39 research outputs found
Perspectives from the French workshop on the development and validation of biomarkers and bioassays for the monitoring of aquatic environments
International audienceDuring the past three decades, there has been an increasing interest in the field of ecotoxicology for development of effect-based monitoring tools (EBMTs) including in vitro tests, biomarkers and whole organism bioassays. This interest is due to the practical application of EBMTs in the surveillance of the quality of water and aquatic ecosystems (ICES, 2008). Within this framework, these ecotoxicological tools seem to offer numerous potential advantages, as they allow one to take into account the cumulative impact of the whole contaminants present in the field, and the bio-available and active fractions of toxicants as well as their degradation bioaccumulation, biotransformation (Lam and Gray, 2003; Hecker and Hollert, 2009). Hence, they are often seen as complementary tools to conventional environmental monitoring approaches, mostly based on the measurement of a predefined list of chemical substances in various aquatic compartments (water, sediments and biota) and the analyses of indices of biological integrity (OSPAR 2004). Due to these research activities, several core EBMTs (SGIMC, 2011) are now well characterised and may be directly used to assess the quality of the aquatic environment under a European consensus (Table 1; Sanchez and Porcher, 2009; Lyons et al., 2010). However, if EBMTs are widely used in research studies and provide, at geographically and temporally limited scales, data on ecotoxicological status of water bodies, few applications of EBMTs are currently implemented in regulatory environmental monitoring programs
Relationship between Processing Method and the Glycemic Indices of Ten Sweet Potato (Ipomoea batatas) Cultivars Commonly Consumed in Jamaica
This study investigated the effect of different traditional cooking methods on glycemic index (GI) and glycemic response of ten Sweet potato (Ipomoea batatas) cultivars commonly eaten in Jamaica. Matured tubers were cooked by roasting, baking, frying, or boiling then immediately consumed by the ten nondiabetic test subjects (5 males and 5 females; mean age of 27 ± 2 years). The GI varied between 41 ± 5–93 ± 5 for the tubers studied. Samples prepared by boiling had the lowest GI (41 ± 5–50 ± 3), while those processed by baking (82 ± 3–94 ± 3) and roasting (79 ± 4–93 ± 2) had the highest GI values. The study indicates that the glycemic index of Jamaican sweet potatoes varies significantly with the method of preparation and to a lesser extent on intravarietal differences. Consumption of boiled sweet potatoes could minimize postprandial blood glucose spikes and therefore, may prove to be more efficacious in the management of type 2 diabetes mellitus
Nationwide PCB congener pattern analysis in freshwater fish samples in France
The 2006 european directive on polychlorodibenzodioxins and related compounds in
foodstuffs prompted in France a nationwide monitoring study of freshwater fish
contamination by these compounds. A database covering about 300 sites (2848 samples of 36
fish species) was obtained from this study. This database was used to explore congener
pattern distributions, in order to identify typical sources and the impact of
biotransformation on these sources. Fish ecological traits and fish size are the main
factors explaining the overall PCB contamination in the two pre-identified categories of
species (high or low propensity to accumulate hydrophobic compounds). Lipid content is
also an influencing factor, but its relationship to other factors remains uncertain.
Species show distinct congener patterns, related more to their physiology than to
ecological traits. Spatial patterns were studied on selected sites having more than five
individuals analysed – either chub (Squalius cephalus) or barbel
(Barbus barbus), the most widespread species in the database –. We
identified six patterns, which mainly differed in the respective proportions of congeners
potentially biotransformed by fish. No connection to typical sources, e.g.
technical mixtures, was identified. These patterns instead represent an ageing
path of the initial mixtures; they could be used for setting remediation priorities
420 Report of 97 transitioning adolescents with cystic fibrosis from paediatric to adult care CF center
International audienc
Vers la mise en œuvre opérationnelle des approches PICT dans un contexte réglementaire du suivi de la qualité des milieux aquatiques et des sédiments
International audienceAssessing the ecological effects of pollutants is an important aspect of regulations dealing with the sustainable management of water resources. In this context, scientists and regulators face the challenge of going beyond the estimation of pollutant concentrations to take into account the ecotoxicological effects on exposed aquatic communities. Among microbial ecotoxicological approaches, the pollution induced community tolerance (PICT) concept has been proven to be a suitable biomonitoring tool for in situ assessmentof either the response of aquatic microbial communities to toxicant exposure or of their recovery following the improvement of water chemical quality. The PICT is a powerful microbial metric to better link the assessment of ecological and chemical status of ecosystems by providing causal analysis in effect-based monitoring of impacted field sites4. However, prior its implementation in regulatory frameworks, further work is required to standardize PICT measurement and define baseline tolerance levels at large geographical scales. In this context, we will present the first results of the application of PICT approaches in the sediment compartment (with copper as model compound). We will specifically focus on both the development of standardized protocols (from sampling to dose-response modeling) and on the evaluation and control of potential confounding factors to make measurements comparable in space and time by considering robust reference conditions
Comment choisir ou déterminer des facteurs d'amplification trophique pour application dans le cadre de la DCE en pratique
International audienceEuropean Union Directive 2013/39/EU, which amended and updated theWater Framework Directive (WFD; 2000/60/EC) and its daughter directive (2008/105/EC), sets Environmental Quality Standards for biota (EQSbiota) for a number of bioaccumulative chemicals. These chemicals pose a threat toboth aquatic wildlife andhumanhealth via the consumptionof 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 EQSbiota. 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), ametric 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-derivedmeasure of trophicmagnification 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 endusers select a reasonable and relevantTMF
Des indicateurs multi-substances basés sur la bioaccumulation lors d'encagement de gammares révèlent l'influence de la contamination chimique sur l'abondance des macroinvertébrés des cours d'eau en France
International audienceMost anthropogenic stressors affecting freshwater systems are qualitatively known. However, the quantitative assessment of contaminant exposure and effects to aquatic communities is still difficult, limiting the understanding of consequences on aquatic ecosystem functioning and the implementation of effective management plans. Here, multisubstance indicators based on caged gammarid bioaccumulated contamination data are proposed (for metals and persistent organic pollutants, POPs) to map the bioavailable contamination level of freshwater ecosystems at a large spatial scale. We assessed the ability of these indicators to highlight the relationships between chemical exposure gradients and alteration in the abundance of macroinvertebrate populations on a data set of 218 watercourses distributed throughout France. We identified spatial regional heterogeneities in the levels of bioavailable contamination of metals (18 compounds) and POPs (43 compounds). Besides this, a degradation of Gammaridae, Ephemeridae, and Hydrobiidae densities with increasing levels of metal contamination are identified relative to Baetidae, Chironomidae, and Hydropsychidae. We show here that active biomonitoring allows the establishment of multisubstance indicators of bioavailable contamination, which reliably quantify chemical exposure gradients in freshwater ecosystems. Our ability to identify species-specific responses to chemical exposure gradients demonstrates the promising possibility to further decipher the effects of chemical contamination on macroinvertebrate assemblages through this type of indicator
Looking at biological community level to improve ecotoxicological assessment of freshwater sediments: report on a first French-Swiss workshop
International audienceThe first French-Swiss workshop on ecotoxicology of freshwater sediment communities was co-organized by the French Research Institute of Science and Technology for Environment and Agriculture (Irstea) and the Swiss Centre for Applied Ecotoxicology (Ecotox Centre EAWAG-EPFL) in Villié-Morgon (Beaujolais Region, France) on April 27-28, 2017. The workshop brought together scientists working in different fields of expertise (ecotoxicologists, ecologists, environmental chemists...), environmental stakeholder groups and managers, as well as economic players (start-ups and consultancies) to better connect research needs of potential end-users with research outputs. The objectives of this workshop were (i) to establish the state of the art of research in the characterization of sediment contamination and in the evaluation of the effects on sediment-associated biological communities and ecosystem functioning and (ii) to give an overview of the French and Swiss regulations dealing with the assessment of contaminated sediments in freshwater ecosystems. The ultimate goal was to collectively identify research needs and knowledge gaps, as well as to highlight ways to improve the ecotoxicological assessment of sediments in freshwater environments by further considering the structure and functions of associated microbial and invertebrate communities
Les biomarqueurs comme outils de surveillance dans le contexte de la directive-cadre sur l'eau : concept, avis et avancement de l'expertise
International audienceTheWater Framework Directive (WFD) currently supports chemical and ecological monitoring programmes in order to achieve the good water surface status. Although chemical and ecological assessments are necessary, they have some limitations. Chemical approaches focus on certain substances identified as priorities, but they do not take into account other potentially harmful substances and also ignore the hazards related to contaminant cocktails. On the other hand, while ecological approaches provide holistic information on the impairment of biological communities in ecosystems, they do not distinguish the role of contaminants in these alterations, and consequently do not allow the establishment of contaminant impact reduction plans. Consequently, ecotoxicologists suggest the use of effect-based tools such as biomarkers. Biomarkers highlight the effect of potentially harmful substances (or a cocktail), and their specificity towards the chemicalsmakes it possible to properly discriminate the role of toxicantswithin biological community impairments. Thus, the integration of such tools (besides existing chemical and ecological tools) in the WFD could considerably improve its biomonitoring strategy. The B n' B project (Biomarkers and Biodiversity) exposes key objectives that will allow to (i) establish an inventory of the biomarkers developed by French laboratories; (ii) determine their methodological advancement and limits and, on this basis, formulate recommendations for biomonitoring use and future research needs; (iii) discuss the biomarkers' ecological significance, specificity to contaminants and interpretation capacity; (iv) establish, in fine, a selection of valuable biomarkers to enter the WFD; and (iv) propose integrative tools to facilitate the decision-taking by stakeholders