled the huge auditorium. Among the works presented, some of them dealt with new approaches to assist the development of bio-analytical tools for the detection of specific activities (such as endocrine disruption) at a concentration low enough to reach resolution at the threshold control concentrations established in legislation. Other researchers introduced “-omics” analyses as effect-based tools. Interestingly, it revealed how some standard procedures without impact on apical endpoints (such as the common use of cosolvents for very hydrophobic chemicals) may result in distorting effects in “-omic” analysis.
The specific issue of mixtures of pharmaceutical pollutants was addressed with two interesting contributions focused on complexity. In one work, the specific issue of transformation products was addressed with dedicated experimental setups. In the other one, a new experimental approach applied the global sensitivity analysis used in computational experiments as a template for the experimental design and data analysis in mixture experimental research. The approach allowed identifying actual drivers of mixture bioactivity at realistic environmental concentrations, independently of any assumption on individual potency or mode of action. This identifies several unexpected pharmaceuticals as important drivers of mixture bioactivity under realistic conditions. Finally, some interesting insights on the concept of planetary boundaries were made. The presenter considered the fact that seven out of nine planetary boundary threats are actually driven by chemical pollution (including greenhouse effect, eutrophication and stratospheric ozone). They further presented a framework proposal for the identification of possible scenarios and characteristics, which may qualify certain pollutants or human activities as a “candidate chemical planetary boundary threat.”
Authors’ contact information: email@example.com and firstname.lastname@example.org
- Emerging Contaminants in the Marine Environment: Presence, Effects and Regulation
Kay Ho, Robert Burgess and Mark Cantwell (USEPA, ORD/NHEERL), Marja H Lamoree and Pim Leonards (VU University Amsterdam)
For the last decade, emerging contaminants (ECs) in freshwater environments have been studied intensively. As a result of this research, the presence and effects of some new use pesticides, pharmaceuticals, personal care products and nanomaterials are much better understood. However, the presence and effects of ECs in the marine environment has not been as well investigated, and much more research needs to be performed. Further, the development of science to support the regulations of ECs in the marine environment is in its infancy. To address these gaps in our understanding, a platform and poster session titled “Emerging Contaminants in the Marine Environment: Presence, Effects, Regulation” was convened. The goal of the session was to provide the audience with an up-to-date overview of aspects of the scientific issues associated with presence, effects and regulation of ECs in the marine environment.
The session consisted of ten poster and 12 platform presentations. Posters addressed both the distribution of ECs in the marine environment and their effects. On the distribution of ECs, poster presenters reported on ultraviolet (UV) light stabilizing chemicals in the Canary Islands, polyfluorinated substances (PFAs) in a French estuary, UV stabilizing benzotriazoles in South Korean sediments, and the interstitial water dispersal of ECs in North Sea sediments. Relative to the measurement in and effects of ECs to marine organisms, the posters covered caffeine impacts on mussels, pyrethroid pesticide use to combat sea lice, persistent ECs found in stranded Australian humpbacked dolphins, and the presence of PFAs and personal care products in European eels in France and Chilean marine organisms, respectively. One poster also investigated the risks associated with shipping solid bulk cargo around the world.
Like the posters, the platform presentations addressed the presence of ECs in the marine environment and included investigations of a wide range of chemicals, including perfluorooctane sulfonate (PFOs) and microplastics, distributed around the French coast and former French colonies, coastal Norway, the Pearl River Estuary in China, and the Scottish maritime region. One presentation also described research on detecting unexploded munitions at coastal locations around the United States and another compared predicted and measured venlafaxine concentrations in coastal areas in France. Relative to the measurement in and effects of ECs to marine organisms, presentations discussed polyfluorinated substances in mussel livers, organophosphate flame retardants accumulation by Mediterranean common dolphins, B-blocker impacts on eel glucose metabolism and sea urchin embryos, and silver nanomaterial effects on mysid, amphipod and polychaete species. On the regulatory front, one presenter reviewed the selection process for ECs to be monitored as part of the implementation of the European Commission’s Marine Strategy Framework Directive.
The poster and platform sessions were well attended, and there was a good exchange of questions and answers between the audience and the presenters. While the session was successful, it demonstrated that despite the excellent research that is ongoing, much more work needs to be performed for the scientific community to properly assess the risks associated with ECs in the marine environment, especially compared with the volume of research in freshwater systems. For example, more efforts need to focus on prioritizing which ECs to monitor for and regulate in the marine environment. Encouraged by the progress made in this session and a previous session at the SETAC North America meeting in Vancouver in November 2014, the organizers held a session at the SETAC North America meeting in Salt Lake City in November 2015.
Authors’ Contact Information: email@example.com, firstname.lastname@example.org, email@example.com and firstname.lastname@example.org
- Monitoring and Modeling-Based Approaches for Identification and Prioritization of Hazardous Emerging Pollutants in European Freshwater Resources
Werner Brack (UFZ Leipzig), Jos van Gils (DELTARES) and Jaroslav Slobodnik (Environmental Institute)
The variety of chemicals emitted to and found in the environment is continuously growing, with today about 90 million known chemicals registered in the CAS, and thousands of compounds that may be detected in environmental samples, many of them unknown. One of the major challenges in pollution research and the regulation of environmental quality is identifying and prioritizing chemicals of concern that might require management and regulation. One major starting point for chemical prioritization is bringing together the chemicals that are produced, used and registered (e.g., under REACH) together with criteria on persistence, mobility, toxicity and modeling of fate, transport and risk. Complementary prioritization can be based on compounds detected in the environment, including transformation products and by-products of technical processes. The latter can be detected by chemical-analytical and effect-based screening tools and identified on a local scale with effect-directed analysis. This will help to answer the key question, “Are we monitoring and assessing the right chemicals?”
Eleven platform presentations and four poster spotlights were delivered in this session. Raquel Carvalho (European Commission – Joint Research Centre ) gave the first talk, presenting the current prioritization approach under the Water Framework Directive (WFD) as a starting point for discussions on new approaches. Complementary to WFD and REACH, the other major piece of regulation supporting the protection of water resources was used by Michael Neumann (Federal Environmental Agency of Germany) to propose an assessment concept of persistent, mobile and toxic chemicals. This approach was complemented by Martin Scheringer (ETH Zürich) with a model to identify those organic chemicals with a potential for long-term environmental contamination. Toxic pressure assessment often relies on data-rich chemicals while Leo Posthuma (RIVM) proposed a novel approach for a solutions-focused approach designed to address the spatio–temporal variability of contaminant mixture risks, including data-poor compounds inspired by the Threshold of Toxicological Concern concept. Prioritization on a European scale is supported by an integrated model system delivered in EU FP7 project SOLUTIONS from emissions via fate and transport up to human and ecological risk assessment presented by Jos van Gils (DELTARES). This approach has been tested and validated for perfluorooctane sulfonate
and perfluorooctanoic acid in the Danube River catchment, where Claudia Lindim (Stockholm University) identified major sources of these compounds. Registered chemicals under REACH and other regulations were analytically screened for in various water types by Rosa Sjerps (KWR Watercycle Research Institute), while Knut Erik Tollefsen (NIVA) promoted a bioassay-assisted identification and prioritization of toxicity drivers. These tools help include the whole mixture of knowns and unknowns into environmental assessment and understand which fraction of observed effects can be actually explained by known chemicals. Beate Escher (Helmholtz Centre for Environmental Research – UFZ) demonstrated that this fraction can be rather small for more integrative endpoints such as oxidative stress. On a more local scale, toxicant identification can be supported by effect-directed analysis (EDA) based on in vitro assays. A new, miniaturized version of AMES test on 384 well plates for EDA was presented by Nick Zwart (VU University Amsterdam). Marius Majewski (Karlsruhe Institute of Technology) showed that transformation products, for example from pharmaceuticals, may retain toxic properties of the parent solution and contribute to overall effects.
The session was very well attended in a room that hardly was able to host the huge audience during many presentations. We saw that big challenges, such as the ever-growing number of anthropogenic chemicals in the environment potentially impacting ecosystems and human health, also promote fireworks of innovative ideas to prioritize chemicals and to reduce complexity without a priori excluding data-poor and unknown chemicals. This session was a big step towards a consistent set of monitoring and modeling-based prioritization concepts and addressing major knowledge gaps and uncertainty. Since the subject is a key issue, and currently significant progress is being made in projects like SOLUTIONS and beyond, this dialogue will be continued in upcoming SETAC meetings.
Author’s contact information: email@example.com
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