Perfluoroalkyl substances (PFASs) are global environmental contaminants and a need for monitoring levels has arisen due to their persistency and their ability to bioaccumulate. One relatively novel method of monitoring for both long and short time intervals and generating time-weighted average (TWA) concentrations is passive sampling for which no power, maintenance and supervision is required. The polar organic compound integrative sampler (POCIS) with a weak anion exchange (WAX) sorbent and the POCIS with a hydrophilic-lipophilic balance (HLB) adsorbent were calibrated for PFASs in a laboratory uptake experiment, and applied at a drinking water treatment plant (DWTP) in Stockholm, Sweden.   In the calibration study, all of the 14 studied PFASs were taken up by both passive samplers. Two and three out of the 14 studied PFASs had reached equilibrium after 28 days using POCIS WAX (PFBA and PFTeDA) and POCIS HLB (PFBA, PFPeA and PFTeDA), respectively. The sampling rate (Rs), which is the extracted water in liters per day, ranged between 0.003 and 0.10 L day-1 for the POCIS WAX and between 0.00052 and 0.13 L day-1 for the POCIS HLB. In general, Rs increased with increasing perfluorocarbon chain-length (C4 to C8) and for a perfluorocarbon chain-length longer than C8, Rs decreased with increasing perfluorocarbon chain-length (C8 to C13) for both passive samplers. FOSA had the highest Rs-value (0.10 and 0.13 L day-1) for both POCIS WAX and POCIS HLB, respectively. The POCIS WAX had a higher uptake for the short-chained PFASs PFBA (134 ng after 28 days), PFPeA (410 ng) and PFHxA (834 ng), compared to the POCIS HLB (0.5 ng, 58 ng, and 373 ng, respectively). For all other compounds, the accumulated amounts in the POCIS HLB were in the same range as in the POCIS WAX.   The application of the passive samplers at the DWTP showed that both passive samplers could detect ultra-trace (pg to ng L-1) levels of PFASs. A comparison of the TWA concentration showed that the two passive samplers had a good linear correlation (R2 = 0.63), but the TWA concentrations derived by POCIS WAX was approximately 40% higher compared to POCIS HLB. A comparison between the passive samplers and the grab samples did not show a correlation (R2 = 0.24 for POCIS WAX and R2 = 0.10 for POCIS HLB). The application also included a comparison of the removal efficiency in the conventional DWTP and a pilot plant with additional treatments steps of granulated activated carbon (GAC) and nanofiltration (NF). For the full-scale DWTP the average removal efficiency was 32% and high removal efficiency was observed for PFBA (81%). For the pilot plant, the removal efficiency was 100% for all the detected PFASs in the raw water. / Perfluoroalkylsubstanser (PFAS) har blivit uppmärksammade som globala miljöföroreningar, och ett behov av att övervaka dessa ämnens förekomst i miljön har uppkommit på grund av hög persistens i kombination med hög förmåga att bioackumulera. En relativt ny metod för tidsintegrerad provtagning är så kallad passiv provtagning. En adsorbent placeras i fält och ackumulerar PFAS från vattnet. Tillgång till elektricitet behövs inte, och behov av övervakning och underhåll är minimalt. I denna studie kalibrerades en så kallad ’polar organic compound integrative sampler’ (POCIS) för mätning av PFAS genom upptagsexperiment med två olika adsorbenter: en svag anjons adsorbent (WAX) och en hydrofil-lipofil balanserad adsorbent (HLB). Metodiken tillämpades sedan på vatten från ett dricksvattenverk i Stockholm, Sverige.   Upptagsexperimenten utfördes med 14 PFAS och samtliga togs upp av båda adsorbenterna. Två respektive tre av de studerade PFAS uppnådde jämvikt efter 28 dagar för WAX (PFBS och PFTeDA) samt HLB (PFBA, PFPeA och PFTeDA). Upptagshastigheten (Rs), det vill säga den volym som extraheras per dag, varierade mellan 0,003 och 0,1 L dag-1 för WAX och mellan 0,00052 och 0,13 L dag-1 för HLB. Generellt ökade Rs med en ökande längd på kedjan av perfluorerade kol upp till C8, för att sedan avta med ökande kedjelängd. FOSA hade det högsta Rs-värdet (0,10 och 0,13 L dag-1) för både WAX och HLB. WAX hade ett högre upptag (upp till 134, 410 och 834 ng) för PFAS med kort perfluorerad kolkedja (PFBA, PFPeA respektive PFHxA) jämfört med HLB (upp till 0,5, 58, och 373 ng). Den ackumulerade mängden för alla andra PFAS överensstämde väl mellan de båda provtagarna.   Mätning av PFAS halter i dricksvattenverket med hjälp av POCIS WAX och POCIS HLB visade att även PFAS kunde detekteras även vid miljörelevanta halter. En jämförelse mellan de båda passiva provtagarna visade på ett linjärt samband (R2 = 0,63), men där POCIS WAX hade en tendens att överskatta koncentrationen med ca 40%. En jämförelse mellan de passiva provtagarna och traditionell uppsamlingsprovtagning visade på låg överrensstämmelse (R2 = 0.24 för POCIS WAX och 0.10 för POCIS HLB). Vid tillämpningen gjordes även en beräkning för reningseffektiviteten av PFAS i dricksvattenverket och i en pilotanläggning där ytterligare rening med granulerat aktivt kol (GAC) och nanofiltration (NF) används. I dricksvattenverket var den genomsnittliga reningen 32%, med den högsta reningseffektiviteten för PFBA (81%). I pilotanläggningen var reningen 100% för alla upptäckta PFAS i råvattnet.

In agricultural watersheds, streams are intimately connected with croplands and may be inadvertently exposed to agrochemicals such as fertilizers and herbicides. Riparian plants and aquatic primary producers (aquatic plants, phytoplankton and periphyton) may be particularly affected by agrochemicals due to their taxonomic similarity to the intended targets (crop and weed species). The overall objective of this thesis was to assess the effects of fertilizers and the herbicide atrazine on riparian plants and aquatic primary producers. Effects were assessed across varying scales of observation ranging from empirical field studies at the watershed scale to in-situ experimental manipulations in two temperate streams to a laboratory concentration-response experiment. Twenty-four stream/river sites located across the South Nation River watershed, Canada ranged in surrounding agricultural land use (6.7-97.4 % annual crops) and in-stream concentrations of reactive phosphate (4-102 μg/L) and nitrate (3-5404 μg/L). A gradient of atrazine contamination spanning two orders of magnitude (56 d time-weighted-average concentrations of 4-412 ng/L) was observed using polar organic chemical integrative samplers (POCIS). A total of 285 riparian and aquatic plant species were identified with species richness ranging from 43-107 species per site. Atrazine and the percentage of surrounding annual crops had no statistically significant effects on community structure. In contrast, an increase in the percentage of non-native species, a decrease in submerged macrophytes and a decrease in overall floristic quality was observed along a gradient of increasing nitrate. Similarly, periphyton biomass increased with increasing nitrate across the watershed and was associated with the Chlorophyta. In contrast, no clear response was observed in periphyton exposed to nutrient enrichment and atrazine contamination in in-situ periphytometer experiments in two streams. Greenhouse concentration-response experiments provided evidence that the sensitivity of duckweed (Lemna minor) to atrazine was lower in populations previously exposed to the herbicide. However, the overall range in biomass 25% inhibition concentrations was small (19-40 μg/L atrazine). A clear gradient in agrochemical contamination was observed at the watershed scale and this research provided evidence of negative effects on riparian and aquatic primary producers. Effects of nutrients, specifically nitrate, superseded observable effects of the herbicide atrazine.

L’objectif général de cette thèse concerne la mise en place et l’évaluation d’une approche de type effect directed analysis (EDA), couplant bioessais in vitro et analyses physico-chimiques, pour la caractérisation de la contamination des milieux aquatiques par les perturbateurs endocriniens (PE) et leur identification. De nouveaux outils in vitro ont été développés et intégrés à une approche multi-bioessais pour la détection de polluants émergents afin de permettre un large diagnostic de la contamination par les PE. Parmi eux, le bioessai basé sur le pregnane X receptor humain s’est avéré complémentaire des cibles classiquement étudiées (e.g. récepteurs des œstrogènes (ER), des androgènes (AR) ou des hydrocarbures aromatiques (AhR)). Combinés, ces bioessais ont permis de déterminer des profils intégrés de la contamination inédits dans le sédiment et les eaux de surface, mettant en lumière la nécessité de considérer d’autres cibles biologiques que ER et AhR et de s’intéresser à l’ensemble des compartiments du milieu aquatique pour une meilleure évaluation de la contamination. En particulier, l’utilisation combinée de ces nouveaux outils à des capteurs passifs de type POCIS (polar organic compound integrative sampler) s’est révélée pertinente pour évaluer la contamination de la colonne d’eau par des composés hydrosolubles. Enfin, une démarche EDA, intégrant ces bioessais et des méthodes physico-chimiques d’extraction et de fractionnement adaptées, a été validée pour l’identification des composés détectés. Son application sur deux sites soumis à des contaminations chimiques différentes (mixte urbaine/agricole et pharmaceutique) a permis d’évaluer la contribution des polluants cibles, dont les prioritaires, dans les réponses des bioessais et d’identifier de nouveaux PE. / The aim of this thesis was to develop and to evaluate an effect directed analysis (EDA) approach, combining in vitro bioassays and chemical analysis for the characterization of aquatic systems contamination by endocrine disrupting chemicals (EDCs) and their identification. For integrative contamination assessment, new in vitro tools have been developed and evaluated for the detection of emerging pollutants, and then integrated in a multi-bioassays approach. In particular, the human pregnane X receptor (PXR) based bioassay provided further information on bioactive contaminants and thereby enhanced the environmental diagnostic as regard to classical biological target (e.g. estrogen (ER), androgen (AR) or aryl hydrocarbon receptors (AhR)). Such multi-receptors approach allowed determining novel integrative toxicity profiles in sediment and surface water. Overall, our results demonstrated the need to integrate other biological target than ER and AhR, and to assess contamination partitioning for a better hazard/risk assessment. For such purpose, combined use of polar organic compound integrative sampler and in vitro bioassays provided suitable tools to assess active hydrosoluble chemicals in surface water. Finally, in order to identify the compounds responsible for the detected activities, the multi-receptors approach has been integrated in EDA strategy applied to two river sites under different chemical pressures (urban/agricultural and pharmaceutical). To tackle this challenge, extraction and fractionation methods were developed and evaluated in order to encompass a diversity of active chemicals that are detected by in vitro bioassays. The EDA approach allowed determining partial contribution of priority pollutants in biological responses as well as the identification of new EDCs.