- Email: [email protected]
Seeking harmonisation in assessing sediments and dredged materials
Meeting report
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
Meeting report Seeking harmonisation in assessing sediments and dredged materials Report on the workshop ‘‘Towards Harmonization of Impact-Assessment Tools for Sediment and Dredged Materials’’, San Sebastian, Spain, 10–11 June 2004
Mira Petrovic, Dami a Barcel o* 1. Workshop organization The workshop was jointly organized by Work Package 3 (WP3) of SedNet, CSIC-Consejo Superior de Investigations Cientificas (Barcelona, Spain) and AZTI (Pasaia, Spain) in the following five sessions: • Harmonization of bio-assays in effect-directed analysis (EDA). • Analytical aspects in EDA. Harmonization of chemical analysis. • EDA in the TRIAD approach. • Harmonization and standardization of impact-assessment tools for dredged materials. • First agreements and further steps towards harmonization/intercomparability of impact-assessment tools for sediment and dredged materials. It was attended by 48 participants from 11 countries, who presented 17 keynote lectures and 12 posters.
2. Workshop objectives The integration of physical/chemical techniques, effect monitoring techniques (e.g., bioassays and functional monitoring) and ecological monitoring/assessment (e.g., community surveys) techniques is crucial for the impact assessment of contaminated sediments. To advance science in this field the complementary integration of ‘‘bridging tools’’, such as EDA), toxicity identification evaluation (TIE), model ecosystems (MEs) and modelling, is also needed (Fig. 1). Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, E-08034, Barcelona, Spain. * Corresponding author. Tel.: +34-93-400-61-70; Fax: +34-93-204-59-04; E-mail: [email protected]
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In many instances, different chemical and biological protocols and EDA/TIE/TRIAD schemes are included in national regulations; however, if not harmonized, the variety of schemes does not allow the data to be compared worldwide, thus creating problems for the interpretation of data by the different regulatory bodies. It is therefore necessary for participants with different fields of expertise to discuss critically possible strategies for harmonizing impact-assessment and source-identification tools. The workshop aimed to make recommendations regarding possible approaches to improve the present situation (e.g., through interlaboratory studies, field validation of different schemes and preparation of certified reference materials). The results obtained from interlaboratory tests are necessary to guarantee robustness, repeatability and reproducibility of each protocol. The planning of the validation exercise, the preparation of the test material for the inter-laboratory tests (round robin tests), the distribution to the laboratories and the evaluation of the results should be carried out in close cooperation with the different laboratories involved together with the relevant standardization bodies. Validation should provide the repeatability and the reproducibility of the different chemical and biological protocols and EDA/TIE/TRIAD schemes that require harmonization and should cover the entire chain: sampling – sample preparation – and final measurements, involving chemical analysis and/or biological and ecological measurement techniques. 3. Summary of key points Because of their great potential for accumulation of contaminants, sediments are particularly sensitive to anthropogenic impacts, which may disturb the natural state of waters. Ignoring their special character as sink 0165-9936/$ - see front matter doi:10.1016/j.trac.2004.07.004
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
Meeting report
and source of contaminants can lead to wrong conclusions concerning the status already reached, so monitoring the aquatic ecosystem, including monitoring and bio-monitoring of sediment quality, as an integral part, is a key issue for implementing the European Union (EU) Water Framework Directive (WFD). It can be argued that chemical analysis should not be used for deciding whether intervention in sediment quality is required, but rather that the effects of anthropogenic contamination on the ecosystem should be the determining factor. Effect-monitoring protocols, which should be able to give us a better understanding about sediment contamination (hazard) and its actual risk to the functioning of the ecosystem (ecological quality), require multi-disciplinary research that integrates physical and chemical techniques, effect-monitoring techniques (e.g., bioassays and functional monitoring) and ecological monitoring/assessment (community surveys) techniques.
should be undertaken; to achieve this, a modular, horizontal approach may be of benefit in rationalising standard methods and promoting their use. This approach was accepted by the EU project HORIZONTAL-ORG and was presented by Hans van der Slot. HORIZONTAL-ORG aims to develop horizontal and harmonised European standards in the field of sludge, soil, contaminated soil and treated biowaste to facilitate regulation of these major streams in many decisions relating to different uses and disposals governed by EU Directives. It is hoped that, if robust methods are developed for sludges, they can then be drafted into broader standards for other matrices. In the longer term, the use of more accessible analytical approaches may assist in harmonizing the standards. Dami a Barcel o focused on the particular problems associated with analysis of brominated flame retardants in sediments, highlighting difficulties in comparison of data and problems with the determination of BDE209.
3.1. Bioassays in EDA A broad variety of biotest methods available was discussed by M. van den Heuvel, P. Hansen and E. de Deckere for evaluating sediments and for integrated assessment when it is necessary to use a complementary combination of several test methods. A tiered testing is suggested in a hierarchical approach covering the cellular, species, population and community levels with a wide range of sensitivity. The evaluation of those hierarchical systems is quite complex and the results difficult to understand and to compare between international waterways. To solve this problem, many so-called harmonization studies are done and well-established standard protocols exist on the international (ISO (International Organisation for Standardisation), European (CEN, European Organisation for Standardisation)) or national level [e.g., under AFNOR (Association Francßaise de Normalisation), BSI (British Standards Institution), DIN (German Organisation for Standardisation)]. Thus, when adopting the most appropriate strategy, the advantage of standards that already exist should be taken into account. Improvements in toxicity testing for dredging materials and sediments should generally be supported in two directions: methods; and, extrapolation of results. For testing methods, the selection of species belonging to different phyla and representative of those inhabiting the disposal site is the best option. Another aspect to be considered is the inclusion of a sensitive response as the endpoint. For extrapolation of results, it can be adequate to include toxicity tests that evaluate effects produced by chronic exposures and expand the range of measurement endpoints.
3.3. EDA in the TRIAD approach The advantages of the TIE concept in the context of chemical analysis and toxic effects were demonstrated and the advantages for ecosystem work shown in the presentation given by Jos Brils. It was apparent that, for validated results, standardisation and harmonisation of the tools used is essential for evaluation and classification of sediments and management of dredged material. It was clearly demonstrated that the tools for sediment assessment are available and only the use of coherent international standards, already implemented and accepted by industry and governmental authorities, will give a clear picture for management on the landscape scale and ecologically relevant handling of sediments. The applicability of the DR-CALUX in vitro bioassay, GC–MS target analyses and GC–MS/MS screening analyses was discussed by Joop Bakker. However, extraction procedures are still an essential issue for standardisation and harmonization, as well as fractionation. Extracting the compounds of interest from the original (sediment) matrix as the test sample can be considered as a first TIE Phase I operation, because a selection of the compounds (viz those that are extracted from the original sample) is tested in the bioassay. The extraction method largely determines which compounds and how much of their initial mass will be transferred to the test sample. A common strategy should be developed. Awareness of this is particularly important when this type of EDA procedure and related biological test systems are the basis for in situ risk assessment or effect-cause identification. Eric de Deckere reported preliminary results of a field study at five sampling locations (i.e. three freshwater, one brackish and one marine within the Scheldt River basin).
3.2. Chemical analysis in EDA To assist in standardisation of chemical methods, a more rational approach to the developing standard methods
http://www.elsevier.com/locate/trac
xi
Meeting report
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
4. Key recommendations
Figure 1. An elaboration of the sediment Triad approach, positioning hazard, risk and impact assessment and positioning the bridging tools Toxicity Identification Evaluation and Model Ecosystems (after J. Brils).
Angel de Val discussed results using the TRIAD concept to characterize dredged materials in estuaries, addressing the improvements needed to determine sediment quality. There has to be SOP (standard operating procedure) taking into account the influence of abiotic parameters (e.g., salinity and temperature) in response to toxicity, histopathology and biomarkers. Specifically-designed toxicity tests should be conducted using truly estuarine species (e.g., caged animals) under correct environmental conditions (e.g., salinity and pH). He demonstrated the essential role of standardisation, harmonisation and clear SOPs for the sediment assessment. Finally, Sandra Caeiro presented a case study on the Sado Estuary, Portugal. To evaluate the environmental significance of sediment contamination, integrative burden-of-evidence was used in the context of the Sediment Quality Triad (SQT) and summarized in the Sediment Quality Guideline Quotients (SQG-Qs) for metals and pesticides; this approach involves assessment of sediment chemistry, sediment toxicity and benthic community structure in so-called management units.
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http://www.elsevier.com/locate/trac
1. The negative effects of some anthropogenic chemicals are relatively well characterised, while others are not well understood or may not even have been identified. For these reasons, chemical analysis is not necessarily a good predictor of environmental diagnosis and effects. We recommend that chemical analysis should not be used for deciding whether intervention in sediment quality is required, but rather that the effects of the anthropogenic contamination on the ecosystem should be the determining factor. 2. We have a large range of tools available for biological characterisation of sediments. However, for in situ evaluation of community structure, for other in vivo assays, such as in situ biological tests and direct toxicity assessment (DTA), and for a range of in vitro assays to check for endocrine effects and genotoxicity, we do not have a set rationale for what to use where. At present, tests do not give a clear indication of what factors may be causing effects. 3. The tools for sediment assessment are available and we recommend the need to use coherent international standards, already implemented and accepted by industry and governmental authorities, that will give a clear picture for management on the landscape scale and ecologically relevant handling of sediments. Thus, it is important take advantage of international standards (e.g., from ISO and CEN), well-established national standard protocols (e.g., from AFNOR, BSI, or DIN), and all the standards developed by ISO Working Groups, and validation studies in ISO and CEN Standards. Acknowledgements Session reports were prepared by P.D. Hansen, M. Scrimshaw and J. Stegemann.
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
Meeting report Seeking harmonisation in assessing sediments and dredged materials Report on the workshop ‘‘Towards Harmonization of Impact-Assessment Tools for Sediment and Dredged Materials’’, San Sebastian, Spain, 10–11 June 2004
Mira Petrovic, Dami a Barcel o* 1. Workshop organization The workshop was jointly organized by Work Package 3 (WP3) of SedNet, CSIC-Consejo Superior de Investigations Cientificas (Barcelona, Spain) and AZTI (Pasaia, Spain) in the following five sessions: • Harmonization of bio-assays in effect-directed analysis (EDA). • Analytical aspects in EDA. Harmonization of chemical analysis. • EDA in the TRIAD approach. • Harmonization and standardization of impact-assessment tools for dredged materials. • First agreements and further steps towards harmonization/intercomparability of impact-assessment tools for sediment and dredged materials. It was attended by 48 participants from 11 countries, who presented 17 keynote lectures and 12 posters.
2. Workshop objectives The integration of physical/chemical techniques, effect monitoring techniques (e.g., bioassays and functional monitoring) and ecological monitoring/assessment (e.g., community surveys) techniques is crucial for the impact assessment of contaminated sediments. To advance science in this field the complementary integration of ‘‘bridging tools’’, such as EDA), toxicity identification evaluation (TIE), model ecosystems (MEs) and modelling, is also needed (Fig. 1). Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, E-08034, Barcelona, Spain. * Corresponding author. Tel.: +34-93-400-61-70; Fax: +34-93-204-59-04; E-mail: [email protected]
x
In many instances, different chemical and biological protocols and EDA/TIE/TRIAD schemes are included in national regulations; however, if not harmonized, the variety of schemes does not allow the data to be compared worldwide, thus creating problems for the interpretation of data by the different regulatory bodies. It is therefore necessary for participants with different fields of expertise to discuss critically possible strategies for harmonizing impact-assessment and source-identification tools. The workshop aimed to make recommendations regarding possible approaches to improve the present situation (e.g., through interlaboratory studies, field validation of different schemes and preparation of certified reference materials). The results obtained from interlaboratory tests are necessary to guarantee robustness, repeatability and reproducibility of each protocol. The planning of the validation exercise, the preparation of the test material for the inter-laboratory tests (round robin tests), the distribution to the laboratories and the evaluation of the results should be carried out in close cooperation with the different laboratories involved together with the relevant standardization bodies. Validation should provide the repeatability and the reproducibility of the different chemical and biological protocols and EDA/TIE/TRIAD schemes that require harmonization and should cover the entire chain: sampling – sample preparation – and final measurements, involving chemical analysis and/or biological and ecological measurement techniques. 3. Summary of key points Because of their great potential for accumulation of contaminants, sediments are particularly sensitive to anthropogenic impacts, which may disturb the natural state of waters. Ignoring their special character as sink 0165-9936/$ - see front matter doi:10.1016/j.trac.2004.07.004
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
Meeting report
and source of contaminants can lead to wrong conclusions concerning the status already reached, so monitoring the aquatic ecosystem, including monitoring and bio-monitoring of sediment quality, as an integral part, is a key issue for implementing the European Union (EU) Water Framework Directive (WFD). It can be argued that chemical analysis should not be used for deciding whether intervention in sediment quality is required, but rather that the effects of anthropogenic contamination on the ecosystem should be the determining factor. Effect-monitoring protocols, which should be able to give us a better understanding about sediment contamination (hazard) and its actual risk to the functioning of the ecosystem (ecological quality), require multi-disciplinary research that integrates physical and chemical techniques, effect-monitoring techniques (e.g., bioassays and functional monitoring) and ecological monitoring/assessment (community surveys) techniques.
should be undertaken; to achieve this, a modular, horizontal approach may be of benefit in rationalising standard methods and promoting their use. This approach was accepted by the EU project HORIZONTAL-ORG and was presented by Hans van der Slot. HORIZONTAL-ORG aims to develop horizontal and harmonised European standards in the field of sludge, soil, contaminated soil and treated biowaste to facilitate regulation of these major streams in many decisions relating to different uses and disposals governed by EU Directives. It is hoped that, if robust methods are developed for sludges, they can then be drafted into broader standards for other matrices. In the longer term, the use of more accessible analytical approaches may assist in harmonizing the standards. Dami a Barcel o focused on the particular problems associated with analysis of brominated flame retardants in sediments, highlighting difficulties in comparison of data and problems with the determination of BDE209.
3.1. Bioassays in EDA A broad variety of biotest methods available was discussed by M. van den Heuvel, P. Hansen and E. de Deckere for evaluating sediments and for integrated assessment when it is necessary to use a complementary combination of several test methods. A tiered testing is suggested in a hierarchical approach covering the cellular, species, population and community levels with a wide range of sensitivity. The evaluation of those hierarchical systems is quite complex and the results difficult to understand and to compare between international waterways. To solve this problem, many so-called harmonization studies are done and well-established standard protocols exist on the international (ISO (International Organisation for Standardisation), European (CEN, European Organisation for Standardisation)) or national level [e.g., under AFNOR (Association Francßaise de Normalisation), BSI (British Standards Institution), DIN (German Organisation for Standardisation)]. Thus, when adopting the most appropriate strategy, the advantage of standards that already exist should be taken into account. Improvements in toxicity testing for dredging materials and sediments should generally be supported in two directions: methods; and, extrapolation of results. For testing methods, the selection of species belonging to different phyla and representative of those inhabiting the disposal site is the best option. Another aspect to be considered is the inclusion of a sensitive response as the endpoint. For extrapolation of results, it can be adequate to include toxicity tests that evaluate effects produced by chronic exposures and expand the range of measurement endpoints.
3.3. EDA in the TRIAD approach The advantages of the TIE concept in the context of chemical analysis and toxic effects were demonstrated and the advantages for ecosystem work shown in the presentation given by Jos Brils. It was apparent that, for validated results, standardisation and harmonisation of the tools used is essential for evaluation and classification of sediments and management of dredged material. It was clearly demonstrated that the tools for sediment assessment are available and only the use of coherent international standards, already implemented and accepted by industry and governmental authorities, will give a clear picture for management on the landscape scale and ecologically relevant handling of sediments. The applicability of the DR-CALUX in vitro bioassay, GC–MS target analyses and GC–MS/MS screening analyses was discussed by Joop Bakker. However, extraction procedures are still an essential issue for standardisation and harmonization, as well as fractionation. Extracting the compounds of interest from the original (sediment) matrix as the test sample can be considered as a first TIE Phase I operation, because a selection of the compounds (viz those that are extracted from the original sample) is tested in the bioassay. The extraction method largely determines which compounds and how much of their initial mass will be transferred to the test sample. A common strategy should be developed. Awareness of this is particularly important when this type of EDA procedure and related biological test systems are the basis for in situ risk assessment or effect-cause identification. Eric de Deckere reported preliminary results of a field study at five sampling locations (i.e. three freshwater, one brackish and one marine within the Scheldt River basin).
3.2. Chemical analysis in EDA To assist in standardisation of chemical methods, a more rational approach to the developing standard methods
http://www.elsevier.com/locate/trac
xi
Meeting report
Trends in Analytical Chemistry, Vol. 23, No. 8, 2004
4. Key recommendations
Figure 1. An elaboration of the sediment Triad approach, positioning hazard, risk and impact assessment and positioning the bridging tools Toxicity Identification Evaluation and Model Ecosystems (after J. Brils).
Angel de Val discussed results using the TRIAD concept to characterize dredged materials in estuaries, addressing the improvements needed to determine sediment quality. There has to be SOP (standard operating procedure) taking into account the influence of abiotic parameters (e.g., salinity and temperature) in response to toxicity, histopathology and biomarkers. Specifically-designed toxicity tests should be conducted using truly estuarine species (e.g., caged animals) under correct environmental conditions (e.g., salinity and pH). He demonstrated the essential role of standardisation, harmonisation and clear SOPs for the sediment assessment. Finally, Sandra Caeiro presented a case study on the Sado Estuary, Portugal. To evaluate the environmental significance of sediment contamination, integrative burden-of-evidence was used in the context of the Sediment Quality Triad (SQT) and summarized in the Sediment Quality Guideline Quotients (SQG-Qs) for metals and pesticides; this approach involves assessment of sediment chemistry, sediment toxicity and benthic community structure in so-called management units.
xii
http://www.elsevier.com/locate/trac
1. The negative effects of some anthropogenic chemicals are relatively well characterised, while others are not well understood or may not even have been identified. For these reasons, chemical analysis is not necessarily a good predictor of environmental diagnosis and effects. We recommend that chemical analysis should not be used for deciding whether intervention in sediment quality is required, but rather that the effects of the anthropogenic contamination on the ecosystem should be the determining factor. 2. We have a large range of tools available for biological characterisation of sediments. However, for in situ evaluation of community structure, for other in vivo assays, such as in situ biological tests and direct toxicity assessment (DTA), and for a range of in vitro assays to check for endocrine effects and genotoxicity, we do not have a set rationale for what to use where. At present, tests do not give a clear indication of what factors may be causing effects. 3. The tools for sediment assessment are available and we recommend the need to use coherent international standards, already implemented and accepted by industry and governmental authorities, that will give a clear picture for management on the landscape scale and ecologically relevant handling of sediments. Thus, it is important take advantage of international standards (e.g., from ISO and CEN), well-established national standard protocols (e.g., from AFNOR, BSI, or DIN), and all the standards developed by ISO Working Groups, and validation studies in ISO and CEN Standards. Acknowledgements Session reports were prepared by P.D. Hansen, M. Scrimshaw and J. Stegemann.