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1.
Sci Total Environ ; 750: 141514, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32835961

RESUMO

The advent of the COVID-19 pandemic has enhanced the complexities of plastic waste management. Our improved, hyper-hygienic way of life in the fear of transmission has conveniently shifted our behavioral patterns like the use of PPE (Personal protective equipment), increased demand for plastic-packaged food and groceries, and the use of disposable utensils. The inadequacies and inefficiencies of our current waste management system to deal with the increased dependence on plastic could aggravate its mismanagement and leakage into the environment, thus triggering a new environmental crisis. Mandating scientific sterilization and the use of sealed bags for safe disposal of contaminated plastic wastes should be an immediate priority to reduce the risk of transmission to sanitation workers. Investments in circular technologies like feedstock recycling, improving the infrastructure and environmental viability of existing techniques could be the key to dealing with the plastic waste fluxes during such a crisis. Transition towards environmentally friendly materials like bioplastics and harboring new sustainable technologies would be crucial to fighting future pandemics. Although the rollbacks and relaxation of single-use plastic bans may be temporary, their likely implications on the consumer perception could hinder our long-term goals of transitioning towards a circular economy. Likewise, any delay in building international willingness and participation to curb any form of pollution through summits and agendas may also delay its implementation. Reduction in plastic pollution and at the same time promoting sustainable plastic waste management technologies can be achieved by prioritizing our policies to instill individual behavioral as well as social, institutional changes. Incentivizing measures that encourage circularity and sustainable practices, and public-private investments in research, infrastructure and marketing would help in bringing the aforementioned changes. Individual responsibility, corporate action, and government policy are all necessary to keep us from transitioning from one disaster to another.


Assuntos
Infecções por Coronavirus , Pandemias , Plásticos , Pneumonia Viral , Gerenciamento de Resíduos , Betacoronavirus , Humanos , Pandemias/prevenção & controle
2.
Sci Total Environ ; 751: 141264, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32871308

RESUMO

Arctic sea ice has alarmingly high concentrations of microplastics (MPs). Additionally, sea ice reduction in the Arctic is opening new opportunities for the oil and maritime industries, which could increase oil pollution in the region. Yet knowledge of the effects of co-exposure to MPs and crude oil on Arctic zooplankton is lacking. We tested the influence of MPs (polyethylene, 20.7 µm) on polycyclic aromatic hydrocarbon (PAH) bioaccumulation and oil toxicity in the key arctic copepod Calanus hyperboreus after exposure to oil with and without dispersant. Up to 30% of the copepods stopped feeding and fecal pellet production rates were reduced after co-exposure to oil (1 µL L-1) and MPs (20 MPs mL-1). The PAH body burden was ~3 times higher in feeding than in non-feeding copepods. Copepods ingested both MPs and crude oil droplets. MPs did not influence bioaccumulation of PAHs in copepods or their fecal pellets, but chemical dispersant increased bioaccumulation, especially of ≥4 ring-PAHs. Our results suggest that MPs do not act as vectors of PAHs in Arctic marine food webs after oil spills, but, at high concentrations (20 MPs mL-1), MPs can trigger behavioral stress responses (e.g., feeding suppression) to oil pollution in zooplankton.


Assuntos
Copépodes , Poluição por Petróleo , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Regiões Árticas , Bioacumulação , Microplásticos , Petróleo/toxicidade , Plásticos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Zooplâncton
3.
Sci Total Environ ; 753: 142024, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33207452

RESUMO

Microplastic and nanoplastic pollution in aquatic environments is a topic of emerging concern due to the internalization, retention time and effects of these particles in aquatic biota. Bivalves are considered bioindicators due to their wide distribution, sessile behaviour, occupation of ecological niches and ability to filter a large water volume. The study of microplastics and nanoplastics in bivalves has revealed the uptake mechanisms, internalization, distribution and depuration of these particles as well as their effects on physiological parameters, morphological alterations, immunotoxicity and changes in gene expression and proteomic profiles. In this review, we examine the primary characteristics of microplastics and nanoplastics (type of material, size, coating, density, additives and shapes) involved in their possible toxicity in bivalves. Furthermore, secondary characteristics such as the suspension media, aggregation stage and adsorption of persistent pollutants were also recorded to assess the impact of these materials on bivalves. Here, we have highlighted the efforts exerted thus far and the remaining gaps in understanding the extent of microplastic and nanoplastic impacts on bivalves on the basis of laboratory experiments and mesocosm bioassays and in the field. Furthermore, further microplastic and nanoplastic toxicological studies are proposed to facilitate the realistic assessment of environmental risk.


Assuntos
Bivalves , Poluentes Ambientais , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Microplásticos , Plásticos/toxicidade , Proteômica , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Sci Total Environ ; 752: 141879, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207490

RESUMO

Fungi not only play important roles in biogeochemical processes but also can form biofilm on plastic debris. However, knowledge of structure composition and spatiotemporal pattern of fungal plastisphere on different kinds of plastic debris in river with specific usages, known as river functional zones, is still missing. In this study, we investigated the spatial distribution of the fungal plastisphere across a complete urban river with different functional zones (drinking, farm irrigation, aquaculture, and tail lake). Our research was performed based on both field residual plastic debris collection and a 30-day field in situ incubation experiments. Our study revealed that plastic debris enriched distinct fungal communities (including pathogenic fungi) significantly different from the surrounding water. Tracking the source of the fungi colonized on plastic debris suggested that the fungal taxa colonized on the different kinds of plastic debris were not from the surrounding water. Human activities had considerable effects on the fungal community structure on plastic debris, and the plastisphere fungal community structure strikingly varied across different river functional zones. Plastisphere may be used as an indicator for fungi biogeography and pathogenic fungi pollution in river with different functional zones. These findings are essential for ecological risk assessment and management decisions for pollution control of plastic debris and maintaining ecological health.


Assuntos
Plásticos , Rios , Biofilmes , Poluição Ambiental , Fungos
5.
Sci Total Environ ; 752: 142256, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207491

RESUMO

The present study used red tilapia (Oreochromis niloticusas) as the model fish to compare the interactive effects between aged and virgin microplastics (MPs) with the antibiotic sulfamethoxazole (SMX) and the ß-blocker propranolol (PRP). To this end, the ultraviolet irradiation was used to simulate the MP aging in the environment. The accumulations of MPs and pharmaceuticals, and changes in enzyme activities and genes expressions in tilapia were also evaluated. Some physical properties of MPs changed during the aging process, reflected by 0.27- and 0.16-fold increases in the specific surface area and average pore volume, respectively. And more carbonyl formation was observed on the surface of aged MPs. Compared to the 14-d coexposure with virgin MPs, the MP aging increased the accumulation of PRP by 82.3% in the brain, whereas decreased the concentration of SMX by 46.1% in the gills. The stress on tilapia caused by the MPs and PRP was alleviated by the aging process, largely related to the lower neurotoxicity and reduced lipid peroxidation damages. However, the coexposure to aged MPs and SMX would result in higher inhibitions of cytochrome P450 enzymes activities. The results of the transcriptomics showed that the MP aging mainly influenced the expression of genes related to the metabolic process, immune system process, and the genetic information process in tilapia under the coexposure to MPs and pharmaceuticals. Collectively, our results suggest that the MP aging could induce complex changes in the interactive effects between MPs and pharmaceuticals on aquatic organisms.


Assuntos
Preparações Farmacêuticas , Tilápia , Poluentes Químicos da Água , Envelhecimento , Animais , Microplásticos , Plásticos , Poluentes Químicos da Água/toxicidade
6.
Sci Total Environ ; 752: 142242, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207500

RESUMO

Microplastics which are gradually and randomly decompose into small fragment by exposure of physical and biological external stress are emerging as a significant threat to the all the environments. Here, we have demonstrated the in vitro toxicity of microplastics of two different shapes. To minimize the chemical effect, polyethylene (PE), was used. PE microplastics with two different shapes were prepared, high-density PE microbeads and irregularly ground low-density PE from bulk pellets. It is hypothesized that morphological characteristics and concentration of PE microplastics could affect cellular viability, immunity, and lysis. To quantify the randomness of the microplastic shape, the edge patterns of the generated PE microplastics were converted into numerical values and analyzed using a statistical method. A 10-fold difference in curvature value was observed between microbeads and ground microfragments. To correlate shape differences to toxicology, cells were exposed to PE microplastics on the demand of toxicology studies. We found that the higher concentration and rough structure were associated with the toxicity of plastics toward cells, pro-inflammatory cytokine release, and hemolysis, even though PE is buoyant onto medium. The PE microbeads did not exhibit severe cytotoxicity at any of the tested concentrations, but induced immune and hemolysis responses at high concentrations. When comparing the toxicity of different shapes of PE microplastics, we confirmed by statistical analysis that irregular-shape plastics with sharp edges and higher curvature differences may adversely affect cells, further having possibility to human toxicity in real environment.


Assuntos
Polietileno , Poluentes Químicos da Água , Monitoramento Ambiental , Microplásticos , Plásticos/toxicidade , Polietileno/análise , Polietileno/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
7.
Sci Total Environ ; 752: 142223, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207502

RESUMO

Microplastics pollution poses a new threat to the environment of intertidal zone. The sea forest, mangrove, has been polluted by a large number of plastic debris worldwide. To fill the gaps in knowledge of mangrove rhizosphere microbes connected with the 'plasticsphere', a semi-controlled in situ exposure experiment for nine different types of microplastics were conducted in mangrove ecosystem. A sign of biodegrading was observed on polyethylene, polyamide 6 and polyvinyl chloride microplastics surface after 3 months exposure. We discovered that the metabolic activities of the dominant bacteria on certain microplastics were related to the specific groups on polymers molecule. The selective colonization may be driven by the chemotaxis of bacteria. Specially, microplastics biofilms of polyethylene, polyamide 6, polyvinyl chloride and expanded polystyrene possess distinctive dominant bacteria assemblages which have great significance in ecosystem processes involving carbon cycle or sulfur cycle. Community of mangrove soil microorganism and microplastic biofilm varies as the seasons changes. As a new niche, microplastics has higher inclusivity to bacteria than surrounding soil. Additionally, pathogens for human beings (Vibrio parahaemolyticus and Escherichia-Shigella) were detected both in microplastics and soil. We stress that the interaction between microplastics and rhizosphere microorganisms may affect the growth and health of mangrove plants. Besides, we point out that mangrove rhizosphere microorganism can be an ideal candidate for plastics-degradation.


Assuntos
Plásticos , Poluentes Químicos da Água , Quimiotaxia , Ecossistema , Monitoramento Ambiental , Microplásticos , Rizosfera , Poluentes Químicos da Água/análise
8.
Sci Total Environ ; 752: 141542, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889256

RESUMO

The occurrence of microplastics (MPs) in the digestive tract of commercial Kutum fish, Rutilus frisii kutum was investigated. Fish samples, ranging from 33 to 48.5 cm fork length which sold for human consumption, were collected from local fish markets in Bandar-e Torkaman (the south-eastern of Caspian Sea) on November 2017, and March 2018. The MPs were characterized using optical microscopy, NR staining, and SEM-EDS for number, shape, color, surface morphology, and elemental composition. On average, 11.4 MP items per fish (0.015 items per 1 g fish wet weight) were found in Kutum's stomach at an individual detection rate of 80%. Around 66% of all identified MP items were < 500 µm, and 53% possessed light colors. Morphological researches indicated that fish ingested the degradation fragments from larger plastic pieces, fibers, and manufactured microbeads. Microfibers are the most dominant items accounting for over 75% of all MPs. The SEM images indicated the various degrees of erosions upon environmental exposure. Some MPs had surface cracks, broken margins, scaly appearances, and obvious pores. Considering the commercial importance which the Kutum plays for Iran's fishery, the potential effect of MPs on the trophic food web, particularly for human consumption and health, should be urgently investigated.


Assuntos
Cyprinidae , Poluentes Químicos da Água , Animais , Mar Cáspio , Monitoramento Ambiental , Humanos , Irã (Geográfico) , Microplásticos , Plásticos , Poluentes Químicos da Água/análise
9.
Sci Total Environ ; 753: 142042, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32892003

RESUMO

Microplastics (MPs) have become a global environmental issue, however, the threats of metal-associated MPs to soil ecosystems and their involved processes have not been fully disclosed. In this study, a microcosm experiment with co-exposure of polyethylene and cadmium was conducted to determine their joint effects on the earthworm Eisenia fetida and to explore their relationship with the soil Cd availability that affected by MPs. The results showed that 28-day co-exposure of MPs and Cd significantly induced higher avoidance responses, weight loss and reduced reproduction of earthworms with the increasing content of pollutants. MPs and Cd jointly inhibited the superoxide enzyme (SOD) and peroxidase (POD) activities while increasing the glutathione (GSH) and malondialdehyde (MDA) activities in E. fetida. Histopathological changes and DNA damage to earthworm sperm also occurred in an MPs-dose-dependent manner. In addition, the presence of MPs significantly increased the soil diethylenetriaminepentaacetic acid (DTPA)-Cd concentrations by 1.20-fold and 1.43-fold while increasing the Cd bioaccumulation in E. fetida by 2.65-fold and 1.42-fold in low- and high-Cd-contaminated soil, respectively, which potentially contributed to the aggravation of the joint toxicity to E. fetida. In conclusion, this study demonstrated that microplastics could enhance the cadmium availability in the co-exposure soil which resulted in the joint toxicity of metal-associated MPs to soil organisms. CAPSULE: MPs increased soil Cd availability and potentially aggravated the joint toxicity with Cd to Eisenia fetida.


Assuntos
Oligoquetos , Poluentes do Solo , Animais , Cádmio/análise , Cádmio/toxicidade , Ecossistema , Microplásticos , Plásticos/toxicidade , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
10.
Sci Total Environ ; 753: 141953, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32896737

RESUMO

Biodegradable plastics made from biopolymers (made in nature) or from bio-based polymers (made in a factory) are becoming increasingly important in replacing the massive amounts of conventional, non-degradable fossil-based plastics that have been produced and disposed over the past decades. In this review we compare the biodegradation rates and mechanisms of the bioplastics thermoplastic starch, cellulose acetate and lignin based bioplastics with the biodegradation rates and mechanisms of starch, cellulose and lignin, which are the unmodified biopolymers from which these bioplastics are produced. With this comparison we aim to determine to what extent the extensive knowledge on unmodified biopolymer biodegradation can be applied to the biodegradation of bioplastics (modified biopolymers) in the terrestrial environment. This knowledge is important, since it can be of great help in giving direction to the future research and development of bioplastics and for the development of bioplastic waste assessments and policies. We found that the similarities and differences in biodegradation are dependent on the structural changes imposed on a biopolymer during the bioplastic production process. A change in higher level structure, as found in thermoplastic starch, only resulted in a limited number of differences in the biodegradation process. However, when the chemical structure of a polymer is changed, as for cellulose acetate, different microorganisms and enzymes are involved in the biodegradation. Based on the cellulose acetate biodegradation process, a conceptual model was proposed that can be used as a starting point in predicting biodegradation rates of other chemically modified biopolymers used as bioplastics. Future bioplastic biodegradation research should focus on conducting long-term field experiments, since most studies are conducted in a laboratory setting and do not capture all processes occurring in the field situation. This applies even more to lignin based bioplastics, since very little experimental data were available on modified lignin biopolymer biodegradation.


Assuntos
Plásticos Biodegradáveis , Plásticos , Biodegradação Ambiental , Biopolímeros , Lignina , Polímeros , Amido
11.
Sci Total Environ ; 753: 141859, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32898808

RESUMO

Monitoring studies have revealed the presence of large numbers of natural as well as anthropogenic microfibers, plastic and non-plastic, in environmental samples. However, the interaction of organisms with microfibers is largely understudied. This is the first ecotoxicological study that compares short-term feeding of anthropogenic plastic and non-plastic microfibers on a consumer (leaf-shredding detritivores) species. The freshwater amphipod Gammarus duebeni was selected for this study as it is a model ecotoxicological species. After a 96-hour exposure, 58.3% and 41.7% of the amphipods contained cellulose or polyester fibers in their digestive tracts, respectively. Microfiber ingestion was analysed per polymers in presence or absence of food. The G. duebeni group exposed to 'polyester fibers in presence of food' accumulated highest numbers of microfibers in their digestive tracts (5.2 ±â€¯3.4 MFs/amphipod) followed by those exposed to 'cellulose in presence of food' (2.5 ±â€¯0.9 MFs/amphipod). A significantly (Three-way ANOVA, p-value <0.05) higher number of microfibers was found in the midgut-hindgut (posterior) sections, compared to the foregut (anterior) section. Microfiber uptake had no apparent short-term negative effect on amphipod survival at 96 h. Yet, as amphipods are both predators and prey, and therefore are key species in the aquatic food web, the rapid accumulation of anthropogenic microfibers in their digestive system has potentially further ecological implications. Future studies need to consider the possible transfer of ingested anthropogenic microfibers to higher trophic levels in freshwater communities.


Assuntos
Anfípodes , Poluentes Químicos da Água , Animais , Celulose , Água Doce , Microesferas , Plásticos , Poliésteres , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Sci Total Environ ; 753: 141981, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32911167

RESUMO

This review discusses the imminent threat that microplastics (MPs) associated with pharmaceuticals represent to the aquatic environment and public health. We initially focused upon recognizing and stressing that MPs are ubiquitous pollutants. The influence of environmental factors, such as pH, mechanical stress, and photodegradation, are examined, aiming to elucidate how both substances might associate, what are their simultaneous degradation pathways and, to understand the interactions between MPs and pharmaceuticals. Mathematical tools, such as modeling and simulations, are presented in detail, aiming to improve how information is interpreted. Furthermore, it is exhibited that MPs sorption and interaction behavior towards organic contaminants play an important role in understanding its dynamics in the environment, as well as their possible interactions with pharmaceuticals that are summarized. At last, MPs and pharmaceuticals toxicity and bioaccumulation are presented.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Adsorção , Microplásticos , Plásticos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
13.
Sci Total Environ ; 753: 142064, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32911172

RESUMO

The cotransport behaviors of colloidal polystyrene microplastic particles (PSMPs) and tetracycline (TC) (20 mg/L) were investigated in saturated porous media in KCl and CaCl2 solutions of various ionic strengths (1, 10, 50, 100 mM). Furthermore, the effects of TC concentration (0, 1, 5, 10, 20 mg/L) on the cotransport behaviors of PSMPs and TC in 100 mM KCl solution were assessed. The cotransport behaviors were analyzed by comparing the individual transport behaviors of PSMPs or TC. When cotransported, the presence of TC (20 mg/L) slightly inhibited PSMPs mobility in K+ solutions (the C/C0 decreased in the range of 0-5.9%), but facilitated it in Ca2+ solutions (the C/C0 increased in the range of 6.7-42.6%). In KCl solutions, although the presence of TC (PSMPs) did not significantly affect the transport behaviors of PSMPs (TC), the attachment efficiencies of both PSMPs and TC showed a non-linear and non-monotonic change with increase in ionic strength. However, in CaCl2 solutions, the effects of TC (PSMPs) on the transport behaviors of PSMPs (TC) were remarkable and a non-linear non-monotonic change was observed. The adsorption of TC on PSMPs might play a critical role during the cotransport. Thus, the balance between the transport-inhibiting (e.g., the reduction in electrostatic repulsive force) and transport-facilitating effects (e.g., the effects on hydrophilicity/hydrophobicity of PSMPs due to TC adsorption) may be responsible for the observed changes. Overall, the results demonstrated that the cotransport behaviors of PSMPs and TC were more complicated than their individual transport behaviors in porous media, which might vary considerably with environmental conditions. This work could greatly improve our understanding of complex cotransport behaviors and environmental risk of PSMPs.


Assuntos
Microplásticos , Poliestirenos , Concentração Osmolar , Plásticos , Porosidade
14.
Sci Total Environ ; 752: 141959, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207527

RESUMO

Increasing amounts of plastic waste in the environment and their fragmentation into smaller particles known as microplastics (particles, <5mm) have raised global concerns due to their persistency in the environment and their potential to act as vectors for harmful substances or pathogenic microorganisms. One possible solution to this problem is biodegradation of plastics by microorganisms. However, the scientific information on plastic-degrading microorganisms is scattered across different scientific publications. We conducted a systematic literature review (SLR) with predefined criteria using the online databases of Scopus and Web of Science to find papers on bacterial biodegradation of synthetic petroleum-based polymers. The aims of this SLR were to provide an updated list of all of the currently known bacteria claimed to biodegrade synthetic plastics, to determine and define the best methods to assess biodegradation, to critically evaluate the existing studies, and to propose directions for future research on polymer biodegradation in support of more rapid development of biodegradation technologies. Most of the bacteria identified here from the 145 reviewed papers belong to the phyla Proteobacteria, Firmicutes and Actinobacteria, and most were isolated from contaminated sites, such as landfill sites. Just under a half of the studies (44%) investigated the biodegradability of polyethylenes and derivates, particularly low-density polyethylenes. The methods used to monitor the biodegradation were mainly scanning electron microscopy and Fourier-transform infrared spectroscopy. We propose that: (1) future research should focus on biodegradation of microplastics arising from the most common pollutants (e.g. polyethylenes); (2) bacteria should be isolated from environments that are permanently contaminated with plastics; and (3) a combination of different observational methods should be used to confirm bacterial biodegradation of these plastics. Finally, when reporting, researchers need to follow standard protocols and include all essential information needed for repetition of the experiments by other research groups.


Assuntos
Petróleo , Plásticos , Biodegradação Ambiental , Microplásticos , Polímeros
15.
Food Chem ; 334: 127547, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32693334

RESUMO

Plastic food packages usually contain additives which may migrate from the package into the food and then be ingested by the consumer, representing a risk for their health. In this study, targeted and untargeted analysis by gas chromatography-mass spectrometry (GC-MS) is proposed to monitor any contaminants of this type in honey. The application of dispersive liquid-liquid microextraction (DLLME) as a preconcentration technique allowed very low detection limits to be reached for all the substances. Fifteen target compounds, including styrene, phthalates, fatty acids, alkylphenols and bisphenol A, were quantified. Untargeted analyses were also carried out, allowing other migrants in the honey samples to be identified, such as two phthalates, four acids, three esters, one aldehyde, one hydrocarbon and two alkyl phenol compounds. The proposed method was seen to be a useful approach for the quantification and identification of potential migrants from plastics in challenging samples such as honey.


Assuntos
Armazenamento de Alimentos/métodos , Mel/análise , Plásticos/química , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Microextração em Fase Líquida , Fenóis/análise , Fenóis/isolamento & purificação , Ácidos Ftálicos/análise , Ácidos Ftálicos/isolamento & purificação , Migrantes
16.
Sci Total Environ ; 751: 142341, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33181980

RESUMO

There is a lack of information on understanding how marine organisms respond to environmentally relevant microplastics (MP) which hampers decision making for waste management strategies. This study addresses this information gap by determining whether responses to MPs are species specific within a functional group. Benthic residing sea urchins, Psammechinus miliaris and Paracentrotus lividus were used as a case study. Psammechinus miliaris are strong omnivores with dietary intake including hard components (e.g. shell, tubeworms) and therefore likely to cope with the ingestion of MPs, while P. lividus are strong herbivores consuming softer dietary items (e.g. biofilms, algae) and therefore more likely sensitive. Responses to environmentally relevant MPs were conducted across two trials. Trial one determined the impact of short term (24 h) external exposure to storm-like sediment resuspension of MP concentrations (53 µm polyvinyl chloride (PVC) 25,000 MP L-1) compared to a control without MPs. No significant impacts were observed for both P. lividus and P. miliaris on metabolic rate or righting time, and urchins were able to remove MPs from the body surface using pedicellariae and cilia. Trial two determined the impact of medium term (2 months) ingestion of a diet laced with PVC MPs (59 µm) at an inclusion rate of 0.5% mass and a control diet (without MPs) on somatic growth and animal condition. The ingestion of MPs did not significantly impact P. miliaris but significantly reduced the alimentary index within P. lividus, indicating a compromised nutritional state. This study shows that responses to microplastics are species-specific and therefore cannot be generalized. Furthermore, feeding habit could act as a potential indicator for sensitivity to MP ingestion which will be important for impact assessments of plastic pollution and management strategies.


Assuntos
Paracentrotus , Poluentes Químicos da Água , Animais , Comportamento Alimentar , Microplásticos , Plásticos , Poluentes Químicos da Água/análise
17.
Sci Total Environ ; 750: 141665, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182169

RESUMO

Reusing microplastics and zeolite waste as free ammonia (FA)-mitigating carrier particle was proven a value-added step towards promoting the serviceability of fluidized bed bioreactor (FBBR) in treating wastewater with a low carbon to nitrogen ratio (i.e. C/N <3.0) in this study. Ammonia (NH4+) adsorption property capacitates zeolite as an FA mitigator. The microplastics and reused zeolite were processed into reused-zeolite/microplastic composite particle (RZ), whose merit of FA mitigation was fully developed via an optimally thermal modification to process modified-zeolite/microplastic particle (MZ). The 171-day biological nutrient removal (BNR) performance in a single integrated fluidized bed bioreactor (SIFBBR) shows that the bioreactor with MZ particle (SIFBBR-MZ) achieved nitrogen removal efficiency 10.0% higher than the bioreactor with RZ particle (SIFBBR-RZ) over the enhanced short-cut nitrification and denitrification. Analysis of microbial community structure unveils that the long-term lower FA inhibition favored more significant ammonia-oxidizing bacteria (AOB) enrichment and acclimated specific MZ biofilm predominant by nitrite (NO2-) denitrifier, contributing to the outperformance in nitrogen removal. Apart from fluidization energy conservation, the techno-economic analysis confirms that using MZ as an FA-mitigating carrier could be of great benefit for FBBR system: realizing waste utilization, reducing carbon addition and alleviating sludge treatment.


Assuntos
Nitrogênio , Águas Residuárias , Amônia , Reatores Biológicos , Carbono , Desnitrificação , Nitrificação , Plásticos , Eliminação de Resíduos Líquidos
18.
Sci Total Environ ; 750: 143085, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182181

RESUMO

Microplastics (MPs) are ubiquitous contaminants in the environment and can be transferred along the food chain, thus causing adverse effects in organisms, even human beings. Therefore, it is of practical importance to identify the environmental risks of MPs, which could lead to a significant impact on public health. In addition to the healthy population, there are large numbers of patients with chronic diseases around the world whose responses to MPs are understudied, representing a significant knowledge gap within the health risk assessment of MPs. In this study, the response sensitivity to MPs of mice with acute colitis was compared with that of healthy mice. The mice were fed water containing polystyrene microplastics (PS MP) at a concentration of 500 µg/L for 28 days. The results showed that PS MP exposure induced inflammatory effects and exerted great disturbance on liver metabolites. Moreover, exposure to PS MP exaggerated dextran sodium sulfate (DSS)-induced acute colitis, as well as lipid disorders, as verified by typical inflammatory factor expression and triglyceride accumulation. The increased intestinal permeability of mice with acute colitis caused by exposure to PS MP may be responsible for the upregulated adverse effects. The results of this study suggest that populations with chronic diseases might be more sensitive to environmental contamination, which should be considered during health risk assessments.


Assuntos
Colite , Poluentes Químicos da Água , Animais , Colite/induzido quimicamente , Humanos , Fígado , Camundongos , Microplásticos , Plásticos , Poliestirenos , Poluentes Químicos da Água/toxicidade
19.
Sci Total Environ ; 750: 142370, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182210

RESUMO

Plastic debris is ubiquitous in aquatic systems and has been proven vehicles for the transport of various pollutants including trace organic compounds. Nanoplastics have large specific surface area and hydrophobic characteristics and therefore are capable of adsorbing other organic or inorganic chemicals from the environment. Antibiotics, as another class of emerging contaminants, have raised significant research concern in recent years as they pose threats to the ecosytems and human health. Nevertheless, little information is available on the adsorption behaviors of antibiotics onto nano-sized plastics. The toxicity of combined nanoplastics and antibiotics is also largely unknown. In this study, the physicochemical and thermodynamic interactions between representative nanoplastics, which containing a carboxyl functional group of polystyrene nanoplastics (PS-COOH), and typical antibiotic, i.e., ciprofloxacin (CIP) were investigated in a batch adsorption experiment. The specific thermodynamic correlation function of PS-COOH combined with CIP was obtained through isothermal titration microcalorimetry (ITC) analysis. The adsorption kinetics and isotherm of CIP on PS-COOH closely fit the pseudo-second-order kinetic model (r2 = 0.99) and Freundlich isotherm (r2 = 0.99). The ITC results showed that the adsorption reaction of PS-COOH with CIP was a spontaneous exothermic reaction. The adsorption of antibiotics on nanoplastics may aggravate the negative impacts of these two pollutants on aqueous ecosystems, and we hypothesized that would be reflected in the survival rate of model organism of Caenorhabditis elegans when exposed to this combination. This work used a mechanistic approach to unravel the adsorption behavior of antibiotics on nanoplastics and shed light on their potential impact on aquatic ecosystems.


Assuntos
Plásticos , Poluentes Químicos da Água , Adsorção , Ciprofloxacino/toxicidade , Ecossistema , Cinética , Plásticos/toxicidade , Poliestirenos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
20.
J Environ Sci (China) ; 99: 175-186, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183695

RESUMO

Microalgae and cyanobacteria are fundamental components of aquatic ecosystems. Pollution in aquatic environment is a worldwide problem. Toxicological research on microalgae and cyanobacteria can help to establish a solid foundation for aquatic ecotoxicological assessments. Algae and cyanobacteria occupy a large proportion of the biomass in aquatic environments; thus, their toxicological responses have been investigated extensively. However, the depth of toxic mechanisms and breadth of toxicological investigations need to be improved. While existing pollutants are being discharged into the environment daily, new ones are also being produced continuously. As a result, the phenomenon of water pollution has become unprecedentedly complex. In this review, we summarize the latest findings on five kinds of aquatic pollutants, namely, metals, nanomaterials, pesticides, pharmaceutical and personal care products (PPCPs), and persistent organic pollutants (POPs). Further, we present information on emerging pollutants such as graphene, microplastics, and ionic liquids. Efforts in studying the toxicological effects of pollutants on microalgae and cyanobacteria must be increased in order to better predict the potential risks posed by these materials to aquatic ecosystems as well as human health.


Assuntos
Cianobactérias , Poluentes Ambientais , Microalgas , Poluentes Químicos da Água , Ecossistema , Humanos , Plásticos , Poluentes Químicos da Água/toxicidade
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