Microplastic Pollutants introduces the reader to the growing problem of microplastic pollution in the aquatic environment and is the first ever book dedicated exclusively to the subject of ...microplastics. Importantly, this timely full-colour illustrated multidisciplinary book highlights the very recent realization that microplastics may transport toxic chemicals into food chains around the world. Microplastic pollutants is currently an important topic in both industry and academia, as well as among legislative bodies, and research in this area is gaining considerable attention from both the worldwide media and scientific community on a rapidly increasing scale. Ultimately, this book provides an excellent source of reference and information on microplastics for scientists, engineers, students, industry, policy makers and citizens alike. * A detailed chronological history of plastic materials from their creation until the present day * Extensive review and discussion of the existing literature on the interactions of microplastics with chemical pollutants and their effects on aquatic life * Explanation and provision of the techniques used for the detection, separation and identification of microplastics * Detailed multidisciplinary information on the way in which plastic materials and microplastics behave in the aquatic environment * The provision of extensive multidisciplinary reference data relating to plastic materials and microplastics
Municipal effluent discharged from wastewater treatment works (WwTW) is suspected to be a significant contributor of microplastics (MP) to the environment as many personal care products contain ...plastic microbeads. A secondary WwTW (population equivalent 650 000) was sampled for microplastics at different stages of the treatment process to ascertain at what stage in the treatment process the MP are being removed. The influent contained on average 15.70 (±5.23) MP·L–1. This was reduced to 0.25 (±0.04) MP·L–1 in the final effluent, a decrease of 98.41%. Despite this large reduction we calculate that this WwTW is releasing 65 million microplastics into the receiving water every day. A significant proportion of the microplastic accumulated in and was removed during the grease removal stage (19.67 (±4.51) MP/2.5 g), it was only in the grease that the much publicised microbeads were found. This study shows that despite the efficient removal rates of MP achieved by this modern treatment plant when dealing with such a large volume of effluent even a modest amount of microplastics being released per liter of effluent could result in significant amounts of microplastics entering the environment. This is the first study to describe in detail the fate of microplastics during the wastewater treatment process.
Reports concerning the quantitative analysis of pharmaceuticals in marine ecosystems are somewhat limited. It is necessary to determine pharmaceutical fate and assess any potential risk of exposure ...to aquatic species and ultimately, seafood consumers. In the work presented herein, analytical methods were optimised and validated for the quantification of pharmaceutical residues in wastewater effluent, receiving marine waters and marine mussels (Mytilus spp.). Selected pharmaceuticals included two non-steroidal anti-inflammatory drugs (NSAIDs) (diclofenac and mefenamic acid), an antibiotic (trimethoprim), an antiepileptic (carbamazepine) and a lipid regulator (gemfibrozil). This paper also presents the results of an in situ study in which caged Mytilus spp. were deployed at three sites on the Irish coastline over a 1-year period. In water samples, pharmaceutical residues were determined using solid phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS). The extraction of pharmaceuticals from mussel tissues used an additional pressurised liquid extraction (PLE) step prior to SPE and LC–MS/MS. Limits of quantification between 15 and 225ng·L−1 were achieved in wastewater effluent, between 3 and 38ng·L−1 in marine surface water and between 4 and 29ng·g−1 dry weight in marine mussels. Method linearity was achieved for pharmaceuticals in each matrix with correlation coefficients of R2≥0.976. All five selected pharmaceuticals were quantified in wastewater effluent and marine surface waters. This work has demonstrated the susceptibility of the Mytilus spp. to pharmaceutical exposure following the detection of pharmaceutical residues in the tissues of this mussel species at measurable concentrations.
•Pharmaceuticals detected in wastewater effluent at concentrations up to 3.16μg·g−1•Pharmaceuticals detected in Irish marine waters at concentrations up to 1.41μg·g−1•Three pharmaceuticals detected in marine mussels after in situ exposure•Trimethoprim measured in mussels at concentrations up to 9.22ng·g−1 dry weight•Low risk of pharmaceutical exposure to humans via ingestion of exposed mussels
Microplastics are widely dispersed through the marine environment. Few studies have assessed the long-term or historic prevalence of microplastics, yet acquiring such data can inform their ...distribution, transport and the environmental risks posed. To quantify the distribution and polymer types temporally, sediment cores were collected from >2000 m water depth in the Rockall Trough, North Atlantic Ocean. As hypothesized, a significant negative trend was observed in the frequency of microplastics with increasing sediment age, however there was an increase in polymer diversity. Microplastics were pervasive throughout the sediment analysed (10 cm depth), yet lead-210 (210Pb) activities were confined to the upper 4 cm, indicating this layer to be ~150 years old and thus the presence of microplastics far exceed the production of modern plastic. A number of mechanisms, including sediment reworking, could redistribute microplastics vertically. Additionally, microplastics abundance was significantly correlated with sediment porosity, suggesting interstitial transport via pore waters.
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•A negative trend was identified between microplastics (MPs) abundance and increasing sediment chronology•MPs were present throughout the sediment depth studied (10cm), which far exceeded the age of plastic production•Polymer diversity was observed to increase through the core depth•Pore water is a potential distribution pathway, as indicated by the positive correlation between MPs and sediment porosity
Microplastics are widespread in the natural environment and present numerous ecological threats. While the ultimate fate of marine microplastics are not well known, it is hypothesized that the deep ...sea is the final sink for this anthropogenic contaminant. This study provides a quantification and characterisation of microplastic pollution ingested by benthic macroinvertebrates with different feeding modes (Ophiomusium lymani, Hymenaster pellucidus and Colus jeffreysianus) and in adjacent deep water > 2200 m, in the Rockall Trough, Northeast Atlantic Ocean. Despite the remote location, microplastic fibres were identified in deep-sea water at a concentration of 70.8 particles m−3, comparable to that in surface waters. Of the invertebrates examined (n = 66), 48% ingested microplastics with quantities enumerated comparable to coastal species. The number of ingested microplastics differed significantly between species and generalized linear modelling identified that the number of microplastics ingested for a given tissue mass was related to species and not organism feeding mode or the length or overall weight of the individual. Deep-sea microplastics were visually highly degraded with surface areas more than double that of pristine particles. The identification of synthetic polymers with densities greater and less than seawater along with comparable quantities to the upper ocean indicates processes of vertical re-distribution. This study presents the first snapshot of deep ocean microplastics and the quantification of microplastic pollution in the Rockall Trough. Additional sampling throughout the deep-sea is required to assess levels of microplastic pollution, vertical transportation and sequestration, which have the potential to impact the largest global ecosystem.
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•Microplastic pollution identified >2200 m deep in the Rockall Trough.•Concentration of microplastics in deep water was comparable to surface values.•Levels ingested by benthic invertebrates were akin to wild coastal species.•Significant interspecific differences in microplastic loads.
Microplastics were identified in deep-sea benthic invertebrates and adjacent water >2200 m deep in the Rockall Trough with quantities comparable to surface concentrations.
Although evidence suggests the ubiquity of microplastics in the marine environment, our knowledge of its occurrence within remote habitats, such as the deep sea, is scarce. Furthermore, long term ...investigations of microplastic abundances are even more limited. Here we present a long-term study of the ingestion of microplastics by two deep-sea benthic invertebrates (Ophiomusium lymani and Hymenaster pellucidus) sampled over four decades. Specimens were collected between the years 1976–2015 from a repeat monitoring site >2000 m deep in the Rockall Trough, North East Atlantic. Microplastics were identified at a relatively consistent level throughout and therefore may have been present at this locality prior to 1976. Considering the mass production of plastics began in the 1940s - 50s our data suggest the relatively rapid occurrence of microplastics within the deep sea. Of the individuals examined (n = 153), 45% had ingested microplastics, of which fibres were most prevalent (95%). A total of eight different polymer types were isolated; polyamide and polyester were found in the highest concentrations and in the majority of years, while low-density polystyrene was only identified in 2015. This study provides an assessment of the historic occurrence of microplastics on the deep seafloor and presents a detailed quantification and characterisation of microplastics ingested by benthic species. Furthermore these data advance our knowledge on the long-term fate of microplastic in marine systems.
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•First long-term study of microplastic pollution in the deep sea.•Ingested microplastic abundance remained relatively consistent 1976–2015.•Data indicate microplastics may have been present at this location prior to 1976.•No trends were observed in polymer type or overall abundance across years.•Eight polymers were identified of which polyamide and polyester dominated.
This unique dataset reveals consistent levels of microplastics were ingested by deep-sea invertebrates since 1976, indicating the long-term occurrence of microplastic pollution in this region.
The clinical translation of bioactive scaffolds for the treatment of large segmental bone defects has remained a challenge due to safety and efficacy concerns as well as prohibitive costs. The design ...of an implantable, biocompatible and resorbable device, which can fill the defect space, allow for cell infiltration, differentiation and neovascularisation, while also recapitulating the natural repair process and inducing cells to lay down new bone tissue, would alleviate the problems with existing treatments. We have developed a gene-activated scaffold platform using a bone-mimicking collagen hydroxyapatite scaffold loaded with chitosan nanoparticles carrying genes encoding osteogenic (BMP-2) and angiogenic (VEGF) proteins. With a single treatment, protein expression by mesenchymal stem cells (MSCs) seeded onto the scaffold is sustained for up to 28 days and is functional in inducing MSC osteogenesis. The in vivo safety and efficacy of this gene-activated scaffold platform was demonstrated resulting in the successful transfection of host cells, abrogating the requirement for multiple procedures to isolate cells or ex vivo cell culture. Furthermore, the level of bone formation at the exceptionally early time-point of 28 days was comparable to that achieved following recombinant BMP-2 protein delivery after 8 weeks in vivo, without the adverse side effects and at a fraction of the cost. This naturally derived cell-free gene-activated scaffold thus represents a new ‘off-the-shelf’ product capable of accelerating bone repair in critical-sized bone defects.
In addition to its widespread clinical use, the intracranial electroencephalogram (iEEG) is increasingly being employed as a tool to map the neural correlates of normal cognitive function as well as ...for developing neuroprosthetics. Despite recent advances, and unlike other established brain-mapping modalities (e.g. functional MRI, magneto- and electroencephalography), registering the iEEG with respect to neuroanatomy in individuals—and coregistering functional results across subjects—remains a significant challenge. Here we describe a method which coregisters high-resolution preoperative MRI with postoperative computerized tomography (CT) for the purpose of individualized functional mapping of both normal and pathological (e.g., interictal discharges and seizures) brain activity. Our method accurately (within 3mm, on average) localizes electrodes with respect to an individual's neuroanatomy. Furthermore, we outline a principled procedure for either volumetric or surface-based group analyses. We demonstrate our method in five patients with medically-intractable epilepsy undergoing invasive monitoring of the seizure focus prior to its surgical removal. The straight-forward application of this procedure to all types of intracranial electrodes, robustness to deformations in both skull and brain, and the ability to compare electrode locations across groups of patients makes this procedure an important tool for basic scientists as well as clinicians.
► We describe a method for localizing intracranial electrodes in individuals. ► Post-implant CT was coregistered with pre-implant MRI. ► An optimization algorithm accounted for the brain shift caused by implantation. ► Surface-based methods were used to coregister electrode arrays across patients.
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