RESUMO

Although Antarctica is the most isolated continent on Earth, its remote location does not protect it from the impacts of human activities. Antarctic metazoans such as filter-feeding invertebrates are a crucial component of the Antarctic benthos. They play a key role in the benthic-pelagic carbon flux in coastal areas by filtering particles and planktonic organisms from the sediment-water interface. Due to their peculiar ecological niche, these organisms can be considered a wasp-waist in the ecosystem, making them highly sensitive to marine pollution. Recently, anthropogenic particles such as micro-nanoplastics and manufactured nanoparticles (MNP) have been classified as contaminants of emerging concern (CEC) due to their small size range, which also overlaps with the preferred particle size ingested by aquatic metazoans. Indeed, it has been demonstrated that some species such as Antarctic krill can ingest, transform, and release MNPs, making them newly bioavailable for other Antarctic filter-feeding organisms. Similarly, the production and use of anthropogenic MNP are rapidly increasing, leading to a growing presence of materials, such as nano-sized metal-oxides, in the environment. For these reasons, it is important to provide evidence of the adverse effects of such emerging contaminants at sub-lethal concentrations in environmental risk assessments. These contaminants may cause cascade effects with consequences not only on individuals but also at the community and ecosystem levels. In this review, we discuss the state-of-the-art knowledge on the physiological and molecular effects of anthropogenic MNP in Antarctic aquatic metazoans. We further highlight the importance of identifying early biomarkers using sessile metazoans as sentinels of environmental health.

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RESUMO

The increasing use and disposal of plastics has become a persistent problem in the marine environment, calling for studies that refer to realistic scenarios to understand their effects on biota. Particularly, the understanding about the effects of co-exposure with nanoplastic particles and metals on aquatic organisms is still limited. The present work aimed to investigate the acute toxicity of amino-functionalized polystyrene nanoparticles (PS-NH2; 50 nm) as proxy for nanoplastics on brine shrimp Artemia franciscana larvae under different culture conditions and at different stages of development, as well as the combined effect with two reference toxicants - potassium dichromate (K2Cr2O7) and copper sulfate (CuSO4). Nauplii (instar II or III larval stages) were exposed to different concentrations of PS-NH2 (0.005 to 5 µg mL-1) for up to 48 h, with or without agitation in order to mimic a more realistic environmental scenario. Larval mobility and PS-NH2 accumulation were monitored under microscopy. PS-NH2 alone showed toxicity only at the highest concentration tested (5 µg mL-1) regardless the incubation method used (61.2 + 3.1% and 65.0 + 4.5% with and without agitation, respectively). Moreover, instar III stage was the most sensitive to PS-NH2 exposure (38.2% immobility in 24 h of exposure; 5 µg mL-1). Evidence of PS-NH2 retention in the gastrointestinal tract in a concentration- and time-dependent manner was also obtained. Mixtures of PS-NH2 (0.005 and 5 µg mL-1) with different concentrations of K2Cr2O7 increased the immobilization rate of the larvae after 48 h of exposure, when compared to the K2Cr2O7 alone. Similar results were observed for CuSO4 in the co-exposure conditions at different concentrations. However, exposing nauplii to a mixture of PS-NH2 (0.005 µg mL-1) and CuSO4 decreased immobilization rate, in comparison to the group exposed to CuSO4 alone. The present work highlights the potential risk posed by nanoplastics to zooplanktonic species through their interaction with other toxicants.

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RESUMO

Titanium Dioxide Nanoparticles (TiO2NPs) could cause alterations in exposed aquatic species, in terms of oxygen consumption, ammonia excretion and tissues functionality therefore, the aim of the present study is to evaluate the effects of acute exposure to different concentrations of TiO2NPs (0.1, 0.5, 1.0 and 2.5 mgL-1) on routine metabolism (oxygen consumption and ammonia excretion) and histological parameters (branchial and hepatic) in Oreochromis niloticus. After 24 hours, we observed an increase in oxygen consumption of 2.36 and 3.23 times in groups exposed to 1.0 and 2.5 mgL-1 of TiO2 NPs respectively, as well as an increase in ammonia excretion of 3.54, 4.0 and 4.82 times higher in groups exposed to 0.5, 1.0 and 2.5 mgL-1 of TiO2 NPs respectively, compared to the control group. Histological analysis showed, after 72 hours, moderate to severe alterations in both gills and liver of TiO2 exposed fish at concentrations 1.0 and 2.5 mgL-1, the severity and occurrence of the alteration observed was grade 3 (severe and extensive pathological alterations). We concluded that waterborne exposure of Nile tilapia to TiO2 NPs caused alteration in routine metabolism and histological parameters in a dose-dependent manner.

Nanoparticulas de Dióxido de Titânio (TiO2NPs) podem causar alterações nas espécies aquáticas expostas, em termos de consumo de oxigênio, excreção de amônia e funcionalidade de tecidos, portanto, o objetivo do presente estudo é avaliar os efeitos da exposição aguda a diferentes concentrações de TiO2NPs (0,1, 0,5, 1,0 e 2,5 mgL-1) sobre o metabolismo de rotina (consumo de oxigênio e excreção de amônia) e parâmetros histológicos (branquiais e hepáticos) em Oreochromis niloticus. Após 24 horas, observamos um aumento no consumo de oxigênio de 2,36 e 3,23 vezes em grupos expostos a 1,0 e 2,5 mgL-1 de TiO2NPs respectivamente, bem como um aumento na excreção de amônia de 3,54, 4,0 e 4,82 vezes maior nos grupos expostos a 0,5, 1,0 e 2,5 mgL-1 de TiO2NPs respectivamente, em comparação com o grupo controle. A análise histológica mostrou, após 72 horas, alterações moderadas a severas tanto nas brânquias quanto no fígado de peixes expostos a TiO2NPs em concentrações de 1,0 e 2,5 mgL-1, a gravidade e a ocorrência da alteração observada foram de grau 3 (alterações patológicas graves e extensas). Concluímos que a exposição à TiO2NPs da tilápia do Nilo causaram alteração no metabolismo de rotina e nos parâmetros histológicos de uma maneira dose-dependente.

Assuntos

RESUMO

Titanium Dioxide Nanoparticles (TiO2NPs) could cause alterations in exposed aquatic species, in terms of oxygen consumption, ammonia excretion and tissues functionality therefore, the aim of the present study is to evaluate the effects of acute exposure to different concentrations of TiO2NPs (0.1, 0.5, 1.0 and 2.5 mgL-1) on routine metabolism (oxygen consumption and ammonia excretion) and histological parameters (branchial and hepatic) in Oreochromis niloticus. After 24 hours, we observed an increase in oxygen consumption of 2.36 and 3.23 times in groups exposed to 1.0 and 2.5 mgL-1 of TiO2 NPs respectively, as well as an increase in ammonia excretion of 3.54, 4.0 and 4.82 times higher in groups exposed to 0.5, 1.0 and 2.5 mgL-1 of TiO2 NPs respectively, compared to the control group. Histological analysis showed, after 72 hours, moderate to severe alterations in both gills and liver of TiO2 exposed fish at concentrations 1.0 and 2.5 mgL-1, the severity and occurrence of the alteration observed was grade 3 (severe and extensive pathological alterations). We concluded that waterborne exposure of Nile tilapia to TiO2 NPs caused alteration in routine metabolism and histological parameters in a dose-dependent manner.(AU)

Nanoparticulas de Dióxido de Titânio (TiO2NPs) podem causar alterações nas espécies aquáticas expostas, em termos de consumo de oxigênio, excreção de amônia e funcionalidade de tecidos, portanto, o objetivo do presente estudo é avaliar os efeitos da exposição aguda a diferentes concentrações de TiO2NPs (0,1, 0,5, 1,0 e 2,5 mgL-1) sobre o metabolismo de rotina (consumo de oxigênio e excreção de amônia) e parâmetros histológicos (branquiais e hepáticos) em Oreochromis niloticus. Após 24 horas, observamos um aumento no consumo de oxigênio de 2,36 e 3,23 vezes em grupos expostos a 1,0 e 2,5 mgL-1 de TiO2NPs respectivamente, bem como um aumento na excreção de amônia de 3,54, 4,0 e 4,82 vezes maior nos grupos expostos a 0,5, 1,0 e 2,5 mgL-1 de TiO2NPs respectivamente, em comparação com o grupo controle. A análise histológica mostrou, após 72 horas, alterações moderadas a severas tanto nas brânquias quanto no fígado de peixes expostos a TiO2NPs em concentrações de 1,0 e 2,5 mgL-1, a gravidade e a ocorrência da alteração observada foram de grau 3 (alterações patológicas graves e extensas). Concluímos que a exposição à TiO2NPs da tilápia do Nilo causaram alteração no metabolismo de rotina e nos parâmetros histológicos de uma maneira dose-dependente.(AU)

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