Blue Fibers Research Articles

Investigation of microplastic pollution index in the urban surface water: A case study in west Godavari district, Andhra Pradesh, India.

Microplastics (MPs) are a growing environmental issue because of their widespread prevalence and their long-term effects on ecosystems and human health. Global studies have identified MPs in various aquatic environments, such as lake, rivers, estuaries, wastewater, and oceans. Although most MPs originate from urban surface water sources, the specific intensity, characteristics, and associated risk assessments remain unclear. This study focuses on west Godavari region of India, specifically analyzing MPs in surface water samples Godavari River and two water treatment plants (WTPs). A total of 330MPs found in the surface water and 121MPs in theWTP. In surface water, MPs were predominantly blue and transparent fibers, with the majority measuring less than 500μm in size. Conversely, at the WTP, larger MPs, primarily in blue fiber form and exceeding 3000μm, were observed. Additionally, μ-Raman spectroscopy analysis identified the presence of various polymers, including PP, PVC, PC, Nylon, and PET, among others. The risks associated with MPs, including their concentration and chemical composition, were assessed across all sample types using various indices such as Contamination Factor (CFi), Pollution Load Index (PLI), Polymer Risk Index (H), Potential Ecological Risk Index (RI), and Estimated Intake (EI) (daily, annually, and lifetime). The risk assessment revealed that the type of polymer poses a greater risk of MP pollution than the concentrations of MPs themselves. These findings provide critical insights into MP contamination patterns and risks, emphasizing the need for targeted mitigation strategies in this region.

Spatial and temporal variation of microplastic in mussels from intertidal and subtidal banks in the Southwestern Atlantic Ocean.

The objective of this study was to identify the presence of MPs in M. platensis tissues and evaluate the spatial and temporal variation of MPs in this species between different zones (Intertidal and Subtidal) and years (2012 and 2019) in Buenos Aires province Villa Gesell, Southwestern Atlantic Ocean. Our hypothesis is that the Intertidal zone will have a greater number of MPs than the Subtidal zone, and this trend will also be observed in 2019 compared to 2012. Specimens of M. platensis from the intertidal zone were hand-collected during low tide on the pier pilings in August 2012 and 2019, and the subtidal specimens were obtained by bottom trawling from a campaign with the Oceanographic ship ARA Puerto Deseado in August 2012. In general, the number of MPs varied between zones, indicating a greater number of this contaminant in the intertidal zone, whereas the same was not observed for the years. Furthermore, among the analyzed specimens, 90% contained MPs, all of which were in the form of fibers, with blue fibers being the predominant type, and polystyrene being the most prevalent polymer. This group of organisms has significant ecological roles and commercial value. Assessing their contamination status and MPs characteristics is important to understand the potential risks to marine ecosystems and human health.

Efficacy of antimicrobial photodynamic therapy in endodontics of primary teeth: a scoping review.

The objective of this study was to identify, describe and synthesize the data published about the effectiveness of antimicrobial photodynamic therapy (aPDT) in the pulpectomy of primary teeth. A search was conducted in six electronic databases and the gray literature in June and July 2023, without restrictions on language or date of publication. The search strategy included indexed terms (MeSH terms) and your synonyms. Clinical trials, in vitro studies, case reports and retrospective studies that used photodynamic therapy in primary teeth pulpectomies were considered eligible. Among the 1,674 articles retrieved, 15 were included, published between 2014 and 2022, comprising six in vitro studies, five clinical trials, and four case reports. The sample consisted of children aged 2 to 8 years of both sexes, and included 1 to 62 teeth, mostly anterior. In two in vitro studies, the sample was taken from root canals. Most studies used a diode laser, methylene blue, and optical fiber. The pre-irradiation time ranged from 1 to 5min. All protocols demonstrated microbial reduction before and after using aPDT, with no statistical difference among the groups. Furthermore, six studies demonstrated treatment success. Despite the divergence in methodology and protocols, aPDT is an effective method for reducing microorganisms, and is a promising adjunct treatment in primary teeth pulpectomies.

Characterization and risk assessment of microplastics pollution in Mohamaya Lake, Bangladesh.

Microplastics (MPs) have recently gained attention as emerging environmental contaminants, yet knowledge of their distribution, sources, and risks in freshwater lakes remains limited. This study examined the occurrence and risk of MPs in water and sediment samples from eight locations in Mohamaya Lake (Bangladesh) collected in April and May 2023. MPs were identified using stereomicroscopy and FTIR, revealing concentrations of 20-95 particles/L in water and 550-1900 particles/kg (d.w.) in sediment, with mean values of 50.62±9.95 particles/L and 1068.75±521.49 particles/kg (d.w.). Dominant MPs were blue fibers, 0-0.5mm in size, with HDPE, PET and LDPE as the most common polymers. This study used four indices (nemerow pollution index-NPI, contamination factor-CF, pollution load index-PLI, and polymer hazard index-PHI) to assess MP pollution, revealing light to high contamination levels. While NPI indicated light pollution, CF, PLI, and PHI highlighted areas of moderate to high risk, with certain polymers showing high to extreme toxicity. This study deepens understanding of MP contamination in Bangladesh's freshwater lakes, underscoring the need for research on ecotoxicology, regulation, and associated challenges.

Plastic ingestion in aquatic insects: Implications of waterbirds and landfills and association with stable isotopes

Wetlands provide numerous ecosystem services including freshwater purification. Nonetheless, their functionality is continuously impacted by many pollutants. Plastics are considered as an emerging threat for these ecosystems, but only recently have studies began to focus on plastic and microplastic (MP) contamination in wetlands, especially in biota. This study aims to investigate the abundance of MPs in two ubiquitous aquatic insect taxa (i.e. Corixidae (Hemiptera) and Chironomidae (Diptera)) collected in twelve zones within Mediterranean wetlands belonging to three basins located in Andalusia (south-west Spain). We compared MP contamination across basins and tested the proximity to landfills and presence of colonial waterbirds [i.e. white storks (Ciconia ciconia) and gulls (Larus michahellis and L. fuscus)] on MP abundance in aquatic insects. We also performed stable isotope analyses of nitrogen and carbon (δ15N and δ13C) to evaluate the potential association between MP abundance and isotopic values. We detected 571 suspected MPs (mostly blue fibers) in insects of different developmental stages (i.e., larvae, pupae, nymphs and adults). Polyesters and polypropylene were the most frequent polymers detected. The generalized linear mixed models indicated that MP abundance decreased with increasing distance from landfills; but it also increased in sites with birds that fed on landfills and roost in wetlands. When controlling for landfill effects, sites in the smallest basin (Guadalete) had lower MP contamination than those in Odiel-Tinto and the much larger (>15×) Guadalquivir. Moreover, we found a negative association between MPs items/g (or mean MPs) and 15N isotopes in adult corixids. Our findings showed that MP pollution is present in all the study areas, including strictly protected wetlands. The use of aquatic insects for biomonitoring of MP pollution can help identify priority areas for management actions to mitigate plastic pollution.

Microplastic-contamination in the flesh and gastrointestinal tract of nile tilapia (Oreochromis niloticus) reared in floating net cages at lake Ranu Grati, Pasuruan, East Java, Indonesia

In recent years, microplastics (MPs) have emerged as a prominent environmental problem in waters and environments, including lake waters. Microplastics in freshwater, such as those in floating net cages (FNC), can be consumed by Nile tilapia (Oreochromis niloticus), one of the commercially available cultivated fish in Indonesia. This study aims to determine the prevalence of microplastics and compare their characteristics in the surface water, flesh, and gastrointestinal tract (GIT) of Nile Tilapia (O. niloticus) at Lake Ranu Grati, Pasuruan, East Java, Indonesia. Visual characteristics of MPs were observed using a stereo microscope, and polymers were analysed by ATR-FTIR (Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy). The abundance of MPs from water sample locations in Lake Ranu Grati reached 1116 MPs particles. In the water samples, the inner and outer sides of the FNC are dominated by the MPs with a size range of 251–500 µm and 1001-2000 µm in the milieu of Ranu Grati Lake. The most common MPs' types and colours are fibre and black, dominated by Polyethylene (PE). In 25 O. niloticus samples, 576 particles of MPs were found in the flesh and 724 particles in the gastrointestinal tract (GIT). This study found no significant variation in microplastic abundance between flesh and GIT samples (p>0.05; Mann-Whitney U test). Microplastics in Nile Tilapia flesh samples were dominated by blue fibres with a size range of 101–250 µm, and the polymer found was PA (polyamide). Meanwhile, in the GIT samples, microplastics were dominated by black fibre, with a size range of 251–500 µm, and the polymer found was PA (polyamide).

The presence of microplastics in Baran's newt (Neurergus barani Öz, 1994) and the spotted newt (Neurergus strauchii Steindachner, 1887).

Microplastics (MPs), tiny plastic particles less than 5mm in size, have emerged as a common and worrying pollutant in marine, freshwater, and terrestrial environments worldwide. In this study, we revealed the microplastic exposure of two endemic newt species for Türkiye. We found that polyethylene terephthalate (PET) was the predominant microplastic polymer type in both species, with the blue fiber shape in particular. We also found that there was a negative correlation between microplastic size and gastrointestinal tract (GIT) weight, but there was no significant difference between body length and GIT weight of both species. Our findings might be surprising as the studied species live in natural spring waters in remote, high-altitude areas. However, the detection of water bottles in their habitats appears to be the reason for their exposure to microplastic pollution. Therefore, reducing the use of single-use plastics is predicted to contribute to the conservation of these endemic newts.

The revelry of plastic! Quali-quantitative variation of microplastics in freshwater before and after Carnival in south-eastern Brazil

Context Pollution by synthetic polymers is even more problematic to the environment when this material is fragmented into small portions, forming microplastics (MPs). Aims We analysed the influence of the Brazilian Carnival on the abundance and richness of MPs in the Paraíba do Sul River (PSR). Specific objectives included classifying MPs by shape, colour and polymer, and quantifying and comparing the abundance and richness of surface-water MPs before, during and after Carnival. Methods Samples were taken from the superficial layer of the water column in 2023, by using manta net. Key results In total, 843 MPs were identified in the surface water of PSR. Higher MP concentrations were observed after the Carnival event than in the other two periods. Blue and black fibres were the predominant MPs. Glitter and sequin occurred only during the Carnival and post-Carnival periods. Polyester, polyamide and polyethylene were the most abundant in all the periods. Conclusions Our findings strongly indicated that Carnival represents a potential short-term source of MP introduction into the PSR basin. Implications A significant 170% increase in MP abundance was observed 10 days after the Carnival, which is an event occurring across multiple locations in the PSR basin.

Impact of Eccentric Exercise Interventions with Small and Large Ranges of Motion on Rat Skeletal Muscle Tissue and Muscle Force Production.

Eccentric training induces greater hypertrophy while causing more muscle damage than concentric training. This study examined the effects of small-range eccentric contractions (SR-ECCs) and large-range eccentric contractions (LR-ECCs) on muscle morphology, contractility, and damage in rats. Thirty male Fischer 344 rats were divided into five groups: small-range ECC single-bout (SR-ECCSB, n = 4), large-range ECC single-bout (LR-ECCSB, n = 4), SR-ECC intervention (SR-ECCIntv, n = 7), LR-ECC intervention (LR-ECCIntv, n = 8), and control (Cont, n = 7). These groups underwent transcutaneous electrical stimulation involving 80 ECCs twice a week for four weeks. The results indicated that the LR-ECCSB group had more Evans blue dye-positive fibers than other groups. The SR-ECCIntv group showed no increase in the mean myofiber cross-sectional area. However, Pax7+ and Ki67+ cells significantly increased in both ECCIntv groups compared to the Cont group, and the connective tissue area was significantly greater in the LR-ECCIntv than in others. Muscle force was lower in both ECCIntv groups compared to the Cont group. These findings suggest that SR-ECC intervention may induce a smaller increase in the number of fibers with a large myofiber cross-sectional area and satellite cell proliferation with less muscle damage and myofibrosis compared to LR-ECCs.

Baseline Study on Microplastic Contamination in Commercial Fish from the Vellar Estuary, South India

Microplastic (MP) contamination has emerged as a serious worldwide issue. Human activity, commercial operations, and fishing are all concentrated around the coast, resulting in high levels of fish MPs contamination. This preliminary investigation aims to examine MP accumulation in commercial fish caught in the Vellar estuary region. Fish samples were collected from the estuary, and MPs in the gills and gastrointestinal tracts of three commercial fish species were analyzed for quantity, type, shape, and color using standard laboratory techniques. MPs particles were found in 2.55-4.35 items per individual fish, with an overall average of 3.2 particles in the gills and 5.5 in the gastrointestinal tract. The majority of the MPs were blue and green fibers with a diameter of 0.5-1 mm. Fragmented pieces of MPs and fibers were abundant in the gut. These findings demonstrated the extent of MPs contamination in Vellar estuary fish tissues, serving as a baseline for MPs loading in the estuary. This study has significant implications for food safety, highlighting the dangers of MPs in fisheries and aquaculture. It also identifies knowledge gaps in the long-term effects of MPs, suggesting a need for further research in this sector.

Comprehensive risk assessment of microplastics in tidal channel sediments in amazonian mangroves (northern Brazil)

Pollution by microplastics (MPs) in mangroves is a growing concern, given its potential ecological and human health impacts. The characteristics of microplastic pollution and a risk assessment of MPs in the Amazon region's coastal sediments are still insufficient, and information about MP pollution in the benthic component of the mangrove ecosystem is lacking. We analyzed MP concentrations in the surface sediment of 9 stations in three tidal channels along the Ajuruteua Peninsula connected to the Caeté River estuary, aiming to assess the hazard level on the environment based on the Pollution Load Index (PLI). Raman and Fourier transform infrared spectroscopy determined the MP's chemical composition. The results showed that the abundance of sediment MPs ranged from 100 to 1200 items kg−1, with an average of 433 ± 261.6 items kg−1. The MPs were mainly composed of transparent and blue fragments and fibers, ranging in size from 100 to 5000 μm. Six types of polymers were identified, including alkyd varnish (AV), resin dispersion (RD), chlorinated polyethylene (CPE), polyethylene-polypropylene (PE-PP), low-density polyethylene (LDPE), and hostaperm blue (HB). Hydrodynamic processes within estuaries and tidal channels play a crucial role in explaining the concentrations found, as circulation determines the pattern of sediment deposition and the particles adhered to it. PLI risk assessment showed that all sampling sites were at hazard level I: a low level of contamination in the mangrove sediments. However, a more comprehensive and systematic monitoring campaign is needed to expand our knowledge about pollution and contamination by MPs in Amazon mangrove areas.

Blue nests: The use of plastics in the nests of the crested oropendola (Psarocolius decumanus) on the Brazilian Amazon coast

Birds have been impacted by plastic pollution via entanglement, accidental ingestion, and exposure to chemical contaminants. However, plastics were also observed as a nesting material for several species. For the first time, we describe the occurrence and composition of plastics in 36 nests of the crested oropendola (Psarocolius decumanus) in three different sites on the Amazon coast. Plastics were present in 67 % of abandoned, fallen nests. At the mangrove site, all nests contained plastics, while at the grassy clearing and the fishermen's village, plastics were present at 35.3 and 90 % of the nests, respectively. Blue fibers and ropes were the main plastics observed, probably derived from discarded fishing gear. Of 79 analyzed fibers, 97.5 % were composed of Polyethylene, and 83.5 % contained Cobalt Phthalocyanine as an additive. Our results showed a widespread use of plastics by P. decumanus, which may increase the exposure of both juveniles and adults to potential contaminants.

Spatial distribution and risk assessment of microplastics in surface waters of the St. Lawrence Estuary

Development of effective prevention and mitigation strategies for marine plastic pollution requires a better understanding of the pathways and transport mechanisms of plastic waste. Yet the role of estuaries as a key interface between riverine inputs of plastic pollution and delivery to receiving marine environments remains poorly understood. This study quantified the concentration and distribution of microplastics (MPs) (50–3200 μm) in surface waters of the St. Lawrence Estuary (SLE) in eastern Canada. Microplastics were identified and enumerated based on particle morphology, colour, and size class. Fourier Transform Infrared (FTIR) spectroscopy was used on a subset of particles to identify polymers. Generalized linear models (Gamma distribution with log-link) examined the relationship between MP concentrations and oceanographic variables and anthropogenic sources. Finally, a risk assessment model, using MP concentrations and chemical hazards based on polymer types, estimated the MP pollution risk to ecosystem health. Mean surface MP concentration in the SLE was 120 ± 42 SD particles m−3; MP concentrations were highest in the fluvial section and lowest in the Northwest Gulf of St. Lawrence. However, MP concentrations exhibited high heterogeneity along the length and width of the SLE. Microplastics were elevated at stations located closer to wastewater treatment plant outflows and downstream sites with more agricultural land. Black, blue, and transparent fibers and fragments ≤250 μm were most commonly encountered. Predominant polymer types included polyethylene terephthalate, regenerated cellulose, polyethylene, and alkyds. While the overall risk to ecosystem health in the entire estuary was considered low, several stations, particularly near urban centres were at high or very high risk. This study provides new insights into the quantification and distribution of MPs and first estimates of the risk of MP pollution to ecosystem health in one of the world's largest estuaries.

Floating microplastic pollution in the vicinity of a marine protected area and semi-enclosed bay of Peru

A baseline survey for floating microplastics (MPs) in the vicinity of a marine protected area and semi-enclosed bay of northern Peru was carried out. An average concentration of 0.22 MPs/L was estimated, primarily dominated by blue polyethylene terephthalate fibers. The distribution of floating MPs suggests that they tend to accumulate within the semi-enclosed Sechura Bay regardless of the sampling season. This behavior may be explained by local surface currents in the bay, which flow inwards and exhibit vorticities that could entrap MPs. Future studies are suggested to investigate the trajectory and fate of floating MPs within semi-enclosed areas. On the other hand, the impact of floating MPs on the trophic chain of coastal marine protected areas requires further research.

The retention of plastic particles by macrophytes in the Amazon River, Brazil.

This study evaluated the presence of plastics and microplastics in macrophytes in an urbanized sector of the Amazon River. A total of 77 quadrats in 23 macrophyte banks were sampled during the dry (September 2020) and rainy (June 2021) season. Five species were identified: Paspalum repens, Pontederia rotundifolia, Pistia stratiotes, Salvinia auriculata and Limnobium laevigatum, with P. repens being dominant during the dry season (47.54%) and P. rotundifolia during the rainy season (78.96%). Most of the plastic particles accumulated in Paspalum repens (49.3%) and P. rotundifolia (32.4%), likely due to their morphological structure and volume. The dry season showed a higher accumulation of plastic particles than the rainy season. Microplastics were found in most samples, during both the dry (75.98%) and rainy seasons (74.03%). The upstream macrophyte banks retained more plastic particles compared to the downstream banks. A moderate positive correlation was observed between the presence of plastic particles and macrophyte biomass, and a weak positive correlation between the occurrence of microplastics and mesoplastics. White and blue fragments, ranging from 1 to 5mm were the most common microplastics found in the macrophyte banks. Green fragments and green and blue fibers were identified as polypropylene, blue and red fragments as polyethylene, and white fragments as polystyrene. Therefore, the results of this study highlight the first evidence of the retention of plastic particles in macrophytes of the Amazon and highlight a significant risk due to the harmful effects that this type of plastic can cause to the fauna and flora of aquatic ecosystems.

Variation in microplastic characteristics among amphibian larvae: a comparative study across different species and the influence of human activity

Microplastic pollution is a significant global environmental issue, and impacts span from individual organisms to the entire ecosystems. This study investigated the properties of microplastics in amphibian larvae, shedding light on their environmental interactions and potential ecological consequences. We examined microplastics extracted from amphibian larvae of 10 taxa, sampled from sites experiencing different levels of human impact. Our findings revealed a predominance of blue microplastics and fibres, each comprising 53% of the total microplastics in amphibian larvae. Microplastic fibres were also notably longer than other morphological types of microplastics. Furthermore, we observed variations in the surface area of microplastics among different amphibian families. An interesting observation from our research is the apparent positive relationship between the size of amphibian larvae and the length of granular and flake-shaped microplastics. Conversely, we observed a negative relationship between the length of these microplastics and human environmental impact. These insights significantly contribute to the understanding of microplastic pollution in freshwater environments, highlighting its complexities beyond marine ecosystems. Our research emphasises the intricate relationships between microplastics and freshwater organisms, underscoring the need for comprehensive strategies to mitigate microplastic pollution.

Dynamic changes in autophagy activity in different degrees of pulmonary fibrosis in mice.

The aim of this study is to observe the changes in autophagy activities in lung tissues of mice with different degrees of pulmonary fibrosis (PF), and explore the association between PF and autophagy activity. The PF model was established by bleomycin (BLM, 25 and 35 mg/kg) atomization inhalation in C57BL/6 mice, samples were collected on the 7, 14, and 28 days after BLM administration. Hematoxylin-eosin staining was used to observe the pathological changes in lung tissues. Masson staining was utilized to assess areas of blue collagen fiber deposition in lung tissues. Quantitative real time polymerase chain reaction was used to detect the mRNA expressions of autophagy-related genes, including Atg5, Atg7, and Atg10 in lung tissues. Western blot was used to detect the protein expressions of autophagy-related genes, including p62 and LC3II/LC3I in lung tissues. Compared with control group, BLM dose-dependently decreased PaO2, mRNA expressions of Atg5, Atg7, Atg10, and LC3II/LC3I, while increased lung wet weight, lung coefficient, PF score, the blue area of collagen fibers, and p62 protein on the 7th, 14th, and 28th days. In conclusion, the more severe the PF induced by BLM, the lower the autophagy activity.

Forsythoside A regulates pulmonary fibrosis by inhibiting endothelial-to-mesenchymal transition and lung fibroblast proliferation via the PTPRB signaling

BackgroundPulmonary fibrosis (PF) is an end-stage change in many interstitial lung diseases, whereas no proven effective anti-pulmonary fibrotic treatments. Forsythoside A (FA) derived from Forsythia suspensa (Thunb.) Vahl, has been found to possess lung-protective effect. However, studies on its anti-pulmonary fibrosis effect are limited and its mechanism of action remains unknown. PurposeThis study aimed to explore the underlying mechanism of FA on PF. MethodsMale C57BL/6 mice were randomized into normal (CON), model (BLM), pirfenidone (PFD), low- and high-dose FA (FA-L, FA-H, respectively). Except for the CON group, which was injected with the same dose of saline, the model of PF was established by intratracheal instillation of BLM, during which the survival rate and body weight changes of the mice were measured. The lung histopathology was evaluated by Hematoxylin–eosin, Sirius red, and Masson staining. Transcriptome analysis was performed to screen for the differential genes associated with the role of FA in PF. Differential genes in normal and pulmonary fibrosis patients with the GSE2052 dataset were analyzed in the GEO database. The levels of CTGF, α-SMA, MMP-8 in lung and TNF-α in bronchoalveolar lavage fluid (BALF) were detected by ELISA. The levels of HYP in lungs were detected by digestion. The mRNA and protein levels of MMP-7, E-cadherin, CD31, α-SMA, TGF-β1, IL-6, β-catenin, ZO-1, PTPRB, E-cadherin, and vimentin in lungs were detected by RT-qPCR and Western blot. The expression of CD31, α-SMA, TGF-β1 and ZO-1 were detected by immunofluorescence. TGF-β1-stimulated HFL1 cells and human umbilical vein endothelial cells (HUVECs) were used in an attempt to explore the possible role of protein tyrosine phosphatase receptor type B (PTPRB) involved in FA-induced improvement of PF. ResultsThe results showed that FA could improve the survival rate and body weight of PF mice. FA could alleviate the symptoms of alveolar wall thickening, inflammatory cell infiltration, blue collagen fiber deposition, collagen fiber type Ⅰ and type Ⅲ in mice with PF. In addition, FA could reduce the levels of HYP, CTGF, α-SMA, TGF-β1, TNF-α, β-catenin and MMP8, and regulate the expression levels of CD31, ZO-1, PTPRB and E-cadherin in lung of mice with PF, inhibiting endothelial-to-mesenchymal transition (EndMT) and fibroblasts proliferation. In the GSE2052 dataset, the expression level of PTPRB is reduced in lung tissue from PF patients, and results from transcriptome sequencing indicate that PTPRB expression is also reduced in PF mice. In addition, the effect of FA on TGF-β1-induced HFL1 or HUVECs cells could be attenuated by the inhibitor of PTPRB, suggesting that the effect of FA on PF is related to PTPRB. ConclusionThis study demonstrated that FA could ameliorate PF by inhibiting lung fibroblast proliferation and EndMT, and that PTPRB might be a target of FA to ameliorate PF, which provided evidence to support FA as a candidate phytochemical for PF.

Assessment of microplastic-contaminated liver through gene expression profiling of four commercial fish species in the Lagos Lagoon, Nigeria

Microplastic (MP) occurrence in the Lagos Lagoon has been on a progressive increase in recent years. The potential impacts and hazards of MPs on commercially available fish species from the Lagoon have been understudied. This study aims to assess molecular damage due to microplastic accumulation in the liver of four commercial fish species (Oreochromis niloticus, Chrysichthys nigrodigitatus, Clarias gariepinus, and Gymnarchus niloticus) sourced directly from the Lagoon. The results revealed that MP load in the liver of the fish species ranged between 7.2 ± 1.9 and 9.5 ± 4.4 particles/individual, with G. niloticus recording the maximum concentration. The observed extracted MPs are predominantly black and blue fibres while the Fourier Transform Infrared spectroscopy revealed polyethylene dominance in the plastic polymers. Relative gene expression results revealed statistically significant downregulation of the CYP 1a gene and upregulation of the HSP 70 gene in all the microplastic-laden liver samples except in G. niloticus. The findings from this study suggest that microplastic contamination in fish tissues may exacerbate cellular toxicity in commercially available biota in the Lagos Lagoon, thereby calling for urgent measures to curb microplastic and ultimately plastic pollution. However, there's a need for in-depth research on the effects of environmentally relevant microplastics on edible fish tissues to further elucidate their molecular impact.

Prussian blue analogues-Derived Iron-Cobalt carbon fiber Binder-Free electrodes for electrocatalytic nitrate reduction

Developing a highly selective and efficient electrocatalytic system for nitrate reduction reaction (NO3RR) is of great significance but still remains challenging for environmental remediation and energy utilization. Herein, we constructed a binder-free cathode consisted of iron-cobalt Prussian blue analogues-based bimetal derived carbon fiber (FC-PBAFC) to enhance NO3RR performances. Significantly, high NO3−-N removal capacity of 169.1 mgN h−1 gcat-1, excellent ammonia Faradic efficiency (FE) of 83.2 ± 0.7 % and high ammonia selectivity of 99.3 ± 0.6 % were achieved by FC-PBAFC binder-free cathode. The excellent NO3RR performance was attributed to the rational polymer tethering strategy for the binder-free cathode construction. The introduction of polyacrylonitrile for electrospinning shaping essentially regulated the structural and compositional distribution of binder-free electrode during followed pyrolysis. The in-situ infrared spectroscopy and DFT calculation demonstrated that the Fe and Co regulation optimized the adsorption energy of key intermediate products with suppressing the side reactions. The bimetal binder-free cathode offers a promising strategy for selective and effective electroreduction of nitrate for ammonia synthesis.