Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 3.955
Filter
1.
PLoS One ; 19(8): e0308026, 2024.
Article in English | MEDLINE | ID: mdl-39088569

ABSTRACT

Electrospinning is a process in which high voltage creates nanostructured fibers with random orientation from a polymer solution. A novel electrospinning instrument was designed and constructed, capable of orienting and collimating the trajectory of the electrified fluid jet. The equipment collimates and adjusts the electrified fluid jet in the X-Y directions using deflector plates connected to a variable electric field. Simultaneously, different membrane thicknesses can be selected, i.e., in the Z direction. Additionally, by programming the sinusoidal function generator to perform an X-Y sweep, Lissajous figures (LF) were obtained. SEM images obtained through XYZ electrospinning of PVC and PVDF membranes were used to determine the control achieved over the orientation distribution of the processed nanofibers and the modification of their diameter, with and without applying the electric field to the deflector plates. The nanofibers obtained from the polymeric membranes, which originated after the straight segment of the Taylor cone, did not exhibit a random trajectory and position. Instead, the collimated electrified fluid jet deposited them in a cross pattern (X-Y) on the collector-cathode plate.


Subject(s)
Electricity , Nanofibers , Polymers , Nanofibers/chemistry , Polymers/chemistry , Polyvinyl Chloride/chemistry , Polyvinyls/chemistry , Fluorocarbon Polymers
2.
Water Sci Technol ; 90(1): 256-269, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39007318

ABSTRACT

Palladium is now frequently utilized in fuel cells, electroplating, electronics, and catalysis. Due to their rarity and high cost, precious metal recovery has taken on a significant role. The extraction method frequently utilized in polymer inclusion membranes (PIMs) is both efficient and simple since it has been demonstrated that precious metal adsorption on the membrane significantly controls the mechanism of chemical adsorption. In this study, polyvinyl chloride (PVC) as a polymer, A336 as a plasticizer, and trioctylamine (TOA) as a carrier were used to produce a PIM by evaporation. After the production of PIMs, palladium extract was studied. The stripping phase, palladium concentration in the feed phase, and components of the membrane were changed to determine the optimum condition with better extraction ability. When 0.5 M of HCl was used, higher kinetic parameter results and higher than 85% extraction efficiency were achieved compared to other concen- trations. When the EDX results were examined, 3.3% palladium was retained on the membrane surface. When the palladium concentration was selected at 2.5 ppm, higher kinetic parameters were observed, and the extraction efficiency was over 90%. The best membrane was the PIM containing 40% PVC-40% A336-20% TOA.


Subject(s)
Membranes, Artificial , Palladium , Palladium/chemistry , Polymers/chemistry , Polyvinyl Chloride/chemistry , Water Pollutants, Chemical/chemistry
3.
PLoS One ; 19(7): e0304739, 2024.
Article in English | MEDLINE | ID: mdl-38985709

ABSTRACT

Ecotoxicological tests used for risk assessment of toxicants and its mixtures rely both on classical life-cycle endpoints and bioindicator organisms usually derived from long-term laboratory cultures. While these cultures are thought to be comparable among laboratories and more sensitive than field organisms, it is not well investigated whether this assumption is met. Therefore, we aimed to investigate differential life-cycle endpoints response of two different strains of C. riparius, one originally from Spain and the other from Germany, kept under the same laboratory conditions for more than five years. To highlight any possible differences, the two populations were challenged with exposure to cadmium (Cd), polyvinyl chloride (PVC) microplastics and a co-exposure with both. Our results showed that significant differences between the strains became evident with the co-exposure of Cd and PVC MPs. The German strain showed attenuation of the deleterious Cd effects with microplastic co-exposure in survival and developmental time. Contrary to that, the Spanish strain showed no interaction between the substances. In conclusion, the toxicity-effects of contaminants may vary strongly among laboratory populations, which makes a universal risk assessment evaluation challenging.


Subject(s)
Cadmium , Chironomidae , Ecotoxicology , Microplastics , Animals , Cadmium/toxicity , Microplastics/toxicity , Chironomidae/drug effects , Chironomidae/growth & development , Ecotoxicology/methods , Water Pollutants, Chemical/toxicity , Life Cycle Stages/drug effects , Polyvinyl Chloride , Spain , Germany
4.
Environ Sci Technol ; 58(28): 12621-12632, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38954776

ABSTRACT

The majority of microplastics (MPs) found in the environment originate from plastic fragmentation occurring in the environment and are influenced by environmental factors such as UV irradiation and biotic interactions. However, the effects of river drying on plastic fragmentation remain unknown, despite the global prevalence of watercourses experiencing flow intermittence. This study investigates, through laboratory experiments, the coupled effects of drying duration and UV irradiation on PVC film fragmentation induced by artificial mechanical abrasion. This study shows that PVC film fragmentation increases with drying duration through an increase in the abundance and size of formed MPs as well as mass loss from the initial plastic item, with significant differences for drying durations >50% of the experiment duration. The average abundance of formed MPs in treatments exposed to severe drying duration was almost two times higher than in treatments nonexposed to drying. Based on these results, we developed as a proof of concept an Intermittence-Based Plastic Fragmentation Index that may provide insights into plastic fragmentation occurring in river catchments experiencing large hydrological variability. The present study suggests that flow intermittence occurring in rivers and streams can lead to increasing plastic fragmentation, unraveling new insights into plastic pollution in freshwater systems.


Subject(s)
Microplastics , Polyvinyl Chloride , Rivers , Rivers/chemistry , Polyvinyl Chloride/chemistry , Water Pollutants, Chemical , Ultraviolet Rays , Environmental Monitoring , Desiccation
5.
Food Res Int ; 191: 114590, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39059891

ABSTRACT

Sanitizer spray and brush roller treatments have been documented as an effective means of reducing Salmonella on the surface of produce. The purpose of this study was to evaluate the efficacy of chlorine (NaOCl), peroxyacetic acid (PAA), and chlorine dioxide (ClO2) sprays to reduce Salmonella populations on the surface of mangoes during washing with brush or polyvinyl chloride (PVC) rollers. Whole mangoes were spot inoculated with 100 µL of a rifampicin-resistant Salmonella (8 log CFU/mL) cocktail at the equator and dried for 1 h. Mangoes were washed with a lab-scale roller system with either ground water (control), or sanitizers (100 ppm NaOCl, 80 ppm PAA, or 5 ppm ClO2) for 0, 5, 15, 30, or 60 s (n = 15 mangoes). Dey/Engley buffer (100 mL) was used to rinse mangoes before plating on media supplemented with rifampicin. NaOCl, PAA, and ClO2 spray (except for ClO2 at 30 s) had significantly higher reduction on Salmonella population than water spray at all treatment times (P ≤ 0.05) when brush rollers were used. All tested sanitizers also achieved a significantly higher reduction than water at 5 s when PVC rollers were used (P ≤ 0.05). Salmonella reductions achieved by brush and PVC rollers was not statistically different (P > 0.05). After a 5 s treatment on brush and PVC rollers, NaOCl, PAA, and ClO2 spray had ca. 3.03 and 3.45 log, 3.96 and 3.28 log, and 2.54 and 2.00 log CFU/mango reductions, respectively, whereas water spray achieved 1.75 and 0.98 log CFU/mango reduction. Addition of sanitizers to spray water used during brush or PVC washing in mango packinghouses can reduce Salmonella on mango surfaces.


Subject(s)
Chlorine Compounds , Colony Count, Microbial , Disinfectants , Mangifera , Oxides , Peracetic Acid , Polyvinyl Chloride , Salmonella , Sodium Hypochlorite , Mangifera/microbiology , Chlorine Compounds/pharmacology , Salmonella/drug effects , Disinfectants/pharmacology , Oxides/pharmacology , Peracetic Acid/pharmacology , Sodium Hypochlorite/pharmacology , Food Handling/methods , Food Microbiology
6.
Anal Chem ; 96(25): 10434-10442, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38866710

ABSTRACT

Plasma protein adsorption on blood-contacting surfaces is the initiating significant event and modulates the subsequent coagulation response. Despite decades of research in this area, Vroman's questions in 1986 "Who gets there first?" and "When does the next protein arrive?" remain unanswered due to the lack of detection techniques with sufficient temporal resolution. In this work, we develop a droplet microfluidic technology to detect protein adsorption sequences on six typical blood-contacting surfaces in milliseconds. Apolipoproteins (Apo) are found to be the first proteins to adsorb onto the surfaces in a plasma droplet, and the specific type of apolipoprotein depends on the surface. Apo CI is the first protein adsorbed on gold, platinum, graphene, stainless steel, and polyvinyl chloride with the adsorption time varying from 0.01 to 1 s, while Apo CIII preferentially reaches the titanium alloy surface within 1 s. Subsequent to the initial adsorption, Apo AI, AII, and other proteins continue to adsorb until albumin arrives. Thus, the adsorption sequence is revealed, and Vroman's questions are answered. Moreover, this finding demonstrates the influence of the initial protein adsorption on subsequent coagulation at the surface, and it offers new insights into the development of anticoagulant surfaces.


Subject(s)
Surface Properties , Adsorption , Humans , Blood Proteins/chemistry , Blood Proteins/metabolism , Gold/chemistry , Stainless Steel/chemistry , Graphite/chemistry , Apolipoproteins/chemistry , Polyvinyl Chloride/chemistry , Platinum/chemistry , Microfluidic Analytical Techniques , Titanium/chemistry
7.
J Hazard Mater ; 475: 134897, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38876018

ABSTRACT

Microplastics (MPs), widely presented in cultivated soil, have caused serious stresses on crop growth. However, the mechanism by which MPs affect legumes and rhizobia symbiosis is still unclear. Here, peanut seedlings were inoculated with Bradyrhizobium zhanjiangense CCBAU 51778 and were grown in vermiculite with 3 %/5 % (w/w) addition of PVC (polyvinyl chloride)-MPs/PBAT (polybutylene adipate)-MPs. PVC-MPs and PBAT-MPs separately decreased nodule number by 33-100 % and 2.62-80.91 %. Transcriptome analysis showed that PVC-MPs affected more DEGs (differentially expressed genes) than PBAT-MPs, indicating PVC-MPs were more devastating for the symbiosis than PBAT-MPs. Functional annotation revealed that PVC-MPs and PBAT-MPs enriched DEGs related to biosynthesis pathways such as flavonoid, isoflavonoid, and phenylpropanoid, in peanut. And when the dose increased from 3 % to 5 %, PVC-MPs mainly enriched the pathways of starch and sucrose metabolism, alanine, aspartate and glutamate metabolism, diterpenoid biosynthesis, etc.; PBAT-MPs enriched cysteine and methionine metabolism, photosynthesis, MAPK signaling, and other pathways. These significantly enriched pathways functioned in reducing nodule number and promoting peanut tolerance to MPs stresses. This study reveals the effect of PVC-MPs and PBAT-MPs on peanut and rhizobium symbiosis, and provides new perspectives for legume production and environmental safety.


Subject(s)
Arachis , Microplastics , Polyvinyl Chloride , Symbiosis , Arachis/microbiology , Arachis/metabolism , Arachis/drug effects , Microplastics/toxicity , Soil Pollutants/toxicity , Soil Pollutants/metabolism , Rhizobium/metabolism , Rhizobium/drug effects , Polyesters/metabolism , Metabolic Networks and Pathways/drug effects , Bradyrhizobium/metabolism , Bradyrhizobium/drug effects
8.
J Hazard Mater ; 475: 134817, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38878444

ABSTRACT

Microplastics and antibiotics coexist in aquatic environments, especially in freshwater aquaculture areas. However, as the second largest production of polyvinyl chloride (PVC) in the world, the effects of co-exposure to microplastics particles and antibiotics on changes in antibiotic resistance gene (ARG) profiles and the microbial community structure of aquatic organism gut microorganisms are poorly understood. Therefore, in this study, carp (Cyprinus carpio) were exposed to single or combined PVC microplastic contamination and oxytetracycline (OTC) or sulfamethazine (SMZ) for 8 weeks. PVC microplastics can enrich potential pathogenic bacteria, such as Enterobacter and Acinetobacter, among intestinal microorganisms. The presence of PVC microplastics enhanced the selective enrichment and dissemination risk of ARGs. PVC microplastics combined with OTC (OPVC) treatment significantly increased the abundance of tetracycline resistance genes (1.40-fold) compared with that in the OTC exposure treatment, revealing an obvious co-selection effect. However, compared with those in the control group, the total abundance of ARGs and MGEs in the OPVC treatment groups were significantly lower, which was correlated with the reduced abundances of the potential host Enterobacter. Overall, our results emphasized the diffusion and spread of ARGs are more influenced by PVC microplastics than by antibiotics, which may lead to antibiotic resistance in aquaculture.


Subject(s)
Anti-Bacterial Agents , Carps , Microplastics , Oxytetracycline , Polyvinyl Chloride , Water Pollutants, Chemical , Animals , Microplastics/toxicity , Water Pollutants, Chemical/toxicity , Oxytetracycline/toxicity , Carps/microbiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/toxicity , Gastrointestinal Microbiome/drug effects , Bacteria/drug effects , Bacteria/genetics , Sulfamethazine/toxicity , Genes, Bacterial/drug effects , Drug Resistance, Microbial/genetics , Drug Resistance, Bacterial/genetics , Drug Resistance, Bacterial/drug effects
9.
J Phys Chem Lett ; 15(25): 6560-6567, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38885454

ABSTRACT

Aggregation of human α-synuclein protein is regarded to be a key stage in the etiology of Parkinson's disease and numerous other neurodegenerative illnesses. Microplastics pollution can be a potential agent to promote various neurodegenerative disorders. In this study, we have employed various multispectroscopic analytical methods to investigate the binding interactions between polyethylene (PE-MPs), polyvinyl chloride (PVC-MPs), polystyrene (PS-MPs) microplastics, and human α-synuclein protein. Spectroscopic investigations using UV-vis absorption, circular dichroism, and Fourier transform infrared have indicated different alterations in α-synuclein protein's secondary structures induced by the formation of the α-synuclein protein-MP binding complex. This study suggests that PS-MPs are found to be the most effective microplastic that promote amyloidogenic oligomer emergence because of their tiny size (100 nm).


Subject(s)
Microplastics , alpha-Synuclein , alpha-Synuclein/chemistry , alpha-Synuclein/metabolism , Humans , Microplastics/chemistry , Polystyrenes/chemistry , Circular Dichroism , Spectroscopy, Fourier Transform Infrared , Protein Binding , Polyvinyl Chloride/chemistry , Polyethylene/chemistry , Protein Structure, Secondary , Amyloid/chemistry , Amyloid/metabolism
10.
Aquat Toxicol ; 272: 106975, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38824744

ABSTRACT

In this study, we investigated the effects of PVC microplastics (PVC-MPs) using two different animal models: the brittle star Ophiactis virens, and the African clawed frog Xenopus laevis. This is the first study using an environmental relevant sample of PVC-MPs obtained through mechanical fragmentation of a common PVC plumbing pipe. Exposure experiments on brittle star were performed on the adult stage for a duration of 14 days, while those on African clawed frog were performed on the embryogenic developmental stage according to the standardized FETAX protocol (Frog Embryo Teratogenesis Assay-Xenopus). For both models, different endpoints were analysed: mortality, developmental parameters, behavioural assays and histological analyses on target organs by optical and electronic microscopy. Results showed that the concentration of 0.1 µg mL-1 PVC do not cause any adverse effects in both models (common NOEC concentration), while exposure to 1 µg mL-1 PVC adversely affected at least one species (common LOEC concentration). In particular arm regeneration efficiency was the most affected parameters in O. virens leading to a significantly lower differentiation pattern at 1 µg mL-1 PVC. On the contrary, in X. laevis larvae histopathological analyses and behavioural tests were the most susceptible endpoints, exhibiting several abnormal figures and different swimming speed at 10 µg mL-1 PVC. Histopathological analyses revealed a higher abundance of degenerating cells, pyknotic nuclei and cellular debris in the gut of exposed larvae in respect to control. The comparative analyses performed in this work allowed to characterize the specificity of action of the PVC-MPs on the two species, underlining the importance of exploring a large spectrum of endpoints to offer adequate protection in the emerging fields of microplastic research.


Subject(s)
Microplastics , Polyvinyl Chloride , Water Pollutants, Chemical , Xenopus laevis , Animals , Polyvinyl Chloride/toxicity , Microplastics/toxicity , Water Pollutants, Chemical/toxicity , Embryo, Nonmammalian/drug effects , Larva/drug effects
11.
Chemosphere ; 361: 142577, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38857632

ABSTRACT

Water distribution networks play a crucial role in ensuring a reliable water supply, yet they encounter challenges such as corrosion, scale formation, and biofilm growth due to interactions with environmental elements. Biofilms and corrosion layers are significant contaminants in water pipes, formed by complex interactions with pipe materials. As the structure of these contamination layers varies depending on the pipe material, it is essential to investigate the contamination layer for each material individually. Specifically, biofilm growth is typically investigated concerning organic sources, while the growth of humus layers is examined in relation to inorganic elements such as manganese (Mn), iron (Fe), and aluminum (Al), which are major elements and organic substances found in water pipes. Real-time imaging of recently contaminated layers can provide important insights to improve system performance by optimizing operations and cleaning processes. In this study, cast iron (7.10 ± 0.78 nm) exhibits greater surface roughness compared to PVC (5.60 ± 0.14 nm) and provides favorable conditions for biofilm formation due to its positive charge. Over a period of 425 h, the fouling layer on cast iron and PVC surfaces gradually increased in fouling thickness, porosity, roughness, and density, reaching maximum value of 29.72 ± 3.6 µm, 11.44 ± 1.1%, 41673 ± 1025.6 pixels, and 0.80 ± 0.3 fouling layer pixel/layer pixel for cast iron, and 8.15 ± 0.4 µm, 20.64 ± 0.9%, 35916.6 ± 755.7 pixels, and 0.58 ± 0.1 fouling layer pixel/layer pixel, respectively. Within the scope of the current research, CNN model demonstrates high correlation coefficients (0.98 and 0.91) in predicting biofilm thickness for cast iron and PVC. The model also presented high accuracy in predicting porosity for both materials (over 0.91 for cast iron and 0.96 for PVC). While the model accurately predicted biofilm roughness and density for cast iron (correlation coefficients 0.98 and 0.94, respectively), it had lower accuracy for PVC (correlation coefficients 0.92 for both parameters).


Subject(s)
Biofilms , Iron , Water Supply , Biofilms/growth & development , Corrosion , Iron/chemistry , Iron/analysis , Environmental Monitoring/methods , Aluminum/chemistry , Polyvinyl Chloride/chemistry
12.
Sci Rep ; 14(1): 13051, 2024 06 06.
Article in English | MEDLINE | ID: mdl-38844516

ABSTRACT

In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10-6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.


Subject(s)
Hemolysis , Polyvinyl Chloride , Sunflower Oil , Sunflower Oil/chemistry , Polyvinyl Chloride/chemistry , Hemolysis/drug effects , Spectroscopy, Fourier Transform Infrared , Humans , Animals , Blood Coagulation/drug effects , Surface Properties , Plant Oils/chemistry
13.
BMC Urol ; 24(1): 122, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38867233

ABSTRACT

BACKGROUND: Neurogenic bladder dysfunction is a major problem for spinal cord injury (SCI) patients not only due to the risk of serious complications but also because of the impact on quality of life. The main aim of this study is to compare the rate of urinary tract infection (UTI) associated with hydrophilic-coated catheters versus uncoated polyvinyl chloride (PVC) catheters among SCI patients presenting with functional neurogenic bladder sphincter disorders. METHODOLOGY: This was a retrospective cohort study from 2005 to 2020 including adult male or female patients who have an SCI at least more than 1 month ago with neurogenic bladder dysfunction and were using intermittent catheterization (single-use hydrophilic-coated or the standard-of-care polyvinyl chloride uncoated standard catheters) at least 3 times a day to maintain bladder emptying. RESULTS: A total of 1000 patients were selected and recruited through a stratified random sampling technique with 467 (47.60%) patients in the uncoated catheter arm and 524 (52.60%) in the coated catheter groups. The three outcome measures, namely: symptomatic UTI, Bacteriuria, and pyuria were significantly higher in the group using uncoated polyvinyl chloride (PVC) catheters compared to hydrophilic-coated catheters at the rate of 79.60% vs.46.60%, 81.10% vs. 64.69, and 53.57% versus 41.79% respectively. Males, elder patients, longer duration, and severity of SCI were associated with increased risk of symptomatic UTI. CONCLUSIONS: The results indicate a beneficial effect regarding clinical UTI when using hydrophilic-coated catheters in terms of fewer cases of symptomatic UTI. Bacteriuria is inevitable in patients with long-term catheterization, however, treatment should not be started unless the clinical symptoms exist. More attention should be given to the high-risk group for symptomatic UTIs.


Subject(s)
Spinal Cord Injuries , Urinary Bladder, Neurogenic , Urinary Tract Infections , Humans , Retrospective Studies , Spinal Cord Injuries/complications , Male , Female , Urinary Tract Infections/etiology , Urinary Tract Infections/epidemiology , Middle Aged , Adult , Urinary Catheters/adverse effects , Intermittent Urethral Catheterization/adverse effects , Hydrophobic and Hydrophilic Interactions , Polyvinyl Chloride , Cohort Studies , Aged , Urinary Catheterization/adverse effects , Catheter-Related Infections/epidemiology , Catheter-Related Infections/etiology
14.
Waste Manag ; 186: 259-270, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-38943817

ABSTRACT

In a world with a population exceeding 8 billion people and continuing to grow, pollution from food and plastic waste is causing long-term issues in ecosystems. Potential solutions may be found by exploiting insect-based bioconversion. In this context, we investigated the impact of polyvinyl chloride microparticles (PVC-MPs) on the development of Hermetia illucens (black soldier fly; BSF) and its midgut bacterial and fungal microbiota. The impact of PVC-MPs was evaluated feeding BSF larvae with a PVC-MPs-supplemented diet. The larvae exposed to different PVC-MPs concentrations (2.5%, 5%, 10% and 20% w/w) developed into adults with no significant increase in pupal mortality. Faster development and smaller pupae were observed when 20% PVC-MPs was provided. The BSF larvae ingest PVC-MPs, resulting in a reduction in MPs size. Larvae exposed to PVC-MPs did not exhibit differences in gut morphology. Regarding the impact of PVC-MPs on the structure of both bacterial and fungal communities, the overall alpha- and beta-diversity did not exhibit significant changes. However, the presence of PVC-MPs significantly affected the relative abundances of Enterobacteriaceae and Paenibacillaceae among the bacteria and of Dipodascaceae and Plectospharellaceae among the fungi (including yeast and filamentous life forms), suggesting that PVC-MP contamination has a taxa-dependent impact. These results indicate that BSF larvae can tolerate PVC-MPs in their diet, supporting the potential use of these insects in organic waste management, even in the presence of high levels of PVC-MP contamination.


Subject(s)
Diptera , Gastrointestinal Microbiome , Larva , Microplastics , Animals , Larva/microbiology , Diptera/microbiology , Gastrointestinal Microbiome/drug effects , Polyvinyl Chloride , Fungi/metabolism , Bacteria/classification , Bacteria/metabolism , Diet , Mycobiome
15.
Mar Environ Res ; 199: 106598, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38865873

ABSTRACT

Marine organisms commonly encounter co-stress resulting from the coexistence of microplastics (MPs) and heavy metals pollution in marine environments. Nevertheless, the combined effects and toxicity mechanisms of MPs and heavy metals on marine organisms remain unclear. This study integrated growth, physiological, morphological, and biochemical markers to assess the individual and combined toxicity of polyvinyl chloride MPs (PVC MPs, 1 × 104 particles/L) and copper (Cu, 200 µg/L) on marine jacopever (Sebastes schlegelii). The results revealed that co-exposure to MPs and Cu had a more detrimental impact on jacopever compared to the single-exposure groups, as evidenced by the enhanced growth inhibition, respiratory stress, and hepatotoxicity. This phenomenon may be attributed to PVC MPs accelerating the accumulation of Cu in jacopever liver. Therefore, peroxidation damage occurred in the co-exposed liver and may result in liver dysfunction. These findings contribute valuable insights into the risks associated with the coexistence of MPs and heavy metal pollution in marine ecosystems.


Subject(s)
Copper , Microplastics , Polyvinyl Chloride , Water Pollutants, Chemical , Polyvinyl Chloride/toxicity , Water Pollutants, Chemical/toxicity , Copper/toxicity , Animals , Microplastics/toxicity , Environmental Monitoring
16.
Environ Sci Technol ; 58(26): 11542-11553, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38871676

ABSTRACT

Nanoplastics (NPs) are emerging pollutants and have been reported to cause the disintegration of anaerobic granular sludge (AnGS). However, the mechanism involved in AnGS disintegration was not clear. In this study, polyvinyl chloride nanoplastics (PVC-NPs) were chosen as target NPs and their long-term impact on AnGS structure was investigated. Results showed that increasing PVC-NPs concentration resulted in the inhibition of acetoclastic methanogens, syntrophic propionate, and butyrate degradation, as well as AnGS disintegration. At the presence of 50 µg·L-1 PVC-NPs, the hydrophobic interaction was weakened with a higher energy barrier due to the relatively higher hydrophilic functional groups in extracellular polymeric substances (EPS). PVC-NPs-induced ROS inhibited quorum sensing, significantly downregulated hydrophobic amino acid synthesis, whereas it highly upregulated the genes related to the synthesis of four hydrophilic amino acids (Cys, Glu, Gly, and Lys), resulting in a higher hydrophily degree of protein secondary structure in EPS. The differential expression of genes involved in EPS biosynthesis and the resulting protein secondary structure contributed to the greater hydrophilic interaction, reducing microbial aggregation ability. The findings provided new insight into the long-term impact of PVC-NPs on AnGS when treating wastewater containing NPs and filled the knowledge gap on the mechanism involved in AnGS disintegration by PVC-NPs.


Subject(s)
Extracellular Polymeric Substance Matrix , Polyvinyl Chloride , Sewage , Sewage/microbiology , Polyvinyl Chloride/chemistry , Extracellular Polymeric Substance Matrix/metabolism , Anaerobiosis , Microbial Interactions
17.
Sci Total Environ ; 945: 174023, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38885711

ABSTRACT

Microplastics in food and drinking water can enter the human body through oral exposure, posing potential health risks to the human health. Most studies on the toxic effects of microplastics have focused on aquatic organisms, but the effects of the human digestive environment on the physicochemical properties of microplastics and their potential toxicity during gastrointestinal digestion are often limited. In this study, we first studied the influence of interactions between digestive tract protein (α-amylase, pepsin, and trypsin) and microplastics on the activity and conformation of digestive enzymes, and the physicochemical properties of polyvinyl chloride microplastics (PVC-MPs). Subsequently, a simulated digestion assay was performed to determine the biotransformation of PVC-MPs in the digestive tract and the intestinal toxicity of PVC-MPs. The in vitro experiments showed that the protein structure and activity of digestive enzymes were changed after adsorption by microplastics. After digestion, the static contact angle of PVC-MPs was decreased, indicating that the hydrophilicity of the PVC-MPs increased, which will increase its mobility in organisms. Cell experiment showed that the altered physicochemical property of PVC-MPs after digestion process also affect its cytotoxicity, including cellular uptake, cell viability, cell membrane integrity, reactive oxygen species levels, and mitochondrial membrane potential. Transcriptome analyses further confirmed the enhanced biotoxic effect of PVC-MPs after digestion treatment. Therefore, the ecological risk of microplastics may be underestimated owing to the interactions of microplastics and digestive tract protein during biological ingestion.


Subject(s)
Gastrointestinal Tract , Microplastics , Polyvinyl Chloride , Water Pollutants, Chemical , Polyvinyl Chloride/toxicity , Microplastics/toxicity , Water Pollutants, Chemical/toxicity , Humans , Gastrointestinal Tract/drug effects , Gastrointestinal Tract/metabolism
18.
J Hazard Mater ; 474: 134735, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38823103

ABSTRACT

Microplastics (MPs) are emerging contaminants in aquatic ecosystems that can profoundly affect carbon and nitrogen cycling. However, the impact mechanisms of MPs on sedimentary greenhouse gas (GHG) emissions at distinct altitudes remain poorly elucidated. Here, we investigated the effects of polyvinyl chloride (PVC) and polylactic acid (PLA) on sedimentary CO2, CH4, and N2O emissions at distinct altitudes of the Yellow River. PVC increased the relative abundance of denitrifiers (e.g., Xanthobacteriaceae, Rhodocyclaceae) to promote N2O emissions, whereas PLA reduced the abundance of AOA gene and denitrifiers (e.g., Pseudomonadaceae, Sphingomonadaceae), impeding N2O emissions. Both PVC and PLA stimulated the growth of microbes (Saprospiraceae, Aquabacterium, and Desulfuromonadia) associated with complex organics degradation, leading to increased CO2 emissions. Notably, the concurrent inhibition of PLA on mcrA and pmoA genes led to its minimal impact on CH4 emissions. High-altitude MQ sediments, characterized by abundant substrate and a higher abundance of functional genes (AOA, AOB, nirK, mcrA), demonstrated higher GHG emissions. Conversely, lower microbial diversity rendered the low-altitude LJ microbial community more susceptible to PVC, leading to a more significant promotion on GHG emissions. This study unequivocally confirms that MPs exacerbate GHG emissions via microbiome-mediated mechanisms, providing a robust theoretical foundation for microplastic control to mitigate global warming.


Subject(s)
Carbon Dioxide , Geologic Sediments , Greenhouse Gases , Microbiota , Microplastics , Polyesters , Geologic Sediments/microbiology , Microbiota/drug effects , Microplastics/toxicity , Carbon Dioxide/analysis , Polyesters/metabolism , Altitude , Methane/metabolism , Polyvinyl Chloride , Bacteria/drug effects , Bacteria/genetics , Bacteria/classification , Bacteria/metabolism , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity , Nitrous Oxide/analysis , Rivers/microbiology , Rivers/chemistry
19.
STAR Protoc ; 5(2): 103104, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38861383

ABSTRACT

Approaches for detecting micro(nano)plastics (MNPs) released from intravenous infusion products (IVIPs) are vital for evaluating the safety of both IVIPs and their derived MNPs on human health, yet current understanding is limited. Here, we present a protocol for detecting polyvinyl chloride (PVC) MNPs by combining Raman spectroscopy, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDS), and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). We describe steps for collecting, pretreating, and measuring PVC MNPs released from IVIPs. For complete details on the use and execution of this protocol, please refer to Li et al.1.


Subject(s)
Spectrum Analysis, Raman , Spectrum Analysis, Raman/methods , Infusions, Intravenous , Gas Chromatography-Mass Spectrometry/methods , Polyvinyl Chloride/chemistry , Humans , Microscopy, Electron, Scanning/methods , Spectrometry, X-Ray Emission/methods , Plastics/chemistry
20.
Environ Pollut ; 355: 124217, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38797346

ABSTRACT

Although di(2-ethylhexyl) terephthalate (DOTP) is being widely adopted as a non-phthalate plasticizer, existing research primarily focuses on human and rat toxicity. This leaves a significant gap in our understanding of their impact on microbial communities. This study assessed the biodegradation and toxicity of DOTP on microbes, focusing on its impact on biofilms and microbial metabolism using Rhodococcus ruber as a representative bacterial strain. DOTP is commonly found in mass fractions between 0.6 and 20% v/v in various soft plastic products. This study used polyvinyl chloride films (PVC) with varying DOTP concentrations (range 1-10% v/v) as a surface for analysis of biofilm growth. Cell viability and bacterial stress responses were tested using LIVE/DEAD™ BacLight™ Bacterial Viability Kit and by the detection of reactive oxygen species using CellROX™ Green Reagent, respectively. An increase in the volume of dead cells (in the plastisphere biofilm) was observed with increasing DOTP concentrations in experiments using PVC films, indicating the potential negative impact of DOTP on microbial communities. Even at a relatively low concentration of DOTP (1%), signs of stress in the microbes were noticed, while concentrations above 5% compromised their ability to survive. This research provides a new understanding of the environmental impacts of alternative plasticizers, prompting the need for additional research into their wider effects on both the environment and human health.


Subject(s)
Biodegradation, Environmental , Biofilms , Phthalic Acids , Plasticizers , Reactive Oxygen Species , Plasticizers/toxicity , Biofilms/drug effects , Reactive Oxygen Species/metabolism , Phthalic Acids/toxicity , Phthalic Acids/metabolism , Rhodococcus/metabolism , Rhodococcus/drug effects , Polyvinyl Chloride/toxicity , Diethylhexyl Phthalate/toxicity
SELECTION OF CITATIONS
SEARCH DETAIL