Microplastic particles (MPs) are widely distributed in aquatic environments and present a potential risk to marine life. This thesis considers several issues relating to methodologies for sampling and analyzing MPs and the sources and fate of these particles in the marine environment, wild and farmed shellfish, and food webs of southern coastal British Columbia, Canada. Chapter 1 introduces MPs as a contaminant, methodologies for studying them, and reviews what is known about their source, fates, and ecotoxicology in marine environments. Chapter 1 also outlines the goals of this thesis. Chapter 2 compares the potential MP concentration estimates provided by two different seawater sampling methods. Jar samples filtered to 8-µm yielded MP concentrations averaging approximately 8.5 times higher than bucket samples filtered to 63 µm, per L of water (at the site level), driven largely by differences in the number of microfibres. An analysis of MP concentrations and mesh sizes reported in the literature suggests that using a 300–350-µm mesh may underestimate total MP concentrations by one to four orders of magnitude compared with samples filtered through much smaller mesh sizes (e.g., less than 100 µm), and despite the effect of sample volume. Particles less than 300 µm in diameter make up a large component of MPs commonly found in fish and invertebrates. As such, common sampling practices fail to adequately measure a biologically relevant class of MPs, thereby undermining the ability to quantify ecological risk. Chapter 3 determines the influence of shellfish aquaculture activity, and its use of plastic equipment, on MPs in bivalves and their environment by comparing MP concentrations in Manila clams (Venerupis philippinarum) and Pacific oysters (Crassostrea gigas) grown on commercial shellfish beaches with those grown on non-aquaculture beaches from six areas. MP concentrations in water and sediment were also determined in four of the areas. MP concentrations did not differ between shellfish aquaculture and non-aquaculture sites for either bivalve species or for sediment and water samples. Beach sediment type had a minor effect, with more gravelly or sandier beaches associated with higher MP concentrations in oysters or clams, respectively. Oysters on sites using many synthetic anti-predator nets had more MPs than those on sites without any plastic, but analysis of particles using Fourier-transform infrared spectroscopy suggested a predominance of textile fibres including nylon and polyester, which are not typically used in shellfish aquaculture. Chapter 4 uses stable isotope food web analysis and hierarchical Bayesian generalized linear mixed models to explore whether bioaccumulation and biomagnification are occurring in coastal marine food webs at three locations. Bioaccumulation was higher for smaller-bodied suspension feeding animals such as bivalves. However, biomagnification was not occurring in animal digestive tracts, and trophic dilution was demonstrated in fish livers. Trophic transfer was shown to occur between prey and predator for rockfish, but higher concentrations in full stomachs compared with empty ones suggested rapid excretion of ingested MPs. Chapter 5 supplies some general conclusions on the status of MPs in the British Columbian environment, as well as risks to seafood consumers. It also explores future work that will be needed to understand the complex ecotoxicology of MPs. / Graduate / 2022-04-12

This thesis presents: 1) the first statistically rigorous support for the longstanding hypothesis that state of satiation modifies diel vertical migration patterns of deep-sea micronektonic crustaceans and fishes; and, 2) the first assessment of microplastic ingestion by deep-pelagic micronekton in the Gulf of Mexico and Straits of Florida. Deep-sea pelagic crustaceans and fishes significantly contribute to abundance and biomass of pelagic ecosystems, are frequently consumed by commercially valuable fishery species, and serve to transport both nutrients and pollutants between shallow and deep waters. The results presented herein will be valuable for assessing risk associated with potential biomagnification of plastic through consumption or indirect consumption of deep-sea biota. Moreover, these data demonstrate that the extent of feeding at depth by non-migratory taxa as well as non-migrating individuals of migratory taxa is substantial. Feeding at depth is usually excluded from biogeochemical models, and these data demonstrate that this is an important factor that must be included to obtain more precise estimates of active nutrient flux by micronekton.

No description available.

På senare tid har mikroplaster i hav och sjöar uppmärksammats som ett potentiellt stortmiljöproblem. Idag finns mikroplaster spridda över hela världens vatten från polerna till ekvatorn.År 2016 uppmärksammades konstgräsplaner som den nästa största källan till spridning avmikroplaster till sjöar och vattendrag i Sverige [1]. Fotboll är Sveriges nationalsport och är densporten som står för flest aktivitetstimmar i Sverige. Konstgräs har gjort det möjligt för fler barnoch ungdomar att få fler speltimmar och idag spelar 90 % av alla fotbollsspelare på konstgräs [2].De olika spridningsvägarna för mikroplaster från konstgräsplaner undersöktes med fokus påspridningsvägen via dagvatten. Det finns fler olika reningsmetoder för dagvatten innehållandemikroplaster, en av dessa är granulatfällan, en filterpåse som placeras i en dagvattenbrunn för attfånga upp granulat och konstgräsfibrer som sprids från konstgräsplanen till dagvattenbrunnen.Syftet med denna studie var att optimera reningsmetoden granulatfälla utifrån möjligavattenflöden och dess effektivitet i att fånga upp mikroplaster. Detta undersöktes genomframtagandet av en vattenflödesmodell vid konstgräsplaner med variationer i konstruktion ochgenom fältstudier av granulatfällans effektivitet vid två konstgräsplaner i Storstockholm.Det regn som undersöktes i vattenflödesmodellen var extremregn för ett 10 års regn under 10minuter. Detta för att hitta det maximala flöde granulatfällorna kommer behöva klara av. Vilkavattenflöden som nådde dagvattenbrunnarna var beroende på antalet dagvattenbrunnarplacerade runt konstgräsplanen, i vilket område i Sverige som konstgräsplanen var placerad, detvill säga hur mycket regn som kom, och konstgräsplanens infiltrationsförmåga.Vattenflödesmodellen fungerar som en mall för möjliga vattenflöden vid en specifik plats i Sverigeoch en viss konstruktion av konstgräsplan.De konstgräsplaner som var med i fältstudierna var Skytteholms IP i Solna och Spånga IP iStockholm. Vid varje konstgräsplan placerades 6 granulatfällor med två filterpåsar på varje fälla,den inre med större maskor och den yttre med mindre maskor. Kombinationerna var 200 μm med100 μm, 200 μm med 50 μm och 100 μm med 50 μm. Totalt fångades 10,3 kg mikroplast vidSkytteholms IP och 1,5 kg vid Spånga IP under de 49 dygn granulatfällorna var utplacerade. Avden totala mängden mikroplast viktmässigt i varje granulatfälla fanns minst 99 % i den inrefilterpåsen och maximalt 1 % i den yttre filterpåsen, det vill säga i storleksfraktionen mellan denyttre och den inre filterpåsen.Slutsatserna från denna studie är att vattenflödet till dagvattenbrunnarna placerade runtkonstgräsplaner kan variera mycket på grund av hur konstgräsplanen är konstruerad. Det berorframförallt på konstgräsplanens infiltrationsförmåga och antal dagvattenbrunnar runtkonstgräsplanen. Utifrån de teoretiska vattenflödena och fältstudierna rekommenderas att enfilterpåse med maskstorlek 200 μm används i granulatfällan. Detta utifrån att den inre filterpåsenfångade minst 99 % av de mikroplaster som nådde granulatfällorna, som var större än 50 μm, ochökad risk för igensättning och tillväxt av biofilm på filterpåsarna med mindre maskor. Vidarestudier bör genomföras på granulatfällans vattenflöde över tid, mikroplaster mindre än 50 μm,IIandra spridningsvägar för mikroplaster från konstgräsplaner, förbättrade konstruktioner avkonstgräsplaner och förbättrat underhållningsarbete för att minska spridningen av mikroplasterfrån konstgräsplaner. / In the recent years microplastics in the marine environment has been recognized as a potentiallyimportant environmental issue. Today there are microplastics spread in the waterbodies all overthe world, from the equator to the poles in south and north. In 2016 artificial turf was labeled thesecond largest source of microplastics to the marine environment in Sweden [1]. Football is thenational sport of Sweden and accounts for the majority of the activity hours among the youth inSweden. The artificial turf has made it possible for more children to play football and for them toget more hours on the field. Today about 90 % of the football players play on artificial turf [2].The microplastics pathways to the nature and the marine environment were studied andtreatment methods were developed. One of these methods is the so called granule trap, a filterbag which is placed in a stormwater drainage well to catch the rubber granulates and the artificialturf fibers which can be spread from the artificial field to the drainage system. The aim of thisstudy was to optimize the granule trap for possible waterflows to the stormwater drainage welland its efficiency to catch microplastics. This was researched through field studies of the efficiencyof the granule trap at two artificial turfs in Stockholm and the development of a waterflow modelof an artificial turf with varying construction.The rainfall which was used in the waterflow model was the 10-year storm with a duration of 10minutes. This to find the maximum waterflow the granuletraps must manage. The waterflows tothe stormwater drainage well were dependent on the number of wells placed around the artificialturf, in which area of Sweden the football field was placed, in other words the amount of rain thatfell, and the infiltration capacity of the artificial turf. The waterflow model works as a templatefor possible waterflows at an artificial turf with a certain construction and at a certain location inSweden.The artificial turfs which were examined in the field studies were Skytteholms IP in Solna andSpånga IP in Stockholm. At each football field 6 granuletraps were placed, each loaded with twofilter bags, the inner with larger sized mesh and the outer with smaller sized mesh. The mesh sizecombinations were 200 μm with 100 μm, 200 μm with 50 μm and 100 μm with 50 μm. atSkytteholms IP a total amount of 10.3 kg microplastics were caught and at Spånga IP a total of 1.5kg microplastics were caught during the 49 days the granuletraps were placed at the footballfields. Out of the total amount of microplastics in each granuletrap at least 99 % by mass was inthe inner filter bag and maximum 1 % by mass was in the outer filter bag, in the size fractionbetween the outer and the inner filter bag..In conclusion this study shows that the waterflow to the stormwater drainage wells placed aroundthe artificial turfs vary a lot depending on the construction of the artificial turf. Foremost itdepends on the infiltration capacity of the artificial turf and the number of stormwater drainagewells around the field. With regards to the waterflows from the waterflow model and the resultsfrom the field studies the recommended mesh size for the filter bags is 200 μm. This since at least99 % by mass of the microplastics, which were larger than 50 μm, that reached the granule trapsIVwere trapped in the inner filter bag and the elevated risk of clogging and biofilm growth on thefilter bags with smaller mesh size. Further studies should be conducted on the waterflow throughthe granuletraps over time, microplastics smaller than 50 μm, other pathways for themicroplastics away from the artificial turf, improved constructions of artificial turfs and improvedmaintenance on the artificial turfs to reduce the risk of spreading of microplastics from artificialturfs.

Microplastics are present in municipal wastewater treatment plant (WWTP) effluents; however, it is unclear whether these contaminants are ingested by biota living downstream of these outfalls. This study examined whether microplastic levels in caged biota, resident fish, and environmental samples were elevated near the Waterloo and Kitchener WWTP outfalls along the Grand River in the fall of 2019. Amphipods (Hyalella azteca), fluted-shell mussels (Lasmigona costata), and rainbow trout (Oncorhynchus mykiss) were caged at one upstream reference site and two impacted sites downstream of the Kitchener WWTP for 14 (amphipods and trout) or 28 (mussels) days. Rainbow darter (Etheostoma caeruleum) were collected using a backpack electrofisher from 10 sites up and downstream of both the Kitchener and Waterloo WWTPs, along with surface water and sediment samples. Whole body Hyalella, fish digestive tracts, and fluted-shell mussel tissues (hemolymph, digestive glands, and gills) were digested in 20% potassium hydroxide. Environmental samples were processed using filtration and density separation, then visual identification of microplastics was done. Elevated particle counts were found in rainbow trout digestive tracts at the Kitchener outfall site, compared to the upstream reference and downstream farfield sites. Additionally, particle concentrations in sediment were significantly higher at the Waterloo outfall, compared to all other sites (except for one upstream location). However, whole Hyalella, fluted-shell mussel tissues (hemolymph, digestive glands, and gills), digestive tracts of rainbow darter, and surface waters did not show elevated counts downstream of these discharges. Across all samples, fibers were the most common morphology, and blue and clear particles were prevalent in samples collected near WWTPs. Overall, these findings suggest that the Kitchener and Waterloo WWTPs could be important sources of particles to the Grand River, adding to our understanding of the fate of this contaminant in freshwater ecosystems. / Thesis / Master of Science (MSc)

Antalet bilar har ökat stadigt genom åren och i mars 2019 befann sig nästan 4,9 miljoner personbilar i aktiv användning i Sverige. Något som inte får lika mycket uppmärksamhet som koldioxidutsläpp från trafiken och slitage av vägar är slitaget av bildäck. Regeringen har därmed tillsatt ett uppdrag där mängden mikroplastutsläpp ska kvantifieras, sprida kunskap om problemet och utveckla åtgärder mot utsläppen. En av myndigheterna som fått detta uppdrag är Statens väg- och transportforskningsinstitut (VTI), med vilka detta arbete genomfördes. Arbetet går ut på att försöka kvantifiera utsläppen av mikroplastutsläpp från personbilar samt undersöka vilka typer av slitage som är vanligast förekommande. Rapporten består av två delar, en litteraturstudie som ska ge en klar bild av nuläget, typer av däck, vad mikroplaster är samt varför slitage uppstår. Under den andra delen genomfördes mätningar på kasserade däck, där mönsterdjupsprofiler, vikt, mönsterdjup, DOT märkning, modell, märke, typ av däck och dimensioner antecknades. Med hjälp av profilerna och originaldata som tillhandahölls av olika däcktillverkare kunde de vanligaste slitagen bestämmas och den bortslitna vikten och volymen kunde uppskattas. De vanligaste typerna av slitage är centrum-, jämnt- och sidoslitage, vilket beror på för högt lufttryck i däcken, samt fel hjulinställningar. Den totala årliga mängden utsläpp av mikroplaster från personbilar uppskattades ligga mellan 8 300 och 16 700 ton. / The number of cars has been on a steady increase in Sweden and in mars 2019 there were almost 4,9 million cars in active use. Nowadays most of the attention is focused on pollution through carbon dioxide and the wear of roads. However, a problem that often goes unrecognized is the tear of car tyres and the release of microplastics into the environment. In order to quantify the amount of microplastics released into the environment, the Swedish government has instructed The Swedish National Road and Transport Research Institute (VTI) to carry through with this. The aim of this report is to, with the help of VTI, try to quantify the amount of microplastics released from private car traffic and examine the main types of tyre wear. This report consists of two parts, one study of what microplastics is and how tyre wear arises. The second part consists of measuring, where used tyres have had their weight and tread measured. The profile of the tear, DOT number, production date, model, dimensions and type of tyre is additional data that was collected. Through the use of data provided by the tyre companies and the collected data, the total loss of weight and volume together with a yearly weight and volume loss could be calculated. Through analysis of the tyre profiles and their tread depths the most occurring type of wear patterns was determined, which were central, even and side wear. The estimated yearly amount of microplastics released in Sweden was between 8 300 and 16 700 tonnes.

The accumulation of microplastics (MPs) are a growing concern for the environment, the maximum contributor to the MP pollution is tyre wear particles or TWPs. TWPs can accumulate in the environment and remain there for long periods of time and hence have the ability to disrupt ecosystems. With nearly 6,000,000 tons of TWPs being emitted each year globally there is a need to study theiroccurrence and fate in terms of why and how these particles get created and where they end up in the environment. The occurrence and fate of tyre wear particles (TWPs) were investigated, and a model was created in Python to simulate the flow of TWPs in a stormwater system at a test site on Highway E18 in Sweden. In the literature review it was found that the generation of TWPs is highly dependent on annual average daily traffic and the type of the road; it is also dependent on the driving behaviour such as acceleration, making unnecessary turns and the use of studded tyres in the winter. The TWPs are generally transported via stormwater but wind also plays a crucial role in transporting TWPs which are of a smaller size than 10 µm. Although the common notion is that the TWPs get washed into rivers,the literature review also suggests that most TWPs get trapped in soil that is covered with vegetation. Three processes were simulated in the developed model, namely transport, hetero-aggregation and settling. The results clearly show that a rainfall with an intensity of 40 mm during 15 min providesminimum settling in the stormwater system, and a 10 mm rainfall with a duration of more than 30 hasmaximum settling. Hetero-aggregation and settling is directly dependent on particle size and hence larger particle sizes have a higher probability of attaching to another particle or to settle in the pipes or wells of the stormwater system. It was also observed that the flow patterns such as depth, discharge and velocity of flow largely affect the settling and hetero-aggregation in the stormwater system. Most particles remain unaffected in short duration and high intensity rainfalls; the opposite is true for the longer duration and lower intensity rainfalls. Using the model, a stormwater system can be designed to trap or to flush out TWPs from the system. Also, the concentration of TWPs in the sinks can be known using the model that is created in this study

Mikroplaster och dess miljöeffekter är ett forskningsområde under utveckling. Provtagning och analysmetoder försvåras av att mikroplaster kan komma från olika råvaror, vilket innebär att dess innehåll, partikelstorlek samt densitet kan variera. Det är däremot tydligt att mikroplaster är ett problem i marina miljöer då intag och ackumulering av mikro- och makroplaster har registrerats i ryggradslösa djur, fiskar, däggdjur och fåglar. Mikroplaster kan påverka bland annat matsmältningen och reproduktionen för vattenlevande djur. Mikroplaster har även registrerats i föda som är relevant för människor, men vilka effekter mikroplaster har på människor är ännu oklart. I en rapport från år 2017 uppskattade Svenska Miljöinstitutet (IVL) konstgräsplaner till att vara den näst största kvantifierade källan till spridning av mikroplaster till miljön med 1638 – 2456 ton per år, efter slitage från däck och vägar. Fotboll är en av Sveriges populäraste sporter och antalet konstgräsplaner i landet uppgick år 2016 till 1336 stycken. Till följd av att konstgräsplaner anses som en viktig källa till spridning av mikroplaster är det viktigt att utröna orsakerna till hur och varför mikroplaster sprids från konstgräsplaner och även vilka åtgärder som kan sättas in för att minska spridningen. Syftet med denna studie är att identifiera orsakerna till spridning av mikroplaster samt att presentera åtgärder som kan minska den totala spridningen av mikroplaster från konstgräsplaner. Metodiken utgick från tidigare studier av mikroplaster i vattenmiljö och vattenprover inhämtades från två konstgräsplaners dräneringsbrunnar och från en konstgräsplans lysimetrar, vilka har samlat upp vatten som har infiltrerat genom planen. Utöver detta har även fältstudier med observationer utförts vid två konstgräsplaner och samtal med driftsansvariga har bidragit med ytterligare relevant information om hur mikroplaster kan spridas. Resultaten visar att mikroplaster sprids från konstgräsplaner och att de identifierade orsakerna till spridningen, utan inbördes storleksordning, främst är: Aktivitet på planen Borstning av planen Snöröjning Regn (vilket innebär infiltration genom planen samt ytavrinning) Dessa orsaker, samt möjliga spridningsvägar för mikroplaster från en konstgräsplan till omgivningen, har visualiserats i en konceptuell modell, figur 11. Modellen har två systemgränser; det inre systemet utgörs av själva konstgräsplanen, medan det yttre systemet utgörs av närområdet runt omkring planen och kan likställas med idrottsanläggningen. Det är endast mikroplaster som sprids från det yttre systemet ut till omgivningen som bedöms kunna ha ekologiska konsekvenser. Okulära mikroskopstudier av vattenprover från dräneringsbrunnar visade på förekomst av mikroplaster. Kvantifiering av mängden fast material som kan nå dräneringsbrunnar, där mikroplaster utgör en okänd andel, uppgick till maximalt 340 – 370 kg per år och konstgräsplan med måtten 105m×65m. Mängden mikroplaster som maximalt kan infiltreras genom en konstgräsplan ner till dess dränering kvantifierades till 0,003 kg per år och konstgräsplan med måtten 105m×65m. Detta indikerar att det kan krävas mer öppna transportvägar, exempelvis öppna brunnar, för att mikroplaster ska kunna nå dräneringsbrunnar i en större viktmässig omfattning. Kvantifieringen av övriga orsaker till spridning av mikroplaster från konstgräsplaner till omgivningen är osäker, men försiktiga uppskattningar visar på att de är viktmässigt omfattande. För att mäta och säkerställa antalet partiklar som sprids från konstgräsplaner skulle mer omfattande provtagningar och analyser behöva genomföras. Konkreta åtgärder som kan tillämpas för att minska den totala spridningen av mikroplaster från konstgräsplaner är att borsta av kläder och skor innan planen eller anläggningen lämnas, informera personer som uppehåller sig vid planerna om problematiken, täcka för brunnar vid driftsaktiviteter, strategisk hantering av snöröjning, återföra granulat från anläggningen till själva planen, installera filter i brunnar samt att tömma brunnar på vatten och material. För att sätta problemet med mikroplaster från konstgräsplaner i sitt sammanhang så är det viktigt att förstå problemet i sin helhet. Vidare studier föreslås fokusera på att kvantifiera ovan nämnda orsaker till spridning av mikroplaster från konstgräsplaner, samt att kartlägga och kvantifiera spridningen utifrån de olika spridningsvägarna. / Microplastics and its environmental impacts is a research area under development. Sampling and analysis methods are complicated by the fact that microplastics may come from different raw materials, which means that its content, particle size and density may vary. It is clear that microplastics is a problem in marine environments as intake and accumulation of micro- and macroplastics have been recorded in invertebrates, fish, mammals and birds. The microplastics may affect, among other things, the digestion and reproduction of aquatic animals. The microplastics have also been recorded in foods that are relevant to humans, but what effects microplastics have on humans is still unclear. In a report from 2017, the Swedish Environmental Research Institute (IVL) estimated artificial turf fields to be the second largest quantified source for spreading the microplastics to the environment with 1638 - 2456 tons per year, after wear of tire and roads. Football is one of Sweden's most popular sports and the number of artificial turf fields in the country in 2016 reached 1336. Due to the fact that artificial turf fields is considered an important reason for the spreading of microplastics, it becomes important to investigate the reasons why and how microplastics are spread from artificial turf fields and also what measures can be taken to reduce the spread. The purpose of this study is to identify the reasons why microplastics are spread, as well as to present measures that can reduce the overall spread of microplastics from artificial turf fields. The methodology is based on previous studies of microplastics in aquatic environments and water samples were collected from drainage wells that belonged to two artificial turf fields and from a “water-infiltration-sampler” from a third field. In addition, field studies with observations have been carried out at two other artificial turf fields, and conversations with maintenance personal have provided additional relevant information on how microplastics can be spread. The results show that microplastics are spread from artificial turf fields and the identified reasons for this spreading, without specific order of magnitude, are mainly: Activity on the field Brushing of the fields Snow plowing of the fields Rain (which means infiltration through the field as well as surface runoff) These causes, as well as possible pathways for the spreading of microplastics from an artificial turf field to the surroundings, have been visualized in a conceptual model, Figure 11. The model has two system boundaries; the inner system consists of the field itself, while the outer system is the direct area around the field and can be equated with the sports facility. It is only microplastics that are spread from the outer system to the environment which is considered to cause ecological consequences. Ocular microscopy studies of water samples from drainage wells showed presence of microplastics. Quantification of the amount of solids that can reach the drainage wells, where microplastics constitute an unknown proportion, amounted to a maximum of 340 – 370 kg per year and artificial turf field measuring 105m×65m. The maximum amount of microplastics that can infiltrate through an artificial turf field down to its drainage system was quantified to 0,003 kg per year and artificial turf of 105m×65m. This indicates that more open transport routes, such as open wells, could be needed to allow microplastics to reach drainage wells to a greater extent. The quantification of other causes for the spreading of microplastics from artificial turf fields to the environment area is uncertain, but careful estimations show that they are weighty comprehensive. To measure and secure the number of particles that are spread from artificial turf fields, more extensive sampling and analysis would have to be carried out.

Microplastic (MP) pollution has recently been recognized as a threat to the biosphere including humans due to its widespread distribution, persistent nature and infinitesimal size. This study focused on the solid phase degradation of microplastic residues (particularly low density polyethylene, LDPE) in water through heterogeneous photocatalysis process by designed photocatalysts of zinc oxide nanorods (ZnO NRs) and platinum nanoparticles deposited on zincoxide nanorods (Pt NPs-ZnO NRs) under visible light irradiation. These photocatalysts were assessed following standard protocol (ISP 10678: 2010), and characterized using SEM, EDX andoptical spectroscopies (UV-VIS and PL). Deposition of Pt-NPs on ZnO NRs for certain minutes has been found optimum that enhanced the photodegradation process about 38% under UV irradiation and 16.5% under visible light irradiation by improving of both electrons-holes pair separation process and visible light absorption. Photocatalytic degradation of LDPE films was confirmed by FTIR spectroscopy, dynamic mechanical analyzer (DMA), optical and electron microscopes. When LDPE film irradiated in presence of Pt-ZnO, degradation was found quicker than ZnO alone of similar concentration which exhibited formation of a large number of wrinkles, cracks and cavities on the film surface. Dynamic mechanical analyzer (DMA) test indicated stiffness and embrittlement of exposed LDPE films in presence of photocatalysts. Thus, the present work provides a new insight about modified catalysts for the degradation of microplastics in water using visible light.

It is estimated that 75 million tons of plastics waste is currently in the ocean and expects to increase in line with plastic consumption. Plastic items in natural or aquatic environments are fragmented into smaller pieces called microplastics. Microplastics can enter rivers and lakes through sewage water to end up in wetlands where they sediment. Due to lack of standard monitoring tools, microplastics in a Scanian context are rather uninvestigated. The current work therefore studies microplastics’ abundance in eleven wetlands along the Sege river and Kävlinge river. The aim is with available methods and tools to examine microplastics in sediment and examine if determined microplastics concentrations can relate to urbanization in the two catchments. The study also looked into wetlands position in relation to stream order to test if microplastics concentrations increase downstream. In the study, density separation has been used to extract microplastics from soil samples and analyzed using correlation. The result showed microplastics concentrations in all sampling sites. There was weak negative or no correlation with degree of urbanization nor a relation to higher concentration further downstream along Sege river and Kävlinge river. However, the study concludes that microplastics do appear in Scanian wetlands and not necessarily in the vicinity of human activity which complies with microplastics' ability to travel long distances. / Idag finns det cirka 75 miljoner ton plastavfall i haven, som förväntas öka i samband med ökad plastkonsumtion. Plastföremål i naturliga eller akvatiska miljöer fragmenteras till mindre bitar som kallas mikroplast. Mikroplast kan transporteras till åar och sjöar genom dagvatten eller avloppsvatten, och slutligen sedimenteras i våtmarker. Inom arbete med plastföroreningar i Skåne saknas övervakning av mikroplast koncentrationen. På grund av brist på standardverktyg för övervakning är mikroplaster i Skåne förhållandevis outforskat. Denna studie tittar därmed på mikroplast förekomsten i elva våtmarker längs Sege å och Kävlingeån. Syftet är att med tillgängliga metoder och verktyg undersöka mikroplast i sediment, om koncentrationer kan relatera till tätorter i närområdet. Studien tittar också på våtmarkernas position i förhållande till stream order för att testa om mikroplast koncentrationerna ökar nedströms. I studien har flotteringsmetoden använts för att extrahera mikroplaster från jordprover och dessa analyserades med korrelation. Resultatet visade på förekomst av mikroplaster i samtliga våtmarker. Dock kunde studien inte påvisa någon relation mellan urbanisering och högre koncentration av mikroplaster och resultaten visade också en svag negativ eller ingen korrelation mellan en ökad koncentration av mikroplaster och stream order. Vad studien kan dra för slutsatsen är att mikroplaster förekommer i skånska våtmarker som inte nödvändigtvis är i närheten av mänsklig aktivitet vilket överensstämmer med mikroplasters förmåga att färdas långa sträckor.