Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chemosphere ; 335: 139140, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37285981

RESUMO

Due to their properties, graphene-based nanomaterials (GBMs) are triggering a great interest leading to an increase of their global production and use in new applications. As a consequence, their release into the environment is expected to increase in the next years. When considering the current knowledge in the evaluation of GBMs ecotoxic potential, studies aiming to evaluate the hazard associated to these nanomaterials towards marine species and particularly considering potential interactions with other environmental pollutants such as metals are scarce. Here we evaluated the embryotoxic potential of GBMs, which include graphene oxide (GO) and its reduced form (rGO), both individually and in combination with copper (Cu) as a referent toxicant, towards early life stages of the Pacific oyster through the use of a standardized method (NF ISO 17244). We found that following exposure to Cu, dose-dependent decrease in the proportion of normal larvae was recorded with an Effective Concentration leading to the occurrence of 50% of abnormal larvae (EC50) of 13.85 ± 1.21 µg/L. Interestingly, the presence of GO at a non-toxic dose of 0.1 mg/L decreased the Cu EC50 to 12.04 ± 0.85 µg/L while it increased to 15.91 ± 1.57 µg/L in presence of rGO. Based on the measurement of copper adsorption, the obtained results suggest that GO enhances Cu bioavailability, potentially modifying its toxic pathways, while rGO mitigates Cu toxicity by decreasing its bioavailability. This research underscores the need to characterize the risk associated to GBMs interactions with other aquatic contaminants and supports the adoption of a safer-by-design strategy using rGO in marine environments. This would contribute to minimize the potential adverse effects on aquatic species and to reduce the risk for economic activities associated to coastal environments.


Assuntos
Grafite , Ostreidae , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Grafite/toxicidade , Larva , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise
2.
Environ Toxicol Chem ; 39(12): 2450-2461, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32833228

RESUMO

A nanometric revolution is underway, promising technical innovations in a wide range of applications and leading to a potential boost in environmental discharges. The propensity of nanoparticles (NPs) to be transferred throughout trophic chains and to generate toxicity was mainly assessed in primary consumers, whereas a lack of knowledge for higher trophic levels persists. The present study focused on a predatory fish, the European eel (Anguilla anguilla) exposed to gold NPs (AuNPs; 10 nm, polyethylene glycol-coated) for 21 d at 3 concentration levels in food: 0 (NP0), 1 (NP1), and 10 (NP10) mg Au kg-1 . Transfer was assessed by Au quantification in eel tissues, and transcriptomic responses in the liver and brain were revealed by a high-throughput RNA-sequencing approach. Eels fed at NP10 presented an erratic feeding behavior, whereas Au quantification only indicated transfer to intestine and kidney of NP1-exposed eels. Sequencing of RNA was performed in NP0 and NP1 eels. A total of 258 genes and 156 genes were significantly differentially transcribed in response to AuNP trophic exposure in the liver and brain, respectively. Enrichment analysis highlighted modifications in the immune system-related processes in the liver. In addition, results pointed out a shared response of both organs regarding 13 genes, most of them being involved in immune functions. This finding may shed light on the mode of action and toxicity of AuNPs in fish. Environ Toxicol Chem 2020;39:2450-2461. © 2020 SETAC.


Assuntos
Anguilla/metabolismo , Encéfalo/efeitos dos fármacos , Ouro/toxicidade , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Anguilla/genética , Anguilla/imunologia , Animais , Encéfalo/imunologia , Encéfalo/metabolismo , Exposição Dietética , Perfilação da Expressão Gênica , Ouro/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/imunologia , Fígado/metabolismo , Alimentos Marinhos , Poluentes Químicos da Água/metabolismo
3.
Environ Sci Technol ; 51(7): 3759-3766, 2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28253613

RESUMO

We present a 3-year time series of lead (Pb) and mercury (Hg) concentrations and isotope signatures in total suspended particulate (TSP) matter and as total gaseous Hg (TGM) in Xi'an, Northwestern China. Mean concentrations of TSP (299 ± 120 µg m-3), PbTSP (0.33 ± 0.15 µg m-3) and HgTSP (0.64 ± 0.54 ng m-3), and TGM (5.7 ± 2.7 ng m-3) were elevated. We find that atmospheric Pb levels in winter in Xi'an have decreased by 4.6% per year since 2003, yet remain elevated relative to air quality guidelines and therefore a major health concern. δ202HgTSP and Δ199HgTSP averaged -0.80 ± 0.30‰ (1σ) and -0.02 ± 0.10‰ (1σ) and δ202HgTGM and Δ199HgTGM averaged -0.08 ± 0.41‰ (1σ) and 0.00 ± 0.04‰ (1σ). Relative to raw coal from Shaanxi and surrounding provinces, δ202HgTSP is enriched in the light Hg isotopes, whereas δ202HgTGM is enriched in the heavy isotopes. TSP and TGM Δ199Hg signatures are indistinguishable from raw coal, indicating little photochemical mass independent fractionation of atmospheric Hg in the near-field urban-industrial environment. δ202HgTGM correlates significantly with TGM levels (r2 = 0.3, p < 0.01) and likely reflects binary mixing of local industrial TGM emissions with global background TGM.


Assuntos
Chumbo , Estações do Ano , Poluentes Atmosféricos , China , Carvão Mineral , Monitoramento Ambiental , Isótopos , Mercúrio , Isótopos de Mercúrio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...