Analysis, occurence, release and degradation of phthalate esters (PAEs) in Mediterranean coastal sea

Phthalic Acid Esters (PAEs) are a group of emerging organic contaminants that have become a serious issue because of their ubiquitous presence on the marine environment worldwide and for the endocrine disrupting effects in animals and humans. However, little is known about their distribution in the Ocean, mainly because of analytical difficulties and the high possibility of ambient sample contamination. Plastic debris in marine environment includes resin pellets, macro- and microplastic fragments, and contains additives such as PAEs that might be released in the aquatic environment in unknown proportion. In our work, we improved an analytical method for the determination of 8 PAEs, at trace levels in marine and fresh waters. In the first part of the thesis, the method was validated for different seawater salinities and wastewater treatment plant outlet. By passing 1 L of sample through glass cartridges packed with 200 mg of Oasis HLB and eluted with 6 mL of ethyl acetate, the recoveries fordimethyl phthalate (DMP), diethyl phthalate (DEP), dipropylphthalate (DPP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BzBP), diethylhexyl phthalate (DEHP) and d-n-octyl-phthalate (DnOP), were 101, 98, 115, 110, 99, 98, 103 and 95 %, respectively, with acceptable blank values (below 0.4-4.0 % of the masses measured in different seawater samples). In a second part, PAE distribution in the Marseille Bay has been evaluated though a one-year monitoring from December 2013 to November 2014. The results showed the occurrence of six PAEs, DMP, DEP, DiBP, DnBP, BzBP and DEHP, with total concentrations ranging from 130 to 1330 ng L-1 (av. 522 ng L-1). DEHP was the most abundant PAE in all of the surface samples and the summer bottom samples, followed by DiBP and DnBP. High concentrations were detected in the bottom water, suggesting that resuspension of PAE-rich sediment, in relation with the accumulation of plastic debris above the seabed plays a significant role in the PAE dynamics in coastal
water. In the last part of this thesis, two common plastic samples as trash plastic bags and insulation layer of electric cables were incubated in natural seawater in laboratory conditions and studied for the release of PAE. Release ws observed for the different PAEs with kinetics varying according to the plastic type. DMP and DEP were preferentially released from the insulation layer of electric cables reaching level of release of 9.5 ± 1.4 and 68.9 ± 10.3 ng g-1, respectively, whereas DiBP and DnBP were released from plastic bags, reaching the highest rate after only one week, at values of 333.4 ± 50.3 and 480.5 ± 72.1 ng g-1, respectively.

Andrea PALUSELLI, Université d’Aix-Marseille, École doctorale Science de l‟environnement, 15-02-2018.

The thesis

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Pollutions du milieu littoral par les microplastiques : Méthodes d’évaluation

Résumé : Les plastiques sont des matériaux techniques nécessaires au fonctionnement des sociétés industrialisées. Cependant, au début des années 2000, des particules de plastique de l’ordre de la dizaine de microns sont observées dans des échantillons d’eau de mer. Ce sont des « microplastiques ». Leur présence dans la plupart des milieux a progressivement été mise en lumière au point d’en faire un marqueur de l’anthropocène. Par ailleurs, ces particules interagissent avec leur environnement et peuvent être vectrices d’additifs toxiques ou de micropolluants. Face aux risques que représentent ces particules, il est important de pouvoir évaluer leur dangerosité pour l’homme et les écosystèmes. Dans ce contexte, les objectifs de ce travail de thèse sont (1) de déterminer les conditions d’extraction des microplastiques présents dans le sable les plus efficaces et les moins coûteuses et (2) de traduire en terme de toxicité les interactions entre micropolluants et plastiques vieillis dans le milieu marin. Pour cela, un prototype de système d’élutriation a été construit et un protocole adapté a été mis en place pour permettre d’extraire les microplastiques du sable. Afin de faciliter la détermination des vitesses de flux optimales pour permettre une élutriation efficace, un modèle numérique simple reposant sur des équations d’hydrodynamique a été développé. La confrontation des résultats théoriques et expérimentaux a ensuite permis de le valider. Ces résultats ont également permis de mettre en évidence que des ajustements du dimensionnement du système d’élutriation étaient nécessaires. En se basant sur différentes contraintes, par exemple sur le temps nécessaire pour réaliser l’élutriation ou encore sur la taille de la colonne, de nouvelles données de dimensionnement ont été acquises. Le vieillissement de 3 types de plastique (PVC, PET et PBAT) dans le port de Kernevel (Larmor- Plage) a été étudié en suivant l’évolution de l’état de surface et la toxicité de ces matériaux durant 502 jours d’immersion. Cette étude a montré des comportements très différents de ces trois plastiques au cours du temps. Ainsi, le PBAT vieillit plus vite que le PVC alors que le PET évolue peu. Le vieillissement du PVC s’accompagne d’une perte de ses composés à activité œstrogénique et d’une adsorption de métaux lourds. En milieu marin, en se dégradant la surface du PBAT forme des cavités dans lesquelles se piègent des argiles ; de plus en vieillissant ce matériau peut présenter une forte activité œstrogénique ponctuelle.

Mikaël Kedzierski, Génie des procédés. Université de Bretagne Sud, 2017. Français. Thèse soutenue le 17 octobre 2017.

Textile microplastics: causes and cures – improving our understanding of the drivers of fibre loss during washing (PhD Project)

Distribution of microplastics in the Scottish marine environment (PhD Project)

This PhD will investigate the prevalence and distribution of microplastics by examining water, sediments and biological samples from a suite of pre-determined locations along the Scottish coastline. Comparisons will be made between rural areas (low population density/small-scale industries) and heavily commercialised regions to elucidate differences between regions, with the expectation that commercial regions have higher levels of microplastics. The potential interaction and impact of microplastics with the bivalve aquaculture sector shall also be investigated. As this is a relatively new area of research, methods for the collection and separation of microplastics from water, sediment and biota samples will need to be developed and validated. Particle-based transport models will be developed, using existing hydrodynamic models and a range of particle behaviours, to predict microplastic distributions and hotspots. Initially, this modelling will be carried out at a national scale using Scottish Shelf Model climatology and hypothetical source regions. Smaller scale models, where available, will be used to investigate local distributions.  (…)

The student will be supervised by Dr Bhavani Narayanaswamy (SAMS – UHI), Dr Neil James (ERI-UHI) and Dr Andrew Dale (SAMS – UHI), in collaboration with Dr Brian Quinn University of the West of Scotland.Deadline 8/05/2017

Presentation

Altération de la physiologie des poissons exposés à des hydrocarbures aromatiques polycycliques (HAP) : comportement et reproduction

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants organiques persistants qui sont présents en mélange complexe dans l’environnement et notamment dans les milieux aquatiques. Ils s’adsorbent sur les particules en suspension, s’accumulent dans les sédiments et dans les premiers maillons de la chaîne trophique. L’objectif de cette étude était de mesurer les effets à long terme d’une contamination par des HAP chez un modèle de vertébrés : le poisson zèbre. Dans un premier temps, des embryons ont été exposés pendant les 4 premiers jours de leur développement sur du sédiment naturel enrobé de 3 HAP individuel (phénanthrène, pyrène et benzo[a]pyrène) puis transférés et élevés en eau propre. Dans un deuxième temps, des poissons ont été exposés par voie alimentaire tout au long du cycle de vie et dès le premier repas à 3 fractions de HAP à doses environnementales enrobées sur les aliments : une fraction pyrolytique (PY) extraite d’un sédiment échantillonné dans la Seine et deux fractions pétrogéniques (un fuel lourd (HO) provenant de l’Erika et un pétrole brut type Arabian light (LO)). Les effets à long terme sur la croissance, la survie, la reproduction et le comportement ont été évalués à différents âges. (…)

Thèse de doctorat en Physiologie, Biologie des organismes, Populations, Interactions, Caroline Vignet, soutenue le 11-02-2014 à La Rochelle, sous la direction de Xavier Cousin.

Long term physiological disruptions in fish after exposure to polycyclic aromatic hydrocarbons (PAHs) : behavior and reproduction

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants (POPs) which are found in complex mixtures in the environment including aquatic ecosystems. They adsorb on particles, accumulate in sediment and in the first link of the food web. The aim of this study was to measure long term effects of PAHs contamination on a vertebrate model : the zebrafish. In a first study, embryos were exposed on natural sediment spiked with 3 individual PAH (phenanthrene, pyrene and benzo[a]pyrene) during the first four days of their development. In a second study, to evaluate the consequences of long-term chronic exposure to PAHs, zebrafish were exposed, from their first meal (5 days post fertilisation) until they became reproducing adults, to diets spiked with three PAHs fractions at environmentally relevant concentrations (0.3X, 1X and 3X; with the 1X concentration being in the range of 4.6-6.7 μg.g-1 for total quantified PAHs). The fractions used were representative of PAHs of pyrolytic (PY) origin or of two different oils of differing compositions (a heavy fuel (HO) and a light crude oil (LO)). Long term effects on growth, survival, reproduction and behavior were evaluated at different ages. (…)

Evaluating the potential of microplastics ingestion to harm the sea cucumber Holothuria sanctori : Results and implications of a feeding experiment conducted on Madeira Island

The omnipresence of microplastic particles (< 5 mm) in the marine environment has raised concerns about their potential to harm organisms both physically and chemically, for example via the transfer of pollutants adsorbed from seawater. While many species are able to ingest microplastics, little is known about the consequences. Moreover, previous studies have mostly applied exaggerated scenarios of microplastics concentrations or associated pollution levels. The present study investigated the potential effects of microplastics ingestion under more realistic conditions. We exposed the sea cucumber Holothuria sanctori – a prevalent deposit feeder of the rocky shores around Madeira Island – to an environmentally relevant concentration of microplastic particles in the feeding sediment for 2 months. The polystyrene beads used as model microplastics were previously exposed in situ to seawater with different levels of pollution (low and high). (…)

Jenni Lisa Grossmann, Master thesis, Institute for Hydrobiology and Fisheries Science, University of Hamburg, 2014

The thesis

Microplastic pollution in the Clyde sea area: a study using the indicator species Nephrops norvegicus

Microplastic pollution has been identified as an ever increasing proportion of marine litter. Despite an increase in microplastic awareness over the last decade, it represents an as yet unquantified threat to the marine environment. The relatively few studies that monitor its distribution and impact have illustrated a range of worrying effects on marine habitats and communities. The Clyde Sea Area (CSA) is subject to many sources of terrestrial and maritime plastic input. The use of plastics in recreational and commercial vessels throughout the CSA is believed to result in large levels of microplastic fibres, which have previously been seen to be ingested by a range of marine organisms. In a study of the breakdown of commonly used polymers in benthic environments, it was found that ropes of 10 mm diameter in sub-tidal conditions release between 0.086 and 0.422g of microfibers per meter per month in the early stages of degradation. (…)

Welden, Natalie Ann Cooper, PhD thesis, University of Glasgow, October 2014

The thesis