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1.
Environ Pollut ; 346: 123543, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38367691

RESUMO

The study focused on detecting and characterizing microplastics in outdoor and indoor air in Ranchi, Jharkhand, India during post-monsoon (2022) and winter (2023). Stereo microscopic analysis showed that plastic fibres had a dominant presence, fragments were less abundant, whereas fewer films could be detected in indoor and outdoor air. The atmospheric deposition of microplastics outdoors observed 465 ± 27 particles/m2/day in PM10 and 12104 ± 665 and 13833 ± 1152 particles/m2/day in PM2.5 in quartz and PTFE, respectively during the post-monsoon months. During winter, microplastic deposition rates in PM10 samples were found to be 689 ± 52 particles/m2/day and 19789 ± 2957 and 30087 ± 13402 in quartz and PTFE particles/m2/day respectively in PM2.5. The mean deposition rate in indoor environment during post-monsoon was 8.3 × 104 and 1.03 × 105 particles/m2/day in winter. During the post-monsoon period in PM10, there were fibres from 7.7 to 40 µm and fragments from 2.3 µm to 8.6 µm. Indoor atmospheric microplastics, fibres ranged from 1.2 to 47 µm and fragments from 0.9 to 16 µm present respectively during the post-monsoon season. Fibres and fragment sizes witnessed during winter were 3.6-6.9 µm and 2.3-34 µm, respectively. Indoor air films measured in the range of 4.1-9.6 µm. Fourier transform infrared analysis showed that outdoor air contained polyethylene, polypropylene, Polystyrene, whereas indoor air had polyvinyl chloride. Polyethylene mainly was present in outdoor air, with lesser polypropylene and polystyrene than indoors, where polyvinyl chloride and polyethylene were in dominant proportions. Elemental mapping of outdoor and indoor air samples showed the presence of elements on the microplastics. The HYSPLIT models suggest that the particles predominantly were coming from North-West during the post-monsoon season. Principal component analysis indicated wind speed and direction influencing the abundance of microplastics. Microplastics concentration showed strong seasonal influence and potential to act as reservoir of contaminants.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluição do Ar em Ambientes Fechados/análise , Poluentes Atmosféricos/análise , Microplásticos/análise , Plásticos/análise , Monitoramento Ambiental , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Quartzo , Índia , Polietileno/análise , Material Particulado/análise , Politetrafluoretileno
2.
Chemosphere ; 338: 139438, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37433409

RESUMO

Bis(2-ethylhexyl) phthalate (DEHP) transfer from a polyvinyl chloride (PVC) sheet to 9 kinds of particles, namely, polyethylene particles (1-10, 45-53, 90-106 µm), soda lime glass particles (1-38, 45-53, 90-106 µm), black forest soil, carbon black, and cotton linter, for the particle weights of 0.3, 1, 3, and 12 mg/cm2, were determined for 1, 3, 7, and 14 days using a passive flux sampler (PFS), as well as standard dust. Transfer amounts to small polyethylene particles (1-10 µm), black forest soil, and carbon black were large (8.5, 16, and 48 µg/mg-particle, respectively, for 0.3 mg/cm2 for 14 days) and were similar to standard house dust (35 µg/mg-particle). On the other hand, transfer amount to large polyethylene particles (0.056-0.12 µg/mg-particle), soda lime glass (0.18-0.31 µg/mg-particle), and cotton linter (0.42-0.78 µg/mg-particle) were much lower. The DEHP transfer amount to the particles was proportional to the surface area of the particles, but not associated with the organic content. The DEHP transfer amount per surface area to small polyethylene particles was larger than that of other particles, suggesting the contribution of absorption into the polyethylene particle. However, for the larger polyethylene particles with different manufacturing process that may have different crystallinity, the contribution of absorption was small. The amount of DEHP transferred to soda lime glass did not differ from 1 to 14 days, suggesting that an adsorption equilibrium was reached after 1 day. The estimated value of particle/gas partition coefficients of DEHP, Kpg, of small polyethylene, black forest soil and carbon black were much higher (3.6, 7.1, and 18 m3/mg, respectively) than those of large polyethylene and soda lime glass particles (0.028-0.11 m3/mg).


Assuntos
Dietilexilftalato , Ácidos Ftálicos , Dietilexilftalato/análise , Cloreto de Polivinila/análise , Fuligem , Ácidos Ftálicos/análise , Poeira , Polietileno
3.
Chemosphere ; 331: 138794, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37116724

RESUMO

Fragmentation of degraded plastics and release of smaller secondary microplastics is usually attributed to the growth of environmental stress cracks. Analysis of crack patterns derived from chemical degradation can be useful not only for assessing the cause of plastic fracture and evaluating the useful lifetime of a product, but it can also potentially provide valuable information on the generation of microplastics. However, the literature with respect to microplastics generation is generally limited to surface observations of polypropylene and polyethylene. Here, we used ion-beam milling to prepare cross-sections of fragments of 15 plastic products made from five commodity plastics (polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate) that were collected at two beaches in Japan, and then we examined the microstructures of those cross-sections by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. Crack growth in the depth direction was examined to provide insights into microplastic generation behavior. In all of the polypropylene samples, and some of the low-density polyethylene and polystyrene samples, cracks with a depth exceeding 100 µm from the sample surface were observed. Considering that crack growth causes fracture of degraded plastic and microplastic release, these observations suggest the release of sharp-edged microplastics from the crack fracture surface. In contrast, in the high-density polyethylene and polyvinyl chloride samples, crack growth was limited to within 20 µm of the sample surface, suggesting the release of irregularly shaped microplastics and additive particles. The present results suggest that the degradation behavior of plastic products in the depth direction is dependent on the type of plastic.


Assuntos
Plásticos , Poluentes Químicos da Água , Plásticos/química , Microplásticos , Polipropilenos/análise , Poliestirenos/análise , Estudos Transversais , Cloreto de Polivinila/análise , Monitoramento Ambiental/métodos , Polietileno/química , Poluentes Químicos da Água/análise
4.
J Environ Sci (China) ; 124: 860-874, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182189

RESUMO

Particulate matter (PM2.5) samples were collected in the vicinity of an industrial chemical pole and analysed for organic and elemental carbon (OC and EC), 47 trace elements and around 150 organic constituents. On average, OC and EC accounted for 25.2% and 11.4% of the PM2.5 mass, respectively. Organic compounds comprised polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, anhydrosugars, phenolics, aromatic ketones, glycerol derivatives, aliphatic alcohols, sterols, and carboxyl groups, including aromatic, carboxylic and dicarboxylic acids. Enrichment factors > 100 were obtained for Pb, Cd, Zn, Cu, Sn, B, Se, Bi, Sb and Mo, showing the contribution of industrial emissions and nearby major roads. Principal component analysis revealed that vehicle, industrial and biomass burning emissions accounted for 66%, 11% and 9%, respectively, of the total PM2.5-bound PAHs. Some of the detected organic constituents are likely associated with plasticiser ingredients and thermal stabilisers used in the manufacture of PVC and other plastics in the industrial complex. Photooxidation products of both anthropogenic (e.g., toluene) and biogenic (e.g., isoprene and pinenes) precursors were also observed. It was estimated that biomass burning accounted for 13.8% of the PM2.5 concentrations and that secondary OC represented 37.6% of the total OC. The lifetime cancer risk from inhalation exposure to PM2.5-bound PAHs was found to be negligible, but it exceeded the threshold of 10-6 for metal(loi)s, mainly due to Cr and As.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Oligoelementos , Poluentes Atmosféricos/análise , Álcoois , Cádmio/análise , Carbono/análise , Ácidos Dicarboxílicos/análise , Monitoramento Ambiental , Cetonas , Chumbo/análise , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Cloreto de Polivinila/análise , Estações do Ano , Esteróis/análise , Tolueno/análise , Oligoelementos/análise , Emissões de Veículos/análise
5.
Chemosphere ; 308(Pt 3): 136449, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36115477

RESUMO

Microscopy is often the first step in microplastic analysis and is generally followed by spectroscopy to confirm material type. The value of microscopy lies in its ability to provide count, size, color, and morphological information to inform toxicity and source apportionment. To assess the accuracy and precision of microscopy, we conducted a method evaluation study. Twenty-two laboratories from six countries were provided three blind spiked clean water samples and asked to follow a standard operating procedure. The samples contained a known number of microplastics with different morphologies (fiber, fragment, sphere), colors (clear, white, green, blue, red, and orange), polymer types (PE, PS, PVC, and PET), and sizes (ranging from roughly 3-2000 µm), and natural materials (natural hair, fibers, and shells; 100-7000 µm) that could be mistaken for microplastics (i.e., false positives). Particle recovery was poor for the smallest size fraction (3-20 µm). Average recovery (±StDev) for all reported particles >50 µm was 94.5 ± 56.3%. After quality checks, recovery for >50 µm spiked particles was 51.3 ± 21.7%. Recovery varied based on morphology and color, with poorest recovery for fibers and the largest deviations for clear and white particles. Experience mattered; less experienced laboratories tended to report higher concentration and had a higher variance among replicates. Participants identified opportunity for increased accuracy and precision through training, improved color and morphology keys, and method alterations relevant to size fractionation. The resulting data informs future work, constraining and highlighting the value of microscopy for microplastics.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Microscopia , Plásticos/análise , Polímeros , Cloreto de Polivinila/análise , Água/análise , Poluentes Químicos da Água/análise
6.
Chemosphere ; 309(Pt 1): 136484, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36174731

RESUMO

VVOCs with a retention range below C6 have become one of the main indoor pollutants that negatively affect human health. Most studies have focused on the emission of VOCs from furniture and decorative materials, seldom consider VVOCs. To close this gap, a 15-L environmental chamber, combined with multi-absorbent tube, was used for gas sampling. Emissions of VVOCs and odors released from decorative medium density fiberboard (MDF) were measured using gas chromatography-mass spectrometry and olfactometry detection. The results demonstrated that multi-absorbent tubes had excellent capture capacity for low-molecular-weight VVOCs. Thickness and decorative materials had conspicuous effects on VVOCs and odor emissions. The total VVOCs (TVVOC) from 18-mm decorative MDF was consistently higher than that of 8-mm samples. The major VVOCs from these decorative MDF were alcohols, esters and ketones, which were the major odor contributors with high odor intensity values. VVOCs concentration generally increased as thickness increased, but it decreased after decorative treatment. Fruity and alcohol-like were the main odor impressions of 8-mm MDF, whereas sweet and fruity were the major odor impressions of 8-mm polyvinyl chloride decorative MDF (PVC-MDF) and melamine impregnated paper decorative MDF (MI-MDF). Fruity was the main odor impression of 18-mm decorative MDF. The overall odor intensity increased and the major odor impression may differ when thickness was changed. Both the MI and the PVC decorative materials blocked some odor emissions but did so to a greater extent with the former than with the latter. Identification and analysis of the composition of VVOCs can supplement a database structure network of volatile pollutants and establish a novel and feasible method to investigate low-molecular-weight substances from wooden materials and their products.


Assuntos
Poluentes Ambientais , Compostos Orgânicos Voláteis , Humanos , Compostos Orgânicos Voláteis/análise , Odorantes/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cloreto de Polivinila/análise , Poluentes Ambientais/análise , Álcoois/análise , Ésteres/análise , Cetonas/análise
7.
Anal Chim Acta ; 1229: 340384, 2022 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-36156235

RESUMO

A novel approach is introduced for the fast, reliable, and low-cost recognition and quantification of plasticizers in plasticizers mixtures. It uses benchtop 1H NMR spectroscopy and indirect hard modeling, a mechanistic multivariate regression technique. The approach is demonstrated on five different PVC plasticizers having similar spectral signatures in proton NMR spectra. With only 16 scans per spectrum, i.e., 2 min 40 s measurement time, quantification limits down to 0.14 mg mL-1, or 0.35 wt% plasticizer in PVC, were achieved. Apart from the rapid data acquisition, the use of spectral hard modeling enabled the quantification of plasticizer mixtures while using only 4 to 6 training samples per component. Despite strongly overlapping signals in the NMR spectra, various plasticizers were differentiated and quantified, as exemplarily demonstrated for binary mixtures. A commercial PVC specimen with three different layers was also examined, confirming the applicability of benchtop NMR spectroscopy. Additionally, the use of the proposed method to validate official regulations concerning the plasticizer content in PVC is assessed. The presented results demonstrate that the combination of benchtop NMR and spectral hard modeling is a very promising analytical tool for rapid PVC plasticizer recognition and quantification with high analytical throughput. Moreover, the results indicate a high potential for benchtop NMR and spectral hard modeling for microchemical analysis, even for complex samples.


Assuntos
Plastificantes , Cloreto de Polivinila , Espectroscopia de Ressonância Magnética , Plastificantes/análise , Cloreto de Polivinila/análise , Cloreto de Polivinila/química , Prótons
8.
Molecules ; 27(18)2022 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-36144641

RESUMO

The ubiquitous presence of nanoplastics (NPs) in natural ecosystems is a serious concern, as NPs are believed to threaten every life form on Earth. Micro- and nanoplastics enter living systems through multiple channels. Cell membranes function as the first barrier of entry to NPs, thus playing an important biological role. However, in-depth studies on the interactions of NPs with cell membranes have not been performed, and effective theoretical models of the underlying molecular details and physicochemical behaviors are lacking. In the present study, we investigated the uptake of polyvinyl chloride (PVC) nanoparticles by Arabidopsis thaliana root cells, which leads to cell membrane leakage and damage to membrane integrity. We performed all-atom molecular dynamics simulations to determine the effects of PVC NPs on the properties of the multicomponent lipid bilayer. These simulations revealed that PVCs easily permeate into model lipid membranes, resulting in significant changes to the membrane, including reduced density and changes in fluidity and membrane thickness. Our exploration of the interaction mechanisms between NPs and the cell membrane provided valuable insights into the effects of NPs on membrane structure and integrity.


Assuntos
Arabidopsis , Nanopartículas , Arabidopsis/metabolismo , Membrana Celular/metabolismo , Ecossistema , Bicamadas Lipídicas/química , Microplásticos , Simulação de Dinâmica Molecular , Nanopartículas/química , Cloreto de Polivinila/análise
9.
Chemosphere ; 307(Pt 3): 135945, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35944680

RESUMO

Microplastics (MPs) are an emerging environmental problem due to their all-around existence and extraordinary stability. A significant number of studies are found in recent literature on the occurrence, distribution, transport, and fate of the MPs in several environmental compartments. In this study, we have investigated the occurrence and characteristics of MPs in the surface water and sediment of the Buriganga river, located beside the mega-city of Dhaka in Bangladesh. In the Buriganga river, the concentration of MPs in the surface water was found from 4.33 ± 0.58 to 43.67 ± 0.58 items L-1, and in the sediment, MPs varied from 17.33 ± 1.53 to 133.67 ± 5.51 items kg-1 of dry sediment. Fragment-type MPs were predominant in the surface water and sediment, which was 72.7% and 85.5% respectively. The most abundant polymer type polypropylene (PP) was found -to be 46% in the surface water and 61% in the sediment sample. The next major category, polyethylene (PE) was found to be 26% and 21%, respectively. Polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polyamide (PA) were other commonly detected polymer types. The MPs were found to be contaminated by Pb, Cd, Cr, Zn, Cu, and Sn from Energy dispersive-X-ray fluorescence (ED-XRF) analysis. Tannery-induced Cr was detected in the highest concentrations in the MPs, which were 20.67 ± 1.66 mg kg-1 (in surface water) and 14.2 ± 1.25 mg kg-1 (in sediment). The pollution load index (PLI) of the MPs contamination in different sampling sites along the Buriganga river was found in the risk level category of I and II. The anthropogenic influence of the city area was reflected in the PLI values, which had an increasing trend from the upstream sampling points (1.00 ± 1.00, 1.00 ± 1.00) to the downstream sites (10.09 ± 1.00, 7.71 ± 3.60).


Assuntos
Microplásticos , Poluentes Químicos da Água , Bangladesh , Cádmio/análise , Monitoramento Ambiental , Sedimentos Geológicos , Chumbo/análise , Nylons , Plásticos , Polietileno/análise , Polietilenotereftalatos , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Água/análise , Poluentes Químicos da Água/análise
10.
Sci Total Environ ; 850: 157983, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35973540

RESUMO

Freshwater pollution is a huge concern. A study aiming to evaluate physico-chemical characteristics, microbiota, occurrence of two groups of persistent environmental pollutants with similar chemical properties (polycyclic aromatic hydrocarbons- PAHs and microplastics - MPs) in Alqueva's surface water was performed during 2021. Water samples were collected at three spots related to touristic activities (two beaches and one marina) during the Winter, Spring, Summer and Autumn seasons. In addition, the presence of biofilms on plastic and natural materials (stone, wood/ vegetal materials) were assessed and compared. Water quality based on physicochemical parameters was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters by international organizations. However, carcinogenic compounds were detected in two sampling locations, which can pose a problem for aquatic ecosystems. PAHs profiles showed significant differences when comparing the dry seasons with the rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weigh compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during the Winter season. The polymers detected were poly(methyl-2-methylpropenoate), polystyrene, polyethylene terephthalate, polyamide, polypropylene, styrene butadiene, polyvinyl chloride and low /high density polyethylene with the last being the most frequent. Biofilms were more often detected on plastics than on natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity (e.g., bacteria, fungi/yeast and phytoplancton organisms) and richer in extrapolymeric material. Based on morphological analysis a good agreement between microbiota and microorganism present in the biofilms was found. Among microbiota were identified microorganisms previously linked to plastic and PAHs detoxification suggesting the need for further studies to evaluate the viability of using biofilms as part of a green bioremediation strategy to mitigate water pollution.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Biofilmes , Butadienos/análise , Ecossistema , Monitoramento Ambiental , Microplásticos , Nylons , Petróleo/análise , Plásticos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Polietileno/análise , Polietilenotereftalatos , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Poluentes Químicos da Água/análise
11.
Environ Toxicol Chem ; 40(10): 2733-2741, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34314525

RESUMO

Microplastics are now recognized as a persistent and global pollutant. To quantitively measure microplastics in environmental matrices, several techniques are used including new methods using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In the present study, a new extraction method using microwave-assisted extraction (MAE) combined with Py-GC/MS was developed to extract and quantify a wide range of plastic polymers, and the method was validated using different environmental matrices. This new extraction method was able to extract polyethylene, polystyrene, polypropylene, poly(methyl-methacrylate) (PMMA), polyvinylchloride (PVC), and polycarbonate in dichloromethane with good recoveries (92.9-119.7%). The limit of detection and limit of quantification (LOQ) of the method ranged from 0.002 to 0.18 µg and from 1.2 to 5.8 µg, respectively. Intra- and interday repeatability values with coefficients of variation less than 25% for all polymers were obtained. Method validation also included a spike and recovery using all polymers from clean water, dirty water, and shrimp and salmon fillet samples, with recoveries of 85 to 111, 87 to 138, 81 to 122, and 50 to 151%, respectively. Finally, the method was tested on unspiked wild mussels and bottled water for proof-of-concept. Both polyethylene and PVC were detected and quantified in mussels, and polycarbonate and polypropylene were detected below the LOQ. For bottled water, polypropylene, polystyrene, and polycarbonate were all detected below the LOQ. We introduce a method combining MAE and Py-GC/MS as a tool for mass quantification of microplastics. This method can be used as a stand-alone, or as a complementary method to spectroscopic techniques. Environ Toxicol Chem 2021;40:2733-2741. © 2021 SETAC.


Assuntos
Água Potável , Poluentes Químicos da Água , Cromatografia Gasosa-Espectrometria de Massas , Microplásticos , Micro-Ondas , Plásticos/análise , Polietileno/análise , Polímeros , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Pirólise , Poluentes Químicos da Água/análise
12.
Molecules ; 26(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668752

RESUMO

Polyvinyl chloride (PVC), one of the most important polymer materials nowadays, has a large variety of formulations through the addition of various plasticizers to meet the property requirements of the different fields of applications. Routine analytical methods able to identify plasticizers and quantify their amount inside a PVC product with a high analysis throughput would promote an improved understanding of their impact on the macroscopic properties and the possible health and environmental risks associated with plasticizer leaching. In this context, a new approach to identify and quantify plasticizers employed in PVC commodities using low-field NMR spectroscopy and an appropriate non-deuterated solvent is introduced. The proposed method allows a low-cost, fast, and simple identification of the different plasticizers, even in the presence of a strong solvent signal. Plasticizer concentrations below 2 mg mL-1 in solution corresponding to 3 wt% in a PVC product can be quantified in just 1 min. The reliability of the proposed method is tested by comparison with results obtained under the same experimental conditions but using deuterated solvents. Additionally, the type and content of plasticizer in plasticized PVC samples were determined following an extraction procedure. Furthermore, possible ways to further decrease the quantification limit are discussed.


Assuntos
Plastificantes/análise , Cloreto de Polivinila/análise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Plastificantes/economia , Cloreto de Polivinila/economia
13.
Chemosphere ; 262: 127784, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32777612

RESUMO

While several studies have investigated the potential impact of nanoplastics, proof of their occurrence in our global environment has not yet been demonstrated. In the present work, by developing an innovative analytical strategy, the presence of nanoplastics in soil was identified for the first time. Our results demonstrate the presence of nanoplastics with a size ranging from 20 to 150 nm and covering three of the most common plastic families: polyethylene, polystyrene and polyvinyl chloride. Given the amount of organic matter in the soil matrix, the discrimination and identification of large nanoplastic aggregates are challenging. However, we provided an innovative methodology to circumvent the organic matter impact on nanoplastic detection by coupling size fractionation to molecular analysis of plastics. While photodegradation has been considered the principal formation pathway of nanoplastics in the environment, this study provides evidence, for the first time, that plastic degradation and nanoplastic production can, however, occur in the soil matrix. Moreover, by providing an innovative and simple extraction/analysis method, this study paves the way to further studies, notably regarding nanoplastic environmental fate and impacts.


Assuntos
Monitoramento Ambiental/métodos , Microplásticos/análise , Nanopartículas/análise , Poluentes do Solo/análise , Solo/química , França , Tamanho da Partícula , Polietileno/análise , Poliestirenos/análise , Cloreto de Polivinila/análise
14.
Braz. arch. biol. technol ; 64: e21200132, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153298

RESUMO

HIGHLIGHTS Arsenic is considered as one of the highly hazardous elements in the environment and a serious carcinogen for the human health. An enzymatic method has been described by using arsenite oxidase for arsenic detection. Residual activity of the immobilized enzyme was 43% of the initial activity after being recycled 10 times.


Abstract Arsenic is considered as one of the highly hazardous elements in the environment and a serious carcinogen for the human health. More attention has taken towards the arsenic due to its presence in ground water in India, China, Bangladesh, Inner Mongolia and several other regions of the world. It's been a challenge to remove arsenic due to the lack of its efficient detection approach in the complicated environmental matrix. The proposed method describes an enzymatic method for arsenic determination using arsenite oxidase, which catalyzes the oxidation of arsenite to arsenate. Hence, a colorimetric PVC strip with immobilized arsenite oxidase has been developed to detect the arsenic concentration and also having potential for the field-testing. The influence of the optimal conditions i.e. pH, temperature, storage stability, and reusability of free and immobilized enzyme were evaluated and compared. The results have shown that the stabilities were significantly enhanced compared with free counterpart. Residual activity of the immobilized enzyme was 43% of the initial activity after being recycled 10 times. We approve that this novel low cost immobilized carrier presents a new approach in large scale applications and expected to act as a model for establishment of indigenous arsenic sensor in miniature form.


Assuntos
Humanos , Arsênio/análise , Cloreto de Polivinila/análise , Poluentes Químicos da Água/análise , Água Subterrânea/análise , Enzimas Imobilizadas/análise , Oxirredutases , Biodegradação Ambiental
15.
Chemosphere ; 255: 126978, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32417514

RESUMO

Bis(2-ethylhexyl) phthalate (DEHP) migration from polyvinyl chloride (PVC) has been studied with infusion, transfusion and extracorporeal oxygenation devices, but no study has been conducted to estimate its migration via respiratory medical devices (MDs). This work aims to develop an ex vivo model to quantify DEHP released doses by these MDs, which will then be used to estimate newborns DEHP exposure from respiratory assistance MDs. We followed the Frensh National Research and Safety Institute (INRS) recommendations for the validation of a collecting and analysing method of DEHP in air, which will be used to quantify DEHP in air passing through PVC respiratory assistance MDs. The developed method met all the validation criteria for DEHP determination in air. DEHP in air passing through MDs on the sixth day reached a cumulative quantity of 122.86 µg when using a flow rate of 4 L min-1 of non-humidified air while it was of 49.22 µg; 58.12 µg and 29.61 µg with flow rates of 2 L min-1 of humidified air, 2 L min-1 of dry air and 4 L min-1 of humidified air, respectively. Model application to two patients undergoing two different respiratory procedure demonstrated that noninvasive ventilation patient received higher dose of inhaled DEHP, confirmed by DEHP metabolites quantification in urine. Although the protective effect of air humidifiers on DEHP exposure was demonstrated, the effect of flow rate is difficult to be established. This developed method should be tested to verify its capacity to collect and quantify other plasticizers used in PVC MDs.


Assuntos
Dietilexilftalato/análise , Exposição Ambiental/análise , Equipamentos e Provisões/efeitos adversos , Ventiladores Mecânicos/efeitos adversos , Dietilexilftalato/metabolismo , Humanos , Recém-Nascido , Plastificantes/análise , Cloreto de Polivinila/análise , Cloreto de Polivinila/química , Tecnologia Assistiva/efeitos adversos
16.
Chemosphere ; 256: 127107, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32445992

RESUMO

The massive use of petroleum-based polymers and their improper waste treatment has brought on significant global environmental problems due to their non-biodegradable nature. Starch/poly(vinyl alcohol) (PVA) bioplastics are suitable substitutes for conventional polymers, such as polyethylene, due to their full biodegradability and excellent mechanical properties. Knowledge of the pollutant emissions during pyrolysis and combustion of starch/PVA films is important because they can arrive at landfills mixed with conventional polymers and be thermally degraded in uncontrolled fires. On the other hand, controlled thermal treatments could result in thermal valorization of the waste. Pyrolysis and combustion experiments were carried out at 650, 750, 850 and 950 °C in a laboratory furnace. The analysis of carbon oxides, light hydrocarbons, and semivolatile compounds, including polycyclic aromatic hydrocarbons (PAHs), is shown. Experiments showed lower pollutant emissions than those found with conventional polymers, such as polyethylene and polyester, in the same equipment. Nevertheless, the pyrolysis run at 950 °C showed the highest light hydrocarbon yield (123013 mg kg-1), but this is considerably lower than the values found for polyethylene. The main semivolatile compounds (not PAHs) emitted, with maximum yields ranging from 1351 to 4694 mg kg-1, were benzaldehyde, phenol, indene, and acetophenone. Specifically, the total semivolatile compounds emitted after pyrolysis and combustion of starch/PVA samples represent only 38 and 50%, respectively, of those emitted with polyethylene. Further, the main PAHs were naphthalene, acenaphthylene, and phenanthrene with maximum values of 4694, 2704 and 1496 mg kg-1, respectively. The PAH yield was considerably higher in experiments with low oxygen content.


Assuntos
Poluentes Atmosféricos/química , Incineração , Álcool de Polivinil/química , Poluentes Atmosféricos/análise , Carbono/análise , Etanol/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Cloreto de Polivinila/análise , Pirólise , Amido/análise
17.
Chemosphere ; 249: 126179, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32078854

RESUMO

The identification and quantification of micro and nanoplastics (MPs and NPs respectively) requires the development of standardised analytical methods. Thermal analysis methods are generally not considered a method of choice for MPs analysis, especially in aqueous samples due to limited sample size introduction to the instrument, decreasing the detection levels. In this article, pyrolysis - Gas chromatography time of flight mass spectrometry (Py-GCToF) is used as a method of choice for detection of MPs and NPs due to its unprecedented detection capabilities, in combination with PTFE membranes as sample support, allow for smaller particle sizes (>0.1 µm) in water samples to be identified. The utilisation of these widely used membranes and the identification of several and specific (marker) ions for the three plastics in study (polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC)), allows for the extraction of individual plastics from complex signals at trace levels. The method was validated against a number of standards, containing known quantities of MPs. Detection levels were then determined for PVC and PS and were found to be below <50 µg/L, with repeatable data showing good precision (%RSD <20%). Further verification of this new method was achieved by the analysis of a complex sample, sourced from a river. The results were positive for the presence of PS with a semi-quantifiable result of 241.8 µg/L. Therefore PY-GCToF seems to be a fit for purpose method for the identification of MPs and NPs from complex mixtures and matrices which have been deposited on PTFE membranes.


Assuntos
Monitoramento Ambiental/métodos , Plásticos/química , Poluentes Químicos da Água/química , Cromatografia Gasosa-Espectrometria de Massas , Tamanho da Partícula , Plásticos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Pirólise , Rios/química , Poluentes Químicos da Água/análise
18.
Regul Toxicol Pharmacol ; 111: 104574, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31917999

RESUMO

Dialkyl phthalates, including diisononyl phthalate (DINP), have been used as plasticizers in children's products made from polyvinyl chloride (PVC), such as teethers and toys. Children may be exposed to phthalates when handling or mouthing PVC products because plasticizers are not covalently bound. The Consumer Product Safety Improvement Act of 2008 prohibited certain phthalates from use in child care articles and children's toys. Thus, manufacturers have changed to other plasticizers or non-PVC plastics and there is interest in evaluating the potential health risks of alternative plasticizers. In 2008, CPSC staff purchased 63 children's products comprising 129 individual pieces (articles). Plastics identified FTIR included PVC, polypropylene, polyethylene, and acrylonitrile butadiene styrene. Plasticizers identified by in the 38 PVC articles included acetyltributyl citrate (ATBC) (20); di (2-ethylhexyl) terephthalate (DEHT) (14); 1,2-cyclohexanedicarboxylic acid diisononyl ester (DINX) (13); 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TPIB) (9); di (2 ethyhexyl) phthalate (DEHP) (1); and DINP (1). Half of the tested articles contained multiple plasticizers. CPSC measured migration rates using the Joint Research Centre method. Migration rates correlated roughly with plasticizer concentration and inversely with the molecular mass of the plasticizer. We then combined the migration rates with data on mouthing duration to estimate children's exposure to plasticizers in toys and child care articles, and estimated margins of exposure. All margins of exposure were >1,000, suggesting a low risk potential. However, the plasticizers in this study have multiple uses. Exposure from other sources and routes of exposure will be considered in future work.


Assuntos
Qualidade de Produtos para o Consumidor , Plastificantes/efeitos adversos , Jogos e Brinquedos , Cloreto de Polivinila/efeitos adversos , Criança , Cuidado da Criança , Equipamentos e Provisões , Humanos , Plastificantes/análise , Cloreto de Polivinila/análise
19.
Mar Pollut Bull ; 150: 110724, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31759635

RESUMO

The microplastics removal and its effects on membrane fouling in membrane bioreactor (MBR) for treating polluted surface water in drinking purpose was investigated in this study. Typical microplastics polyvinylchloride (PVC) with concentration 10 particles/L was added in the feed water. MBR was effective in treating organic matters and ammonia with removal rate over 80% and 95%, respectively. The removal performance was immediately inhibited with the microplastics PVC added into the MBR system, and recovered after operated for few days. The membrane fouling and cleaning results indicated that microplastics contamination could led to higher membrane fouling, and also the irreversible membrane fouling. The main contributor of rejection is the membrane module and the adsorption onto bio-carrier. The microbial community of the system before and after PVC addition did not show obvious difference. MBR has the potential to be used as effective technology in treating microplastics contaminated polluted surface water.


Assuntos
Reatores Biológicos , Microplásticos/química , Cloreto de Polivinila/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Membranas Artificiais , Microplásticos/análise , Plásticos , Cloreto de Polivinila/análise , Águas Residuárias , Poluentes Químicos da Água/análise , Purificação da Água
20.
Molecules ; 24(17)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466267

RESUMO

In this study, an accelerated migration test on food can coatings into food simulants was investigated. Food simulants covering a wide range of polarity were used to conduct migration tests at 60 °C with storage times ranging from 4 h to 30 days. Epoxy-resins, acrylic-phenolic, polyester, and vinyl coatings were exposed to water, 3% acetic acid, 50% ethanol, and Miglyol 812®. Using liquid chromatography coupled to a variety of detectors (UHPLC-Q-Orbitrap-MS, UFLC-MS/MS, and HPLC-DAD), migration of several monomers and previously identified oligomers, as well as some unidentified migrants, were determined during the experiment. The data from this study was compared to our findings from previous long-term migration studies with storage times ranging from 24 h to 540 days at 40 °C using the same can coating applications. The results illustrate that performing migration experiments for short time periods at 60 °C may mimic migration results that would be obtained at 40 °C after long-term migration tests (up to 1.5 years) from food can coatings into food simulants.


Assuntos
Contaminação de Alimentos/análise , Embalagem de Alimentos/instrumentação , Cromatografia Líquida , Resinas Epóxi/análise , Armazenamento de Alimentos , Temperatura Alta , Fenóis/análise , Poliésteres/análise , Cloreto de Polivinila/análise , Espectrometria de Massas em Tandem
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