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1.
Mar Pollut Bull ; 204: 116562, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38850757

RESUMO

The rise of plastics in the 20th century revolutionized modern life but inadvertently exacerbated the marine litter crisis. The proliferation of wastes such as single-use plastics has escalated pollution along the coastline, demanding coordinated, decisive, and unified action. While the absence of specific national marine litter policies is concerning, there is growing recognition of urgency to address this issue. A group of experts and stakeholders was involved through a multi-staged workshop to assess the generated information based on scientific evidence and formulate a framework for the National Marine Litter Policy (NMLP). This paper proposes policy options (4 targets & 20 strategies) to address marine litter pollution, especially plastics, and aims to elucidate the urgency and significance of implementing an NMLP as a comprehensive strategy to combat plastics pollution. Implementing dedicated policies and action plans tailored to the unique challenges faced by each country is a vital step towards sustainable oceans.


Assuntos
Política Ambiental , Plásticos , Índia , Monitoramento Ambiental , Poluição da Água/prevenção & controle , Poluição da Água/estatística & dados numéricos , Resíduos
2.
Heliyon ; 10(9): e30403, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38726173

RESUMO

Aquaculture is essential for meeting the growing global demand for fish consumption. However, the widespread use of plastic and the presence of microplastics in aquaculture systems raise concerns about their impact on fish health and the safety of aquaculture products. This study focused on the Nile tilapia (Oreochromis niloticus), one of the most important aquaculture fish species globally. The aim of this study was to investigate the effects of dietary exposure to a mixture of four conventional fossil fuel-based polymers (microplastics) on the health of adult and juvenile Nile tilapia. Two experiments were conducted, with 36 juvenile tilapia (10-40 g weight) exposed for 30 days and 24 adult tilapia (600-1000 g) exposed for 7 days, the former including a natural particle (kaolin) treatment. In the adult tilapia experiment, no significant effects on intestinal health (Ussing chamber method), oxidative stress, or inflammatory pathways (enzymatic and genetic biomarkers) were observed after exposure to the microplastic mixture. However, in the juvenile tilapia experiment, significant alterations in inflammatory pathways were observed following 30 days of exposure to the microplastic mixture, indicating potential adverse effects on fish health. These results highlight the potential negative impacts of microplastics on fish health and the economics and safety of aquaculture.

3.
Environ Int ; 186: 108633, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38603814

RESUMO

In the severe pollution area of nanoplastics (NPs) and cadmium ions (Cd2+), the joint effects of their high environmental concentrations on primary producers may differ from those of low environmental doses. Thus, we investigated the physiological changes, cell morphology, molecular dynamic simulation, phenotypic interactions, and metabolomics responses of C. pyrenoidosa to high environmental concentrations of NPs and Cd2+ after 12-d acclimation. After 12-d cultivation, mono-NPs and mono-Cd2+ reduced cell density and triggered antioxidant enzymes, extracellular polymeric substances (EPS) production, and cell aggregation to defend their unfavorable effects. Based on the molecular dynamic simulation, the chlorine atoms of the NPs and Cd2+ had charge attraction with the nitrogen and phosphorus atoms in the choline and phosphate groups in the cell membrane, thereby NPs and Cd2+ could adsorb on the cells to destroy them. In the joint exposure, NPs dominated the variations of ultrastructure and metabolomics and alleviated the toxicity of NPs and Cd2+. Due to its high environmental concentration, more NPs could compete with the microalgae for Cd2+ and thicken cell walls, diminishing the Cd2+ content and antioxidant enzymes of microalgae. NPs addition also decreased the EPS content, while the bound EPS with -CN bond was kept to detoxicate Cd2+. Metabolomics results showed that the NPs downregulated nucleotide, arachidonic acid, and tryptophan metabolisms, while the Cd2+ showed an opposite trend. Compared with their respective exposures, metabolomics results found the changes in metabolic molecules, suggesting the NPs_Cd2+ toxicity was mitigated by balancing nucleotide, arachidonic acid, tryptophan, and arginine and proline metabolisms. Consequently, this study provided new insights that simultaneous exposure to high environmental concentrations of NPs and Cd2+ mitigated microalgae cellular toxicity, which may change their fates and biogeochemical cycles in aquatic systems.


Assuntos
Cádmio , Metabolômica , Microalgas , Cádmio/toxicidade , Microalgas/efeitos dos fármacos , Microalgas/metabolismo , Simulação de Dinâmica Molecular , Poluentes Químicos da Água/toxicidade , Microplásticos/toxicidade
4.
Int Rev Adm Sci ; 90(1): 237-258, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38481579

RESUMO

Although science diplomacy has been gaining relevance in foreign policy to solve environmental challenges, critical questions concerning what different instruments mean under the term 'science diplomacy' and whether science diplomacy does contribute to the progress in solving environmental issues remain unanswered. We explore those questions by linking science diplomacy salient features through documentary analysis of international instruments addressing the plastics pollution in the ocean. We find that from a science diplomacy and multi-level governance perspective, the responsibilities and capabilities of emergent actors of cross-level governance are also important, leading to more attention being paid to changes in the role of national authorities, away from passive leadership to cross-cutting coalitions supported by the salient features of science diplomacy, and redefining dominant discursive approaches that have framed plastics waste. Points for practitioners: As a result of the cost and limitations of the current international mechanisms, there is currently no incentive for individual countries to take action against marine plastic pollution.Science diplomacy and multi-level governance can contribute to international cooperation, foreign policy and national strategies.Leading efforts to engage countries with fewer scientific and technological capabilities could benefit countries' foreign policy.

5.
Sci Total Environ ; 905: 167184, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37730030

RESUMO

Microplastics (MPs) have been widely found in soils, however, the mechanism of MPs influencing plant growth is still debated and possibly attributed to the soil environment changed by MPs. In this study, 0.0 %, 0.1 %, 0.5 %, 1.0 %, 2.0 %, and 5.0 % (w/w) content of low-density polyethylene MPs (LDPE-MPs) with the particle sizes of 75-2000 µm was used to test how MPs alter the germination and the early growth of lettuce (Lactuca sativa var. ramosa Hort.) in Mollisols under both natural condition and regular incubation condition. Soil temperature (ST), soil moisture (SM) and the ratio of cracks area to surface soil area (CA) and cracks length to surface soil area (CL) were monitored. As well, the dynamics of water and nutrient infiltration reported by our previous publication were combined to analyze the relationship between soil properties and crop growth influenced by MP concentration. The main results showed that: (1) compared with CK (0.0 %), the germination and plant height of lettuce were lowest in treatments with the middle concentration of MPs (0.5 % and 1 %, w/w), but was highest in treatments of high concentration of MPs (5.0 %, w/w) during the whole 14 days of incubation; (2) increasing MP concentration weakened the influence of SM on ST in Mollisols; (3) the average of SM and ST were highest at 5 % of MP concentration, while was lowest at 0.5 % and 1 % of MP concentration from the 2nd to the 9th day; (3) compared with CK and other treatments, the CA and CL were lowest in 1.0 % MP concentration, but were highest in 0.1 % and 5.0 % of MP concentration. This study provides insight that middle, rather than high and low levels of MP concentration, significantly decrease the SM and ST and increase nitrogen leaching which further leads to negative impacts on emergent and early growth of crops in soils with heavy texture (Mollisols).


Assuntos
Germinação , Lactuca , Microplásticos , Plásticos , Temperatura , Polietileno , Solo
6.
Mar Pollut Bull ; 195: 115510, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37683394

RESUMO

Plastic pollution is a critical environmental issue with far-reaching and not yet fully explored consequences. This study uncovered a significant source of plastic contamination arising from improper application and management of expanded polystyrene (EPS) utilised as expansion joints at a construction site near the coast of Antofagasta, Chile. Through meticulous field observations and calculations, we estimate that a staggering 82.9 million EPS spheres have the potential to be released into the environment from the 7.62 m3 of this material used for the construction of this coastal promenade, constituting a chronic source of pollution. Despite the ongoing construction, we have already evidenced mechanical fragmentation and dispersion of EPS microplastic pollution in the surrounding natural environment. To our knowledge, this is the first study that documents misused construction materials contributing to plastic pollution. In addition to the EPS pollution, our findings reveal an alarming accumulation of litter - an acute pollution source - including plastic cups, bottles, carrier bags, and several other construction materials (e.g. plastic nets, films) that are exacerbating the pollution problems within the region and potentially endangering marine and terrestrial organisms. These observations highlight the urgent need for mitigating measures and intervention policies targeting construction-related plastic and microplastic pollution, along with a more robust regulatory framework for construction activities as well as adequate surveillance and enforcement.

7.
Sci Total Environ ; 898: 165437, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37437636

RESUMO

Oceans have been considered as an unlimited supply of goods and services, but resource extraction and waste disposal became ubiquitous and have been damaging the health of marine ecosystems. Finding suitable sentinel species of the human impacts on the oceans is thus imperative, since they may work as early warnings of disruptive situations. In this study, we investigated how taxonomy and foraging distribution influenced the occurrence of anthropogenic debris among five seabird species inhabiting the tropical Atlantic region. Occurrence of anthropogenic debris was assessed using faeces of breeding individuals as a proxy of ingestion. A total of 268 particles were extracted from all samples. The categories "fragments" and "fibres", as well as the colour "blue", were the most prevalent characteristics across species. There was a high diversity of polymers from cellulosic particles to synthetic plastics (Anthropogenic Cellulosic 26.9 %; Polyester 7.7 %; Varnish 5.8 %; Polypropylene 1.9 %). Species with a more coastal foraging strategy exhibited higher occurrence and number of anthropogenic debris when compared to species foraging comparably more in pelagic areas. This suggests that anthropogenic debris are more prevalent in coastal foraging areas, where human activities occur in higher number and frequency (e.g., fisheries) and sources of freshwater input from inland are at close distance. These results provide more evidence to the growing perception on the ubiquity and diversity of anthropogenic debris in the marine environment, and further support the usefulness of using seabirds as bio-indicators of anthropogenic pollution in both neritic and oceanic regions.


Assuntos
Ecossistema , Resíduos , Humanos , Animais , Resíduos/análise , Monitoramento Ambiental/métodos , Plásticos , Aves , Ingestão de Alimentos
8.
J Hazard Mater ; 459: 132098, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37490799

RESUMO

Landfilling is the most traditional disposal method of domestic waste. Plastic waste in landfill sites could degrade to microplastics (MPs) and diffuse to the surrounding environment with leachate. However, MPs pollution in landfill mineralized refuse has not been well recognized. In the present research, a detection method for mixed MPs of polyethylene (PE), polypropylene (PP), and polystyrene (PS) based on Py-GC/MS was established and verified. The method is suitable for the rapid quantitative detection of large-batch of complex solid matrix samples, with an average deviation of less than 10%. Based on the method, samples from a landfill site in South China were studied, where PE was found to be the main component. The total concentration of MPs in mineralized refuse was 7.62 kg/t in the old area and 5.49 kg/t in the young area. Further analysis showed that the content of MPs was correlated with that of plastic waste and the landfill age, indicating that a considerable proportion was secondary MPs. The reserves of MPs in landfill sites may have reached an alarming number. In the absence of adequate safeguards, quantities of MPs may spread from the landfill sites, resulting in serious pollution of the surrounding soil and groundwater.

9.
Environ Pollut ; 333: 122095, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37385357

RESUMO

The widespread existence of microplastics (MPs) in soil has been extensively demonstrated, and their presence would ineluctably change soil physicochemical properties and microbial community composition. However, there is limited understanding of how MPs affect soil microbial assembly. In this study, three different polymer types of MPs, i.e., high-density polyethylene (HDPE), polystyrene (PS), and polylactic acid (PLA), with the same particle size (100 µm) and dose (2%) were applied under the planted and unplanted condition, Pennisetum alopecuroides was chosen as a model species. Plant growth parameters, soil physicochemical properties, and microbial communities (including bacteria and eukaryotes) were determined. The assembly and the co-occurrence network of microbial communities were analyzed. Results revealed that the effect of MPs on soil physicochemical properties was type-dependent and could influenced by the presence of P . alopecuroides. MPs could enrich bacterial genera related to nitrogen cycle and some pathogens of eukaryotes. The presence of MPs changed bacterial and eukaryotic community assembly, in which diversity drove the deterministic/stochastic assembly processes. MPs addition increased the complexity of bacterial network, while had a minor effect on eukaryotic network. The inhibition of MPs on P . alopecuroides growth decayed over time, HDPE MPs was more harmful to P . alopecuroides growth than PS and PLA MPs. Our findings enormously improved our comprehensions of MPs-induced ecological impacts and interactions of soil bacterial and eukaryotic communities .


Assuntos
Microplásticos , Solo , Plásticos , Polietileno , Microbiologia do Solo , Eucariotos , Poliésteres , Poliestirenos
10.
Animals (Basel) ; 13(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36978580

RESUMO

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.

11.
Microplast nanoplast ; 3(1): 3, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36748026

RESUMO

The intensive global plastic production, use and associated plastic pollution have caused concern for the potential risks to human health and the environment. This has led to the adoption of numerous regulatory initiatives aiming to combat plastic pollution. Despite the considerable regulatory activity in the field of plastic, it appears that there is still debate about the actual risks of plastic to humans and the environment. This raises the question of to what extent the current plastic regulation is evidence-based, a declared ambition in the European Union. Therefore, the aim of this study was to investigate to what extent key policy initiatives targeting plastic pollution are based on scientific evidence. Selection of initiatives was based on expert elicitation accounting for the opinions of persons involved in the development of the policy initiatives, and a thorough assessment of the historical development of plastic pollution regulation, with focus on their importance both with respect to regulation of plastics as well as their historical importance as drivers for societal actions on plastic pollution. We find that scientific evidence appears to be generally present in the scientific foundation for the policy initiatives analysed in this study. All the initiatives are supported by scientific articles and reports about among others plastic sources, ecological impacts of plastic production and consumption patterns. Marine litter monitoring data was found to contribute to the evidence base for 4 out of the 6 policy initiatives and thereby appears to be one of the central scientific drivers behind the societal actions on plastic pollution. Other scientific tools applied when shaping the policy initiatives include risk assessment, impact assessment and life cycle assessment. Despite the prevalent consideration and application of scientific evidence, there seems to be a broad recognition in the preparatory work of the initiatives that there is still a lot of uncertainty related to determining the harm of plastic pollution. In these cases, taking precautionary actions seems however to be justified, recalling not least the precautionary principle. As the issue of plastic pollution is complex and still subject to uncertainty, it seems important both that policy initiatives allow for flexibility and continuing adjustment to the on-going knowledge generation and that the scientific community provides the needed research to continue the science-informed policy development.

12.
Mar Pollut Bull ; 186: 114489, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36549238

RESUMO

Litter is a serious threat to the marine environment, with detrimental effects on wildlife and marine biodiversity. Limited data as a result of funding and logistical challenges in developing countries hamper our understanding of the problem. Here, we employed commercial unmanned aerial vehicle (UAV) as a cost-effective tool to study the exposure of marine turtles to floating marine litter (FML) in waters of Mayo Bay, Philippines. A quadcopter UAV was flown autonomously with on-board camera capturing videos during the flight. Still frames were extracted when either turtle or litter were detected in post-flight processing. The extracted frames were georeferenced and mapped using QGIS software. Results showed that turtles are highly exposed to FML in nearshore waters. Moreover, spatial dependence between FML and turtles was also observed. The study highlights the effectiveness of UAVs in marine litter research and underscores the threat of FML to turtles in nearshore waters.


Assuntos
Tartarugas , Animais , Monitoramento Ambiental/métodos , Filipinas , Fluormetolona , Dispositivos Aéreos não Tripulados , Baías , Plásticos/análise
13.
Sci Total Environ ; 858(Pt 1): 159834, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36461575

RESUMO

While versatile application of plastics has generated huge benefits in our life, the 'plastic end-of-life' comes with downsides of emerging concern is plastic particles within all parts of environments. Plastics are highly resistant to degradation and sustain in the environment for a prolonged period resulting in easy access of microplastics into human food chain. Microplastic exposure to humans is caused by foods of both animal and plant origin, food additives, drinks, and plastic food packaging. Living organisms can accumulate microplastics in cells and tissues which results in threats of chronic biological effects and potential health hazards for humans including body gastrointestinal disorders, immunity, respiratory problem, cancer, infertility, and alteration in chromosomes. Because of the threat of microplastics on human health, it is essential to ensure food safety as well as control plastic use with strict regulation of proper management. This study aims to enlighten future research into the core component of microplastics, their exposure to human food, prevention to human food chain, and biological reactions in human body. Finally, it is recommended to consider the presence of microplastics in different foods, as most of the existing research mainly focused on sea foods. And it is important to study the mechanism of toxicity with pathways in the human body based on the different types, shapes, and sizes of plastic particles.


Assuntos
Microplásticos , Plásticos , Animais , Humanos , Plásticos/toxicidade , Cadeia Alimentar , Alimentos Marinhos , Aditivos Alimentares
14.
Front Endocrinol (Lausanne) ; 14: 1330396, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38239985

RESUMO

Plastics found in our everyday environment are becoming an increasing concern for individual and population-level health, and the extent of exposure and potential toxic effects of these contaminants on numerous human organ systems are becoming clear. Microplastics (MPs), tiny plastic particles, appear to have many of the same biological effects as their plastic precursors and have the compounded effect of potential accumulation in different organs. Recently, microplastic accumulation was observed in the human placenta, raising important questions related to the biological effects of these contaminants on the health of pregnancies and offspring. These concerns are particularly heightened considering the developmental origins of health and disease (DOHaD) framework, which postulates that in utero exposure can programme the lifelong health of the offspring. The current review examines the state of knowledge on this topic and highlights important avenues for future investigation.


Assuntos
Microplásticos , Poluentes Químicos da Água , Criança , Humanos , Gravidez , Feminino , Microplásticos/toxicidade , Plásticos/toxicidade , Saúde da Criança , Poluentes Químicos da Água/toxicidade , Monitoramento Ambiental , Fertilidade
15.
Mar Drugs ; 20(12)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36547907

RESUMO

Plastics are present in the majority of daily-use products worldwide. Due to society's production and consumption patterns, plastics are accumulating in the environment, causing global pollution issues and intergenerational impacts. Our work aims to contribute to the development of solutions and sustainable methods to mitigate this pressing problem, focusing on the ability of marine-derived actinomycetes to accelerate plastics biodegradation and produce polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics. The thin plastic films' biodegradation was monitored by weight loss, changes in the surface chemical structure (Infra-Red spectroscopy FTIR-ATR), and by mechanical properties (tensile strength tests). Thirty-six marine-derived actinomycete strains were screened for their plastic biodegradability potential. Among these, Streptomyces gougerotti, Micromonospora matsumotoense, and Nocardiopsis prasina revealed ability to degrade plastic films-low-density polyethylene (LDPE), polystyrene (PS) and polylactic acid (PLA) in varying conditions, namely upon the addition of yeast extract to the culture media and the use of UV pre-treated thin plastic films. Enhanced biodegradation by these bacteria was observed in both cases. S. gougerotti degraded 0.56% of LDPE films treated with UV radiation and 0.67% of PS films when inoculated with yeast extract. Additionally, N. prasina degraded 1.27% of PLA films when these were treated with UV radiation, and yeast extract was added to the culture medium. The main and most frequent differences observed in FTIR-ATR spectra during biodegradation occurred at 1740 cm-1, indicating the formation of carbonyl groups and an increase in the intensity of the bands, which indicates oxidation. Young Modulus decreased by 30% on average. In addition, S. gougerotti and M. matsumotoense, besides biodegrading conventional plastics (LDPE and PS), were also able to use these as a carbon source to produce degradable PHA bioplastics in a circular economy concept.


Assuntos
Actinobacteria , Plásticos , Polietileno/metabolismo , Actinobacteria/metabolismo , Actinomyces/metabolismo , Biodegradação Ambiental , Biopolímeros , Poliésteres , Poliestirenos
16.
J Hazard Mater ; 437: 129375, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-35724616

RESUMO

Shallow lakes and ponds, providing essential ecological and environmental services, are simultaneously disrupted by various pollutants of emerging concern (PECs). As a group of PECs, microplastics (MPs) ubiquitously found in freshwater are toxic to a huge variety of organisms. However, the consequence of secondary factors such as food quantity determining MPs toxicity, and the corresponding water safety risks await assessment is still poorly understood. Accordingly, we investigated how MPs across three particle sizes (10, 1 and 0.07 µm) interacted with food abundance to affect survival, reproduction and population performance in the waterflea Daphnia magna. Across multiple population traits, we found that MPs toxicity on Daphnia population performance was attenuated by higher food quantity, but this attenuation size was strongly dependent on MPs size. Path analysis results showed population growth rate was mainly constrained by reduced survival rather than fecundity. Furthermore, the additive null model revealed that the interactive effects of food abundance and MPs were predominately recognized as synergism and trait dependency. The present findings underscore the importance of considering the complexity of interactions that can occur in the wild, when assessing the effects of plastics pollution on population dynamics of the basic trophic level in lakes and ponds.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Daphnia , Lagos , Microplásticos/toxicidade , Plásticos/toxicidade , Poluentes Químicos da Água/análise
17.
Sci Total Environ ; 832: 155026, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35390363

RESUMO

Microplastics (MPs) are regarded as transport media for heavy metals in aquatic systems, whereas the effects of the heavy metal-enriched MPs on microbial biofilms are still unclear. In this study, Pb(II) sorption onto polyvinyl chloride (PVC) MPs and its effects on the formation and ecological functions of microbial biofilms were investigated. The results showed that the interaction between Pb(II) and PVC MPs was dominated by physisorption. The maximum sorption amount reached 1.25 mg/g. Afterward, microbial biofilms were exposed to the Pb(II)-enriched PVC particles. It is suggested that Pb(II)-enriched PVC exposure reduced productivities of polysaccharides and proteins in extracellular polymeric substances, which restricted the formation of microbial biofilms. Meanwhile, microbial community structure was reassembled accompanying the decline of capacities for nitrate and phosphate removal. Therefore, this study examines the ecological risk associated with the heavy metal-enriched MPs that can adversely affect microbial biofilms.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Biofilmes , Chumbo , Microplásticos , Plásticos/química , Cloreto de Polivinila , Poluentes Químicos da Água/análise
18.
Mar Pollut Bull ; 175: 113386, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35124374

RESUMO

Floating marine litter (FML) surveys were conducted in the near shore waters of Mombasa, Kilifi and Kwale Counties of Kenya through trawling using a manta net. A mean density of 26,665 ± 2869 items km-2 composed of 34.8% hard plastic, 40.5% soft plastics and 22.0% plastic lines/fibers was reported in this study. Litter densities in Kwale, Kilifi and Mombasa Counties were not influenced by monsoons, however, litter composition was influenced by monsoons with NEM and SEM being dominated mainly by hard plastics and soft plastics respectively. Litter categories diversity, evenness and richness were also not influenced by the monsoons during both NEM (1.01, 0.78 and 3, respectively) and SEM (1.09, 0.78 and 4, respectively). Fishing and recreational beaches had higher litter densities during NEM compared to SEM attributed to higher beach visitation and increased fishing activities during the calmer NEM season.


Assuntos
Praias , Resíduos , Monitoramento Ambiental , Quênia , Plásticos , Resíduos/análise
19.
Polymers (Basel) ; 15(1)2022 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-36616431

RESUMO

Developing degradable bio-plastics has been considered feasible to lessen marine plastic pollution. However, unanimity is still elusive regarding the actual degradability of bio-plastics such as polylactide (PLA) and poly(hydroxybutyrate) (PHB). Thus, herein, we studied the degradability of fabrics made from PLA/PHB blends in marine seawater. The dry-mass percentage of the PLA/PHB fabrics decreased progressively from 100% to 85~90% after eight weeks of immersion. Two environmental aging parameters (UV irradiation and aerating) were also confirmed to accelerate the abiotic hydrolysis of the incubated fabrics. The variation in the molecular structure of the PLA/PHB polymers after the degradation process was investigated by electrospray ionization mass spectrometry (ESI-MS). However, the hydrolysis degradability of bulky PLA/PHB blends, which were used to produce such PLA/PHB fabrics, was negligible under identical conditions. There was no mass loss in these solid PLA/PHB plastics except for a decrease in their tensile strength. Finally, a deep learning artificial neural network model was proposed to model and predict the nonlinear abiotic hydrolysis behavior of PLA/PHB fabrics. The degradability of PLA/PHB fabrics in marine water under the synergistic destructive effects of seawater, UV, and dissolved oxygen provides a pathway for more sustainable textile fibers and apparel products.

20.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34845018

RESUMO

The Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) can be further strengthened to control ozone-depleting substances and hydrofluorocarbons used as feedstocks to provide additional protection of the stratospheric ozone layer and the climate system while also mitigating plastics pollution. The feedstock exemptions were premised on the assumption that feedstocks presented an insignificant threat to the environment; experience has shown that this is incorrect. Through its adjustment procedures, the Montreal Protocol can narrow the scope of feedstock exemptions to reduce inadvertent and unauthorized emissions while continuing to exempt production of feedstocks for time-limited, essential uses. This upstream approach can be an effective and efficient complement to other efforts to reduce plastic pollution. Existing mechanisms in the Montreal Protocol such as the Assessment Panels and national implementation strategies can guide the choice of environmentally superior substitutes for feedstock-derived plastics. This paper provides a framework for policy makers, industries, and civil society to consider how stronger actions under the Montreal Protocol can complement other chemical and environmental treaties.


Assuntos
Poluentes Atmosféricos , Poluição do Ar/legislação & jurisprudência , Clorofluorcarbonetos/análise , Efeito Estufa , Ozônio Estratosférico , Poluição do Ar/prevenção & controle , Saúde Global , Humanos , Cooperação Internacional , Saúde Pública , Política Pública
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