Behavioural and Physiological Responses of Gammarus pulex Exposed to Cadmium and Arsenate at Three Temperatures: Individual and Combined Effects

This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and15°C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, survival, [AsV] or [Cd] in body tissues, behavioural (ventilatory and locomotor activities) and physiological responses (iono-regulation of [Na+] and [Cl−] in haemolymph) were examined. The interactive effects (antagonistic, additive or synergistic) of binary mixtures were evaluated for each tested temperature using a predictive model for the theoretically expected interactive effect of chemicals. In single metal exposure, both the internal metal concentration in body tissues and the mortality rate increased along metallic gradient concentration. Cd alone significantly impaired both [Na+] and [Cl−] while AsV alone had a weak impact only on [Cl−]. The behavioural responses of G. pulex declined with increasing metal concentration suggesting a reallocation of energy from behavioural responses to maintenance functions. The interaction between AsV and Cd was considered as ‘additive’ for all the tested binary mixtures and temperatures (except for the lowest combination at 10°C considered as “antagonistic”). In binary mixtures, the decrease in both ventilatory and locomotor activities and the decline in haemolymphatic [Cl−] were amplified when respectively compared to those observed with the same concentrations of AsV or Cd alone. However, the presence of AsV decreased the haemolymphatic [Na+] loss when G. pulex was exposed to the lowest Cd concentration. Finally, the observed physiological and behavioural effects (except ventilation) in G. pulex exposed to AsV and/or Cd were exacerbated under the highest temperature. The discussion encompasses both the toxicity mechanisms of these metals and their interaction with rising temperature

Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032).As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants from three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years, and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, and benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs, and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with the highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European-wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability, and will give leverage to national policymakers for the implementation of targeted measures.info:eu-repo/semantics/publishedVersio

EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

Funding Information: The authors would like to thank everybody who contributed to the HBM4EU Aligned Studies: the participating children, teenagers, adults and their families, the fieldworkers that collected the samples and database managers that made the information available to HBM4EU, the HBM4EU project partners, especially those from WP7 for developing all materials supporting the fieldwork, WP9 for organizing the QA/QC scheme under HBM4EU and all laboratories who performed the analytical measurements. We would like to acknowledge Sun Kyoung Jung from the National Institute of Environmental Research of South-Korea for providing the KoNEHS Cycle III results (crt adjusted). HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032). The authors thank all principal investigators of the contributing studies for their participation and contribution to the HBM4EU Aligned Studies and the national program owners for their financial support. Further details on funding for all the participating studies can be found in the Supplemental Material, Table S12.As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6–12 years, (ii) 3,117 teenagers aged 12–18 years and (iii) 4,102 young adults aged 20–39 years. The participants were recruited between 2014 and 2021 in 11–12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.publishersversionpublishe

Antagonistic toxicity of arsenate and cadmium in a freshwater amphipod (Gammarus pulex)

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Design de plan expérimental optimal : vers une approche basée sur la logique floue

International audienceWe present in this article the foundation of a method using fuzzy logic for experimental plan design under constraints and with few data. The goal is to provide experimenters with an interpretable / explicable algorithm, allowing them to sample optimally. We detail the different steps of our algorithm (generation of the rule system, fuzzy inference,...), the results obtained, and the comparison with Bayesian optimizationNous présentons dans cet article les fondements d'une méthode basée sur la logique floue pour le design de planexpérimental, sous contraintes et avec peu de données. L'objectif est de fournir aux expérimentateurs un algorithme interprétable / explicable, leur permettant d'échantillonner de manière optimale. Nous détaillons les différentes étapes de notre algorithme (génération du système de règles, inférence floue), les résultats obtenus, ainsi que la comparaison avec l'optimisation bayésienne

Commons as a risk-management tool : theoretical predictions and an experimental test

Common-pool resources (CPR) are frequently used as risk-management tools against risk on private activities. The impact of this safety-net use of CPR on the individual investment into and extraction from the commons is analyzed in this paper. Agents of the community first choose to invest in their private project and in the CPR; second, they choose how much to extract from their private project and the commons. The model compares two types of risk-management tool: CPR as (ex post) risk-coping and (ex ante) risk-diversification mechanisms. It also compares two situations regarding risk: risk on a private project and uncertainty on CPR investment by other community members. The theoretical predictions are empirically tested with experimental economics. To this end, we propose an original CPR game composed of an investment period and an extraction period. Our result clearly shows that risk reduction in the private project unambiguously decreases investment in the CPR, while it does not impact CPR extraction. We also show that a risk-coping strategy is well understood as more flexible and influenced by the outcome in terms of private project yield.Les biens communs sont fréquemment utilisés comme outils de gestion des risques liés aux activités privées. Dans cet article, nous analysons l’impact de cette utilisation du bien commun en tant que filet de sécurité pour les choix d’investissement et d’extraction de ressources naturelles communes. Les agents de la communauté choisissent d’abord d’investir dans leur projet privé et dans le bien commun ; ensuite, ils choisissent la quantité à extraire de leur projet privé et du bien commun. Le modèle compare le bien commun en tant que mécanisme de gestion des risques (ex post) et en tant que mécanisme de diversification des risques (ex ante). Il compare également deux situations : le risque sur le projet privé et l’incertitude concernant l’investissement des autres membres de la communauté dans le bien commun. Les prédictions théoriques sont testées empiriquement via une expérience de laboratoire. Pour cela, nous proposons un jeu de bien commun original composé d’une période d’investissement et d’une période d’extraction. Notre résultat montre clairement que la réduction des risques associés au projet privé diminue l’investissement dans le bien commun, alors qu’elle n’a pas d’effet sur l’extraction. Nous montrons également que le bien commun en tant que mécanisme de gestion des risques est une stratégie comprise comme plus flexible et qu’elle est influencée par les rendements du projet privé

Commons as insurance: theoretical predictions and an experimental test

In this paper, we deal with the impact of the safety-net use of Common Pool Resource (CPR) on the individual investment into and extraction from the commons. We propose a theoretical model with two steps: agents of the community choose to invest in their private project and in the commons; second, they choose how much to extract from their private project and the commons. The model compares two types of risk-management tool: CPR as risk coping and risk diversification mechanisms. It also compares two types of risk: risk on a private project and risk on CPR investment by other community members. In a second part of the paper, we test empirically the theoretical results through experimental economics. Such a test needs to propose a new CPR game composed of two periods, an investment one and an extraction one. We propose such an original game inspired from the two existing CPR games, Investment game (Olstrom et al., 1994) and Request game (Budescu et al., 1992)

MIE And Flame Velocity Of Partially Oxidised Aluminium Dust

International audienceThis work presents experimental tools for the determination of Minimum Ignition Energy (MIE) and results concerning the influence of an initial oxidation state on ignition threshold energies and flame velocity. These studies are carried out with micrometric aluminium particles which are oxidised using an anodising process. The first part of this work concerns the description of the experimental devices (Hartmann tube, for MIE measurements, and constant volume combustion chamber for flame velocity measurement with using high speed recording shadowgraphy). In the second part, a review of some results obtained for the sensitivity (MIE) of aluminium particle evolution versus particle diameter, air-fuel equivalence ratio and oxide content is presented. The effect of the oxide content is demonstrated: the MIE increases with the initial oxide content. The sensitivity of oxidised dust remains relatively high for high oxide contents (17.1wt%). The flame velocity is also modified and decreases as the oxide content increases. The most important result seems to be the role of the water content contained in the oxide shell which increases the reactivity of the oxidised aluminium dust