Bioassay-based profiling of steroid- and dioxin-like activities in French river waters using grab and integrative sampling

Effect-based methods (EBM) are relevant tools to monitor chemical quality of aquatic systems as they provide integrative assessment of contamination components and inform on hazard associated with complex mixtures. In the frame of a French national program aiming at demonstrating the operational performance of passive sampling to monitor priority chemicals in surface waters, we applied a panel of in vitro bioassays to investigate 1) the occurrence of steroid- and dioxin- /PAH-like activities, 2) their distribution in the water column using grab sampling and integrative passive sampling. In addition, we looked into the relevance of in vitro estrogenicity in the water as compared to established trigger values and in vivo assessment in zebrafish. Twenty surface water sites of different anthropogenic pressures were studied. For each of them, both grab (dissolved phase and particulate matter) and integrative sampling (POCIS and Silicone Rubber membranes) were performed over a 15 days period and organic extract of each sample was analyzed with the bioassays. In vitro toxicity profiles in grab water organic extracts showed contrasted contamination patterns depending on the time of sampling (T0 and T15) and the studied sites. Estrogenic and PAH-like activities were the most occurent activities, while glucocorticoidic and anti-androgenic ones were detected at specific sites. No androgenic activity was detected. PAH-like activity was associated with both the dissolved and particulate matter phases while endocrine activities were only found in the dissolved phase. At some sites, in vitro estradiol-equivalents were found above the generic trigger value considering environmental risk (0.4 ng E2Eq/L). For 7 sites out of the 10 tested in vivo, activities were coherent with those predicted by in vitro bioassays. The present study highlights the relevance of combining a set of effect-based tools and smart sampling to monitor site-specific contamination of surface water chemical quality and the partitioning of measured activities in the water column. Our approach further includes in vivo mechanism-based assays, which enhances the toxicological relevance of the assessment. Comparison of our data with established trigger values for some activities will be discussed. Finally, ongoing chemical analyses of more than 100 priority substances, including estrogenic hormones, will allow the determination of their contribution to the biological activities detected

Bioassay-based profiling of steroid- and dioxin-like activities in French river waters using grab and integrative sampling

Effect-based methods (EBM) are relevant tools to monitor chemical quality of aquatic systems as they provide integrative assessment of contamination components and inform on hazard associated with complex mixtures. In the frame of a French national program aiming at demonstrating the operational performance of passive sampling to monitor priority chemicals in surface waters, we applied a panel of in vitro bioassays to investigate 1) the occurrence of steroid- and dioxin- /PAH-like activities, 2) their distribution in the water column using grab sampling and integrative passive sampling. In addition, we looked into the relevance of in vitro estrogenicity in the water as compared to established trigger values and in vivo assessment in zebrafish. Twenty surface water sites of different anthropogenic pressures were studied. For each of them, both grab (dissolved phase and particulate matter) and integrative sampling (POCIS and Silicone Rubber membranes) were performed over a 15 days period and organic extract of each sample was analyzed with the bioassays. In vitro toxicity profiles in grab water organic extracts showed contrasted contamination patterns depending on the time of sampling (T0 and T15) and the studied sites. Estrogenic and PAH-like activities were the most occurent activities, while glucocorticoidic and anti-androgenic ones were detected at specific sites. No androgenic activity was detected. PAH-like activity was associated with both the dissolved and particulate matter phases while endocrine activities were only found in the dissolved phase. At some sites, in vitro estradiol-equivalents were found above the generic trigger value considering environmental risk (0.4 ng E2Eq/L). For 7 sites out of the 10 tested in vivo, activities were coherent with those predicted by in vitro bioassays. The present study highlights the relevance of combining a set of effect-based tools and smart sampling to monitor site-specific contamination of surface water chemical quality and the partitioning of measured activities in the water column. Our approach further includes in vivo mechanism-based assays, which enhances the toxicological relevance of the assessment. Comparison of our data with established trigger values for some activities will be discussed. Finally, ongoing chemical analyses of more than 100 priority substances, including estrogenic hormones, will allow the determination of their contribution to the biological activities detected

Passive integrative samplers, relevant tools to improve regulatory monitoring of chemical quality of aquatic environments?

In the context of the Water Framework Directive (WFD), we have set up a national demonstration to identify the advantages and limitations of integrative passive samplers (IPS) for regulatory chemical monitoring of waters. Thus, deployments of "diffusive gradient in thin films" (DGT), polar organic chemical integrative samplers (Pocis) and silicon rubber (SR) were carried out on 20 sites (1 campaign) but also continuously for one year on 3 sites (26 campaigns). In parallel and for comparison, spot water samples were taken for each campaign (during the installation and removal of the IPSs). The relevance but also the drawbacks of these tools are discussed with regard to the practical aspects and the information generated on the state of the chemical contamination of the water. The results confirm the interest of using chemical monitoring by IPS, and demonstrate their applicability in the context of regulatory control networks. Except for some parameters for which there are problems of contamination of the tools, IPS allows a lowering of the limits of quantification and, mainly for Pocis and SR, an increased frequency of quantification, which translates into the detection of more molecules, and uncertainties decreased on the annual average concentrations (AAs). Finally, the assessment of chemical status (comparison of AAs) with environmental quality standards (EQS) based on AAs determined by IPS is consistent with those determined from spot sampling. It even allows in some cases to better qualify a 'good status when the spot sample does not allow it.Dans le contexte de la directive cadre sur l’eau (DCE), nous avons mis en place une démonstration à l’échelle nationale afin d’identifier les atouts et les limites des échantillonneurs intégratifs passifs (EIP) pour la surveillance chimique réglementaire des eaux. Ainsi des déploiements de diffusive gradient in thin films (DGT), de polar organic chemical integrative samplers (Pocis) et de membranes silicone (SR) ont été réalisés sur 20 sites (une campagne), mais aussi en continu pendant un an sur trois sites (26 campagnes). En parallèle et pour comparaison, des prélèvements ponctuels d’eau ont été réalisés pour chaque campagne (lors des déploiements et récupérations des EIP). La pertinence mais aussi les limites de ces outils sont discutées au regard des aspects pratiques et des informations générées sur l’état de la contamination chimique des eaux. Les résultats confirment l’intérêt du recours à une surveillance chimique par EIP et démontrent leur applicabilité dans un contexte de réseaux de contrôle réglementaires. Hormis pour certains paramètres pour lesquels il existe des problèmes de contamination des outils, les EIP permettent un abaissement des limites de quantification et, principalement pour les Pocis et les SR, une fréquence de quantification augmentée, qui se traduit par la détection de davantage de molécules, et par des incertitudes diminuées sur les concentrations moyennes annuelles (MA). Enfin, l’évaluation de l’état chimique (comparaison des MA avec les normes de qualité environnementale (NQE)) à partir des MA déterminées par EIP est en cohérence avec celle déterminée à partir d’un échantillonnage ponctuel. Elle permet même dans certains cas de mieux qualifier un état alors que l’échantillonnage ponctuel ne le permet pas