||15 September 2011
Volume 12 Issue 9
More from Milan
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- New Developments from SETAC Milan in Aquatic Macrophyte Testing, Higher Tier Risk Assessment and Ecotoxicology
- Chris Wilson, Silvia Mohr and Jo Davies (Steering Committee of Aquatic Macrophyte Ecotoxicology Group)
Macrophytes are key components of aquatic systems, serving as primary producers, and providing habitat and food for animals. As such, these resources need to be protected from non-target effects of contaminants. The poster corner and poster session organized by the Aquatic Macrophyte Ecotoxicology Group (AMEG) focused on new developments in the field, including test methodology and risk assessment. Highlights included presentations on alternatives to Lemna tests, assessment of different endpoints, the recovery potential of macrophytes, as well as the influence of macrophytes on the aquatic environment.
The use of duckweeds as the sole macrophyte species for pesticide risk assessment has been criticized because they may not be representative of dicotyledonous and more complex, submersed and emergent macrophytes, especially in scenarios where plant exposure occurs primarily via sediment. As a result, alternative species methods are being evaluated. Preliminary results for a sterile, sediment-free assay (Maletzki, WEPC2-3 and WE 1821) and a sediment-water assay using Myriophyllum spicatum (Buresova, WEPC2-4), a dicotyledonous species, look promising, but indicate that there are still opportunities for improvement regarding standardization of test conditions, reducing inter-laboratory variation and selecting test duration. Other promising methods focused on the use of filamentous green algae (Oedogonium sp. and Cladophora sp.) to represent metaphyton in water-only and sediment+water systems (Strauss, WEPC2-5).
Further presentations investigated the relative sensitivity of endpoints based on different growth parameters. The sensitivities of Landoltia punctata, Glyceria maxima, and Myriophyllum spicatum to auxins and fatty acid inhibitors were found to differ significantly with M. spicatum being particularly sensitive to an auxin with total shoot length, giving low variability, while the monocot G. maxima was particularly sensitive to a grass herbicide (Schott, WE 186). For photosynthesis inhibitors taken up primarily through the leaves, biomass of M. spicatum was more sensitive; whereas biomass of Lemna minor was more sensitive for photosynthesis inhibitors primarily taken up through the roots. Root elongation was identified as a valuable complement to currently recommended endpoints with duckweed assays for some contaminant classes (Hanson, WEPC2-1). This endpoint is also well suited for measurement in the field and is consistent with the development of a Biotic Ligand Model for plants. Dry mass was the most sensitive endpoint, followed by root length and frond counts in Lemna spp. assays using Cu, Ni, and Pb. Examples of glyphosate-induced photosynthetic hormesis were also reported in Lemna minor and Vallisneria spiralis (Sáenz, WE 184). These results illustrate some of the complexities associated with plant ecotoxicology, particularly effects characterization due to the varying modes-of-action for different contaminants.
Other work focused on facilitating and validating measurement of shoot elongation using digital photography and computer processing (Zweers, WE 183). Advantages of such techniques include traceability/archiveability of measurements and reductions in biases associated with measurement techniques and handling procedures. The use of the COMET assay was also presented for assessing the potential for genotoxic effects of endosulfan on seeds of the emergent macrophyte, Bidens laevis (Perez, WE 185). In this case, effects were found to be associated with cell division rather than chromosome breakage.
The potential for recovery from adverse effects was evaluated in a further presentation, which reported that the duckweed quickly recovered (5 to 6 days) following atrazine exposure, whereas M. spicatum recovery was slower, and irreversible, at very high concentrations (Knezevic, WEPC2-2).
Similar results were reported for M. spicatum exposed to the herbicide indaziflam (Brock, WEPC2-7). In this case, Lemna gibba and Spirodela polyrhiza were the most sensitive species; non-duckweed species, including Myriophyllum spicatum, Elodea canadensis, Salvinia natans, Potamogeton natans, Saggitaria sagittifolia showed intermediate sensitivity; and macrophytes showing little growth in the controls (Ceratophyllum demersum, Ranunculus circinatus, Lemna trisulca) were the least sensitive.
In addition to the ecotoxicology-focused work, researchers also highlighted the effects of aquatic macrophytes on the aquatic environment and the fate of other contaminants. Work was presented that illustrated the influence of submersed, floating, and emergent macrophytes on pH. They found that submerged aquatic macrophytes (especially Myriophyllum) and mixed Lemna/algae layers have a higher stimulating impact on pH-level than emergent macrophytes (Arts, WEPC2-8). The aquatic macrophyte Ceratophyllum demersum was also found to accumulate and biotransform several pharmaceutical compounds commonly found in the environment (Wrede, WEPC2-6).
In summary, the array of work presented in Milan by researchers from industry, academia and government triggered many thoughtful and fruitful discussions, as well as cementing the importance of macrophytes in environmental protection. The session also helped to unveil the many of the new questions that will need to be addressed as we attempt to integrate the ecological with the toxicological in our work.
1 Citation references the speaker and session number from the SETAC Europe annual meeting.
Authors’ contact information: email@example.com, firstname.lastname@example.org, email@example.com
- Risk Communication for Environmental Protection: Scientific and Regulatory Needs
- Jose Tarazona (European Chemicals Agency (ECHA)) and Yvonne Mullooly (Health & Safety Authority, Ireland)
Risk communication is an interactive, complex, multidisciplinary and multi-dimensional process intended to exchange risk-related information and opinions among decision makers, interested parties and the general public.
Recent EU legislative developments impose a duty to communicate risks. There are many ways of determining the hazard and risk of substances; however, the purpose of why we are communicating these risks is important. The presenters examined how environmental risks are assessed, what are the gaps, and what we need to communicate especially regarding risks and risk management measures to protect the environment.
The following provides a brief summary of the presentations in this session:
Development of realistic and effective risk mitigation measures within authorization of human and veterinary pharmaceuticals.
Markus Liebig—The environmental impact/effects of veterinary and human pharmaceuticals do not receive the same attention for authorization as plant protection products (PPPs). Often the same active ingredients might have different risk management measures (RMMs). The study examined the various exposure models, legislative and guidance requirements to develop a catalogue of more appropriate and targeted RMM’s.
Communication about environmental risks of human pharmaceuticals and the therapeutic diseases of patients. Is there an overlap?
Reinhard Lange—This study examined the impact of the release of hormone EE2 into the environment compared to the societal benefits. In general, the societal impacts from taking contraceptives were large and standard WWTPs removed 80-90% of the hormone. The study found that often the most appropriate RMM is upgrading WWTPs to improve their removal efficiency rather than to control the use.
The application of CLP/GHS to pesticides: impact of new hazard communication elements. Emanuela Andreini—The supply chain of PPPs was surveyed with respect to its knowledge of the new CLP/GHS classification and labeling requirements. The findings showed that while those at the top of the supply chain (manufactures and regulators) were aware of their requirements and had commenced strategies to implement, retailers and downstream users were not. Also in general retailers and farmers/consumers were of the opinion that it was the role of the manufacturers, regulators and trade affiliations to educate them.
To inform or not to inform, that is the question.
Misse Wester—This study examined the information exchange about hazardous substances between producers of articles and consumers. While producers of articles know about their substances, their focus is on internal RMMs to protect the environment and human health during production. While most manufacturers inform their consumers through labeling and tables of contents, they are willing to change following consumer communication. The most important factor is to determine the purpose of the communication: is it to have dialogue to facilitate understanding and change or just to inform. In general the real driver for change is regulatory requirements.
How can the cautious policy of acceptance “case by case” become a mechanism of progress towards the rigorous, successful and extensive use of QSARs within REACH?
Simon Pardoe—The plenary heard how the need for data to market substances under the REACH Regulation has afforded QSARs an opportunity to be used in order to fill this data gap. However, the policy for the use of QSARs on a case-by-case basis poses challenges regarding how we learn about risks/uncertainties from these case-by-case examples especially because much of the information and the models are confidential. As information is only available to ECHA and REACH Member State Competent Authority’s then the challenge lies with them to determine the best way to communicate the knowledge from the case-by-case examples.
How to improve the safe use, explanation and acceptance of QSAR models for REACH?
Authors’ contact information: firstname.lastname@example.org; email@example.com
Emilio Benfenati—The plenary heard while there are many positives to the use of QSARs: reduced animal testing, a useful tool for the prioritisation of substances for management, as a tool for assisting in the registration and classification and labeling. The main concern is their acceptance and reliability. If we are to achieve greater acceptance and reliability in use of QSARS then there is a need for regulators, model developers and users to work closely together to ensure that the models are developed for a practical endpoint.
- Integrated Chemical and Biological Approaches for Toxicant Identification
- Werner Brack (UFZ Centre for Environmental Research, Germany), Juliane Hollender (EAWAG, Switzerland), and Marja Lamoree (Institute for Environmental Studies, the Netherlands)
Effect-directed analysis is a powerful tool to support EU legislation and to identify compounds that have an adverse effect in the environment, without knowing beforehand what compounds one deals with. Based on the awareness that an enormous number of potentially hazardous chemicals are accumulated in many environmental compartments, integrated chemical and biological approaches such as effect-directed analysis are required to identify those chemicals causing major effects.
Freshwater, marine and terrestrial environments, as well as also consumer products, are contaminated with a huge and still increasing number of chemicals. For risk assessment and management, it is crucial to identify and prioritize chemicals having adverse effects or posing a risk to ecosystem and human health. This session presented integrated approaches and novel tools helping to establish reliable cause-effect relationships between chemical contamination and measurable effects. Topics included effect-directed analysis (EDA) and toxicity identification evaluation (TIE) with a major focus on the following challenges:
- Integration of bioavailability in EDA
- Innovative fractionation procedures
- Novel biological tools for effect diagnosis and mechanism-based toxicant discrimination
- Bioresponse-linked instrumental analysis
- Structure elucidation of environmental toxicants including GC-MS and LC-MS-based techniques and other spectroscopic approaches as well as innovative computer tools
- QSAR techniques to identify potential toxicants
- Confirmation approaches
This session provided excellent examples for new method development and successful application of this approach to many different matrices including sediments, river water and snow but also in biota such as polar bear plasma and fish bile. The major focus on the effect side was on mutagenicity and endocrine disruption extending the classical endpoints estrogenicity and androgenicity by investigating also progestagenic and glucocorticoid compounds.
As yet, no “xeno-glucocorticoids” have been reported. More testing of standards might indicate whether there are any man-made chemicals other than drugs specifically designed to have an effect may activate the glucocorticoid receptor.
The application of a battery of bioassays covering multiple endpoints in combination with a two-step fractionation scheme revealed the true toxicological identity of riverine sediment samples. Masking effects that can occur in unfractionated samples were demonstrated. Powerful new tools were also presented in the field of structure elucidation involving high resolution mass spectrometry and various innovative computer tools.
In fish bile, triclosan and chlorophene accounted for >50% of anti-androgenicity, which supports their relevance for monitoring, prioritization and management. In polar bear plasma, hydroxy-PCBs and –PBDEs have been identified as major thyroid hormone-like toxicants. In road side snow, identification studies are underway. In this specific matrix, bioavailability aspects need to be taken into account, as the snow contains certain amounts of black carbon that is able to bind the toxicants present.
The implementation of powerful mass spectrometric equipment has significantly progressed the identification of the compounds causing the observed (in vitro) effects, but it is still an enormous task to unravel the identity of the toxicants in the responsive fractions. Application of fragmentation (in combination with fragmentation software), the use of different ionization techniques and LC solvents and deuterium exchange were applied to facilitate identification of mutagenic compounds. It is expected that the identification aspect of EDA will be investigated in more detail in the coming years. Currently, a MassBank (www.massbank.jp) connected database is being set up in Europe to enable researchers to share their LC-MS spectra and to jointly develop a reliable database that can be used for identification of unknown (toxic) compounds.
You may contact Werner Brack (firstname.lastname@example.org) for a link to the European branch of the MassBank database.
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- Outcomes from the Session on Risk assessment in the Marine Environment and Regulation
Matthieu Duchemin (Consultancy for Environment and Human Toxicology and Risk Assessment, France), Steven Eisenreich (EC/ Directorate at JRC, Belgium), and Kari Lethonen (University of Helsinki, Finland)
More and more risk assessments of the marine environment need to be conducted for chemical management purposes, water policies, or other regulations. Here are the outcomes for this session of last SETAC Europe meeting in Milan.
Before being used the chemical undergoes hazard assessment based on approximations of ecotoxicity and worst case assumptions for exposure assessment. While the basis for regulatory risk assessment before putting on the market chemicals remains very similar, data requirements, derivation of threshold values and tools for exposure assessment or risk characterization may lead to different levels of protection. Currently due to the lack of data on seawater species compared with freshwater species, many probabilistic (SSD) and deterministic (PNEC) risk assessments for the marine environment are conducted by combining freshwater data and estuarine data. Thus, there is a true need for further standardized protocols and data on the sensitivity of various marine species. Regulations need also to harmonize methodologies. More tools to help risk assessment of chemicals and mathematical models to effects of mixtures need to be developed.
On the other hand, the use of different integrated batteries of endpoints consisting of different levels of biological organization (biomarkers, behavior, etc.) may reveal relevant remediated regions due to the impact of regulations but also regions where lack of appropriate regulations is still of high concern. However, the choice of an optimal suite of endpoints should rely on scientifically sound endpoints but also include practical compromises. Early warning responses (biomarkers) linked with higher traits of the ecosystem could bring further valuable information in a second phase of risk assessment monitoring the risk of chemicals to refine the estimated risk assessment once they have entered the marine environment. This field also needs further research.
Finally the session was successful in offering 6 oral presentations in a 170 person-capacity room (almost full!), posters and poster corner. It was a great experience shared by all congress participants (industrial companies or groups, consultancies, academics and authorities). A forum may be set up to share within this community on specific issues of that topic and to continue to the next steps with more industry/regulators/academics combined projects.
Author’s contact information: firstname.lastname@example.org
- Tracking community consumption of illicit drugs and other substances by measuring human metabolic residues in urban wastewater
- Sara Castiglioni (Mario Negri Institute, Milan, Italy)
This session presented a novel field of environmental chemistry called “sewage epidemiology” consisting of the chemical analysis of the urban wastewater produced by a population to study the collective exposure of the community to chemicals. The metabolic residues of almost any chemical taken voluntarily or involuntarily by a subject, or to which the subjects are exposed, are commonly excreted with urine or faeces in wastewater where they can be measured. This novel approach is based on analytical chemistry, and mass spectrometry, due to its specificity and sensitivity, is considered the most suitable technique for multi-trace analysis of chemicals in a complex matrix, such as urban wastewater. The aim of this session was to discuss this topic for the first time and present various different applications of the sewage epidemiology approach. The first part of the session focused on the description of the sewage epidemiology approach and the presentation of several potential fields of application. Several technical issues related to sampling and analysis of chemicals have been also presented and discussed. The second part of the session focused on the most common application of sewage epidemiology till now, i.e. the estimation of illicit drugs consumption in a population by wastewater analysis. This approach is currently employed to estimate illicit drug consumption in several countries. Some examples have been provided here from Europe, USA, and Australia dealing with the general population and also with the prison population in Spain.
The session is very relevant in the field of environmental chemistry because of the development of several new analytical methods to detect chemicals in a complex matrix such as urban wastewater. The approach is also relevant for environmental epidemiology, since it can be used to produce epidemiological data from environmental data.
First block of the session
Zuccato provided a general overview of the sewage epidemiology approach and described in detail the rationale. Sewage epidemiology was first applied to illicit drug use to estimate drug consumption in a community by measuring the residues of the main drugs of abuse in urban wastewater. Other potential applications of this approach were also reviewed such as the study of the compliance of pharmaceuticals to the treatment, the exposure of a population to pesticides, PCBs and food contaminants.
Ort discussed the importance of sampling to advance wastewater analysis in order to obtain reliable estimates of illicit drugs abuse. Sampling is the first and most crucial step to maximize data quality and several recommendations have been provided to control or avoid systematic biases and random errors that could result in sampling artifacts. An example of an high temporal resolution sampling for 11 legal and illicit drugs was presented to emphasize the importance of sampling.
Kasprzyk-Hordern aimed to raise awareness of the importance of the phenomenon of chirality1 in forensic estimation of drugs abuse via sewage epidemiology approach. The identification of the different enantiomers2 of some amphetamine type substances and ephedrine is crucial to understand their legal or illegal use and their stereo-selective disposition in the human body. This was discussed as part of a presentation of the results of a 10-month long monitoring of several wastewater treatment plants (WWTPs) in the UK.
Reid presented an application of sewage epidemiology for the quantitative measurements of regional alcohol consumption. Two ethanol metabolites (ethyl sulphate and ethyl glucuronide) have been measured in sewage effluents and were then used to estimate combined alcohol consumption rates in Oslo, Norway. The estimates from ethyl sulphate were in accordance with the sales statistics.
Emke presented a methodology to perform trace analysis of barbiturates in wastewater that has been applied in several WWTPs in the Netherlands to study the behaviour of these substances during wastewater treatment. The total consumption of phenobarbital was back-calculated from the measured concentrations and some hypotheses about legal and illegal use of this substance have been drawn.
The poster spotlight focused on the latest analytical techniques developed to measure illicit drugs in wastewater. First, Harman presented the measurement of drug use over a period of one year using the polar organic chemical integrative samplers (POCIS) with in situ calibration. Then, Quintana presented an analytical method based on selective determination of illicit drugs by mixed-mode sorbents and quadrupole-time-of-flight (QTOF) mass spectrometric analysis in order to increase selectivity and reduce matrix effects. Bijlsma illustrated the potential of LC coupled to LTQ FT Orbitrap MS for qualitative and quantitative analysis of drugs of abuse in urban wastewater. Finally, Mathieu presented a comparison between GC/MS and direct injection coupled to HPLC-MS/MS analysis providing results from several Swiss cities.
Second block of the session
Ort presented the results of a year-long weekly monitoring campaign in 18 cities in the Northwest region of the United States aimed at determining the most reliable methodology to obtain annual estimates of drug excretion. Sampling was identified as a crucial step that should be carefully set up considering the community characteristics.
Postigo studied use and trends of illicit drugs consumption in a prison using the sewage epidemiology approach. This study allowed the pattern of use of several illicit and prescribed drugs to be identified and showed that moderate or at least lower illicit drugs consumption takes place among the prison inmates compared with the general population of a nearby city.
Castiglioni presented the application of the sewage epidemiology approach to estimate the consumption of the main illicit drugs in a five year-long investigation in Italy. This study allowed identification of different patterns of consumption in various areas in Italy and weekly patterns of consumption of the different substances. Finally, the monitoring of the same city for five years allowed the identification of relevant changing trends in drug consumption.
Van Nuijs presented the estimation of illicit drugs consumption in Belgium during a year-long sampling campaign that was set up in the largest WWTPs in Belgium. The back-calculation of drug use estimates was refined taking into account the stability of the compounds in wastewater and a real-time (daily) calculation of the amount of served inhabitants for each sample.
Yargeau applied the wastewater analysis method to estimate community drug use in three municipalities located in the eastern Canada. The removal of illicit drugs during wastewater treatment and the estimates of community drug use obtained by wastewater analysis were consistent with the World Drug Report data on the prevalence of drug use in Canada. Drug use was higher in large Canadian cities.
Foon Yin showed a methodology to evaluate the uncertainty associated with all aspects of the procedures used to estimate illicit drug consumption by wastewater analysis. The sampling methodology was optimized to reduce sampling uncertainty, and the total uncertainty associated with per capita drug consumption estimates was evaluated. Finally, an estimation of drug consumption over 12 days in South East Queensland, Australia was performed.
1 Chiralty—the characteristic of a structure (usually a molecule ) that makes it impossible to superimpose it on its mirror image Also called handedness.
2Enantiomer—either of two stereoisomers that are mirror images of one another but cannot be superimposed on one another and that rotate the plane of polarized light in opposite directions. Enantiomers usually behave the same chemically but differ in optical behavior and sometimes in how quickly they react with other enantiomers. Also called optical isomer, enantiomorph.
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- Environmental Fate and Exposure of Pharmaceuticals and Personal Care Products (PPCPs)
Michael Radke (Stockholm University) and Benoit Roig (LERES/EHESP , France)
Pharmaceuticals and personal care products (PPCPs), either unaltered or transformed to metabolites, are frequently detected organic micropollutants in many surface water and groundwater bodies. Consequently, PPCPs and their metabolites or transformation products have become a major environmental and public health concern examined through many research programs. While we know much about their occurrence in the environment today, our knowledge on the behavior and fate of these rather polar pollutants in aquatic systems is still limited, especially from a process-oriented point of view. Understanding the effects of individual processes in aquatic systems on the fate of PPCPs and identifying parameters constraining these processes, however, is crucial for analyzing potential risks caused by their presence in the environment.
This session provided an opportunity for scientists and environmental authorities to present the most recent findings and to point out the research needs in 3 main topics:
- Analytical methods: recent advances in the sampling, extraction or detection of PPCPs
- Fate in the environment and water treatment: biodegradation, removal rate, characterization of by-products and transformation products
- Exposure assessment of aquatic systems including rivers used as resource for drinking water production.
The contributions comprised a wide spectrum of topics, ranging from analytical chemistry to the prediction of PPCP levels in rivers on a continental scale. In the field of analytical chemistry, innovative approaches for the determination of PPCPs were presented. One current trend is the increased application of liquid chromatography coupled with high-resolution mass spectrometry for the analysis of PPCPs and their transformation products. Many studies focused on developing new analytical methods or on improving sample preparation techniques. As one example, a highly efficient method based on hollow fiber microextraction was presented. Innovative experimental approaches to assess the fate of PPCPs in aquatic systems and soil were also presented. These studies focused on the processes and mechanisms controlling the transport and fate of PPCPs under field conditions. Some of these studies highlighted the need for a detailed systems analysis in order to relate the fate of PPCPs to the environmental boundary conditions.
Moreover, a number of contributions presented data on the removal of PPCPs during treatment of drinking or wastewater by conventional or advanced treatment processes. Studies on the uptake of PPCPs into aquatic organisms, their transformation within the organism and their transfer along an aquatic food chain highlighted the potential of some PPCPs to bioconcentrate in organisms and the complexity when dealing with transformation products. Finally, two presentations focused on the prediction of PPCP concentrations on a nationwide (China) or continental scale, facing the challenge of providing spatially more resolved predictions of PPCPs with manageable effort or of generalizing results from individual sampling campaigns to an integrated scale.
Understanding the fate of polar organic micropollutants such as the PPCPs discussed in this session is a crucial prerequisite for assessing their environmental risk. Solid data on occurrence and fate of PPCPs in receiving systems will be necessary to develop or enhance current risk management practices.
Author’s contact information: firstname.lastname@example.org
- The Future of Ecotoxicological Risk assessment—Biological Traits, Ecological Vulnerability, Improved SSDs, Indirect Ecological Effects
- Ben Kefford (University of Technology Sydney, Australia)
Environmental management of toxicants requires that an assessment of the risk, including the ecological effects posed by their application, is made. From these assessments, regulatory decisions and guidelines regarding the use of substances are determined. Risk assessments used by ecotoxicologists have been criticized for lacking ecological realism and making unlikely model assumptions. In recent years a variety of new approaches and extensions of old ones have emerged to addresses these criticisms and thus improve the ecological risk assessment of toxicants. These approaches include the use of biological traits, development of the species sensitivity distribution (SSD) concept, including better use of historical data, and an appreciation of the need to increase ecological realism by considering competition, predation and the temporal scale of toxicant exposure.
Biological traits, such as reproductive potential and migration ability, give important information on ecological sensitivity. In the context of pesticide management, when such traits are combined with physiological sensitivity to toxicants, a robust predictive indicator has been developed with stream invertebrates. There is much potential for using biological traits with a range of chemical stressors and taxa to improve prospective and retrospective risk assessment.
SSDs are cumulative distributions of species sensitivities to toxicants from which the concentration to protect some predetermined fraction of species can be estimated and uncertainty quantified. Application is contingent on several assumptions, including distribution and model choice. In particular, the representativeness of the sample of observed species sensitivities randomly drawn from an ecological assemblage relevant to where the risk assessment is to be applied is highly contentious as the selection of species is not contingent on the community composition occurring in the ecosystems. Experimental and field survey methods, including some which take advantage of alternative statistical tools, have been recently developed which allow for SSDs to better reflect the composition of real communities and will thus improve risk assessments.
Recent experiments have shown that the amount of competition and predation and the time-scales over which multi-species experiments are conducted can have effects on community sensitivity exceeding three orders of magnitude. It is clear that risk assessment of toxicants needs to appreciate and incorporate these results. The more difficult issue is how? This session brought together the originators of these and other developments. We included statistical, ecological and ecotoxicological perspectives.
In this session we heard about various ideas to improve ecological risk assessment of toxicants. We started with a theme that was mentioned several times— although certain species may not be physiologically sensitive, they can still be vulnerable to toxicants by having traits that result in low resilience to recover from disturbances from toxicants or their populations are already under stress from other factors. Macro-ecology was discussed as a promising approach to complement the many uncertainties with traditional bottom up ecotoxicology, such as additional stressors (parasites, competition and predation) that species experience in the real world.
Numerous presentations were made on SSDs. All acknowledged that there are many assumptions regarding SSDs that are not generally met and thus there are problems with their use; BUT a range of techniques and approaches were suggested or discussed to improve SSDs. This new generation of SSD methods will result in their assumptions being better met and will also make use of important data which are not currently being used.
We also had a session on biological traits, with several other talks mentioning traits (e.g. in the SSD session). Biological traits can be useful for detecting effects of environmental stressors (including toxicants) in the field in both water and soil. One talk looked at the potential for traits in estimating the sensitivity of species to a pesticide. The presenter found that while combinations of targeted traits were good estimates of up-take, out-put and body burdens, they provided poorer estimates of traditional sensitivity(e.g., LC50 and EC50 values).
In our final session we learned about pollution-induced community tolerance (PICT), a novel method of estimating guideline values based on changes in the sensitivity of microbial communities. We also learned about a new SPEcies At Risk index for pesticides (SPEARpesticides) in standing water, rather than the standard SPEARpesticides for flowing waters. We also learned of the need to turn uncertainty factors in to more certainty factors by quantifying the differences in sensitivity between species and environmental variables. The general idea/awareness shared by these four sessions was improving ecological risk assessment by increasing field relevance and/or ecological relevance. It is tempting to see each method as a separate method. But optimal risk assessment may be achieved by combining multiple approaches. For example, traits might be included in SSDs to assess ecological sensitivity, PICT might be used with SSDs and these bottom-up approaches might be validated using the top-down macro-ecology.
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- Emission of Chemicals from Consumer Goods—from Emissions to Effects
- Patrik Andersson (Umea University, Sweden) and Sverker Molander (Chalmers, Sweden)
Chemicals are emitted from consumer goods during their life cycle including production, use, recycling, and disposal. Little is understood regarding the magnitude of the problem of these emissions and the processes governing the release and possible effects on humans and the environment. We are, however, surrounded by a huge number of products containing a vast number of chemicals with many functions spanning from fire retardants over pigments to UV-filters. The associated chemical properties that govern their release and environmental fate are diverse adding to the challenge of describing the consequences. We know today that, for example, the brominated flame retardants and the perfluorinated hydrocarbons are ubiquitous in the environment and most probably major sources are consumer goods. Basic data are lacking to understand and evaluate the risk of most chemicals used in everyday life products.
The aim of the session was to exchange information on theoretical and experimental studies of chemicals in consumer goods and their emission patterns. The presentations of the session were highly relevant for the development of a sustainable society; diffuse emissions of organics from consumer goods were considered, critical chemical factors related to emissions were discussed, new emerging pollutants released from consumer goods were highlighted, and new and innovative molecular level and conceptual models were presented.
Tomas Holmgren and colleagues presented a general model that can predict emissions of organic compounds from articles based on material properties and the chemical structure of the organic compounds. The model was validated measuring plasticizers in PVC flooring focusing on DEHP, DINP and their replacement alternatives. This molecular level approach fits well into the conceptual modeling approach presented by Sverker Molander linking chemicals in products to their occurrence in environmental samples. This work builds on earlier work that applied the concepts of substance and material flow analysis combined with chemical diffusive mass-transfer models. Natalie Von Goetz and coworkers presented new model approaches to assess exposure to brominated flame retardants comparing exposure situations in Europe with the US. Human exposure was clearly correlated to oral uptake of food and dust and dermal uptake of dust since PBDE applications occur in products that are mainly used indoors. Legislative requirements on fire protection were also discussed in relation to the exposure situation in Europe and North America.
Miriam Diamond presented the validation of a conceptual model for human exposure to chemicals contained within a stock or inventory of mainly indoor materials and products. From indoors, chemicals migrate outdoors into the urban environment. Emissions, movement and inventory of 4 classes of compounds (PCBs, PBDEs, polycyclic musks and PAHs) in Toronto were evaluated through substance flow analysis, multimedia measurements and mass balance modeling. Modeling results showed that 85-98% of emissions are advected via air from the urban area allowing for persistent PCBs and PBDEs to enter the terrestrial food web.
Because PCB 11 is not among the PCBs commercially produced, the hazards associated with this PCB are poorly known. Keri Hornbuckle and colleagues showed in their study that this compound originated from byproducts of paint pigment production and can now be found in the environment. The environmental concentration data correlated well with historical pigment production data.
Daniele Coppola, with coworkers, showed that synthetic fields using granulates from used tires release PAHs; such release were also shown to be dependent on temperature. Theoretical estimates showed the significance of this exposure route to people, particularly athletes.
All in all the session provided very interesting contributions to the scientific understanding of this emerging field and the results provided point to further studies that are needed to throw more light on the role of consumer goods as vectors for environmental contaminants.
Authors’ contact information: firstname.lastname@example.org, email@example.com
- Moving Towards a Systems Biology Approach to Predictive Ecotoxicology
- Francesco Falciani and Natalia Reyero
Systems Biology is a novel approach to understanding complex biological systems. It works on the assumption that in order to fully understand complex biological processes, such as organismal response to environmental pollutants, it is not sufficient to analyse a small number of its molecular and physiological response variables. Instead, it aims to develop comprehensive models representing the interaction between the activity of several molecular pathways. The results presented in this session are promising and show the full potential of this approach
Ecotoxicology is concerned with understanding how animals are affected by pollutants in the ecosystem. Recent developments in this area empowered by the widespread availability of functional genomics technologies (e.g. high throughput sequencing, expression profiling, proteomics and metabolomics) have been successful in increasing our understanding of specific mechanism of actions and have provided the community with useful biomarkers. However, the full potential of predictive toxicology can only be achieved by taking a systems level approach, which integrate these complex multi-level molecular and physiological measurements within a unifying interpretative model. In order to address this issue, a number of approaches have been developed to infer computational models of regulatory networks from experimental data. Given the overall lack of information on the specific dynamics of the interactions for the majority of the biological components, network inference methods tend to be based on information theory or probabilistic methods. However, more recently approaches that allow modeling complex process dynamics such as State Space models and Ordinary Differential Equations approaches have become commonly used. This session aims to present to a broad audience an overview of the research ongoing in the area of predictive Ecotoxicology, with a specific focus on case studies based on a Systems biology approach. The ultimate aim of this session was to provide an overview of very recent approaches in the area of predictive toxicology and promote a broader application of Systems Biology approaches in ecotoxicology.
The session comprised six communications ranging from the development of graphical models representing organismal response to laboratory or environmental exposures to mechanistic models representing the diffusion of a contaminant within a cell. Philipp Antczak (University of Birmingham, UK) presented a model representing molecular networks involved in the response to in vitro chemical exposure in Daphnia magna. His results were extremely exciting providing for the first time an integrated model linking physical-chemical features with molecular and physiological responses in a crustacean that already play an important role in water quality assessment. Francesco Falciani (University of Birmingham, UK) instead presented a methodologically similar approach to model the adaptation of fish populations sampled from the environment. This study provides several pathways modulated during adaptation and potentially linking fish physiology to broader population effects. results presented by Carvalho (Ispra, Italy) suggested that diatoms may be a suitable system for a systems biology approach broadening the spectrum of species of environmental relevance suitable for this approach. Extremely interesting were two presentations from Mai, Juliane and Trump, S, Michaelson (Leipzig, Germany), which presented a spatial model of chemical diffusion and a computational approach for distinguishing regulatory and toxic transcriptional signatures of xenobiotic compounds. This work represents ad advanced application of more mechanistic modeling, which is a fundamental part of systems biology approaches.
Antczak P, Ortega F, Chipman JK, and Falciani F. Mapping drug physico-chemical features to pathway activity reveals molecular networks linked to toxicity outcome. PLoS One. 2010 Aug 27; 5(8):e12385.
Carvalho RN and Lettieri, T. Proteomic analysis of the marine diatom Thalassiosira pseudonana upon exposure to benzo(a)pyrene. BMC Genomics. 2011 Mar 24; 12:159.
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- Metals and Metalloids in the Environment: Adaptation, Bioavailability and Speciation
- Erik Smolders (Catholic University Leuven, Belgium), Karel A. C. De Schamphelaere (Ghent University, Belgium), Marie-Helene Tusseau (CEMAGREF, France)
Metals are relevant environmental contaminants. They are widely used in daily life and their persistence and toxicity prompts research and regulations. They are also contaminants of choice to study microevolution because of their persistence and because these elements resemble, or even are, nutrients for biota.
Regulatory needs such as the Water Framework Directive and Existing Substance Regulation have prompted the development of integrative models on metals and metalloids bioavailability in water, sediments and soils. These models are beginning to be accepted worldwide in risk assessments. By applying these models to field data, questions emerge about validity and applicability of the models and about their integration in risk assessment. In addition, community adaptation to metals is a reality that is yet difficult to take into account in risk assessments. This session convened ecotoxicologists and environmental chemist to discuss mechanisms and consequences of community adaptation to metals and metalloids, bioavailability models and new tools to assess bioavailability mechanisms, including stable isotope methods and the application of analytical speciation methods.
Several relevant conclusions or observations were drawn from the presentations in this session:
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- Some waters contain appreciable concentrations of lipophillic metal complexes; synthetic analogues of these are highly bioavailable; however, what these natural complexes do to biota needs to be explored.
- Many regulators of different countries have adopted the bioavailability models
- Lead 'toxicity' is probably explained by lead-induced phosphorus deficiency in plants and algae
- Improved wastewater treatment oxygenates surface water and restores ecological quality of water; a downside is that it leads to a release of metals from the sediment in lab studies, the chemical time bomb is not yet documented in the field
- Pollution-induced community tolerance (PICT) showed that copper tolerance of biofilms collected in contrasting waters is observed in the field at metal concentrations below current EU limits; however, in general, genetic adaptation responses is not found in single species studies reported in literature.
- Plastic Pollution—Polluted Plastics: Fate, effects and Life cycle Assessment
- Christiane Zarfl (University of Osnabrueck, Germany) and Heather Leslie (Institute for Environmental Studies, VU University Amsterdam, The Netherlands)
Pollution of the environment by plastics is drawing more and more attention from the media, governance bodies, the plastics industry and the environmental science community. This session followed up on the fruitful discussions which took place during the first plastic session at SETAC 2010 in Seville and in Madrid 2011 focused on fate, effects and life cycle assessment (LCA) of this widely applied material.
Six platform and 11 poster presentations were given on Tuesday, 17th of May 2011, and covered a broad range of research questions. The talks dealt with the development of extraction methods for microplastics in sediment samples to monitor exposure in the marine environment, investigations of degradation behavior of plastic products in soil, identified pollutants within the plastic matrix, discussed the meaning of additive leaching into the environment and human food (via packaging) as well as further improvements in life cycle assessment of plastics by considering the impact of additives. One talk even combined two hot topics by addressing the association of nanoparticles to plastics in the environment. Posters added topics such as the distribution of microplastics in marine surface waters, bioaccumulation of plastics and associated organic substances in fish, and LCA of alternative biocomposites. Compared to the 2010 session on plastics, it was striking how the presentations were more specialized, possibly indicating a trend towards maturation of this research area.
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- Linking Chemical Residues with Biological Responses in Wildlife
- Judit Smits (University of Calgary), Vince Palace (Department of Fisheries and Oceans, Canada) and Kim Fernie (Environment Canada)
The recognition of a growing list of persistent contaminants in the environment from multiple sources, has stimulated renewed efforts to identify not only systemic effects of exposure in wildlife and domestic animals, but also the development of validated early indicators of compromised biological function in test animals. Proteomics and genomics have accelerated the development of innovative methods for diagnosing toxicity at tissue or cellular levels, which are providing insight into toxic effects that have remained undetectable using standard biomarker techniques. These approaches are exposing a previously unrecognized range of toxic responses to historically important environmental toxicants. This session included presentations from speakers who have used molecular, biochemical and physiological tests to describe and measure the true impacts of exposure to persistent organic compounds (e.g., PCBs, PCDFs, brominated flame retardants, pesticides and hormone mimics) in wildlife. Specifically, alterations in gene expression, protein synthesis, hormone regulation, as well as immunological, physiological, reproductive and behavioural endpoints that can be directly related to internal dose or chemical residues in tissues were discussed. The session featured work from several vertebrate models including birds, mammals, amphibians and fish, as well as from both terrestrial and aquatic habitats. The focus was the connections/relationships between measurable residues or doses of POPs and biological responses that are known to be related to population stability of the wild species investigated.
Considering the theme of this year’s SETAC Europe meeting, the session addressed how to bring together, logically, the science that drives the policy decisions, and the regulations that are meant to provide meaningful, protective, environmentally sound regulation. This session strongly supported the mission of SETAC in presenting research that addresses sustainable environmental quality by focusing, not only on residues in animal tissues or water, but on what the real biological costs might be. Many of our presentations had in their core, the consideration of population level impacts that must be extrapolated from studies based on biomarker, behavioural, pathological or residue information.
The presentations covered most “corners” of the globe, ranging from Antarctica to northern Scandinavia and Canada. We also shared work on vertebrates ranging from fish and marine mammals, to domestic ruminants and avian wildlife. Important questions that arose included the constant challenge of how to extrapolate information studied in more common species, to other, more rare species. The challenge comes because the more rare species are doubtlessly more sensitive to anthropogenic disturbances than the common ones, but researchers must take care to limit their own “investigator impact.” One of the compelling thoughts left hovering after the session is how to interpret increases in inducible enzymes, when we discover through our research, that they are not due to toxicity from anthropogenic compounds, which has been the common assumption by many toxicologists. As well, there is a general caution for young researchers to be careful not to over-interpret their findings, but to continue to develop a holistic understanding of the animal systems they are studying, and how it relates to ecosystem integrity.
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