8807 research outputs found

    Immunotoxicologie environnementale et biosurveillance des milieux

    No full text

    WEEE plastic sorting for bromine essential to enforce EU regulation

    No full text
    International audienceThe plastics of waste of electric and electronic equipment (WEEE) are improved for fire safety by flame retardants, and particularly brominated flame retardants (BFR). As waste, the management of these plastic fractions must comply with the update of the regulation of waste hazard classification (2014, 2017), the publication of a technical standard on management of WEEE (2015), and a restriction of use for decabromodiphenylether in the product regulation (2017). Data of bromine (n = 4283) and BFR concentrations (n = 98) in plastics from electric and electronic equipment (EEE), and from WEEE processing facilities before and after sorting for bromine in four sites in France have been studied for chemical composition and for regulatory classification. The WEEE was analysed by handheld X-ray fluorescence, and the waste was sorted after shredding, by on-line X-ray transmission for total bromine content ( 2000 mg/kg) in small household appliances (SHA), cathode ray tubes (CRT) and flat screens plastics. In equipment (n = 347), 15% of the equipment items have no bromine, while 46% have at least one part with bromine, and 39% have all parts brominated. The bromine concentration in plastics is very heterogeneous, found in high concentrations in large household appliance (LHA) plastics, and also found in unexpected product categories, as observed by other authors. Clearly, an unwanted global loop of brominated substances occurs via the international recycling of plastic scrap. In waste (n = 65), polybromobiphenyls, polybromodiphenylethers (PBDE), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane were analysed. The most concentrated BFRs are decaBDE (3000 mg/kg) and TBBPA (8000 mg/kg). The bromine concentration of regulated brominated substances was identified in 2014 and 2015 to be up to 86% of total bromine in “old” waste (SHA, CRT), 30–50% in “younger” waste (Flat screens), and a mean of only 8% in recent products (2009–2013). Regulated substances are a minority of all the brominated substances and the only practical way to sort is to measure total bromine on-line. The sorting reduces the mean bromine concentration in the “Low Br” fraction in all sites, and reduces the decaBDE concentration to levels below the restricted use limit. After sorting, the concentration in the “High Br” fractions exceeds all present or future regulatory limits. In conclusion, sorting of small household appliances, cathode ray tubes and flat screen plastics is necessary to avoid uncontrolled dispersion of regulated substances in recycled raw material. Other categories (large household appliances, electric and electronic tools, lighting equipment) should also be considered, since their total bromine content (unweighted mean concentration) is high for some of these products. A European campaign consisting of 7 countries and 35 sites will begin in 2017, directed by WEEE Forum, the European association speaking for thirty-one not-for-profit e-waste producer responsibility organisations, to assess the mean bromine content of plastics from large household appliances after shredding

    Exposure assessment of Nanomaterials at production sites by a Short Time Sampling (STS) approach : Strategy and first results of measurement campaigns

    No full text
    International audienceCharacterization of the exposition to nanoparticles and nano-objects at workplaces is a huge technical challenge. Workplace exposure during short durations is particularly difficult to detect due to the low performances of the samplers. This article proposes a solution allowing for characterizing emissions at workplaces and presents the results obtained from a nanomaterials exposure measurement campaign performed on six different process lines (PLs) distributed all over Europe. By using our Short Time Sampling (STS) approach, the emitted nanomaterials are characterized in terms of their number concentration, size, shape and chemical composition. The background noise without any production activity is first measured for each PL and then it is distinguished from the emitted nanomaterials during production. The PLs yield different nanomaterial emission levels: the PL using the extrusion of polymer composites shows high emission whereas the PL dealing with the electrospinning of polyamide nanofibers shows the least i.e. no significant change in the background noise during the process and no detectable nanofiber emission either. The nanomaterials get emitted in the form of nanoparticles or submicronic fibers, or their agglomerates and aggregates i.e. Nano Objects, Agglomerates and Aggregates (NOAA). By the developed technique, 9 out of 37 of the studied steps have been shown to exhibit exposures to nanoparticles and nano-objects. For nanosafety measures, the energetic processes like spraying, extrusion, transport and cleaning activities of the nanomaterials in the powder form require most attention

    A physiologically based toxicokinetic (PBTK) model describing the bioaccumulation of two perfluorinated substances in rainbow trout (Onchorynchus mykiss)

    No full text
    International audiencePer- and poly-fluorinated substances (PFASs) are ubiquitous in the environment, specifically in aquatic systems. While several PFASs are acknowledged to be bioaccumulated by vertebrate species, including fish, their absorption, distribution, metabolisation and elimination (ADME) remain incompletely understood yet. The aim of this study is to develop a physiologically based toxicokinetic (PBTK) model in order to describe the mechanisms in rainbow trout (Oncorhynchus mykiss) exposed through the diet to two selected PFASs, namely perfluorooctane sulfonic acid - PFOS - and perfluorohexane sulfonic acid – PFHxS. Here PFOS is considered as a model compound, as it remains the dominant PFAS in environmental matrices. PFHxS represents an industrial alternative to PFOS, since its addition to Annex B of the Stockholm convention in 2009. Dietary exposure experiments were performed on adult rainbow trouts at two water temperatures (7°C and 11°C). 200 fish were fed daily using pellets spiked with a mixture of PFOS and PFHxS during several weeks. Then, fish were allowed to depurate, in the same tanks, where non contaminated food was supplied daily. During both phases, 5 randomly selected fish were periodically sacrificed. Organs and blood were sampled, weighted, and prepared for PFOS and PFHxS analysis (UPLC-MS/MS). Data from these two dietary experiments, as well as this obtained from the literature, were used for the model calibration. The present PBTK model comprises seven compartments: arterial and venous blood, liver, viscera, brain, kidney, and muscle. Uptake is considered to occur exclusively by diet and no biotransformation of the selected PFASs is considered, since PFOS and PFHxS are final products of precursor degradation. Also, the model took into account growth of individuals and temperature variation, both variables which may influence ADME processes in fish

    Effects of a mixture of pharmaceuticals in a freshwater model ecosystem

    No full text
    International audienceOwing to their ecological importance, freshwaters provide important services which leads to a strong societal demand concerning the preservation of their quality. They are the receptors of many contaminants emitted by human activities and more specifically by wastewater treatment plants effluents. Water resources of the Meuse watershed are used on both sides of the French-Belgian border which involves a coherent and joint management. In that framework, the DIADeM project suggests developing and spreading out a cross-border multidisciplinary approach to improve the diagnosis and the chemical and biological (biomarkers) monitoring of freshwaters using the Meuse river as a case study. In the past, results from chemical surface water monitoring of the Meuse has revealed the occurrence of numerous substances and more particularly pharmaceuticals. Overall, the project suggests coupling chemical and biomarkers analysis on caged organisms (a crustacean, a mollusk, a moss and a fish species) with predictive mathematical population level models. In order to calibrate and validate these models, a lotic mesocosm experiment was set up. Five substances were chosen: diclofenac, carbamazepine, naproxen, paracetamol and irbesartan. An environmental realistic mixture M of the five substances was tested along with MX10 and MX100. The study was carried out in twelve 20 m long lotic channels. The mesocosms were set up with artificial sediments, macrophytes, periphyton, benthic and pelagic invertebrates, decomposers and one fish species (Gasterosteus aculeatus). zebra mussels, Fontinalis antipyretica and Gammarus fossarum were also caged in the mesocosms. After 3 months of stabilization, treatment lasted 5 months. Periphyton biomass, macrophyte biovolume, zebra mussel biomarkers and growth, G. fossarum survival, reproduction and growth, F. antipyretica biomarkers and growth, zooplankton and invertebrate abundance and diversity, and fish individual physiological responses along with population dynamics were the main measured biological endpoints. The concentrations of each substance in water was monitored monthly along with some physico-chemical parameters. The overall experimental design will be presented along with the results related to the monitoring of substance concentrations in water, physico-chemical parameters, macrophyte biovolume, invertebrate community response, fish larvae densities. A brief discussion of the direct and/or indirect effects will then be performed

    Climate sensitivity of different organic aerosol schemes over the Mediterranean basin

    No full text
    International audienceThe Mediterranean basin is among one of the areas that can be most sensitive to climate change (Giorgi et al, 2006). This fact, along with the population density around this basin, the high burden in aerosol concentration that the basin experiences throughout the year and the increasing projections for shipping emissions in the future make it an important area to explore. While the organic aerosol can have an important impact on the local and also the regional air quality presently and in the future, the simulation of this aerosol in the western part of the Mediterranean basin is a subject that has not been studied thoroughly for present conditions and has been studied even less for the future. The present work consists of two phases. The first phase explores existing climatic runs performed with CHIMERE chemistry transport model with climate inputs corresponding to RCP2.6, RCP4.5 and RCP8.5 during the French PRIMEQUAL Salut’air project; with a focus on the Mediterranean basin and the changes that these scenarios induce in the concentration of particulate matter and especially organic aerosols. The effects of boundary conditions, and anthropogenic emission changes are assessed. Major driving climate variables affecting organic and fine aerosol levels over the basin are identified. During the second phase, sensitivity runs of the RCP4.5 scenario are performed, in which three different aerosol models are used, including a VBS scheme with and without biogenic aging (Robinson et al. 2007, Lane et al. 2008), and a modified VBS scheme containing fragmentation and formation of non-volatile organic aerosols (Shrivastava et al., 2013). These schemes have been previously compared to measurements obtained during the MISTRAL / CHARMEX summer 2013 campaign (Cholakian, 2017, in preparation). 10 years of historic and years 10 future runs have been performed, and a specific method allows chosing years maximizing the temperature and organic aerosol differences between past and future runs. This allows assessing the climate sensitivity of different organic aerosol schemes. This is a new and complex topic, as organic aerosol formation depends on several parameters (temperature playing on biogenic VOC emissions and phase partition of semi-volatile compounds, winds impacting advection, and precipitation impacting aerosol removal) and their representation in a model

    A Coupled Hydro-Mechanical Modeling of Tunnel Leakage in Sand Layer

    No full text
    International audienceThe tunnel leakage in sand layer plays an important role in the evolution of the lining stresses and the ground movement. The phenomenon of internal erosion occurs when underground water leaks into the tunnel from the damaged joints or the cracks of the linings. Fines in sand are pulled off by seepage forces and transported throughout the soil matrix into the tunnel. The loss of fines due to seepage flow affects the mechanical behavior of the soil around the tunnel. Conversely, the change of porosity influences the permeability of the soil and, therefore, its hydraulic conductivity. In this study, the effect of tunnel leakage in sand layer is investigated numerically with a coupled hydro-mechanical approach, considering the internal erosion phenomenon induced by the local flows of underground water, using the continuous porous medium theory and a critical-state based constitutive model. Simulation results show that the loss of fines as well as the leakage locations have significant impacts on the tunnel lining and the ground movement

    1,210

    full texts

    8,807

    metadata records
    Updated in last 30 days.
    HAL-INERIS
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇