The ubiquitous nature of plastics, particularly nanoplastics, raises concern about their potential effects on primary producer microalgae. Currently, the impacts and potential mechanisms of ...nanoplastics on microalgae are not fully understood. In this study, the effects of two plain commercial polystyrene nanoplastics (PS-NPs) with different sizes (50 nm and 70 nm) on C. vulgaris were assessed in a concentration range of 0–50 mg/L during 72 h exposure periods. Results revealed that both PS-NPs have dose-dependent toxicity effects on C. vulgaris, as confirmed by the decrease of growth rates, chlorophyll a and esterase activities, and the increase of ROS, MDA, and membrane damage. The membrane damage was caused by the agglomeration of PS-NPs on microalgae and may be the key reason for the toxicity. Compared with 70 nm PS-NPs (72 h ECsub.50 >50 mg/L), 50 nm PS-NPs posed greater adverse effects on algae, with an ECsub.50–72h of 19.89 mg/L. FTIR results also proved the stronger variation of macromolecules in the 50 nm PS-NPs treatment group. This phenomenon might be related to the properties of PS-NPs in exposure medium. The lower absolute zeta potential value of 50 nm PS-NPs induced the stronger interaction between PS-NPs and algae as compared to 70 nm PS-NPs, leading to severe membrane damage and the loss of esterase activity as well as settlement. These findings emphasized the importance of considering the impacts of commercial PS-NPs properties in toxicity evaluation.
Plastic Legacies Trisia Farrelly, Sy Taffel, Ian Shaw
2021, 2021-07-09
eBook
Odprti dostop
There is virtually nowhere on earth that remains untouched by plastics and the situation presents a serious threat to our natural world. Despite the magnitude of the problem, the interventions most ...often put in place are consumer-led and market-based and only nominally capable of addressing the issue. As the problem worsens and neoliberal ideologies limit the world's responses to this crisis, there is a growing need for legislative frameworks that attend to the complex social and ecological issues associated with plastics. The contributors to this volume bring expertise from across academic disciplines to illustrate how plastics are produced, consumed, and discarded and to find holistic and integrated approaches that demonstrate an understanding of the wide-ranging problem. From the plasticization of earth's oceans to the endocrine disrupting chemicals that have the potential to seriously harm life as we know it, these essays beg the question that we all must answer: what is our plastic legacy? With contributions by: Imogen E. Napper, Sabine Pahl, Richard C. Thompson, Sasha Adkins, Stephanie B. Borrelle, Jennifer Provencher, Tina Ngata, Sven Bergmann, Christina Gerhardt, Elyse Stanes, Tridibesh Dey, Mike Michael, Laura McLauchlan, Johanne Tarpgaard, Deirdre McKay, Padmapani Perez, Lei Xiaoyu, and John Holland.
Of Poverty and Plastic applies an interdisciplinary, 'field economics' approach to poverty analysis, using a mix of survey and ethnographic data to challenge received notions of the nature and extent ...of narrow income poverty and multiple deprivations experienced by those working in the informal waste recovery and plastic recycling economy of Delhi. A detailed analysis of specialization, capital, and value in various segments of this labour-intensive, 'green' informal market is undertaken, with explicit recognition of its wider social and political institutional context, and how it is shaped by unequal interactions with civil society and the state. In particular, the book focuses on the identity and agency of subordinate scheduled caste groups-living literally and metaphorically on the edge of the city-in negotiating 'a decent life' in today's neoliberal environment. The case studies of the ban on recycled polythene bags and the industrial relocation order illustrate the channels through which these actors collectively seek to resist the perceived anti-urban poor status quo, driven by powerful middle class coalitions through legislation or judicial fiat, with varying degrees of success. In doing so, the book exposes the complex, and at times contrary, policy reality binding poverty and deprivation, formal and informal markets, the state and citizenship in contemporary urban India.
The blackmouth catshark has a habitat range that spans from the Norwegian seas to Senegal and throughout the Mediterranean Sea, and it is one of the most common sharks in Italian waters. The aim of ...this work is to investigate, through the analyses of the stomach contents of five populations from the Tyrrhenian and Ionian Seas, the diet of blackmouth catsharks. The analyses showed that the most frequent items were Osteichthyes of the family Myctophidae, except for one population, in which the most common items were Cephalopods and Crustacean of the Decapods order. Plastic debris was also found in all populations analysed and classified by colour and shape. This study ought to increase the knowledge of the feeding ecology of the blackmouth catshark, thus improving the meagre literature about Tyrrhenian and Ionian waters. Galeus melastomus is the most common Pentanchidae in the Mediterranean Sea. A scavenger and opportunistic feeder, and despite the wide distribution, little is known about its feeding habits in Italian waters. The main purpose of this study was to investigate the diet of the blackmouth catshark by analysing the stomach contents. The specimens analysed were obtained from five populations of the Tyrrhenian and of the Ionian Seas, collected from a depth between 40 and 700 m. A total of 259 stomachs were analysed. The stomach contents were grouped into macro-categories and identified to the lowest taxonomic level possible. Crustaceans such as Parapenaeus longirostris, the Cephalopods Heteroteuthis dispar and Onychoteuthis banksii, and Osteichthyes, mostly Myctophidae, were identified. Plastic debris was also found among the stomach contents and classified according to its colour and shape. Osteichthyes represent the most abundant item (44%), above all the Myctophidae family, except for the catshark population from Tuscany, in which the most frequent species were Cephalopods, such as Abralia veranyi and Heteroteuthis dispar. Differences in the plastic debris contents were also observed between the Tuscany population and other populations. These could be explained as a probable consequence of the different depths at which the blackmouth catshark populations were sampled.
Nowadays, plastic materials are extensively used in the agri-food sector for multiple purposes. The end-of-life management of these plastics is an environmental challenge because frequent incomplete ...recoveries after the crop seasons lead to the accumulation of plastics debris in agricultural waste, which is now recognized as an emerging environmental issue of global concern. However, the effects of plastic debris in agricultural waste undergoing biotreatment have been poorly studied. This study assesses the effects of agricultural plastic waste (APW) (LDPE + LLDPE and EPS) (1.25% f.w.) on the vermicomposting process (45 days) in terms of earthworm health by measuring biomarker responses and the enzymatic activity and quality/stabilization of the vermicompost obtained. The results showed that exposure to all the plastic materials tested had negative morphological effects on earthworm survival and body biomass. In the vermicomposting process, the changes detected in the enzymatic activity of the vermicompost and the biofilm seemed to affect the degradation rate of earthworms and the microbiome of the substrate, as demonstrated by the low organic matter mineralization in the vermicompost exposed to plastic. Although no significant changes were recorded in several biomarkers, signs of oxidative stress were evidenced throughout the glutathione S-transferase and carboxylesterase activity, mainly involving balanced oxidative stress and xenobiotic resistance systems.
The contamination of aquatic ecosystems with microplastics has recently been reported through many studies, and negative impacts on the aquatic biota have been described. For the chemical ...identification of microplastics, mainly Fourier transform infrared (FTIR) and Raman spectroscopy are used. But up to now, a critical comparison and validation of both spectroscopic methods with respect to microplastics analysis is missing. To close this knowledge gap, we investigated environmental samples by both Raman and FTIR spectroscopy. Firstly, particles and fibres >500 μm extracted from beach sediment samples were analysed by Raman and FTIR microspectroscopic single measurements. Our results illustrate that both methods are in principle suitable to identify microplastics from the environment. However, in some cases, especially for coloured particles, a combination of both spectroscopic methods is necessary for a complete and reliable characterisation of the chemical composition. Secondly, a marine sample containing particles <400 μm was investigated by Raman imaging and FTIR transmission imaging. The results were compared regarding number, size and type of detectable microplastics as well as spectra quality, measurement time and handling. We show that FTIR imaging leads to significant underestimation (about 35 %) of microplastics compared to Raman imaging, especially in the size range <20 μm. However, the measurement time of Raman imaging is considerably higher compared to FTIR imaging. In summary, we propose a further size division within the smaller microplastics fraction into 500–50 μm (rapid and reliable analysis by FTIR imaging) and into 50–1 μm (detailed and more time-consuming analysis by Raman imaging).
Graphical Abstract
Marine microplastic sample (fraction <400 μm) on a silicon filter (middle) with the corresponding Raman and IR images
► Types of plastic and the methods used to prepare plastic aggregate for concrete. ► Methods of assessing the various properties of aggregate and concrete. ► Properties of plastic aggregates. ► Fresh ...and hardened properties of cement mortar and concrete with plastic aggregate.
A substantial growth in the consumption of plastic is observed all over the world in recent years, which has led to huge quantities of plastic-related waste. Recycling of plastic waste to produce new materials like concrete or mortar appears as one of the best solution for disposing of plastic waste, due to its economic and ecological advantages. Several works have been performed or are under way to evaluate the properties of cement-composites containing various types of plastic waste as aggregate, filler or fibre. This paper presents a review on the recycling plastic waste as aggregate in cement mortar and concrete productions.
For better presentation, the paper is divided into four different sections along with introduction and conclusion sections. In the first section, types of plastics and types of methods used to prepare plastic aggregate as well as the methods of evaluation of various properties of aggregate and concrete were briefly discussed. In the next two sections, the properties of plastic aggregates and the various fresh and hardened concrete properties of cement mortar and concrete in presence of plastic aggregate are discussed. The fourth section focus on the practical implications of the use of plastic waste in concrete production and future research needs.
We report for the first time the ingestion of microplastics by scleractinian corals, and the presence of microplastics in coral reef waters adjacent to inshore reefs on Australia’s Great Barrier Reef ...(GRE, 18°31′S 146°23′E). Analysis of samples from sub-surface plankton tows conducted in close proximity to inshore reefs on the central GBR revealed microplastics, similar to those used in marine paints and fishing floats, were present in low concentrations at all water sampling locations. Experimental feeding trials revealed that corals mistake microplastics for prey and can consume up to ~50 μg plastic cm
−2
h
−1
, rates similar to their consumption of plankton and
Artemia
nauplii in experimental feeding assays. Ingested microplastics were found wrapped in mesenterial tissue within the coral gut cavity, suggesting that ingestion of high concentrations of microplastic debris could potentially impair the health of corals.
The signal crayfish Pacifastacus leniusculus is one of the most widespread non-indigenous crayfish in Europe and is of interest to aquaculture in many countries. Once they escape into the wild, they ...disperse and become a potential source of food exploited for consumption by local inhabitants. The ingestion of plastics by the invasive signal crayfish in the Wieprza River, a tributary to the Baltic Sea, was determined by the FTIR identification of plastic compounds found in stomachs. The occurrence of plastic debris in the stomachs of P. leniusculus is reported for the first time. Plastic particles with the size range between 70 and 450 µm were observed only among crayfish inhabiting the lower, urbanized part of the river (7.3% of specimens). The presence of PTFE (polytetrafluoroethylene), cellophane, PP (polypropylene), PE (polyethylene), PMMA (polymethyl methacrylate), and nylon was confirmed with the highest frequency of PTFE in the stomachs of crayfish. Fibres were the predominant type of microplastics in crayfish stomachs. The results indicated the size-selective uptake and ingestion of plastics depending on the traits of the species and environment.
