Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Chem Eng J ; 426: 131201, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35791349

RESUMEN

Landfilling and illegal waste disposal have risen to deal with the COVID-19 potentially infectious waste, particularly in developing countries, which aggravates plastic pollution and inherent environmental threats to human and animal health. It is estimated that 3.5 million metric tonnes of masks (equivalent to 601 TIR containers) have been landfilled worldwide in the first year, with the potential to increase global plastic municipal solid waste by 3.5%, alter biogas composition, and release 2.3 × 1021 microplastics to leachates or adjacent environments, in the coming years. This paper reviews the challenges raised in the pandemic scenario on landfills and discusses the potential environmental and health implications that might drive us apart from the 2030 U.N. sustainable goals. Also, it highlights some innovative technologies to improve waste management (from collection to disposal, waste reduction, sterilization) and mitigates plastic leakage (emission control approaches, application of biotechnological and monitoring/computational tools) that can pave the way to environmental recovery. COVID-19 will eventually subside, but if no action is taken in the short-term towards effective plastic policies, replacement of plastics for sustainable alternatives (e.g., biobased plastics), improvement of waste management streams (prioritising flexible and decentralized approaches), and a greater awareness and responsibility of the general public, stakeholders, industries; we will soon reach a tipping-point in natural environments worldwide.

2.
Chem Eng J ; 405: 126683, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32834764

RESUMEN

Plastics have become a severe transboundary threat to natural ecosystems and human health, with studies predicting a twofold increase in the number of plastic debris (including micro and nano-sized plastics) by 2030. However, such predictions will likely be aggravated by the excessive use and consumption of single-use plastics (including personal protective equipment such as masks and gloves) due to COVID-19 pandemic. This review aimed to provide a comprehensive overview on the effects of COVID-19 on macroplastic pollution and its potential implications on the environment and human health considering short- and long-term scenarios; addressing the main challenges and discussing potential strategies to overcome them. It emphasises that future measures, involved in an emergent health crisis or not, should reflect a balance between public health and environmental safety as they are both undoubtedly connected. Although the use and consumption of plastics significantly improved our quality of life, it is crucial to shift towards sustainable alternatives, such as bio-based plastics. Plastics should remain in the top of the political agenda in Europe and across the world, not only to minimise plastic leakage and pollution, but to promote sustainable growth and to stimulate both green and blue- economies. Discussions on this topic, particularly considering the excessive use of plastic, should start soon with the involvement of the scientific community, plastic producers and politicians in order to be prepared for the near future.

3.
Environ Sci Technol ; 54(13): 7760-7765, 2020 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-32531154

RESUMEN

Plastics are essential in society as a widely available and inexpensive material. Mismanagement of personal protective equipment (PPE) during the COVID-19 pandemic, with a monthly estimated use of 129 billion face masks and 65 billion gloves globally, is resulting in widespread environmental contamination. This poses a risk to public health as waste is a vector for SARS-CoV-2 virus, which survives up to 3 days on plastics, and there are also broad impacts to ecosystems and organisms. Concerns over the role of reusable plastics as vectors for SARS-CoV-2 virus contributed to the reversal of bans on single-use plastics, highly supported by the plastic industry. While not underestimating the importance of plastics in the prevention of COVID-19 transmission, it is imperative not to undermine recent progress made in the sustainable use of plastics. There is a need to assess alternatives that allow reductions of PPE and reinforce awareness on the proper public use and disposal. Finally, assessment of contamination and impacts of plastics driven by the pandemic will be required once the outbreak ends.


Asunto(s)
Infecciones por Coronavirus , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Pandemias , Neumonía Viral , Betacoronavirus , COVID-19 , Ecosistema , Humanos , Plásticos , SARS-CoV-2
4.
Ecotoxicol Environ Saf ; 200: 110753, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32450440

RESUMEN

Plastics and microplastics are ubiquitous contaminants in aquatic ecosystems. This critical review is the first attempt at analyzing sources, concentration, impacts and solutions of (micro)plastic litter in Portugal based on all currently available literature. We found that, besides sea-based sources (e.g. shipping, fishing), 5717 t of mismanaged waste and 4.1 trillion microplastics from wastewater, mostly from untreated wastewater, are released to the environment every year. The highest concentrations are found in the North, Center and Lisbon regions, mostly comprised of consumer products, fishing gear and microplastics (<5 mm), especially fragments and pellets. This contamination has resulted in ingestion of plastics by organisms, including mussels, fishes, birds and turtles. Thus, every Portuguese citizen may consume 1440 microplastics a year based on the consumption of mollusks. Awareness campaigns, improvements in waste management and reductions in the release of untreated wastewater are recommended measures to reduce plastic pollution in Portugal.


Asunto(s)
Microplásticos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Aves , Bivalvos , Ecosistema , Monitoreo del Ambiente , Peces , Humanos , Microplásticos/toxicidad , Portugal , Tortugas , Administración de Residuos , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidad
5.
J Toxicol Environ Health A ; 82(9): 550-563, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31266404

RESUMEN

The volatile organic compounds benzene, toluene, ethylbenzene, and xylene (BTEX) are emitted into the atmosphere at gas stations (GS) leading to chronic exposure of nearby residents, which raises public health concerns. This study aimes at determining the contribution of GS emissions to BTEX exposure in nearby residents. Three Control and Exposed areas to BTEX emissions from GS were defined in a medium-sized European city (Porto, Portugal). BTEX atmospheric levels were determined in Control and Exposed areas using passive samplers deployed outdoors (n = 48) and indoors (n = 36), and human exposure was estimated for 119 non-smoking residents using the first urine of the day. Results showed that median BTEX outdoor and indoor concentrations were significantly higher for Exposed than Control areas, with exception of ethylbenzene and xylene indoor concentrations, where no marked differences were found. Comparison of urinary concentrations between Exposed and Control residents demonstrated no significant differences for benzene and ethylbenzene, whereas levels of toluene and xylene were significantly higher in Exposed residents. No marked correlation was obtained between atmospheric BTEX concentrations and urinary concentrations. Data indicate the potential impact on air quality of BTEX emissions from GS, which confirms the importance of these findings in urban planning in order to minimize the impact on health and well-being of surrounding populations.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Petróleo/análisis , Compuestos Orgánicos Volátiles/análisis , Adulto , Anciano , Anciano de 80 o más Años , Monitoreo Biológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Portugal , Adulto Joven
6.
Microorganisms ; 12(4)2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38674729

RESUMEN

Listeria monocytogenes poses a threat to both human and animal health. This work describes an L. monocytogenes outbreak in a Portuguese rabbit farm, detailing the isolates' clinical manifestations, necropsy findings, and phenotypic and genomic profiles. Clinical signs, exclusively observed in does, included lethargy and reproductive signs. Post-mortem examination of does revealed splenomegaly, hepatomegaly with a reticular pattern, pulmonary congestion, and haemorrhagic lesions in the uterus, with thickening of the uterine wall and purulent greyish exudates. Positive L. monocytogenes samples were identified in fattening and maternity units across different samples, encompassing does and environmental samples. Core-genome Multi Locus Sequence Typing (cgMLST) analysis confirmed the outbreak, with the 16 sequenced isolates (lineage II, CC31, and ST325) clustering within a ≤2 allelic difference (AD) threshold. Antimicrobial susceptibility testing for five antibiotics revealed that 15 out of 19 outbreak isolates were resistant to sulfamethoxazole-trimethoprim (SXT). Concordantly, all SXT-resistant sequenced isolates were found to exclusively harbour a plasmid containing a trimethoprim-resistance gene (dfrD), along with loci linked to resistance to lincosamides (lnuG), macrolides (mphB), and polyether ionophores (NarAB operon). All sequenced outbreak isolates carried the antibiotic resistance-related genes tetM, fosX, lin, norB, lmrB, sul, and mprF. The outbreak cluster comprises isolates from does and the environment, which underscores the ubiquitous presence of L. monocytogenes and emphasizes the importance of biosecurity measures. Despite limited data on listeriosis in rabbit farming, this outbreak reveals its significant impact on animal welfare and production.

7.
Animals (Basel) ; 13(4)2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36830448

RESUMEN

Terrestrial domestic animals are exposed to microplastics, therefore, contaminating the food chain, in the case of livestock, or acting as sentinels for human exposure, in the case of companion animals. The aim of this review was to address the importance of terrestrial domestic animals on human exposure to microplastics. Animal products may already show some microplastics contamination, which may occur during their lifetime, possibly also compromising productivity, and during processing, originating from equipment and packaging. Moreover, release of microplastics in animal feces (or manure) leads to the contamination of agricultural fields, with possible impacts and internalization in plants. Therefore, microplastics pose a threat to food security, compromising food productivity, and food safety, by being a foreign material found in animal products. Conversely, in urban environments, companion animals (cats and dogs) may be relevant sentinels for human exposure. While oral exposure may vary in pets compared to humans, due to indiscriminate ingestion and chewing or licking behaviors, airborne exposure is likely to be a good indicator for human exposure. Therefore, future studies should address the importance of terrestrial domestic animals for human exposure of microplastics, both in the food chain and as sentinels for environmental exposure.

8.
Sci Total Environ ; 859(Pt 2): 160426, 2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36427728

RESUMEN

Chironomids inhabit freshwater benthic ecosystems which are prone to microplastic contamination. This work aimed at understanding the factors and mechanisms influencing microplastic uptake and related adverse effects on Chironomus riparius, by exploring an extensive project database, conducting a literature review, and performing an agent-based model to explore trends in data. Results reveal that high concentrations of small microplastics fill the gut of fourth instar C. riparius (99.7 %). Ingested microplastics had an average size of 38-61 µm, presenting slower elimination rates than undigested organic or mineral particles. Ingestion rates of microplastics depend mainly on encounter rates, and therefore on available concentrations, until reaching a plateau corresponding to the maximum gut volume. Short-term toxicity of microplastics seems to result from damage to gut epithelium, with inflammatory reactions, production of reactive oxygen species, and a negative energy balance exacerbated by the lack of food (organic matter). Long-term toxicity is characterized by a reduction in larval body length and increase in mean time to emergence, seemly from increased energy costs rather than a decrease in nutrient absorption. Wild chironomids already present microplastics in their guts and environmental concentrations in hotspots may already exceed no effect concentrations. Therefore, environmental exposure to microplastics may induce adverse effects to wild C. riparius in freshwater benthic ecosystems, which could compromise their ecologic role as deposit-feeders (e.g., reducing their nutrient cycling ability) and key-stone species in aquatic food webs.


Asunto(s)
Chironomidae , Contaminantes Químicos del Agua , Animales , Microplásticos/toxicidad , Plásticos/toxicidad , Ecosistema , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Invertebrados
9.
Vet Sci ; 10(5)2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37235409

RESUMEN

Because of public health concerns, much greater scrutiny is now placed on antibiotic use in pets, especially for antimicrobial agents that have human analogs. Therefore, this study aimed to characterize the phenotypic and genotypic profiles of multidrug-resistant bacteria isolated from nasal swabs samples taken from a one-year-old male Serra da Estrela dog with rhinorrhea that was treated with amikacin. An extended-spectrum ß-lactamases (ESBL) Klebsiella pneumoniae was isolated in the first sample taken from the left nasal cavity of the dog. Seven days later, methicillin-resistant (MRSP) Staphylococcus pseudintermedius was also isolated. Nevertheless, no alterations to the therapeutic protocol were performed. Once the inhibitory action of the antibiotic disappeared, the competitive advantage of the amikacin-resistant MRSP was lost, and only commensal flora was observed on both nasal cavities. The genotypic profile of extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae revealed the same characteristics and close relation to other strains, mainly from Estonia, Slovakia and Romania. Regarding MRSP isolates, although resistance to aminoglycosides was present in the first MRSP, the second isolate carried aac(6')-aph(2″), which enhanced its resistance to amikacin. However, the veterinary action was focused on the treatment of the primary agent (ESBL K. pneumoniae), and the antibiotic applied was according to its phenotypic profile, which may have led to the resolution of the infectious process. Therefore, this study highlights the importance of targeted therapy, proper clinical practice and laboratory-hospital communication to safeguard animal, human and environmental health.

10.
Sci Total Environ ; 875: 162556, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-36870489

RESUMEN

Freshwater benthic environments are among the major sinks of microplastics (MPs, < 5 mm) sourced on inland anthropogenic activities. The ecotoxicological effects of MPs on benthic macroinvertebrates have been assessed preferably in collectors, shredders, and filter-feeders, but resulting in insufficient knowledge on the potential trophic transfer and its effects on macroinvertebrates with predator behaviour such as planarians. This work evaluated the behavioural (feeding, locomotion), physiological (regeneration) and biochemical responses (aerobic metabolism, energy reserves, oxidative damage) of the planarian Girardia tigrina after consuming contaminated live prey Chironomus riparius larvae previously exposed to microplastics of polyurethane (PU-MPs; 7-9 µm in size; 375 mg PU-MPs/kg). After the feeding period (3 h), planarians consumed 20 % more contaminated prey than uncontaminated prey, probably related to increased curling/uncurling movements of larvae (that might be more appellative to planarians). Histological analysis revealed planarians' limited intake of PU-MPs, mainly detected near the pharynx. The consumption of contaminated prey (and intake of PU-MPs) did not result in oxidative damage but slightly increased the aerobic metabolism and energy reserves which show that the consumption of more prey was sufficient to cope with the potential adverse effects of internalized MPs. Moreover, no effects were observed in the locomotion of planarians in good agreement with the hypothesis of sufficient energy acquired by the exposed planarians. Despite the previous, it seems that the energy acquired was not allocated for planarians' regeneration since a significant delay in the regeneration of the auricles was observed for planarians feeding on contaminated prey. Therefore, further studies should be performed considering the potential long-term effects (i.e., reproduction/fitness) and the effects of MPs that might result from continuous feeding on contaminated prey, representing a more realistic exposure scenario.


Asunto(s)
Planarias , Contaminantes Químicos del Agua , Animales , Microplásticos , Plásticos , Planarias/fisiología , Contaminantes Químicos del Agua/toxicidad , Agua Dulce
11.
Vet Sci ; 10(7)2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37505828

RESUMEN

A growing population increases the demand for food, but short shelf-lives and microbial hazards reduce supply and increase food waste. Fresh fish is highly perishable and may be consumed raw, such as salmon in sushi. This work aims to identify strategies to improve the shelf-life and safety of fresh salmon, using available methods (i.e., vacuum) and exploring the use of natural preservatives (i.e., seasonings). Vacuum packaging and good hygiene practices (which reduce initial flora) extended shelf-life up to 20 days. Carnobacterium maltaromaticum was dominant in vacuum packaging conditions and showed potential for inhibiting Listeria monocytogenes. For natural preservatives, L. monocytogenes required higher inhibitory concentrations in vitro when compared to the 10 spoilage bacteria isolated from fresh salmon fillets, presenting a minimum inhibitory concentration (MIC) of 0.13% for oregano essential oil (OEO), 10% for lemon juice, 50 mg mL-1 for garlic powder, and >10% for NaCl. A good bacteriostatic and bactericidal effect was observed for a mixture containing 5% NaCl, 0.002% OEO, 2.5% lemon juice, and 0.08 mg mL-1 garlic powder. Finally, using the salmon medium showed an adequate correlation with the commercial culture medium.

12.
Microorganisms ; 12(1)2023 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-38257887

RESUMEN

Gulls act as intermediaries in the exchange of microorganisms between the environment and human settlements, including Salmonella spp. This study assessed the antimicrobial resistance and molecular profiles of Salmonella spp. isolates obtained from fecal samples of gulls in the city of Porto, Portugal, in 2008 and 2023 and from water samples in 2023. Antimicrobial susceptibility profiling revealed an improvement in the prevalence (71% to 17%) and antimicrobial resistance between the two collection dates. Two isolate collections from both 2008 and 2023 underwent serotyping and whole-genome sequencing, revealing genotypic changes, including an increased frequency in the monophasic variant of S. Typhimurium. qacE was identified in 2008 and 2023 in both water and fecal samples, with most isolates exhibiting an MDR profile. The most frequently observed plasmid types were IncF in 2008 (23%), while IncQ1 predominated in 2023 (43%). Findings suggest that Salmonella spp. circulate between humans, animals, and the environment. However, the genetic heterogeneity among the isolates from the gulls' feces and the surface water may indicate a complex ecological and evolutionary dynamic shaped by changing conditions. The observed improvements are likely due to measures to reduce biological contamination and antimicrobial resistance. Nevertheless, additional strategies must be implemented to reduce the public health risk modeled by the dissemination of pathogens by gulls.

13.
Animals (Basel) ; 12(20)2022 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-36290160

RESUMEN

Feeding practices and perceptions of pet owners determine consumer decisions on pet foods and influence the health of companion animals. The objective of the survey was to study emerging trends on pet food diets in Portugal by conducting a preliminary survey. A survey of 74 pet owners revealed that most fed pets with commercial diets (67.6%) bought in supermarkets (40.3%), spending a monthly average of EUR 30, following healthy practices (e.g., ≥30 min of exercise), which translated to an average self-reported pet body condition score of 3. Information about pet foods mainly originates from the animal's veterinarian (64.9%), followed by the internet (16.2%). A trend for a growing interest in alternative diets (e.g., natural and organic) was identified, being already the second most consumed diet type (19.0%), perceived as being of a higher quality, and as a topic of interest (38.6%). This interest likely originates from a higher weighting of the ingredient list (31.5%) in consumer choices and beliefs that commercial diets should consist of a higher proportion of meat (29.3%) and less carbohydrates (38.7%). Therefore, more research is needed on the nutritional adequacy of alternative diets and uncommon ingredients, the pet food industry will have to adapt to changing consumer behaviors, and veterinarians should be available to discuss and oversee novel dietary practices in companion animals.

14.
Top Companion Anim Med ; 51: 100738, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36306992

RESUMEN

Internet use for pet health information is increasing in popularity among pet owners. So far, evidence on motivations and topics of interest is limited to surveys on English speaking countries. The objective was to evaluate the motivations of Portuguese-speaking pet owners when visiting a pet information website, written by a certified veterinarian. In situ needs and motivations of visitors were evaluated by classifying online questions (n = 202) and conducting a short questionnaire in the website sidebar (n = 453). Most pet owners were looking for general advice (73.9%), especially on systems with visible disease signs, being motivated by the lack of access to veterinary services due to costs (17.7%), support from other pet owners (11.3%), and complementing the insufficient information provided by the veterinarian (7.7%). Brazilians reported more lack of veterinary access due to costs compared to Portuguese respondents. Thus, Portuguese-speaking pet owners engaged in online searches to seek affordable veterinary care, better information, and emotional support.


Asunto(s)
Uso de Internet , Medicina Veterinaria , Animales , Humanos , Motivación , Portugal , Encuestas y Cuestionarios , Uso de Internet/estadística & datos numéricos
15.
Mar Pollut Bull ; 174: 113249, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34953263

RESUMEN

Microplastics have been found in fish, but most studies have focused on the digestive system without considering additional organs. Herein, the objective was to assess the presence of microplastics in internal organs (gills, guts, kidney, heart) of the Atlantic horse mackerel (Trachurus trachurus) captured of the coast of Portugal (Northeast Atlantic Ocean). Suspected microplastics were present in all organs, with particles of larger size (i.e., equivalent diameter) found in the gut and those of lower size in the heart and its luminal blood. Suspected microplastics of 1-10 µm were the most abundant (65.4%), more likely to translocate, owing to their minute size, but more difficult to properly characterize. These results highlight the need to expand the analytical work on organs and tissues for assessing microplastics in organisms, but also emphasize the actual need for developing analytical methods that allow for an accurate isolation, identification, and characterization of microplastics in biota.


Asunto(s)
Perciformes , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Peces , Microplásticos , Plásticos , Portugal , Contaminantes Químicos del Agua/análisis
16.
Front Environ Sci Eng ; 16(1): 5, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34697576

RESUMEN

As a European Union (EU) member, Portugal must comply with reductions in plastic waste. In Portugal, the 330 items/100 m of beach litter, comprising up to 3.9 million pieces and of which 88% is plastic, is higher than the EU median (149 items/100 m) and must be reduced to 20 items/100 m (94%). Integrative measures are needed to reduce littering and improve plastics' use and disposal under the circular economy. Of this 414 kt of plastic packaging waste, 163 kt were declared plastic packaging, 140 kt subjected to recycling, and 94 kt to energy recovery. The current recycling rate of plastic packaging (34%) should be improved to reach EU recycling averages (42%) and goals and to provide widespread benefits, considering revenues of 167 €/t. As a net importer of waste, Portugal could benefit from the valorization of imported waste. Besides increased recycling, pyrolysis and gasification could provide short-term alternatives for producing value-added substances from plastic waste, such as hydrogen, consistent with the National Plan of Hydrogen and improving ongoing regulations on single-use plastics. This manuscript provides an integrative view of plastics in Portugal, from use to disposal, providing specific recommendations under the circular economy. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available in the online version of this article at 10.1007/s11783-021-1439-x and is accessible for authorized users.

17.
Sci Total Environ ; 815: 152941, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35007581

RESUMEN

The extraction of microplastics from organic-rich freshwater samples is challenging and limited information is available in the literature. This study aims at developing efficient methods for water volume reduction and organic matter removal in freshwater samples, while focusing on the reduction of the economic and environmental costs, maintaining microplastics integrity and avoiding contamination. For the water volume reduction approach, centrifuging freshwater samples (water, sediment, algae, leaves, driftwood, fish tissue) at different speeds (3500, 6000 rpm) and times (5, 10 min) showed that 3500 rpm for 5 min was efficient to settle the mineral and organic material, while preserving the polymers and showing high microplastic recovering rates (93 ± 6%). These recovery rates were significantly higher than the traditional sieving approach (77 ± 22%). The posterior minimal consumption of reagents resulting from the reduction of water volume helped to reduce the economic and environmental costs of the devised methodology, becoming more aligned with green chemistry principles. For biogenic organic matter removal, four digestion solutions were tested on freshwater samples, namely 10% potassium hydroxide, Fenton reagent (30% H2O2 + Fe(II)), 7% and 10% sodium hypochlorite (NaClO), under 3 periods of time (1, 6 and 15 h), at 50 °C. Both 7% and 10% NaClO showed the highest rates of organic matter removal (86 ± 1% and 90 ± 1%, respectively), after 6 h at 50 °C. Exposure of virgin and aged polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride, nylon, polyethylene terephthalate) to NaClO showed no weight, visual, surface structure, Fourier transform infrared spectra and carbonyl index changes, except for nylon, although not to an extent that affected its identification. This method resulted in high recovery rates of polymers (92 ± 6%). Thus, 7% NaClO at 50 °C for 6 h (or overnight) may be efficiently used for microplastic analysis in organic-rich freshwater samples.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Agua Dulce , Peróxido de Hidrógeno , Plásticos , Contaminantes Químicos del Agua/análisis
18.
Sci Total Environ ; 816: 151642, 2022 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-34822904

RESUMEN

Microplastics are ubiquitous contaminants of freshwater ecosystems. However, few ecotoxicity assays have been conducted on freshwater organisms using environmentally relevant concentrations of virgin and weathered microplastics. This work assessed the adverse effects of virgin and artificially weathered fragments of polystyrene and polypropylene on the microalga Raphidocelis subcapitata (72 h growth inhibition assay) and on embryos of the fish Danio rerio (96 h fish embryo assay) under environmentally relevant concentrations (2000-200,000 MP L-1) and high concentrations (12.5-100 mg L-1). Sizes of microplastics were measured as tens (polystyrene) to hundreds (polypropylene) of micrometers, while aging was assessed by measuring the carbonyl index. In the microalga, the tested high concentrations promoted growth, while environmentally relevant concentration induced either growth inhibition or promotion. In zebrafish embryos, environmentally relevant concentrations decreased body length and heart rates. No relevant effects were observed in organisms exposed to high concentrations for mortality, malformations, hatching rates, and swimming bladder inflation. Virgin microplastics presented slightly higher toxicity but direct comparison was hindered by the lack of a linear dose-response curve. Despite the lack of a clear pattern, adverse effects were often observed in the lowest environmentally relevant concentrations, raising concerns over the impacts of microplastics on freshwater ecosystems.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Ecosistema , Plásticos/toxicidad , Polipropilenos , Poliestirenos/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
19.
Animals (Basel) ; 12(15)2022 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-35953968

RESUMEN

Companion animals living in urban areas are exposed to environmental contaminants, which may include microplastics. A preliminary study was conducted by collecting postmortem samples from the internal tissue (lungs, ileum, liver, kidney, and blood clots) of 25 dogs (Canis familiaris) and 24 cats (Felis catus) living in an urban environment in Porto metropolitan area, Portugal. Suspected microplastics were found in 80 samples from 35 animals (18 cats and 17 dogs), often occurring in more than one tissue of the same animal (71.4%), primarily under small sizes (50.3% as 1-10 µm). Micro-Raman spectroscopy confirmed a fraction of particles as common polymer types (e.g., polyethylene terephthalate). However, the number of particles was very low. This study highlights the possibilities of the internalization and distribution of microplastics in the internal tissues of terrestrial vertebrates.

20.
Sci Total Environ ; 783: 146979, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-33866182

RESUMEN

Nile Red staining enables visual identification and quantification of fluorescent particles as a proxy to microplastics at low cost and high throughput, including those of small sizes (≥2 µm), when preceded by proper natural organic matter removal, but providing no chemical characterization. On the other hand, micro-spectroscopy methods allow chemical characterization of particles based on their spectra, essential for polymer identification, but are costly and time-consuming. This work addresses the combination of both Nile Red staining with micro-Raman spectroscopy for the identification of microplastics. Besides being useful for quantification, Nile Red staining can be advantageously used as an objective criterion for pre-selection of particles for micro-Raman spectroscopy, producing little interference. The use of the 442 nm laser in micro-Raman spectroscopy induces Nile Red luminescence thus allowing to target the specific suspected microplastics when using an orange filter, reducing the number of particles subjected to identification and improving sample throughput. Staining dyes could also be used for mapping suspected microplastics before targeted analysis by micro-Raman spectroscopy. Thus, coupling Nile Red with micro-Raman spectroscopy can be useful to improve time efficiency while using this equipment.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA