Environmental forensics in groundwater coupling passive sampling and high resolution mass spectrometry for screening

International audienceOne of the difficulties encountered when monitoring groundwater quality is low and fluctuating concentration levels and complex mixtures of micropollutants, including emerging substances or transformation products. Combining passive sampling techniques with analysis by high resolution mass spectrometry (HRMS) should improve environmental metrology. Passive samplers accumulate compounds during exposure, which improves the detection of organic compounds and integrates pollution fluctuations. The Polar Organic Chemical Integrative Sampler (POCIS) were used in this study to sequester polar to semi-polar compounds. The methodology described here improves our knowledge of environmental pollution by highlighting and identifying pertinent compounds to be monitored in groundwater.The advantage of combining these two approaches is demonstrated on two different sites impacted by agricultural and/or urban pollution sources where groundwater was sampled for several months. Grab and passive sampling were done and analyzed by liquid chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer (LC-QTOF). Various data processing approaches were used (target, suspect and non-target screening). Target screening was based on research from compounds listed in a homemade database and suspect screening used a database compiled using literature data. The non-target screening was done using statistical tools such as principal components analysis (PCA) with direct connections between original chromatograms and ion intensity. Trend plots were used to highlight relevant compounds for their identification. The advantage of using POCIS to improve screening of polar organic compounds was demonstrated. Compounds undetected in water samples were detected with these tools. The subsequent data processing identified sentinel molecules, molecular clusters as compounds never revealed in these sampling sites, and molecular fingerprints. Samples were compared and multidimensional visualization of chemical patterns such as molecular fingerprints and recurrent or specific markers of each site were given

Multidisciplinary subsurface monitoring for a better understanding of Soil Aquifer Treatment capacity applied on coastal operational wastewater treatment plant (Agon-Coutainville, France)

International audienceUnconfined coastal aquifers are potentially subject to both saline intrusion near the seashore and over discharge of treated wastewater in the surficial environment during the tourist season. In Agon-Coutainville (Normandy, France), managed aquifer recharge (MAR) system, combined with Soil Aquifer Treatment (SAT), was integrated as part of the full-scale operational wastewater treatment plant. Such integrated natural/engineered water treatment system ensure the sustainability of the seaside activities (seafood production, beach) and locally supply freshwater for the irrigational needs of the golf course. Concerning the MAR system, the secondary treated wastewater is infiltrated alternatively into three natural reed bed areas before reaching the sand dune aquifer and thus to enhance the quantity of freshwater in the aquifer. Treated wastewater potentially contains various compounds (chemical, virus, pathogen) which can, however, affect the groundwater quality. Nevertheless, some of these compounds are partly removed, during the SAT. To assess performance and efficiency of the integrated system in the natural environment, we have designed and performed an innovating and multidisciplinary monitoring dedicated to 1) spatial evolution of the freshwater generating by the MAR system, 2) mean residence time of water during SAT and 3) potential reactivity occurring during SAT. Spatial field campaigns and tracer tests were conducted by associating classical and innovative approaches including physico-chemical measurements and quantitative analyses, non target analysis for screening organic compounds, ecotoxicological bioassays, online biomonitoring BACTcontrol® system to detect fecal contamination and online system monitoring device dedicated to saline intrusion. Results show that the MAR system provides a freshwater barrier in the aquifer which is seasonally affected by saline intrusion. A part of the aquifer is assessed for freshwater potential production regardless of the natural and anthropogenic recharge. SAT mean residence time is around two weeks that allows SAT reactivity and thus increases quality of the pumped groundwater. This novel subsurface monitoring provides a better understanding of the SAT capacity to enhance the quantity of freshwater and improve its quality

An in situ intercomparison exercise on passive samplers for the monitoring of metals, polycyclic aromatic hydrocarbons and pesticides in surface water

An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 for the measurement of selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at 2 rivers sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant outputs from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and its uncertainties, the representativity of DGT samples, the ability of PSs to lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compounds (PRC) approach for POCIS with pesticides. These in situ intercomparison exercises should enable to progress on the harmonization of practices for the use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD)

Cowries in the archaeology of West Africa: the present picture

Despite the perceived importance of cowrie shells as indicators of long-distance connections in the West African past, their distribution and consumption patterns in archaeological contexts remain surprisingly underexplored, a gap that is only partly explicable by the sparse distribution of archaeological sites within the sub-continent. General writings on the timeline of importation of cowries into West Africa often fail to take into account the latest archaeological evidence and rely instead on accounts drawn from historical or ethnographic documents. This paper is based on a first-hand assessment of over 4500 shells from 78 sites across West Africa, examining chronology, shell species and processes of modification to assess what distribution patterns can tell us about the history of importation and usage of cowries. These first-hand analyses are paralleled by a consideration of published materials. We re-examine the default assumption that two distinct routes of entry existed — one overland from North Africa before the fifteenth century, another coming into use from the time sea links were established with the East African coast and becoming predominant by the middle of the nineteenth century. We focus on the eastern part of West Africa, where the importance of imported cowries to local communities in relatively recent periods is well known and from where we have a good archaeological sample. The conclusion is that on suitably large assemblages shell size can be an indication of provenance and that, while the present archaeological picture seems largely to confirm historical sources, much of this may be due to the discrepancy in archaeological data available from the Sahara/Sahel zone compared to the more forested regions of the sub-continent. Future archaeological work will clarify this matter

The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate! [Commentary]

The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis for chemical risk assessment in the EU. The plan is to bring chemical risk assessors and managers together with scientists to accelerate method development and the production of necessary data and knowledge, and to facilitate the transition to next-generation evidence-based risk assessment, a non-toxic environment and the European Green Deal. The NORMAN Network is an independent, well-established and competent network of more than 80 organisations in the field of emerging substances and has enormous potential to contribute to the implementation of the PARC partnership. NORMAN stands ready to provide expert advice to PARC, drawing on its long experience in the development, harmonisation and testing of advanced tools in relation to chemicals of emerging concern and in support of a European Early Warning System to unravel the risks of contaminants of emerging concern (CECs) and close the gap between research and innovation and regulatory processes. In this commentary we highlight the tools developed by NORMAN that we consider most relevant to supporting the PARC initiative: (i) joint data space and cutting-edge research tools for risk assessment of contaminants of emerging concern; (ii) collaborative European framework to improve data quality and comparability; (iii) advanced data analysis tools for a European early warning system and (iv) support to national and European chemical risk assessment thanks to harnessing, combining and sharing evidence and expertise on CECs. By combining the extensive knowledge and experience of the NORMAN network with the financial and policy-related strengths of the PARC initiative, a large step towards the goal of a non-toxic environment can be taken

Présence et devenir des substances pharmaceutiques dans les écosystèmes aquatiques

Les substances pharmaceutiques appartiennent à la classe des contaminants émergents qui sont depuis peu étudiés dans les milieux naturels. Ces composés d’usage très répandu et consommés en quantités très importantes sont introduits dans le milieu aquatique via les stations d’épuration. La première partie de ce travail de thèse a consisté en la mise au point et en la comparaison de différents protocoles d’échantillonnage (ponctuel et intégratif (POCIS)), d’extraction (SPE, SPME, extraction assistée par micro-ondes) et d’analyse (GC/MS), nécessaires pour le dosage des composés pharmaceutiques dans différents compartiments des systèmes aquatiques (phases dissoute, particulaire et sédimentaire, organismes biologiques). Ensuite, un premier bilan de la contamination de différents systèmes aquatiques (Seine, Gironde, Loire, Adour, milieu marin côtier) a été dressé. Une contamination du milieu aquatique par ces composés a été mise en évidence pour tous les systèmes étudiés. Les concentrations mesurées vont selon les composés, les stations et les saisons de quelques ng.l-1 à quelques dizaines de μg.l-1. Ces études ont permis de documenter les origines (qualification et quantification des sources) et le devenir (phénomènes de dégradation) de ces composés. Elles ont aussi permis de mettre en évidence les phénomènes de partition entre les différentes phases et le potentiel de bioaccumulation de certaines substances.Pharmaceutical substances belong to the class of the emerging contaminants which have started recently to be studied in natural environments. The widespread use and the large consumed quantities of these compounds can lead to important inputs into the aquatic environment through wastewater treatment plants. The first part of this work consisted in the development and the comparison of various procedures concerning sampling (spot sampling and passive sampling), extraction step (Solid Phase Extraction , Microwave-assisted extraction) and analysis (Gas chromatography / mass spectrometry), needed for pharmaceutical analysis in various aquatic compartments (dissolved, particulate and sedimentary phases, biological organisms). Thus a first assessment of pharmaceutical contamination of various aquatic systems (Seine, Loire, Adour and Garonne estuaries, Mediterranean coastal water...) has been undertaken. A contamination of aquatic compartments with pharmaceutical substances has been highlighted for all studied systems. Concentrations ranging from few ng.l-1 to several μg.l-1 have been measured, depending on compounds, sampling stations and seasonal variations. This work has allowed to document the origins (quantification and qualification of inputs) and the fate (degradation phenomena) of those compounds. It has also highlighted partition phenomena between the different phases (ie particulate matter and dissolved phase) and the bioaccumulation capability of some of those substances

Analytical and processing methodologies for non-target screening by coupling passive sampling and high resolution mass spectrometry

International audienceNowadays with technological advances, the use of environmental forensic approaches could help to characterize the various sources of groundwater contamination. This implies the need of specific analytical methodology to identify micropollutants, emerging substances or transformation products present at low concentrations. The high resolution mass spectrometry (HRMS) has gained increasingly in importance for monitoring organic compounds. Its high resolving power, mass accuracy and the sensitive full spectrum acquisition are the key points. Contamination profile and pattern of a specific site could be highlighted by this technique with the use of automatic data processing softwares. The aim is to support public policy development by highlighting and identifying relevant compounds to be monitored in groundwater. The main difficulties for the implementation of monitoring are sometimes low and fluctuating concentration levels and complex mixture of pollutants. No therefore there is a strong interest to combine passive sampling to HRMS. Passive samplers allow accumulating compounds during exposure that improve trace detection and integrating pollution fluctuations. The Polar Organic Chemical Integrative Sampler (POCIS) was employed to sampling polar and semi-polar compounds (pesticides, pharmaceuticals, phenolic compounds, triazoles….). Different sites impacted by agricultural, urban or industrial pollution sources were investigated and sampled during several months. Grab and passive sampling were deployed and analyzed by LC-QTof. To process data, different approaches were investigated according to identification confidence of NORMAN Network (Schymanski et al., 2014). The first one is based on research from target compounds listed on our homemade database (around 450 with experimental data on our system as retention time, exact masses for molecular and fragment ions) or in bibliography. The second one concerns non-targeted screening. The identification of unknown compounds was tried by using several databases such as Norman Mass Bank or Chemspider and different application manager for MassLynx software. This approach allows highlighting the use of passive samplers as storage tool because more compounds are identified with POCIS. Transformation products of pesticides or pharmaceutical compounds were present in most of samples

JEUX ET ENJEUX AUTOUR DE LA REVIVIFICATION DES RESEAUX DE LA TIJANIYYA

International audienc

JEUX ET ENJEUX AUTOUR DE LA REVIVIFICATION DES RESEAUX DE LA TIJANIYYA

International audienc