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Microplastic in three urban estuaries, China
2015
Zhao, Shiye | Zhu, Lixin | Li, Daoji
Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions.
Show more [+] Less [-]Influence of polyethylene microplastic beads on the uptake and localization of silver in zebrafish (Danio rerio)
2015
Khan, Farhan R. | Syberg, Kristian | Shashoua, Yvonne | Bury, Nicolas R.
This study aimed to determine whether the uptake and localization of Ag in zebrafish was affected by the presence of polyethylene microplastic beads (PE MPBs). Zebrafish were exposed to 1 μg Ag L−1 (radiolabelled with 110mAg) for 4 and 24 h in the presence or absence of PE MPBs (10, 100 or 1000 MPBs mL−1), and one treatment in which MPBs (1000 MPBs mL−1) were incubated with Ag to promote adsorption. The presence of MPBs, at any of the tested doses, had no effect on the uptake or localization of Ag. However, exposure to the Ag-incubated MPBs (∽75% of the Ag bound to MPBs) significantly reduced Ag uptake at both time points and also significantly increased the proportion of intestinal Ag. This study demonstrates that microplastics can alter the bioavailability and uptake route of a metal contaminant in a model fish species.
Show more [+] Less [-]Pollutants bioavailability and toxicological risk from microplastics to marine mussels
2015
Avio, Carlo Giacomo | Gorbi, Stefania | Milan, Massimo | Benedetti, Maura | Fattorini, Daniele | D'Errico, Giuseppe | Pauletto, Marianna | Bargelloni, Luca | Regoli, Francesco
Microplastics represent a growing environmental concern for the oceans due to their potential of adsorbing chemical pollutants, thus representing a still unexplored source of exposure for aquatic organisms. In this study polyethylene (PE) and polystyrene (PS) microplastics were shown to adsorb pyrene with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated microplastics to transfer this model PAH to exposed mussels Mytilus galloprovincialis; tissue localization of microplastics occurred in haemolymph, gills and especially digestive tissues where a marked accumulation of pyrene was also observed. Cellular effects included alterations of immunological responses, lysosomal compartment, peroxisomal proliferation, antioxidant system, neurotoxic effects, onset of genotoxicity; changes in gene expression profile was also demonstrated through a new DNA microarray platform. The study provided the evidence that microplastics adsorb PAHs, emphasizing an elevated bioavailability of these chemicals after the ingestion, and the toxicological implications due to responsiveness of several molecular and cellular pathways to microplastics.
Show more [+] Less [-]Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication
2015
Dunck, Bárbara | Lima-Fernandes, Eva | Cássio, Fernanda | Cunha, Ana | Rodrigues, Liliana | Pascoal, Cláudia
We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient.
Show more [+] Less [-]Accumulation of floating microplastics behind the Three Gorges Dam
2015
Zhang, Kai | Gong, Wen | Lv, Jizhong | Xiong, Xiong | Wu, Chenxi
We investigated the occurrence and distribution of microplastics in surface water from the Three Gorges Reservoir. Nine samples were collected via trawl sampling with a 112 μmmesh net. The abundances of microplastics were from 3407.7 × 103 to 13,617.5 × 103 items per square kilometer in the main stream of the Yangtze River and from 192.5 × 103 to 11,889.7 × 103 items per square kilometer in the estuarine areas of four tributaries. The abundance of microplastics in the main stream of the Yangtze River generally increased as moving closer to the Three Gorges Dam. The microplastics are made exclusively of polyethylene (PE), polypropylene (PP), and polystyrene (PS). Together with microplastics, high abundance of coal/fly ash was also observed in the surface water samples. Comparing with previously reported data, microplastics in the TGR were approximately one to three orders of magnitudes greater, suggesting reservoirs as potential hot spot for microplastic pollution.
Show more [+] Less [-]Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): Confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions
2015
de Sá, Luís Carlos | Luís, Luís G. | Guilhermino, Lúcia
Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the prey selection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey. All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (up to 50%), while M-est fish did not, suggesting that developmental conditions may influence the prey selection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.
Show more [+] Less [-]Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics
2015
Napper, Imogen E. | Bakir, Adil | Rowland, Steven J. | Thompson, Richard C.
Cosmetic products, such as facial scrubs, have been identified as potentially important primary sources of microplastics to the marine environment. This study characterises, quantifies and then investigates the sorptive properties of plastic microbeads that are used as exfoliants in cosmetics. Polyethylene microbeads were extracted from several products, and shown to have a wide size range (mean diameters between 164 and 327μm). We estimated that between 4594 and 94,500 microbeads could be released in a single use. To examine the potential for microbeads to accumulate and transport chemicals they were exposed to a binary mixture of 3H-phenanthrene and 14C-DDT in seawater. The potential for transport of sorbed chemicals by microbeads was broadly similar to that of polythene (PE) particles used in previous sorption studies. In conclusion, cosmetic exfoliants are a potentially important, yet preventable source of microplastic contamination in the marine environment.
Show more [+] Less [-]Abundance, size and polymer composition of marine microplastics ≥10μm in the Atlantic Ocean and their modelled vertical distribution
2015
Enders, Kristina | Lenz, Robin | Stedmon, Colin A. | Nielsen, Torkel G.
We studied abundance, size and polymer type of microplastic down to 10μm along a transect from the European Coast to the North Atlantic Subtropical Gyre (NASG) using an underway intake filtration technique and Raman micro-spectrometry. Concentrations ranged from 13 to 501itemsm−3. Highest concentrations were observed at the European coast, decreasing towards mid-Atlantic waters but elevated in the western NASG. We observed highest numbers among particles in the 10–20μm size fraction, whereas the total volume was highest in the 50–80μm range. Based on a numerical model size-dependent depth profiles of polyethylene microspheres in a range from 10–1000μm were calculated and show a strong dispersal throughout the surface mixed layer for sizes smaller than 200μm. From model and field study results we conclude that small microplastic is ubiquitously distributed over the ocean surface layer and has a lower residence time than larger plastic debris in this compartment.
Show more [+] Less [-]Occurrence of microplastics in the coastal marine environment: First observation on sediment of China
2015
Qiu, Qiongxuan | Peng, Jinping | Yu, Xubiao | Chen, Fangchaizi | Wang, Jundong | Dong, Fenqiang
Microplastics in sediments from the Beibu Gulf and the coastline of China Sea were investigated to evaluate the occurrence and abundance of microplastics in China for the first time. Microplastics (<5mm) were taken from sediments by a flotation method. The number of microplastics was counted by a fluorescence microscope, an instrument that is rarely used in the detection of microplastics in sediments. This instrument led to results that were satisfactory. Compared with other sampled areas, microplastics were found in massive concentrations in China. Four types of microplastics, HDPE, PET, PE and PS, were identified. The results will provide useful background information for further investigations.
Show more [+] Less [-]Reducing microplastics from facial exfoliating cleansers in wastewater through treatment versus consumer product decisions
2015
Chang, Michelle
Microplastics (<5mm) have been discovered in fresh and saltwater ecosystems, sediments, and wastewater effluent around the world. Their ability to persist and accumulate up food chains should be a concern as research is still experimenting with techniques to assess their long-term effects on the environment. I sought to characterize the microbeads found in facial exfoliating cleansers so as to better understand how to reduce this source of pollution through consumer use and wastewater treatment solutions. By sampling products from national-grossing cosmetic personal care brands, I was able to gather information on the size, color, volume, mass, and concentration of polyethylene beads in the cleansers. From that data, I modeled onto a consumer survey the estimated volume of microplastics entering a wastewater stream. Through inquiry, I learned the practices of two local wastewater treatment facilities. My findings show that consumer decisions and treatment protocols both play crucial parts in minimizing microplastic pollution.
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