The beginning of the nineties saw a remarkable boom of scientific exploration of the Oderhaff are... more The beginning of the nineties saw a remarkable boom of scientific exploration of the Oderhaff area. The political and economical changes in middle and eastern Europe led to a general increase of interest in this region. Especially the co-operation of German and Polish scientists was intensified during this time. Now, after a few years of work in the frame of several national and international projects, a number of new and interesting results are available. Only some few aspects have been published in different scientific journals already. With the present monograph, we intend to give an overwiew of the geosciences progress and state-of-the-art in the investigation of this area. The Oderhaff is a shallow lagoon-like basin that acts as a buffer between the Oder river discharge and the open Baltic Sea waters. Thus, the Oderhaff may be considered a model region to study physical, geological, geochemical, and ecological processes in the land-sea interaction zone. Besides the investigatio...
Additional file 1: Table S1. Biometric data and information on the tissue treatment of the sample... more Additional file 1: Table S1. Biometric data and information on the tissue treatment of the sampled fish. Table S2. Sampling stations in the German part of the River Elbe including the station name, river km, matrix (sediment or suspended particulate matter (SPM)), the geographical position (latitude, longitude) and the sampler. Sediment samples were collected in July and SPM in September 2014. Table S3. Ctotal of seven PCBs in sediment samples from the River Elbe in µg kg−1 (dw). Table S4. Ctotal of PAHs in sediment samples from the River Elbe in µg kg−1 (dw). Table S5. Ctotal of seven PCBs in SPM samples from the River Elbe in µg kg−1 (dw). Table S6. Ctotal of PAHs in SPM samples from the River Elbe in µg kg−1 (dw). Table S7. Cfree of PCBs in sediment samples from the River Elbe in pg L−1. Table S8. Cfree of PAHs in sediment samples from the River Elbe in pg L−1. Table S9. Cfree of PCBs in SPM samples from the River Elbe in pg L−1. Table S10. Cfree of PAHs in SPM samples from the R...
Background: Chemical quality of sediment and suspended particulate matter (SPM) is usually assess... more Background: Chemical quality of sediment and suspended particulate matter (SPM) is usually assessed by total chemical concentrations (C total). However, the freely dissolved concentration (C free) is the ecologically more relevant parameter for bioavailability, diffusion and bioaccumulation. In recent studies, equilibrium sampling has been applied to determine C free of hydrophobic organic contaminants (HOCs) in the sediment pore water, whereas such data are missing for SPM. We applied solid-phase micro-extraction to measure and compare C free of PAHs and PCBs in pore water of sediments and SPM sampled along the German part of the river Elbe. Moreover, site-specific distribution ratios were evaluated and C bio,lipid was predicted using C free. Results: C free of PAHs remained largely constant while C free of PCBs varied along the Elbe River. The highest C total of PCBs and PAHs were found at Prossen (km 13) and Meißen (km 96). PCB C total even exceeded the environmental quality standard for sediment and SPM in Prossen. Site-specific distribution ratios (K D) revealed a stronger sorption for PAHs compared to PCBs, indicating a higher availability of PCBs. Equilibrium partitioning concentrations in lipids (C lip↔sed) showed a high correlation with actually measured lipid-normalised concentrations (C bio,lipid) in bream. This indicates that PCB bioaccumulation in this benthic fish species is closely linked to the sediment contamination. Conclusions: In rivers, SPM functions as a transportation vehicle for HOCs along the stream until it eventually deposits to the sediment. This study demonstrates that due to weaker sorption of PAHs and PCBs to the SPM this matrix poses a higher risk to the aquatic environment compared to the sediment. The prediction of C bio,lipid of PCBs was correct and shows that solid-phase micro-extraction is highly suited to predict lipid concentration, and thus a valuable tool for risk-assessment or sediment management.
Geografisk Tidsskrift-Danish Journal of Geography, 2009
Abstract Geografisk Tidsskrift—Danish Journal of Geography 109(1):81–94, 2009 A total of 63 sedim... more Abstract Geografisk Tidsskrift—Danish Journal of Geography 109(1):81–94, 2009 A total of 63 sediment samples were collected in the North Sea—Baltic Sea transition zone using hydraulically damped box-corer. Analysis of the top one cm sediments shows a north to south trend in Li, Ca and methylated PAHs suggesting transport of these elements and micro pollutants from the North Sea to the Baltic Sea. The sediment content of a high C/N ratio reflects preferential N decomposition during transport whereas a low P content in the northern and deepest part of the study area may result from early diagenesis effects. The spatial distributions of Zn and Pb with highest concentrations in the southern part of the study area imply local terrestrial supply and transport. In general, the PCB and PAH concentrations were high both in the northern and the southern parts of the area and low in-between. The relative constant ratio between the analyzed PCBs on all the stations suggests atmospheric deposition as the main source of PCB. Fluoranthene/Pyrene ratios >1 and Phenenthrene/Anthracene ratios <15 point at combustion of fossilfuel as the main source of PAH.
Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This ap... more Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This approach was extended to biological material. In this work, a passive equilibrium sampling method for the measurement of HOCs in biota was developed as an innovative alternative because classical exhaustive extraction techniques are time-consuming and error-prone. The newly developed method is based on the well-proven SPME fiber method for sediment. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. Partition coefficients of PAHs and PCBs between the lugworm tissue and the PDMS sampling phase were determined. Polydimethylsiloxane (PDMS) coated glass fibers were directly inserted in homogenized lugworm tissue and glass fibers were analyzed using gas chromatography coupled to mass spectrometry. The method application on lugworms from tidal sand flats near Wilhelmshaven showed that the mean body residue values of PCBs (4 μg g-1) and PAHs (256 μg g-1) were about five times higher for PCBs and more than 22 times higher for PAHs compared to literature data for the North Sea area. This high level of contamination might be a consequence of the oil processing refinery located in direct proximity to the sampling site. This novel approach of applying the SPME method to biota will make biological monitoring more effective and holistic, because seasonally and area-wide changes in all environmental compartments can be recorded quickly.
marine algae Phaeodactylum tricornutum DTU Orbit (10/12/2018) Comparison of passive and standard ... more marine algae Phaeodactylum tricornutum DTU Orbit (10/12/2018) Comparison of passive and standard dosing of polycyclic aromatic hydrocarbons to the marine algae Phaeodactylum tricornutum Testing hydrophobic organic compounds (HOCs), like polycyclic aromatic hydrocarbons (PAHs), in aquatic toxicity tests is difficult due to compound losses through volatilization, sorption to the test vessel and culture medium constituents. This results in poorly defined exposure, the bioavailable concentration is reduced and concentration-effect-relation might be underestimated. Passive dosing can overcome these problems by the continual partitioning of HOCs from a dominating reservoir loaded in a biologically inert polymer such as silicone. This procedure provides defined and constant freely dissolved concentrations and eliminates spiking with cosolvents. Passive dosing using silicone Orings as donor and PAHs as test substances (fluoranthene, naphthalene, phenanthrene, acenaphthene, fluorene, benzo[a...
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Equilibrium passive sampling methods (EPSM) allow quantification of freely dissolved contaminant ... more Equilibrium passive sampling methods (EPSM) allow quantification of freely dissolved contaminant concentrations (Cfree ) in sediment porewater. Polydimethylsiloxane (PDMS) is a convenient sampling polymer that can be equilibrated in field (in-situ) or laboratory sediments (ex-situ) to determine Cfree providing reliable compound-specific PDMS-water partition coefficients (KPDMS-water ) are available. Polycyclic aromatic hydrocarbons (PAHs) are an important class of sediment contaminants comprised of parent and alkylated homologs. However, application of EPSM to alkylated PAHs is challenged by lack of KPDMS-water measurements. Our first objective was to obtain KPDMS-water for nine alkylated PAHs and biphenyl using three different PDMS coated fibers. Quantitative relationships were then established to define KPDMS-water for 18 parent and 16 alkyl PAHs included in USEPA's sediment quality benchmark method for benthic life protection based on additive toxic units (∑TUs). The second objective was to compare Cfree in porewater obtained using both in-situ and ex-situ EPSM at six Baltic Sea locations. Results indicated that in-situ and ex-situ Cfree for alkyl PAHs generally agreed within a factor of three. Further, all sites exhibited ∑TUs < 1 indicating PAHs pose a low risk to benthos. Results extend practical application of EPSM for improved risk assessment and derivation of porewater-based remediation goals for PAH contaminated sediments. This article is protected by copyright. All rights reserved.
In this study the miniaturised Marine Algae Test (mMAT) using passive dosing was developed based ... more In this study the miniaturised Marine Algae Test (mMAT) using passive dosing was developed based on the ISO EN DIN10253 to investigate the growth inhibition of the marine diatom Phaeodactylum tricornutum caused by polycyclic aromatic hydrocarbons (PAHs). Risk assessment of hydrophobic organic compounds (HOCs) like PAHs in aquatic toxicity tests is very difficult due to their low aqueous solubilities, losses via sorption to the wells and volatilisation. However, passive dosing can overcome these challenges. In this study biocompatible silicone O-rings were used as PAH reservoir. Individual PAHs at saturation were tested using passive dosing and in comparison with nominal spiking. Additionally, a recreated mixture of PAHs reflecting the field composition of the sediment pore water was tested with passive dosing. PAHs revealed strong growth inhibiting effects on algal growth in passive dosing tests, while nominal spiking had only slightly growth inhibiting effects in the highest concentration. The recreated PAH mixture revealed slightly inhibiting effects using passive dosing when tested with a factor of 5000 of the field concentration. This study demonstrates the superiority of passive dosing to spiking and further the successful implementation of passive dosing in the marine algae test maintaining a constant concentration for HOCs with a log KOW > 4.6.
Passive sampling (PS, equally used for passive sampler) methods have successfully been applied in... more Passive sampling (PS, equally used for passive sampler) methods have successfully been applied in situ to quantify the bioavailability of hydrophobic organic compounds in air, water and sediments. However, very little is known on the applicability of PS in unsaturated soils. Here, we present the results of a greenhouse experiment in which we applied in situ PS methods in pots. Low density polyethylene (LDPE) and polydimethylsiloxane (PDMS) fibres with a newly developed PS holder were used to analyse freely dissolved polycyclic aromatic hydrocarbon (PAH) concentrations (Cfree) in a skeet shooting range soil and an uncontaminated control soil under water saturated and unsaturated conditions for up to nine months. A short exposure time of three months was not sufficient for the PDMS samplers to reach distribution equilibrium with the surrounding soil. Under saturated water conditions, the in situ results agreed well with measurements obtained from the conventional ex situ soil suspension method. They were in accordance with similar comparisons made in previous studies on sediments, as well as with model predictions. However, for unsaturated water conditions, the results differed considerably from the ex situ Cfree values, in particular for the light molecular weight (LMW) PAHs such as phenanthrene, fluoranthene, and pyrene. The results of the two in situ PS methods were in good agreement with each other under both soil water conditions, indicating that dissipation mechanisms, such as degradation or volatilization, led to a substantial decrease in Cfree under unsaturated conditions, especially for the LMW PAHs (log10KOW < 5.85) over a period of six months or more. Thus, in their current state of development, in situ PS methods can be used in soils under water-saturated conditions. However, an adequate method to correct for non-equilibrium conditions needs to be developed before they can be applied to unsaturated conditions, mainly for LMW PAHs.
The freely dissolved concentration (Cfree) was measured for PAHs and PCBs in sediments of the Ger... more The freely dissolved concentration (Cfree) was measured for PAHs and PCBs in sediments of the German Bight and Wadden Sea. Ex-situ Solid Phase Microextraction (SPME) was applied using Polydimethlysiloxane (PDMS) coated glass fibers followed by automated thermal desorption and GC-MS analysis. This study provides the first dataset on the spatial distribution of Cfree for PAHs and PCBs in the German Bight and the Wadden Sea. We found elevated PCB concentrations in the Wadden Sea and especially in the Weser estuary. Sandy North Sea sediments were rather less contaminated, except for some former dumping sites. The sorption strength of PAHs was generally stronger, while PCBs in the Wadden Sea sediments were only weakly bound. This SPME method is a rapid and sensitive tool to study Cfree of hydrophobic organic chemicals to improve todays sediment risk assessment.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Advances in biochemical engineering/biotechnology, Jan 4, 2016
The combination of polymer-based passive sampling to collect complex environmental mixtures of po... more The combination of polymer-based passive sampling to collect complex environmental mixtures of pollutants, the transfer of these mixtures into bioassays, and their related toxicological characterization is still in its infancy. However, this approach has considerable potential to improve environmental hazard and risk assessment for two reasons. First, the passive sampler collects a broad range of chemicals representing the fraction of compounds available for diffusion and (bio)uptake, excluding a large part of the matrix; thus, extensive sample cleanup which could discriminate certain compounds can be avoided. Second, the toxicological characterization of samples using bioassays is complementary to chemical (target) analysis within environmental monitoring because it captures all chemicals exerting the same mode of toxic action and acting jointly in mixtures, thus providing a comprehensive picture of their overall combined effects. The scientific literature describes a range of exam...
Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistenc... more Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing. M any of the chemicals that we use in our daily lives end up in multimedia environments including biota where they may pose a risk to ecosystems and human health as part of mixtures and together with their transformation products. The related hazard potential can be assessed in a large variety of in vivo and in vitro bioassays that serve different purposes (Box 1). However, the quantitative link between the exposure in the environment and that in the bioassay is often missing. Establishing the link is difficult because different chemicals have distinct enrichment factors and sampling rates. Furthermore, they sorb to different extents to sorptive phases present in bioassays, which reduces exposure. A major challenge is how to combine sampling, extraction and dosing of a mixture while conserving or re-establishing its composition at adjustable levels for concentration-effect assessment. Here we discuss strategies for chemicals present in the aquatic environment, that is, water, sediment, and aquatic biota. Bioassays provide an integrative measure of the overall toxic potential of a sample and are complementary to chemical analysis providing quantitative information on selected chemicals. Chemicals with a common mode of toxic action add up to a joint response. 1 A comprehensive set of bioassays is available for the assessment of combination effects. 2 The major obstacles to successfully applying bioassays for assessing environmentally relevant mixtures of organic pollutants are to collect, extract and dose the mixture into the bioassay without the mixture composition being altered while linking the observed effect back to the concentrations in the original medium. In this article, we focus on the sampling of environmental pollutants (Section 1), their dosing into bioassays (Section 2), general transfer strategies of compounds from the environment into bioassays taking into account the mixture composition (Section 3), and specific combinations of sampling and dosing approaches for mixtures of chemicals present in the aquatic environment (Section 4, Figure 1). ■ SECTION 1. SAMPLING APPROACHES IN DIVERSE AQUATIC MEDIA AND BIOTA The goal of sampling in water, sediment and biota is to reduce the sample's heterogeneity, enhance stability, remove matrix constituents, and enrich the chemicals of interest to increase sensitivity. When sampling mixtures in the environment,
The beginning of the nineties saw a remarkable boom of scientific exploration of the Oderhaff are... more The beginning of the nineties saw a remarkable boom of scientific exploration of the Oderhaff area. The political and economical changes in middle and eastern Europe led to a general increase of interest in this region. Especially the co-operation of German and Polish scientists was intensified during this time. Now, after a few years of work in the frame of several national and international projects, a number of new and interesting results are available. Only some few aspects have been published in different scientific journals already. With the present monograph, we intend to give an overwiew of the geosciences progress and state-of-the-art in the investigation of this area. The Oderhaff is a shallow lagoon-like basin that acts as a buffer between the Oder river discharge and the open Baltic Sea waters. Thus, the Oderhaff may be considered a model region to study physical, geological, geochemical, and ecological processes in the land-sea interaction zone. Besides the investigatio...
Additional file 1: Table S1. Biometric data and information on the tissue treatment of the sample... more Additional file 1: Table S1. Biometric data and information on the tissue treatment of the sampled fish. Table S2. Sampling stations in the German part of the River Elbe including the station name, river km, matrix (sediment or suspended particulate matter (SPM)), the geographical position (latitude, longitude) and the sampler. Sediment samples were collected in July and SPM in September 2014. Table S3. Ctotal of seven PCBs in sediment samples from the River Elbe in µg kg−1 (dw). Table S4. Ctotal of PAHs in sediment samples from the River Elbe in µg kg−1 (dw). Table S5. Ctotal of seven PCBs in SPM samples from the River Elbe in µg kg−1 (dw). Table S6. Ctotal of PAHs in SPM samples from the River Elbe in µg kg−1 (dw). Table S7. Cfree of PCBs in sediment samples from the River Elbe in pg L−1. Table S8. Cfree of PAHs in sediment samples from the River Elbe in pg L−1. Table S9. Cfree of PCBs in SPM samples from the River Elbe in pg L−1. Table S10. Cfree of PAHs in SPM samples from the R...
Background: Chemical quality of sediment and suspended particulate matter (SPM) is usually assess... more Background: Chemical quality of sediment and suspended particulate matter (SPM) is usually assessed by total chemical concentrations (C total). However, the freely dissolved concentration (C free) is the ecologically more relevant parameter for bioavailability, diffusion and bioaccumulation. In recent studies, equilibrium sampling has been applied to determine C free of hydrophobic organic contaminants (HOCs) in the sediment pore water, whereas such data are missing for SPM. We applied solid-phase micro-extraction to measure and compare C free of PAHs and PCBs in pore water of sediments and SPM sampled along the German part of the river Elbe. Moreover, site-specific distribution ratios were evaluated and C bio,lipid was predicted using C free. Results: C free of PAHs remained largely constant while C free of PCBs varied along the Elbe River. The highest C total of PCBs and PAHs were found at Prossen (km 13) and Meißen (km 96). PCB C total even exceeded the environmental quality standard for sediment and SPM in Prossen. Site-specific distribution ratios (K D) revealed a stronger sorption for PAHs compared to PCBs, indicating a higher availability of PCBs. Equilibrium partitioning concentrations in lipids (C lip↔sed) showed a high correlation with actually measured lipid-normalised concentrations (C bio,lipid) in bream. This indicates that PCB bioaccumulation in this benthic fish species is closely linked to the sediment contamination. Conclusions: In rivers, SPM functions as a transportation vehicle for HOCs along the stream until it eventually deposits to the sediment. This study demonstrates that due to weaker sorption of PAHs and PCBs to the SPM this matrix poses a higher risk to the aquatic environment compared to the sediment. The prediction of C bio,lipid of PCBs was correct and shows that solid-phase micro-extraction is highly suited to predict lipid concentration, and thus a valuable tool for risk-assessment or sediment management.
Geografisk Tidsskrift-Danish Journal of Geography, 2009
Abstract Geografisk Tidsskrift—Danish Journal of Geography 109(1):81–94, 2009 A total of 63 sedim... more Abstract Geografisk Tidsskrift—Danish Journal of Geography 109(1):81–94, 2009 A total of 63 sediment samples were collected in the North Sea—Baltic Sea transition zone using hydraulically damped box-corer. Analysis of the top one cm sediments shows a north to south trend in Li, Ca and methylated PAHs suggesting transport of these elements and micro pollutants from the North Sea to the Baltic Sea. The sediment content of a high C/N ratio reflects preferential N decomposition during transport whereas a low P content in the northern and deepest part of the study area may result from early diagenesis effects. The spatial distributions of Zn and Pb with highest concentrations in the southern part of the study area imply local terrestrial supply and transport. In general, the PCB and PAH concentrations were high both in the northern and the southern parts of the area and low in-between. The relative constant ratio between the analyzed PCBs on all the stations suggests atmospheric deposition as the main source of PCB. Fluoranthene/Pyrene ratios >1 and Phenenthrene/Anthracene ratios <15 point at combustion of fossilfuel as the main source of PAH.
Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This ap... more Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This approach was extended to biological material. In this work, a passive equilibrium sampling method for the measurement of HOCs in biota was developed as an innovative alternative because classical exhaustive extraction techniques are time-consuming and error-prone. The newly developed method is based on the well-proven SPME fiber method for sediment. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. Partition coefficients of PAHs and PCBs between the lugworm tissue and the PDMS sampling phase were determined. Polydimethylsiloxane (PDMS) coated glass fibers were directly inserted in homogenized lugworm tissue and glass fibers were analyzed using gas chromatography coupled to mass spectrometry. The method application on lugworms from tidal sand flats near Wilhelmshaven showed that the mean body residue values of PCBs (4 μg g-1) and PAHs (256 μg g-1) were about five times higher for PCBs and more than 22 times higher for PAHs compared to literature data for the North Sea area. This high level of contamination might be a consequence of the oil processing refinery located in direct proximity to the sampling site. This novel approach of applying the SPME method to biota will make biological monitoring more effective and holistic, because seasonally and area-wide changes in all environmental compartments can be recorded quickly.
marine algae Phaeodactylum tricornutum DTU Orbit (10/12/2018) Comparison of passive and standard ... more marine algae Phaeodactylum tricornutum DTU Orbit (10/12/2018) Comparison of passive and standard dosing of polycyclic aromatic hydrocarbons to the marine algae Phaeodactylum tricornutum Testing hydrophobic organic compounds (HOCs), like polycyclic aromatic hydrocarbons (PAHs), in aquatic toxicity tests is difficult due to compound losses through volatilization, sorption to the test vessel and culture medium constituents. This results in poorly defined exposure, the bioavailable concentration is reduced and concentration-effect-relation might be underestimated. Passive dosing can overcome these problems by the continual partitioning of HOCs from a dominating reservoir loaded in a biologically inert polymer such as silicone. This procedure provides defined and constant freely dissolved concentrations and eliminates spiking with cosolvents. Passive dosing using silicone Orings as donor and PAHs as test substances (fluoranthene, naphthalene, phenanthrene, acenaphthene, fluorene, benzo[a...
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Equilibrium passive sampling methods (EPSM) allow quantification of freely dissolved contaminant ... more Equilibrium passive sampling methods (EPSM) allow quantification of freely dissolved contaminant concentrations (Cfree ) in sediment porewater. Polydimethylsiloxane (PDMS) is a convenient sampling polymer that can be equilibrated in field (in-situ) or laboratory sediments (ex-situ) to determine Cfree providing reliable compound-specific PDMS-water partition coefficients (KPDMS-water ) are available. Polycyclic aromatic hydrocarbons (PAHs) are an important class of sediment contaminants comprised of parent and alkylated homologs. However, application of EPSM to alkylated PAHs is challenged by lack of KPDMS-water measurements. Our first objective was to obtain KPDMS-water for nine alkylated PAHs and biphenyl using three different PDMS coated fibers. Quantitative relationships were then established to define KPDMS-water for 18 parent and 16 alkyl PAHs included in USEPA's sediment quality benchmark method for benthic life protection based on additive toxic units (∑TUs). The second objective was to compare Cfree in porewater obtained using both in-situ and ex-situ EPSM at six Baltic Sea locations. Results indicated that in-situ and ex-situ Cfree for alkyl PAHs generally agreed within a factor of three. Further, all sites exhibited ∑TUs < 1 indicating PAHs pose a low risk to benthos. Results extend practical application of EPSM for improved risk assessment and derivation of porewater-based remediation goals for PAH contaminated sediments. This article is protected by copyright. All rights reserved.
In this study the miniaturised Marine Algae Test (mMAT) using passive dosing was developed based ... more In this study the miniaturised Marine Algae Test (mMAT) using passive dosing was developed based on the ISO EN DIN10253 to investigate the growth inhibition of the marine diatom Phaeodactylum tricornutum caused by polycyclic aromatic hydrocarbons (PAHs). Risk assessment of hydrophobic organic compounds (HOCs) like PAHs in aquatic toxicity tests is very difficult due to their low aqueous solubilities, losses via sorption to the wells and volatilisation. However, passive dosing can overcome these challenges. In this study biocompatible silicone O-rings were used as PAH reservoir. Individual PAHs at saturation were tested using passive dosing and in comparison with nominal spiking. Additionally, a recreated mixture of PAHs reflecting the field composition of the sediment pore water was tested with passive dosing. PAHs revealed strong growth inhibiting effects on algal growth in passive dosing tests, while nominal spiking had only slightly growth inhibiting effects in the highest concentration. The recreated PAH mixture revealed slightly inhibiting effects using passive dosing when tested with a factor of 5000 of the field concentration. This study demonstrates the superiority of passive dosing to spiking and further the successful implementation of passive dosing in the marine algae test maintaining a constant concentration for HOCs with a log KOW > 4.6.
Passive sampling (PS, equally used for passive sampler) methods have successfully been applied in... more Passive sampling (PS, equally used for passive sampler) methods have successfully been applied in situ to quantify the bioavailability of hydrophobic organic compounds in air, water and sediments. However, very little is known on the applicability of PS in unsaturated soils. Here, we present the results of a greenhouse experiment in which we applied in situ PS methods in pots. Low density polyethylene (LDPE) and polydimethylsiloxane (PDMS) fibres with a newly developed PS holder were used to analyse freely dissolved polycyclic aromatic hydrocarbon (PAH) concentrations (Cfree) in a skeet shooting range soil and an uncontaminated control soil under water saturated and unsaturated conditions for up to nine months. A short exposure time of three months was not sufficient for the PDMS samplers to reach distribution equilibrium with the surrounding soil. Under saturated water conditions, the in situ results agreed well with measurements obtained from the conventional ex situ soil suspension method. They were in accordance with similar comparisons made in previous studies on sediments, as well as with model predictions. However, for unsaturated water conditions, the results differed considerably from the ex situ Cfree values, in particular for the light molecular weight (LMW) PAHs such as phenanthrene, fluoranthene, and pyrene. The results of the two in situ PS methods were in good agreement with each other under both soil water conditions, indicating that dissipation mechanisms, such as degradation or volatilization, led to a substantial decrease in Cfree under unsaturated conditions, especially for the LMW PAHs (log10KOW < 5.85) over a period of six months or more. Thus, in their current state of development, in situ PS methods can be used in soils under water-saturated conditions. However, an adequate method to correct for non-equilibrium conditions needs to be developed before they can be applied to unsaturated conditions, mainly for LMW PAHs.
The freely dissolved concentration (Cfree) was measured for PAHs and PCBs in sediments of the Ger... more The freely dissolved concentration (Cfree) was measured for PAHs and PCBs in sediments of the German Bight and Wadden Sea. Ex-situ Solid Phase Microextraction (SPME) was applied using Polydimethlysiloxane (PDMS) coated glass fibers followed by automated thermal desorption and GC-MS analysis. This study provides the first dataset on the spatial distribution of Cfree for PAHs and PCBs in the German Bight and the Wadden Sea. We found elevated PCB concentrations in the Wadden Sea and especially in the Weser estuary. Sandy North Sea sediments were rather less contaminated, except for some former dumping sites. The sorption strength of PAHs was generally stronger, while PCBs in the Wadden Sea sediments were only weakly bound. This SPME method is a rapid and sensitive tool to study Cfree of hydrophobic organic chemicals to improve todays sediment risk assessment.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Advances in biochemical engineering/biotechnology, Jan 4, 2016
The combination of polymer-based passive sampling to collect complex environmental mixtures of po... more The combination of polymer-based passive sampling to collect complex environmental mixtures of pollutants, the transfer of these mixtures into bioassays, and their related toxicological characterization is still in its infancy. However, this approach has considerable potential to improve environmental hazard and risk assessment for two reasons. First, the passive sampler collects a broad range of chemicals representing the fraction of compounds available for diffusion and (bio)uptake, excluding a large part of the matrix; thus, extensive sample cleanup which could discriminate certain compounds can be avoided. Second, the toxicological characterization of samples using bioassays is complementary to chemical (target) analysis within environmental monitoring because it captures all chemicals exerting the same mode of toxic action and acting jointly in mixtures, thus providing a comprehensive picture of their overall combined effects. The scientific literature describes a range of exam...
Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistenc... more Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing. M any of the chemicals that we use in our daily lives end up in multimedia environments including biota where they may pose a risk to ecosystems and human health as part of mixtures and together with their transformation products. The related hazard potential can be assessed in a large variety of in vivo and in vitro bioassays that serve different purposes (Box 1). However, the quantitative link between the exposure in the environment and that in the bioassay is often missing. Establishing the link is difficult because different chemicals have distinct enrichment factors and sampling rates. Furthermore, they sorb to different extents to sorptive phases present in bioassays, which reduces exposure. A major challenge is how to combine sampling, extraction and dosing of a mixture while conserving or re-establishing its composition at adjustable levels for concentration-effect assessment. Here we discuss strategies for chemicals present in the aquatic environment, that is, water, sediment, and aquatic biota. Bioassays provide an integrative measure of the overall toxic potential of a sample and are complementary to chemical analysis providing quantitative information on selected chemicals. Chemicals with a common mode of toxic action add up to a joint response. 1 A comprehensive set of bioassays is available for the assessment of combination effects. 2 The major obstacles to successfully applying bioassays for assessing environmentally relevant mixtures of organic pollutants are to collect, extract and dose the mixture into the bioassay without the mixture composition being altered while linking the observed effect back to the concentrations in the original medium. In this article, we focus on the sampling of environmental pollutants (Section 1), their dosing into bioassays (Section 2), general transfer strategies of compounds from the environment into bioassays taking into account the mixture composition (Section 3), and specific combinations of sampling and dosing approaches for mixtures of chemicals present in the aquatic environment (Section 4, Figure 1). ■ SECTION 1. SAMPLING APPROACHES IN DIVERSE AQUATIC MEDIA AND BIOTA The goal of sampling in water, sediment and biota is to reduce the sample's heterogeneity, enhance stability, remove matrix constituents, and enrich the chemicals of interest to increase sensitivity. When sampling mixtures in the environment,
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Papers by Gesine Witt