Publications by authors named "Marc Babut"

35 Publications

The added value of Bayesian inference for estimating biotransformation rates of organic contaminants in aquatic invertebrates.

Aquat Toxicol 2021 May 20;234:105811. Epub 2021 Mar 20.

INRAE, RiverLy, Ecotoxicology Laboratory, 5 Avenue de la Doua, CS20244, 69625 Villeurbanne Cedex, France.

Toxicokinetic (TK) models refer to the process of contaminant bioaccumulation as a balance between rate of uptake from different sources (e.g., water or food), and rate of elimination via different processes such as excretion, growth and/or biotransformation. Biotransformation can considerably modify the fate of chemicals in an organism, especially their bioavailability, residence time, and toxicity. Invertebrate models generally neglect this process as they assume a low metabolic activity. However, some species such as Gammarus sp. amphipods are able to metabolize a vast range of organic compounds. Some recent TK models include biotransformation, but they prove limited for estimating related parameters by giving negative values and/or large uncertainties for biotransformation rate(s). Here we propose a generic TK model accounting for biotransformation using a Bayesian framework for simultaneously estimating the parameters. We illustrated the added value of our method by fitting this generic TK model to 22 published datasets of several benthic invertebrate species exposed to different chemicals. All parameters are estimated simultaneously for all datasets and showed narrow estimates. Furthermore, the median model predictions and their 95% credibility intervals showed that the model confidently fitted the data. In most cases the uncertainties around biotransformation rate(s) were reduced in comparison to the original studies. From a methodology standpoint, this paper reflects that Bayesian inference has real added value for simultaneously estimating all TK parameters for parent chemicals and their metabolite(s) based on all available data, while accounting for different types of data and the correlation between parameters. Bayesian inference was able to overcome the limits of previous methods, since no parameters were fixed and no irrelevant negative values were obtained. Moreover, the 95% credibility intervals around model predictions, which are core uncertainties for Environmental Risk Assessment, were easily acquired.
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http://dx.doi.org/10.1016/j.aquatox.2021.105811DOI Listing
May 2021

Sediment quality assessment framework for per- and polyfluoroalkyl substances: results from a preparatory study and REGULATORY IMPLICATIONS.

Integr Environ Assess Manag 2021 Mar 19. Epub 2021 Mar 19.

Swiss Centre for Applied Ecotoxicology, Lausanne, CH.

A preparatory study was performed for the development of a sediment quality and risk assessment strategy for Switzerland addressing the following questions: the sediment fraction to be analyzed chemically (<63 µm or alternatively <2 mm); the suitability of using perfluorooctanesulfonic acid (PFOS) as an indicator of per- and polyfluoroalkyl substances (PFASs) contamination in sediments; the availability of data for the derivation of sediment quality guidelines; and the suitability of normalization to total organic carbon (TOC). The results confirmed PFOS as a suitable indicator of PFAS contamination in sediments from small streams, being the most detected and on average with the highest concentrations among the analyzed PFAS. The fine fraction (<63 µm) was more appropriate to screen for possible sources and studying the compounds profile at the study sites, but the analysis of the <2 mm fraction and the normalization to a sample consisting of 100% of the <63 μm fraction was in principle feasible for PFOS. Sediment quality guidelines for PFOS aiming to protect benthic invertebrates from generic adverse effects could be derived but the available toxicity database is still too sparse. It was only possible to derive preliminary values. Sediment quality guidelines to protect wildlife and human health from secondary poisoning using the Equilibrium Partitioning approach and simple trophic web models were also derived. The use of food web models to derive sediment quality guidelines has not been validated while the available database of Biota-Sediment Accumulation Factors and Trophic Magnification Factors for PFOS remains still limited. However it is still larger than the effect concentrations database based on sediment studies using benthic invertebrates. Normalization to TOC content in the field (0.2 to 12.9%) was determinant in the quality assessment outcome. This is a widely accepted practice for hydrophobic organic contaminants but its endorsement for PFOS would also benefit from validation. This article is protected by copyright. All rights reserved.
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http://dx.doi.org/10.1002/ieam.4412DOI Listing
March 2021

Legacy and alternative halogenated flame retardants in Lake Geneva fish.

Environ Sci Pollut Res Int 2021 Feb 9;28(7):7766-7773. Epub 2020 Oct 9.

CIPEL Scientific Council, Agroscope Changins Bâtiment DC Route de Duillier 50 Case postale 1080, CH-1260, Nyon, Switzerland.

Legacy (i.e., polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD)) and alternative halogenated flame retardants (HFRs) were analyzed in 31 whole fish samples from Lake Geneva in 2018. Two fish species, namely, the burbot (Lota lota) and the roach (Rutilus rutilus), were selected, hypothetically representing different habitats, feeding behaviors, and different metabolic capacities. Roach (N = 20) and burbot (N = 11) displayed similar size and mass, but the latter species was overall leaner than the former. The sum of individual PBDE concentrations (0.54-9.86 ng g wet weight (ww)) was similar in both species, but the respective molecular profiles suggested contrasted metabolic capacities. HBCDD sum of isomer concentrations ranged from non-detected to 3.477 ng g (ww), also similar in both species. Both PBDEs and HBCDD levels were far below the threshold that indicates a risk to fish predators. Referring to previous surveys, which involved a wider range of species, PBDE concentrations have declined or are stable. HBCDD concentrations remained low, despite the PBDE ban, which could have fostered the consumption of other HFRs. The occurrence of alternative HFRs was also low for most compounds analyzed. Only dechloranes and decabromodiphenyl ethane (DBDPE) had detection rates above 50%. Dechloranes spanned a concentration range between 5 and 10 times the quantification limits (0.002 to 0.005 ng g wet weight), lower than DBDPE (< 0.005 to 2.89 ng g wet weight). Quality standards targeting biota are currently missing for these emerging chemicals.
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http://dx.doi.org/10.1007/s11356-020-11118-yDOI Listing
February 2021

Sedimentological and geochemical data in bed sediments from a tropical river-estuary system impacted by a developing megacity, Ho Chi Minh City - Vietnam.

Data Brief 2020 Aug 27;31:105938. Epub 2020 Jun 27.

CARE, Ho Chi Minh City University of Technology, VNU-HCM, Viet Nam.

Sedimentological and geochemical data were obtained for bed sediments from a tropical estuary environment in Vietnam in October 2014, January 2016, and November 2016. The data include grain-size distribution, percentage of clay, silt and sand, percentage of organic matter, concentration of total particulate phosphorus (TPP), concentration of particulate inorganic phosphorus (PIP), concentration of particulate organic phosphorus (POP), percentage of total nitrogen (TN), percentage of total carbon (TC), trace metals concentrations (V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Pb) and major elements (Al, Fe, Mn). Geochemical indexes (Enrichment factor EF and Geo-accumulation Index I-geo) and sediment quality guideline (mean Effect Range Median quotients) were calculated.
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http://dx.doi.org/10.1016/j.dib.2020.105938DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7339034PMC
August 2020

Per- and Polyfluoroalkyl Substances (PFAS) in Fish from European Lakes: Current Contamination Status, Sources, and Perspectives for Monitoring.

Environ Toxicol Chem 2021 Mar 24;40(3):658-676. Epub 2020 Aug 24.

Water Research Institute, National Research Council of Italy (IRSA-CNR), Brugherio, Italy.

Concentrations in fish of per- and polyfluoroalkyl substances (PFAS) were reported for 7 deep lakes in the European subalpine area: Lakes Geneva, Lugano, Maggiore, Iseo, Como, Garda, and Mergozzo; one shallow lowland lake (Varese); and 2 high-altitude alpine lakes (>2000 m a.s.l). Fillets and, in selected cases, other body fractions (viscera, liver, and residual carcass) from 8 fish species were analyzed. The possibility of harmonizing the monitoring protocols was tested. Results suggest that the sampling season is not critical for PFASs and the total protein content cannot be used for normalization of tissue concentrations because PFASs bind to specific proteins. Moreover, the polar lipid content could be used to reduce the variability of PFAS concentrations in phospholipid rich fractions of fish such as viscera and carcass. The data comparison and analysis show that the PFAS contamination in lake fish is generally correlated with the degree of urbanization of the lake catchment; however, it is sometimes difficult to compare absolute concentrations in lake fish because the lake hydro-morphological characteristics play a substantial role in determining the chemical concentrations of persistent and mobile contaminants. Environ Toxicol Chem 2021;40:658-676. © 2020 SETAC.
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http://dx.doi.org/10.1002/etc.4815DOI Listing
March 2021

Temperature effect on perfluorooctane sulfonate toxicokinetics in rainbow trout (Oncorhynchus mykiss): Exploration via a physiologically based toxicokinetic model.

Aquat Toxicol 2020 Aug 12;225:105545. Epub 2020 Jun 12.

UMR-I 02 SEBIO, Models for Ecotoxicology and Toxicology Unit (METO), INERIS, 60550 Verneuil en Halatte, France. Electronic address:

Salmonids are poikilotherms, which means that their internal temperature varies with that of water. Water temperature thus controls many of their lifecycle processes and physiological functions, which could influence the mechanisms of absorption, distribution, metabolism and excretion (ADME) of many substances, including perfluorinated alkyl acids (PFAAs). However, the processes governing the fate of PFAAs are still poorly understood in fish. Here we developed a physiologically-based toxicokinetic (PBTK) model for rainbow trout (Oncorhynchus mykiss) to study changes in physiological functions and PFAA ADME at different temperatures. The model was calibrated using experimental data from dietary exposure to perfluorooctane sulfonate at 7 °C and 19 °C. Predictions of PFOS concentrations were globally satisfactory at both temperatures, when accounting for the influence of temperature on growth, ventilation rate, cardiac output, clearances, and absorption rates. Accounting for the influence of temperature on tissue-plasma partition coefficients significantly improved predicted in-organ PFOS concentrations.
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http://dx.doi.org/10.1016/j.aquatox.2020.105545DOI Listing
August 2020

Role of Biofilms in Contaminant Bioaccumulation and Trophic Transfer in Aquatic Ecosystems: Current State of Knowledge and Future Challenges.

Rev Environ Contam Toxicol 2021 ;253:115-153

INRAE, UR RiverLy, Villeurbanne, France.

In freshwater environments, microbial assemblages attached to submerged substrates play an essential role in ecosystem processes such as primary production, supported by periphyton, or organic matter decomposition, supported by microbial communities attached to leaf litter or sediments. These microbial assemblages, also called biofilms, are not only involved in nutrients fluxes but also in contaminants dynamics. Biofilms can accumulate metals and organic contaminants transported by the water flow and/or adsorbed onto substrates. Furthermore, due to their high metabolic activity and their role in aquatic food webs, microbial biofilms are also likely to influence contaminant fate in aquatic ecosystems. In this review, we provide (1) a critical overview of the analytical methods currently in use for detecting and quantifying metals and organic micropollutants in microbial biofilms attached to benthic substrata (rocks, sediments, leaf litter); (2) a review of the distribution of those contaminants within aquatic biofilms and the role of these benthic microbial communities in contaminant fate; (3) a set of future challenges concerning the role of biofilms in contaminant accumulation and trophic transfers in the aquatic food web. This literature review highlighted that most knowledge on the interaction between biofilm and contaminants is focused on contaminants dynamics in periphyton while technical limitations are still preventing a thorough estimation of contaminants accumulation in biofilms attached to leaf litter or sediments. In addition, microbial biofilms represent an important food resource in freshwater ecosystems, yet their role in dietary contaminant exposure has been neglected for a long time, and the importance of biofilms in trophic transfer of contaminants is still understudied.
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http://dx.doi.org/10.1007/398_2019_39DOI Listing
February 2021

Elucidating the fate of perfluorooctanoate sulfonate using a rainbow trout (Oncorhynchus mykiss) physiologically-based toxicokinetic model.

Sci Total Environ 2019 Nov 15;691:1297-1309. Epub 2019 Jul 15.

UMR-I 02 SEBIO, Unit of Models for Ecotoxicology and Toxicology (METO), INERIS, 60550 Verneuil en Halatte, France. Electronic address:

Per- and poly-fluorinated substances (PFAS) are widely found in freshwater ecosystems because of their resistance to degradation. Among them, several long-chain perfluoroalkyl acids bioaccumulate in aquatic vertebrates, but our understanding of the mechanisms of absorption, distribution and elimination is still limited in fish. For this purpose, we developed a 10-compartment physiologically-based toxicokinetic (PBTK) model to elucidate perfluorooctane sulfonate (PFOS) kinetics in adult rainbow trout. This PBTK model included various physiological characteristics: blood perfusion to each organ, plasmatic fraction, PFOS free fraction, and growth of individuals. The parameters were optimized using Bayesian inferences. First, only PFOS absorption by diet was considered in the model as well as its elimination by urine, bile and feces. Then two mechanistic hypotheses, assumed to govern PFOS toxicokinetics in fish, namely the enterohepatic cycle and the absorption and elimination though gills, were tested. Improvement of the model's fit to the data was studied in each organ by comparing predictions with observed data using relative error. The experimental data set was obtained from an exposure experiment, where adult rainbow trout were fed with a PFOS-spiked diet for 42 days, followed by a 35-day depuration period. In all cases, PFOS concentrations were accurately predicted in organs and feces by the model. The results of this PBTK model demonstrated that feces represented the major elimination route for PFOS while urine was a minor route. Also, PFOS branchial uptake can be substantial despite low concentrations of the compound in water, and elimination through gills should not be neglected. Finally, the enterohepatic cycle is likely to play a minor role in PFOS toxicokinetics. Overall, this PBTK model accurately described PFOS distribution in rainbow trout and provides information on the relative contribution of absorption and elimination pathways.
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http://dx.doi.org/10.1016/j.scitotenv.2019.07.105DOI Listing
November 2019

Investigation of the spatial variability of poly- and perfluoroalkyl substance trophic magnification in selected riverine ecosystems.

Sci Total Environ 2019 Oct 4;686:393-401. Epub 2019 Jun 4.

CNRS, EPOC, UMR 5805, LPTC research group, F-33400 Talence, France. Electronic address:

The occurrence at different trophic levels of 17 poly- and perfluoroalkyl substances (PFASs), including perfluoroalkyl acids (PFAAs) and some of their precursors (e.g., perfluoroalkane sulfonamides, 6:2 fluorotelomer sulfonate (6:2 FTSA)), was investigated in riverine freshwater food webs in Southeastern France. Two fish species (Barbus barbus and Squalius cephalus) and various invertebrate taxa were collected in five rivers to assess the spatial variability of trophic magnification factors (TMFs). Particular attention was devoted to sample and data processing to minimize potential biases associated with the TMF determination. Fish were significantly more contaminated than invertebrates (ΣPFAS = 7-1811 vs. 0.9-213 ng g wet weight (ww)). Those from the Rhône River presented significantly higher levels due to high concentrations of perfluoroundecanoic acid (406 ng g ww) and perfluorotridecanoic acid (566 ng g ww) ascribed to an industrial point source. Perfluorooctane sulfonate (PFOS) was dominant at the other sites (concentration range = 3.6-134 ng g ww). Two linear regression models were compared (i.e., Kendall regression vs. Generalized Linear Mixed-Effect Model, GLMM). Results showed that TMFs calculated using the non-weighted Kendall regression were higher than those obtained using the GLMM approach. GLMM-based TMFs were consistently >1 for C-C perfluorocarboxylic acids (PFCAs), PFOS and perfluorodecane sulfonate (PFDS), indicating their apparent biomagnification in the investigated food webs. Comparatively, 6:2 FTSA and N-ethylperfluorooctane sulfonamidoacetic acid (N-EtFOSAA) were less often detected and were not significantly biomagnified, probably because of metabolization. TMF estimates were generally consistent across sites although some PFASs (in particular C, C and C PFCAs) displayed higher variability, due to a unique extreme value that may have resulted from the contribution of unattributed precursor biotransformation.
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http://dx.doi.org/10.1016/j.scitotenv.2019.05.461DOI Listing
October 2019

Temporal variations of perfluoroalkyl substances partitioning between surface water, suspended sediment, and biota in a macrotidal estuary.

Chemosphere 2019 Oct 31;233:319-326. Epub 2019 May 31.

CNRS, EPOC, UMR 5805, LPTC Research Group, 33400, Talence, France. Electronic address:

A one-year monitoring study was conducted in a macrotidal estuary to assess the temporal variations and partitioning behavior of perfluoroalkyl and polyfluoroalkyl substances (PFASs). Surface water, suspended particulate matter (SPM), and invertebrates including zooplankton (copepods, mysids) and shrimps were sampled on a monthly basis in the Gironde Estuary (SW France). Environmental parameters such as suspended solid loads, salinity, and river water flow rate were highly variable at the study site. However, moderate seasonal variations were observed in terms of PFAS levels and profiles. Summed PFAS (ΣPFASs) concentrations averaged 6.5 ± 2.7 ng L in the dissolved phase and 3.0 ± 1.2 ng g dry weight in the SPM. The ΣPFASs was in the range of 1.7-13 ng g wet weight in invertebrates. C-C perfluoroalkyl carboxylates (PFCAs) generally prevailed in the dissolved phase, while perfluorooctane sulfonate (PFOS) was dominant in the SPM and biota. Suspended sediment-water partitioning coefficients Log K and Log K were correlated with the perfluoroalkyl chain length, as were the particle-bound fraction and bioaccumulation factors (Log BAF). Compound-specific Log BAFs varied within a limited range over the period surveyed. Biomagnification factors (mysids/copepods) were consistently >1 for PFOS, perfluorooctane sulfonamide, and long-chain PFCAs (perfluorodecanoate and perfluorododecanoate), suggesting biomagnification at the base of the estuarine food web.
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http://dx.doi.org/10.1016/j.chemosphere.2019.05.281DOI Listing
October 2019

A Bayesian framework for estimating parameters of a generic toxicokinetic model for the bioaccumulation of organic chemicals by benthic invertebrates: Proof of concept with PCB153 and two freshwater species.

Ecotoxicol Environ Saf 2019 Sep 3;180:33-42. Epub 2019 May 3.

Irstea, UR RiverLy, Centre de Lyon-Villeurbanne, 5 Avenue de la Doua, CS20244, 69625, Villeurbanne, Cedex, France.

Toxicokinetic (TK) models are relevant and widely used to predict chemical concentrations in biological organisms. The importance of dietary uptake for aquatic invertebrates has been increasingly assessed in recent years. However, the model parameters are estimated on limited specific laboratory data sets that are bounded by several uncertainties. The aim of this study was to implement a Bayesian framework for simultaneously estimating the parameters of a generic TK model for benthic invertebrate species from all data collected. We illustrate our approach on the bioaccumulation of PCB153 by two species with different life traits and therefore exposure routes: Chironomus riparius larvae exposed to spiked sediment for 7 days and Gammarus fossarum exposed to spiked sediment and/or leaves for 7 days and then transferred to a clean media for 7 more days. The TK models assuming first-order kinetics were fitted to the data using Bayesian inference. The median model predictions and their 95% credibility intervals showed that the model fit the data well. From a methodological point of view, this paper illustrates that simultaneously estimating all model parameters from all available data by Bayesian inference, while considering the correlation between parameters and different types of data, is a real added value for TK modeling. Moreover, we demonstrated the ability of a generic TK model considering uptake and elimination routes as modules to add according to the availability of the data measured. From an ecotoxicological point of view, we show differences in PCB153 bioaccumulation between chironomids and gammarids, explained by the different life traits of these two organisms.
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http://dx.doi.org/10.1016/j.ecoenv.2019.04.080DOI Listing
September 2019

Does water temperature influence the distribution and elimination of perfluorinated substances in rainbow trout (Oncorhynchus mykiss)?

Environ Sci Pollut Res Int 2019 Jun 13;26(16):16355-16365. Epub 2019 Apr 13.

Irstea, RIVERLY Research Unit, 5 rue de la Doua CS 20244, 69625, Villeurbanne Cedex, France.

Perfluorinated and polyfluorinated substances (PFASs) are widely found in freshwater ecosystems because of their resistance to degradation and their ability to accumulate in aquatic organisms. While water temperature controls many physiological processes in fish, knowledge of the effects of this factor on PFAS toxicokinetic is still limited. This study presents experimental results of internal distribution and elimination rates of two perfluorinated acid compounds, namely perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) in adult rainbow trout (Oncorhynchus mykiss) exposed to three temperatures. Dietary exposure experiments were conducted at 7 °C, 11 °C, and 19 °C and liver, blood, muscle, brain, and kidney were sampled for analysis. PFOS concentrations were comparable to or exceeded those of PFHxS, while PFHxS was eliminated faster than PFOS, whatever the temperature. Internal distribution changed significantly for both substances when fish were exposed to a range of temperatures from 7 to 19 °C. Indeed, PFOS and PFHxS relative distribution increased in blood, liver, and brain while they decreased in muscle when the water temperature rose. The water temperature variation affected the elimination half-lives, depending on the substances and organs.
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http://dx.doi.org/10.1007/s11356-019-05029-wDOI Listing
June 2019

Evidence for the widespread occurrence of short- and medium-chain chlorinated paraffins in fish collected from the Rhône River basin (France).

Chemosphere 2019 May 13;223:232-239. Epub 2019 Feb 13.

CNRS, University of Bordeaux, EPOC, UMR 5805, F-33400, Talence, France.

Chlorinated paraffins (CPs) are high-volume chemicals used in numerous industrial applications. Their quantitative analysis is extremely challenging and this work presents the optimization of an analytical method based on gas chromatography hyphenated with electron capture negative ionization time-of-flight high-resolution mass spectrometry (GC-ECNI-TOF HRMS) for the simultaneous determination of short-chain and medium-chain CPs (SCCPs and MCCPs, respectively) in fish tissues (i.e. dorsal muscle). The resolution of the TOF-MS analyzer reduced or eliminated isobaric interferences and the CP response was optimized through Design of Experiment. A simple clean-up procedure based on adsorption chromatography further removed some potentially interfering organochlorines. Good selectivity, linearity and accuracy were achieved; method detection limits or limits of reporting were compatible with expected levels in wild fish (0.03-0.35 ng g wet weight, ww, depending on the congener). This method was proven suitable for the analysis of CPs in tissues of common barbel Barbus, a fish species frequently used for water quality monitoring purposes in Europe. SCCPs and MCCPs were found to be widespread within the Rhône river basin (France). At all locations, MCCP concentrations (1.3-72.7 ng g ww) were higher than those of SCCPs (0.3-10.6 ng g ww) and levels were systematically lower than the proposed Predicted No Effect Concentrations (PNECs). Spatial variations of SCCP composition profiles largely surpassed those of MCCPs, suggesting the influence of local sources.
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http://dx.doi.org/10.1016/j.chemosphere.2019.02.069DOI Listing
May 2019

Where has the pollution gone? A survey of organic contaminants in Ho Chi Minh city / Saigon River (Vietnam) bed sediments.

Chemosphere 2019 Feb 2;217:261-269. Epub 2018 Nov 2.

Centre Asiatique de Recherche sur l'Eau, Ho Chi Minh University of Technology, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam; University Grenoble-Alpes, UMR5001 CNRS, IRD, Grenoble INP, IGE, CS 40700, F-38000, Grenoble, France.

A wide range of persistent organic chemicals, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), some insecticides, as well as polybrominated diphenyl ethers (PBDEs) and some perfluoroalkyl substances (PFASs) were analyzed in 17 bed sediments collected along the Saigon River and at adjacent canal mouths from upstream to downstream in Ho Chi Minh City (Vietnam). Concentrations were rather low for PAHs, as well as for legacy PCBs and dichloro-diphenyl-trichlorethane and metabolites (DDTs), or below detection limits for several PFASs and all PBDEs measured. Several insecticides (chlorpyrifos-ethyl, and the pyrethroids cypermethrin and λ-cyhalothrin) displayed rather high concentrations at a few sites within the city. There was no distinct upstream - downstream trend for PAHs, (DDTs) or PCBs. Although adjacent canal sediments tended to be more contaminated than Saigon River sediments, the differences were not significant. Emissions are almost certainly substantial for PAHs, and probably also for other contaminants such as PBDEs and some PFASs. During the dry season, contaminants are presumably stored in the city, either in canals or on urban surfaces. Heavy rainfall during the monsoon period carries away contaminated particle flows into the canals and then the Saigon River. The strong tidal influence in the river channel hinders the accumulation of contaminated particles. Contaminated deposits should accordingly be investigated further downstream in depositional environments, such as the mangrove.
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http://dx.doi.org/10.1016/j.chemosphere.2018.11.008DOI Listing
February 2019

Practical advice for selecting or determining trophic magnification factors for application under the European Union Water Framework Directive.

Integr Environ Assess Manag 2019 Mar 26;15(2):266-277. Epub 2018 Nov 26.

Health and Environmental Sciences Institute, Washington, DC, USA.

European Union Directive 2013/39/EU, which amended and updated the Water Framework Directive (WFD; 2000/60/EC) and its daughter directive (2008/105/EC), sets Environmental Quality Standards for biota (EQS ) for a number of bioaccumulative chemicals. These chemicals pose a threat to both aquatic wildlife and human health via the consumption of contaminated prey or the intake of contaminated food originating from the aquatic environment. EU member states will need to establish programs to monitor the concentration of 11 priority substances in biota and assess compliance against these new standards for the classification of surface water bodies. An EU-wide guidance effectively addresses the implementation of EQS . Flexibility is allowed in the choice of target species used for monitoring to account for both diversity of habitats and aquatic community composition across Europe. According to that guidance, the consistency and comparability of monitoring data across member states should be enhanced by adjusting the data on biota contaminant concentrations to a standard trophic level by use of the appropriate trophic magnification factor (TMF), a metric of contaminant biomagnification through the food web. In this context, the selection of a TMF value for a given substance is a critical issue, because this field-derived measure of trophic magnification can show variability related to the characteristics of ecosystems, the biology and ecology of organisms, the experimental design, and the statistical methods used for TMF calculation. This paper provides general practical advice and guidance for the selection or determination of TMFs for reliable application within the context of the WFD (i.e., adjustment of monitoring data and EQS derivation). Based on a series of quality attributes for TMFs, a decision tree is presented to help end users select a reasonable and relevant TMF. Integr Environ Assess Manag 2019;15:266-277. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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http://dx.doi.org/10.1002/ieam.4102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6719707PMC
March 2019

Occurrence of Dechlorane Plus and related compounds in catfish (Silurus spp.) from rivers in France.

Chemosphere 2018 Sep 20;207:413-420. Epub 2018 May 20.

LABERCA, Oniris, INRA, Université Bretagne Loire, F-44307, Nantes, France.

Dechlorane related compounds (DRCs), including Dechlorane Plus (syn-DP and anti-DP), Dechlorane-601, -602, -603 and Chlordene Plus (CP), constitute a group of polychlorinated flame retardants (FRs) that are still of industrial use. In particular, DRCs have been detected in various environmental matrices and in different aquatic and terrestrial biota, thus exhibiting bioaccumulation and biomagnification potentials. The present study aimed at producing first occurrence data of a range of DRCs in Silurus spp. samples from different rivers located in France. Determination was carried out by gas chromatography high-resolution mass spectrometry after a sample clean-up based on a multilayer silica column and gel permeation chromatography. The concentration of monitored ΣDRCs ranged from 1.58 to 408 pg g wet weight (54-11100 pg g lipid weight). The fractional abundance of syn- and anti-DP stereoisomers was similar to that reported by other studies with an average equal to 0.60. Dec-601 was not detected in any sample. Detection frequencies ranged between 34 and 100% for other DRCs. Investigated correlations between DRCs and polychlorobiphenyls (PCBs) suggest a link with lipid content but independent contamination sources.
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http://dx.doi.org/10.1016/j.chemosphere.2018.05.101DOI Listing
September 2018

Refining uptake and depuration constants for fluoroalkyl chemicals in Chironomus riparius larvae on the basis of experimental results and modelling.

Ecotoxicol Environ Saf 2018 Mar 16;149:284-290. Epub 2017 Dec 16.

IRSTEA, UR MALY, 5 rue de la Doua, 32108 CS 20244, F-69625 Villeurbanne, France. Electronic address:

The aims of this study were to determine depuration rates for a range of per- and polyfluoroalkyl substances (PFASs) using Chironomus riparius, and to test a concentration-dependency hypothesis for the long-chain perfluorotridecanoic acid (PFTrDA) for this species. Midge larvae were exposed to field sediments collected downstream of a fluorotelomer plant, and to the same sediment spiked with PFTrDA. Elimination kinetics results indicated complete elimination of all PFASs by chironomids after 42h. These data were used to develop two PFTrDA bioaccumulation models accounting for chironomid growth and for compound concentration dependency or not. There was much better agreement between observed and simulated data under the concentration-dependency hypothesis than under the alternative one (passive diffusion). The PFTrDA uptake rate derived from the concentration-dependency model equaled 0.013 ± 0.008ggh, and the depuration rate 0.032 ± 0.009h.
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http://dx.doi.org/10.1016/j.ecoenv.2017.12.011DOI Listing
March 2018

Evidence for the Trophic Transfer of Perfluoroalkylated Substances in a Temperate Macrotidal Estuary.

Environ Sci Technol 2017 Aug 18;51(15):8450-8459. Epub 2017 Jul 18.

CNRS, EPOC, UMR 5805 , F-33400 Talence, France.

The present survey examines the trophodynamics of a suite of 19 perfluoroalkyl substances (PFASs) in a temperate macrotidal estuary (Gironde, SW France). Across the 147 biota samples (18 taxa) collected, perfluorooctane sulfonate (PFOS), perfluorooctane sulfonamide (FOSA), and C-C perfluoroalkyl carboxylates (PFCAs) were the most-recurrent analytes. ΣPFASs ranged between 0.66-45 ng per g of wet weight of the whole body. Benthic organisms had relatively high ΣPFASs compared to demersal organisms and displayed specific composition profiles with higher relative abundances of C and C PFCAs. Trophic magnification factors (TMFs) were determined through the use of linear mixed effect models including censored data, thereby considering data below detection limits as well as the interspecific variability of δN and PFAS levels (random effects). TMFs were almost consistently >1 in the benthic food web as well as when considering all data pooled together, providing evidence for the biomagnification of several PFASs in estuarine environments. In addition, in contrast with previous observations, TMFs determined in the estuarine benthic web were found to significantly decrease with increasing chain length for C-C PFCAs and C-C perfluoroalkyl sulfonates. This suggests that PFAS chemical structure might not be necessarily predictive of TMFs, which are also influenced by the trophic web characteristics.
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http://dx.doi.org/10.1021/acs.est.7b02399DOI Listing
August 2017

Per- and poly-fluoroalkyl compounds in freshwater fish from the Rhône River: Influence of fish size, diet, prey contamination and biotransformation.

Sci Total Environ 2017 Dec 24;605-606:38-47. Epub 2017 Jun 24.

Rhone-Mediterranean and Corsica Water Agency, 2-4 allée de Lodz, 69363 Lyon, France.

Pools of aquatic plants and benthic invertebrates were collected along with 47 individuals from three cyprinid fish species (Barbus barbus, Gobio gobio, Rutilus rutilus) at a site in the Rhône River (France). Carbon and nitrogen isotopic ratios (δC and δN) and a wide range of per- and poly-fluorinated chemicals (PFASs) were analysed in all samples. The sum of PFAS concentrations (ΣPFAS) increased from aquatic plants to fish dorsal muscles; molecular profiles were dominated by C9-C13 perfluorocarboxylic acids (PFCAs), while perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (FOSA) were detected in all samples at lower concentrations. ΣPFAS and especially ΣPFCAs were higher in barbels (B. barbus) than in other species, while roaches (R. rutilus) were less contaminated by PFOS than barbels and gudgeons (G. gobio). Gudgeons accumulated significantly higher FOSA concentrations. Young (small) barbels displayed significantly higher PFOS, perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) concentrations than did large specimens; conversely, perfluorotetradecanoic acid (PFTeDA) concentrations were significantly higher in large barbels. Multiple linear regressions were performed on the whole set of fish samples with size, mass and isotopic ratios as explicative variables, and several single compounds as explained variables. Regardless of the compound, the regressions did not explain much of the contamination variability. However, adding species as a qualitative variable, i.e. performing analyses of covariance (ANCOVAs) improved the fit greatly, while adding sex did not. Diet (i.e. δC and δN) was the main factor explaining interspecific differences. Biotransformation was assessed by comparing concentration ratios of PFOS or FOSA to their precursors in the food-web compartments. These ratios increased from invertebrates to fish, and differed among fish species, suggesting that biotransformation occurred but was species-specific. Biomagnification factor calculations showed that C11-C13 PFCAs, PFOS and FOSA were apparently biomagnified in barbels and gudgeons.
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http://dx.doi.org/10.1016/j.scitotenv.2017.06.111DOI Listing
December 2017

Potential exposure routes and accumulation kinetics for poly- and perfluorinated alkyl compounds for a freshwater amphipod: Gammarus spp. (Crustacea).

Chemosphere 2016 Jul 30;155:380-387. Epub 2016 Apr 30.

Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, BP 32108, 69626 Villeurbanne Cedex, France. Electronic address:

Gammarids were exposed to sediments from a deposition site located on the Rhône River (France) downstream of a fluoropolymer manufacturing plant. Gammarids accumulated to various extents four long-chain perfluoroalkyl carboxylic acids (PFCAs) from C9 to C13, one sulfonate, perfluorooctane sulfonate (PFOS) and three of its precursors (the perflurooctane sulfonamide (FOSA), the N-methyl perfluorooctane sulfonamidoacetic acid (MeFOSAA), the N-ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA) and the 6:2 fluorotelomer sulfonic acid (6:2 FTSA). Whatever the compound, the steady state was not achieved after a 3-week exposure; elimination was almost complete after a 3-week depuration period for perfluorononanoic acid (PFNA), PFOS, the three precursors and the 6:2FTSA. However, this was not the case for long-chain PFCAs, whose elimination rates decreased with increasing chain length. PFAS accumulation in gammarids occurred via the trophic and respiratory pathways, in proportions varying with the carbon chain length and the terminal moiety.
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http://dx.doi.org/10.1016/j.chemosphere.2016.04.006DOI Listing
July 2016

Declining Dioxin Concentrations in the Rhone River Basin, France, Attest to the Effectiveness of Emissions Controls.

Environ Sci Technol 2015 Nov 19;49(21):12723-30. Epub 2015 Oct 19.

Université de Tours, GéHCO EA 6293, F-37000 Tours, France.

Emission-control policies have been implemented in Europe and North America since the 1990s for polychlorodibenzodioxins (PCDDs) and furans (PCDFs). To assess the effect of these policies on temporal trends and spatial patterns for these compounds in a large European river system, sediment cores were collected in seven depositional areas along the Rhone River in France, dated, and analyzed for PCDDs and PCDFs. Results show concentrations increase in the downstream direction and have decreased temporally at all sites during the last two decades, with an average decrease of 83% from 1992 to 2010. The time for a 50% decrease in concentrations (t1/2) averaged 6.9±2.6 and 9.1±2.9 years for the sum of measured PCDDs and PCDFs, respectively. Congener patterns are similar among cores and indicate dominance of regional atmospheric deposition and possibly weathered local sources. Local sources are clearly indicated at the most downstream site, where concentrations of the most toxic dioxin, TCDD, are about 2 orders of magnitude higher than at the other six sites. The relatively steep downward trends attest to the effects of the dioxin emissions reduction policy in Europe and suggest that risks posed to aquatic life in the Rhone River basin from dioxins and furans have been greatly reduced.
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http://dx.doi.org/10.1021/acs.est.5b03416DOI Listing
November 2015

Bioaccumulation of perfluoroalkyl compounds in midge (Chironomus riparius) larvae exposed to sediment.

Environ Pollut 2014 Jun 12;189:27-34. Epub 2014 Mar 12.

IRSTEA, UR MALY, 5 rue de la Doua, CS 70077, F-69626 Villeurbanne, France. Electronic address:

Midge larvae (Chironomus riparius) were exposed to sediments from a deposition sampled at a site along the Rhône River (France) downstream of an industrial site releasing various perfluorinated chemicals. This sediment is characterized by high concentrations of perfluoroundecanoic acid (PFUnA) and perfluorotridecanoic acid (PFTrDA) and a low perfluorooctane sulfonate (PFOS) concentration. Concentrations of 23 perfluoroalkyl compounds, including C4-C14 carboxylate acids, C4-C10 sulfonates, and seven precursors, were analyzed in overlying and pore water, sediment, and larvae. Midge larvae accumulated carboxylate acids (C11-C14), PFOS, and two precursors (perfluorooctane sulfonamide: FOSA and 6:2 fluorotelomer sulfonic acid, 6:2 FTSA). These substances accumulated mainly during the fourth instar larvae exponential growth phase. Accumulation of 6:2 FTSA, PFUnA, and PFOS occured via trophic and tegumentary routes. Other compounds mainly accumulated from food. Kinetics followed a partition model, from which uptake and elimination constants were derived.
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http://dx.doi.org/10.1016/j.envpol.2014.02.018DOI Listing
June 2014

Historical records, sources, and spatial trends of PCBs along the Rhône River (France).

Sci Total Environ 2014 Apr 2;476-477:568-76. Epub 2014 Feb 2.

Irstea, UR MALY, rue de la Doua, CS70077, F-69626 Villeurbanne, France. Electronic address:

Despite bans on PCB use since 1975 (open systems) and 1987 (closed systems), concentrations of PCBs in riverine fish in France continue to exceed regulatory levels. We present historical records of PCB concentrations in sediment cores from eight sites on the Rhône River, from Lake Geneva to the Mediterranean Sea. Maximum PCB concentrations (sum of seven indicator PCBs) increase downstream, from 11.50 μg/kg at the most upstream site to 417.1 μg/kg at the most downstream site. At some sites peak concentrations occur in sediment deposited as recently as the 2000s. Hierarchical clustering (five clusters) identified differences in PCB congener profiles within and between sites. Exponential models fit to decadal time windows indicate that rapid reductions in concentrations during about 1990-2000 have slowed, and that it might be decades before target concentrations in sediment that correspond to regulatory thresholds in fish will be reached at some sites.
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http://dx.doi.org/10.1016/j.scitotenv.2014.01.026DOI Listing
April 2014

Sediment contamination assessment in urban areas based on total suspended solids.

Water Res 2013 Jan 13;47(1):339-50. Epub 2012 Oct 13.

Laboratoire de technologie écologique, Institut d'ingénierie de l'environnement, Faculté de l'environnement naturel, architectural et construit (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.

Sediment represents an important compartment in surface waters. It constitutes a habitat or spawning site for many organisms and is an essential trophic resource for higher level organisms. It can be impacted by anthropogenic activities, particularly through urban wet-weather discharges like stormwater and combined sewer overflows. An approach was presented for assessing the risks caused by urban wet-weather discharges to the sediment compartment based on total suspended solids (TSS). TSS is routinely measured in field surveys and can be considered as a tracer for urban wet-weather contamination. Three assessment endpoints linked with TSS were proposed: a) siltation of the riverbed, b) oxygen demand due to organic matter degradation and c) accumulation of ecotoxic contaminants on the riverbed (heavy metals, PAHs). These criteria were translated in terms of the maximal TSS accumulation load and exposure time (percentage of time exceeding the accumulation criteria) to account for sediment accumulation dynamics and resuspension in streams impacted by urban wet-weather discharges. These assessment endpoints were implemented in a stochastic model that calculates TSS behavior in receiving waters and allows therefore an assessment of potential impacts. The approach was applied to three Swiss case studies. For each, good agreement was found between the risk predictions and the field measurements confirming the reliability of the approach.
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http://dx.doi.org/10.1016/j.watres.2012.10.011DOI Listing
January 2013

Spatial and temporal trends in PCBs in sediment along the lower Rhône River, France.

Sci Total Environ 2012 Sep 11;433:189-97. Epub 2012 Jul 11.

EA 6293 GéHCO Université François-Rabelais de Tours, Parc de Grandmont, 37200 Tours, France.

Despite increasingly strict control of polychlorinated biphenyl (PCB) releases in France since the mid-1970s, PCB contamination of fish recently has emerged as a major concern in the lower Rhône River basin. We measured PCB concentrations in Rhône sediment to evaluate the effects of PCB releases from major urban and industrial areas, sediment redistribution by large floods, and regulatory controls on PCB trends from 1970 to present. Profiles of PCBs (the sum of seven indicator PCB congeners) were reconstructed from sediment cores collected from an off-river rural reference site and from three depositional areas along the Rhône upstream and downstream from the city of Lyon, France. Core chronology was determined from radionuclide profiles and flood deposits. PCB concentrations increased progressively in the downstream direction, and reached a maximum concentration in 1991 of 281 μg/kg at the most downstream site. At the rural reference site and at the upstream Rhône site, PCB concentrations peaked in the 1970s (maximum concentration of 13 and 78 μg/kg, respectively) and have decreased exponentially since then. PCB concentrations in the middle and downstream cores were elevated into the early 1990s, decreased very rapidly until 2000, and since then have remained relatively stable. Congener profiles for three time windows (1965-80, 1986-93, and 2000-08) were similar in the three sediment cores from the Rhône and different from those at the rural reference site. The results indicate that permitted discharges from a hazardous-waste treatment facility upstream from Lyon might have contributed to high concentrations into the 1980-90s, but that industrial discharges from the greater Lyon area and tributaries to the Rhône near Lyon have had a greater contribution since the 1990s. There is little indication that PCB concentration in sediments downstream from Lyon will decrease over at least the short term.
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http://dx.doi.org/10.1016/j.scitotenv.2012.06.044DOI Listing
September 2012

Towards a renewed research agenda in ecotoxicology.

Environ Pollut 2012 Jan 20;160(1):201-6. Epub 2011 Oct 20.

Cemagref, UR MALY, 3 Quai Chauveau, F-69336 Lyon Cedex 09, France.

New concerns about biodiversity, ecosystem services and human health triggered several new regulations increasing the need for sound ecotoxicological risk assessment. The PEER network aims to share its view on the research issues that this challenges. PEER scientists call for an improved biologically relevant exposure assessment. They promote comprehensive effect assessment at several biological levels. Biological traits should be used for Environmental risk assessment (ERA) as promising tools to better understand relationships between structure and functioning of ecosystems. The use of modern high throughput methods could also enhance the amount of data for a better risk assessment. Improved models coping with multiple stressors or biological levels are necessary to answer for a more scientifically based risk assessment. Those methods must be embedded within life cycle analysis or economical models for efficient regulations. Joint research programmes involving humanities with ecological sciences should be developed for a sound risk management.
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http://dx.doi.org/10.1016/j.envpol.2011.08.011DOI Listing
January 2012

Efficiency of sediment quality guidelines for predicting toxicity: the case of the St. Lawrence River.

Integr Environ Assess Manag 2010 Apr;6(2):225-39

Cemagref UR MALY, 3bis quai Chauveau CP 220, 69336 Lyon Cedex 9, France.

Multitiered frameworks that are designed for risk assessment of contaminated sediment rely on sediment quality guidelines (SQGs) at the first tier or screening level. In the case of contamination by multiple pollutants, results can be aggregated under indices such as the mean quotient. A decision is then reached (e.g., to dispose of dredged materials in open water) without further investigation, provided that the SQGs or the specific values of indices or quotients derived from the SQGs are not exceeded. In this way, SQGs and quotients play a critical role in environmental protection. As part of the development of a tiered framework to assess the environmental risk of materials dredged from the St. Lawrence River, we evaluated various quotients based on SQGs available for this river with a data set that matches chemistry and toxicity test endpoints. The overall efficiency of all tested quotients was rather low, and we then examined factors such as sediment grain size, nutrients, metal-binding phases (e.g., Al, Fe), and dissolved organic carbon to explain misclassified samples. This examination led to the design of a modified tier 1 framework in which SQGs are used in combination with decision rules based on certain explanatory factors.
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http://dx.doi.org/10.1897/IEAM_2009-026.1DOI Listing
April 2010

Relationships among total recoverable and reactive metals and metalloid in St. Lawrence River sediment: bioaccumulation by chironomids and implications for ecological risk assessment.

Sci Total Environ 2008 Jan 27;389(1):101-14. Epub 2007 Sep 27.

Cemagref-Groupement de Lyon, Ecotoxicology Laboratory, 3 bis Quai Chauveau, CP 220, 69336 Lyon Cedex 9, France.

The availability and bioaccumulation of metals and metalloids, and the geochemical interactions among them, are essential to developing an ecological risk assessment (ERA) framework and determining threshold concentrations for these elements. The purpose of this study was to explore the relationships among total recoverable and reactive metals and metalloid in sediment and their bioaccumulation by chironomids. In the fall of 2004 and 2005, 58 stations located in the three fluvial lakes of the St. Lawrence River and its largest harbour area in Montreal, Canada, were sampled. Nine total recoverable and reactive metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and one metalloid (As) were measured in whole sediment using two extraction methods: HCl/HNO(3) and HCl 1N, respectively. The bioaccumulation of six metals (Cd, Cr, Cu, Ni, Pb and Zn) and As by chironomids was evaluated in a subset of 22 stations. Strong collinearities were observed between some total recoverable or reactive metal concentrations in sediment; two principal clusters, including collinear metals, were obtained. The first one included metals of mainly geological origin (Al, Cr, Fe, Mn, Ni), while the second one included As, Cd, Cu, Pb and Zn, which likely derive mainly from point sources of anthropogenic contamination. Each element also showed strong collinearity between their total recoverable and reactive forms (0.65< or =r < or =0.97). We can conclude that both chemical forms are equivalent for use in statistical models needed to explain biological responses and also in screening risk assessment. However, these relationships are not always proportional. Lower availability percentages were observed for Cd, Cu and Zn in the highly mixed-contaminated area of the Montreal Harbour, even though concentrations in sediment were higher. We observed a significant correlation (0.50< or =r < or =0.56) between concentrations in chironomids and concentrations of both total recoverable and reactive Cr and Pb in sediment. Arsenic was an exception, with accumulation by chironomids being highly related to reactive sediment concentrations. Finally, we observed variable influences of explanatory factors (e.g. sediment grain size, Al, Fe, Mn, S, TOC), depending on which metal or metalloid was being predicted in chironomids. In this context, it is difficult to choose a universal predictive method to explain the bioaccumulation of specific metals, and more research is still needed into normalization procedures that consider a combination of explanatory factors.
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http://dx.doi.org/10.1016/j.scitotenv.2007.08.019DOI Listing
January 2008

Environmental quality standards for water framework directive priority substances: challenges and opportunities.

Integr Environ Assess Manag 2007 Apr;3(2):290-6

Watts & Crane Associates, 23 London Street, Faringdon, Oxfordshire SN7 7AG, United Kingdom.

The recently published Daughter Directive on priority substances is the culmination of several years of effort by the European Commission to develop consistent, Europe-wide environmental quality standards (EQS) that are scientifically based and protective of Europe's surface waters. This commentary describes progress to date in deriving EQS under the Water Framework Directive and identifies some remaining challenges and opportunities. In the Daughter Directive, annual average EQS are set for surface waters for all 33 priority substances. No sediment standards are included, and biota EQS are proposed for methyl-mercury, hexachlorobenzene and hexachlorobutadiene. Important remaining questions include whether the standard chemical risk assessment methodology is appropriate for deriving water column EQS and whether it would be appropriate to derive EQS for sediment or biota or to adopt alternative strategies. Moreover, some cross-cutting issues about the cessation of discharges of naturally occurring or ubiquitous substances and the advantages and disadvantages of member states setting their own EQS are briefly addressed.
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http://dx.doi.org/10.1897/ieam_2006-045.1DOI Listing
April 2007