Pesticide runoff from agricultural applications poses a potential threat to water quality in the world heritage listed Great Barrier Reef (GBR) and sensitive monitoring tools are needed to facilitate effective monitoring of these pollutants. This thesis has worked to advance passive sampling tools for monitoring trace organic pollutants and their potential impacts on the GBR. The suitability of several available passive sampling tools for detecting trace concentrations of target pesticide analytes was investigated in a laboratory calibration chamber before experiments were conducted to further understanding of the response of Chemcatcher passive samplers in environmental conditions likely to be experienced in the GBR. Passive samplers were deployed in a survey of pesticides in the GBR environment and extracts were applied in bioassays to investigate their application for predicting mixture toxicity to GBR biota. When employed and interpreted appropriately, passive sampling tools have been shown to provide for sensitive and reproducible detection of organic pollutants in relatively pristine environments. While considerable research has been conducted into the performance and theory of analyte uptake by a range of passive sampling devices, several key knowledge gaps existed and were addressed in this study. The applicability of the performance reference compound (PRC) concept as an in situ calibration method for passive samplers using Empore Disk sampling phases (Chemcatchers) to monitor polar compounds was investigated. This experiment showed that while uptake of pesticides was linear and reproducible, PRC loss was not linear, meaning that the dissipation rates of these PRCs cannot be used to estimate the effect of field exposure conditions on uptake rates. An alternative in situ calibration technique using PRC loaded polydimethylsiloxane (PDMS) disks deployed alongside the Chemcatchers as a surrogate calibration phase has been tested and shows promise for future applications. Pesticide concentrations in waters flowing to the GBR have been shown to undergo dramatic fluctuations over short time periods and the potential for these conditions to limit the integrative period of sampling was investigated by simulating a changing concentration event in a calibration chamber. The ability for samplers to predict average concentrations was dependant on the deployment configuration (with or without membrane) used and the period of deployment relative to the changing concentration event. Passive samplers were employed in a survey of pesticides in GBR waters during a wet and dry season at river mouths, two nearshore regions and an offshore region. The nearshore marine environment was shown to be contaminated with pesticides in both the dry and wet seasons (average water concentrations of 1.3-3.8 ng L-1 and 2.2-6.4 ng L-1, respectively), while no pesticides were detected further offshore. Continuous monitoring of two rivers over 13 months showed waters flowing to the GBR were contaminated with herbicides (diuron, atrazine, hexazinone) year round, with highest average concentrations present during summer months (350 ng L-1). The use of passive samplers has enabled identification of insecticides in GBR waters which have not been reported in the literature previously. Extracts from passive samplers deployed at three sites in the GBR were applied to bioassays targeting integral life stages or functions of coral reef biota: scleractinian coral larvae, sea urchin larvae, a marine diatom and marine bacteria. The results demonstrate the utility of pairing passive sampling with bioassays and reveal that mixtures of organic pollutants in the GBR have the potential to cause detrimental effects to coral reef biota. This research outlines an approach that reduces one of the levels of simplification of risk assessment of pollutants to ecosystems by incorporating mixtures of chemicals present in the environment. The use of passive sampler extracts in toxicity testing allows pollutant mixtures to be assessed at a range of enrichment factors and, with the inclusion of biota from the ecosystem of concern, improves the relevance of results for predicting real world effects. The findings of this thesis are intended to be used to improve the application of passive sampling tools for routine monitoring to provide managers with understanding of the pesticides present, the potential effects of those pollutant mixtures and feedback on the efficacy of implemented land management practices in halting and reversing the impacts of pesticides on the GBR.

Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-03-27T15:24:14Z No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-15T14:01:43Z (GMT) No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) / Made available in DSpace on 2013-04-15T14:01:43Z (GMT). No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) Previous issue date: 2012 / CAPES / Neste trabalho foram usados amostradores passivos POCIS e Chemcatcher com a técnica de Extração em Fase Sólida SPE e a Cromatografia Gasosa acoplada à Espectrometria de Massas, GC/MS. O objetivo geral do trabalho foi desenvolver uma metodologia para os amostradores passivos POCIS e Chemcatcher para a análise de agrotóxicos em água superficial e os objetivos específicos: estudar o desempenho dos amostradores passivos através de desenvolvimento de metodologia SPE e GC/MS, calibrar em laboratório, determinando as taxas de amostragem e implantar os amostradores na região do Vale do São Francisco, em Petrolina, Pernambuco. O sorvente usado na SPE foi à base de sílica modificada (C18) e os solventes foram metanol e diclorometano. A validação do método foi feita para disco e cartucho, onde, o LD para disco variou de 0,0080 a 0,096 μg L-1 e para cartucho 0,0070 a 0,43 μg L-1, o LQ de 0,026 a 0,32 μg L-1 e 0,024 a 1,4 μg L-1, respectivamente. Os percentuais de recuperação para o disco variaram de 70,0 a 119,9 para disco e 70,2 a 119,7 para cartucho. Os desvios-padrões para o disco variaram de 2,86 a 19,9 e para cartucho 1,89 a 19,8. A repetitividade com 95% de confiança para disco variou de 0,0070 a 0,089 e 0,0070 a 0,41 para cartucho. As taxas de amostragem para os dispositivos POCIS e Chemcatcher variaram, respectivamente: para 1 dia: sem membrana, 0,105 a 0,693 L dia-1 e 0,100 a 0,757 L dia-1; com membrana PES < 0,0080 a 0,069 L dia-1 e <0,0080 a 0,050 L dia-1; com malha de nylon 0,103 a 0,333 L dia-1 e 0,093 a 0,33 L dia-1. Para 3 dias com renovação de água: com membrana PES < 0,011 a 0,083 L dia-1 e < 0,011 a 0,042 Ldia-1; com malha de nylon 0,077 a 0,80 L dia-1 e 0,074 a 0,95 L dia-1. Durante três dias sem renovação de água: com malha de nylon 0,067 a 0,28 L dia-1 e 0,064 a 0,31 L dia-1. Taxas de amostragem teóricas foram calculadas em função dos coeficientes de difusão dos pesticidas em água e do desenho e configuração dos dois modelos de amostradores passivos. As taxas de amostragem para o POCIS e Chemcatcher variaram respectivamente de 0,11 a 0,23 L dia-1 e 0,077 a 0,16 L dia-1. Considerando-se um ambiente aquático com baixa contaminação (ao nível do LQ do método) o tempo de exposição dos amostradores para captar os pesticidas pode variar, a depender do composto, de 3 a 9 dias para o POCIS e de 4 a 10 dias para o Chemcatcher. O desempenho dos dois modelos pode ser considerado semelhante e seu uso com a técnica SPE e GC/MS é uma alternativa para a metodologia de determinação de pesticidas em água, uma vez que o procedimento é simples, rápido e econômico. / Salvador

Le POCIS (Polar Organic Chemical Integrative Sampler) est un outil d'échantillonnage intégratif alternatif aux techniques d'échantillonnages classiques (ponctuelle ou automatisée) dédié à la mesure de micropolluants organiques relativement hydrophiles dans les eaux. Cet outil permet d'intégrer les concentrations dans le temps (CTWA, Time-Weighted Average Concentration) et, dans certains cas, d'abaisser les limites de quantification. Une revue bibliographique détaillée a montré la forte variabilité des données de performances du POCIS mesurées en laboratoire (notamment les taux d'échantillonnage ou Rs). Cette variabilité résulte en majeure partie de systèmes expérimentaux d'étalonnage différents selon les études et pas toujours renseignés. Dans la littérature, les CTWA obtenues in situ sont comparées aux concentrations obtenues après échantillonnage classique, tel que mis en œuvre actuellement dans les programmes de surveillance européens ; ces concentrations sont dans la plupart des cas du même ordre de grandeur, même si elles ne représentent pas tout à fait la même information. Avec comme objectif d'obtenir des CTWA les plus justes et robustes possibles, nous avons étudié le comportement du POCIS « pharmaceutique » en laboratoire vis-à-vis de 56 micropolluants (hormones, pharmaceutiques, alkylphénols, pesticides, filtre UV), dans un système expérimental d'étalonnage conçu spécifiquement pour contrôler l'ensemble des conditions expérimentales ayant une influence sur les Rs. Nous avons ainsi déterminé 43 Rs robustes et démontré que le POCIS est bien adapté à l'échantillonnage de la plupart des molécules étudiées. De plus, l'allure des cinétiques d'accumulation est expliquée à l'aide des propriétés physico-chimiques des molécules (log D , surface polaire). Cinq homologues deutérés ont été identifiés en tant que PRC (Performance Reference Compounds), c'est-à-dire qu'ils peuvent être utilisés pour corriger les différences de conditions entre le laboratoire et le terrain. Nous avons également comparé le POCIS au Chemcatcher « polaire » en laboratoire et montré qu'en terme de domaine d'application et de performances, le POCIS est mieux adapté pour les micropolluants étudiés. Enfin, nous avons testé la justesse et la robustesse du POCIS lors de deux essais inter-laboratoires (EIL). Le premier EIL, portant sur l'étalonnage de l'outil en laboratoire, a démontré la robustesse de ses performances pour 3 pesticides. Le deuxième EIL in situ a démontré la pertinence du POCIS pour échantillonner des hormones, des pharmaceutiques et des pesticides dans un effluent de station d'épuration. Cette thèse permet d'avancer dans le domaine des connaissances sur l'outil POCIS et de favoriser son application dans le cadre de la directive sur l'eau / The POCIS (Polar Organic Chemical Integrative Sampler) is an alternative integrative sampling tool to conventional sampling methods (grab or automated) for measuring hydrophilic organic micropollutants in water. This tool permits to supply time-weighted average concentrations (TWAC) and, sometimes, to decrease limits of quantification. A detailed bibliographic review showed the important variability of POCIS performance data measured in laboratory (notably the sampling rates or Rs). This variability is in majority due to different experimental calibration systems, not always well detailed, among studies. In the literature, in situ TWAC are compared to concentrations from conventional sampling, actually used in European monitoring programs ; these concentrations are generally of the same order of magnitude, even if they do not represent the same information. In order to obtain accurate and robust TWAC, we studied in laboratory the “pharmaceutical” POCIS behavior for 56 micropollutants (hormones, pharmaceuticals, alkylphenols, pesticides, UV filter), in a calibration system specifically made for controlling the whole experimental conditions having an influence on Rs. We determined 43 robust RS and demonstrated that POCIS is well adapted for sampling most of studied molecules. Moreover, the pattern of kinetic accumulations is explained using molecule physical-chemical properties (log D, polar surface). Five deuterated homologues were identified as PRCs, meaning that they can be used for correcting differences in conditions between the laboratory and the field. We also compared the POCIS with the “polar” Chemcatcher and we showed that in term of application field and performances, the POCIS is better adapted for studied micropollutants. At last, we tested the accuracy and the robustness of the POCIS during two inter-laboratory studies (ILSs). The first ILS, dealing with the laboratory calibration of the tool, demonstrated performance robustness for 3 pesticides. The second in situ ILS demonstrated the relevance of the POCIS for sampling hormones, pharmaceuticals and pesticides from a waste water treatment plant effluent. This thesis permits to improve knowledge on the POCIS and to promote its application for the water framework directive