RESUMO
Although carbon nanotubes' (CNTs) toxicity in different experimental systems (in vivo and in vitro) is known, little is known about the toxic effects of carbon nanofibers (CNFs) on aquatic vertebrates. We herein investigated the potential impact of CNFs (1 and 10 mg/L) by using Physalaemus cuvieri tadpoles as experimental model. CNFs were able to induce nutritional deficit in animals after 48-h exposure to them, and this finding was inferred by reductions observed in body concentrations of total soluble carbohydrates, total proteins, and triglycerides. The increased production of hydrogen peroxide, reactive oxygen species and thiobarbituric acid reactive substances in tadpoles exposed to CNFs has suggested REDOX homeostasis change into oxidative stress. This process was correlated to the largest number of apoptotic and necrotic cells in the blood of these animals. On the other hand, the increased superoxide dismutase and catalase activity has suggested that the antioxidant system of animals exposed to CNFs was not enough to maintain REDOX balance. In addition, CNFs induced increase in acetylcholinesterase and butyrylcholinesterase activity, as well as changes in the number of neuromasts evaluated on body surface (which is indicative of the neurotoxic effect of nanomaterials on the assessed model system). To the best of our knowledge, this is the first report on the impact of CNFs on amphibians; therefore, it broadened our understanding about ecotoxicological risks associated with their dispersion in freshwater ecosystems and possible contribution to the decline in the populations of anurofauna species.
Assuntos
Carbono/toxicidade , Larva/efeitos dos fármacos , Larva/metabolismo , Nanofibras/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Antioxidantes/metabolismo , Anuros , Ecossistema , Modelos Teóricos , Estresse Oxidativo/efeitos dos fármacos , Projetos de PesquisaRESUMO
BACKGROUND: For more than a decade, water-soluble, eco-friendly, biocompatible, and low-toxicity fluorescent nanomaterials have received considerable attention for their numerous in vivo and in vitro applications in biomedical imaging, disease diagnostics, and environmental monitoring. Owing to their tunable photoluminescence properties, carbon-based luminescent nanomaterials have shown great potential in bioimaging, photocatalysis, and biosensing among other applications. RESULTS: Marine environments provide excellent resources for the fabrication of these nanomaterials, because many marine organisms contain interesting trigger organic compounds that can be used as precursors. Herein, we synthesize multi-color emissive carbon dots (CDs) with an intrinsic photoluminescence quantum yield of 20.46%. These nanostructures were achieved through the one-step hydrothermal treatment of marine polysaccharide chondroitin sulfate, obtained from shark cartilage, in aqueous solution. CONCLUSIONS: We successfully demonstrate the low toxicity of our marine resource-derived CDs in zebrafish, and provide an initial assessment of their possible use as a bioimaging agent. Notably, the newly synthesized CDs localize in the intestines of zebrafish larvae, thereby indicating their biocompatibility and potential use as in vivo dyes.
Assuntos
Animais , Polissacarídeos/química , Tubarões , Carbono/química , Pontos Quânticos/química , Peixe-Zebra , Carbono/toxicidade , Cartilagem , Pontos Quânticos/toxicidade , Luminescência , Nanoestruturas , Corantes/toxicidade , Corantes/químicaRESUMO
ABSTRACT Climate change is a social justice as well as an environmental issue. The magnitude and pattern of changes in weather and climate variables are creating differential exposures, vulnerabilities, and health risks that increase stress on health systems while exacerbating existing and creating new health inequities. Examples from national and local health adaptation projects highlight that developing partnerships across sectors and levels are critical for building climate-resilient health systems and communities. Strengthening current and implementing new health interventions, such as using environmental information to develop early warning systems, can be effective in protecting the most vulnerable. However, not all projected risks of climate change can be avoided by climate policies and programs, so health system strengthening is also critical. Applying a health inequity lens can reduce current vulnerabilities while building resilience to longer-term climate change. Taking inequities into account is critical if societies are to effectively prepare for and manage the challenges ahead.
RESUMEN El cambio climático es un asunto no solo ambiental, sino también de justicia social. La magnitud y naturaleza de los cambios observados en las variables de tiempo meteorológico y clima están llevando a exposiciones, vulnerabilidades y riesgos de salud diferenciales que incrementan la sobrecarga de los sistemas de salud y exacerban las inequidades sanitarias existentes, a la vez que generan nuevas inequidades. Los proyectos nacionales y locales de adaptación al cambio climático para proteger la salud humana ponen de manifiesto que la creación de alianzas entre diferentes sectores y en distintos niveles es fundamental para lograr que haya sistemas de salud y comunidades capaces de recuperarse de los efectos del clima. El fortalecimiento de las intervenciones de salud en curso y la aplicación de nuevas intervenciones, tales como el uso de información de tipo ambiental para crear sistemas de alerta temprana, pueden ser eficaces para proteger a los grupos más vulnerables. Sin embargo, no todos los riesgos previstos en relación con el cambio climático pueden evitarse por medio de políticas y programas climáticos, de manera que el fortalecimiento de los sistemas de salud también es fundamental. La aplicación de una óptica de inequidad sanitaria puede reducir las vulnerabilidades actuales y al mismo tiempo crear capacidad de recuperación frente a los efectos del cambio climático a más largo plazo. Si las sociedades han de prepararse para los retos que se avecinan y hacerles frente de una manera eficaz, es imprescindible que se tengan en cuenta las inequidades.
Assuntos
Carbono/toxicidade , Poluentes Ambientais/toxicidade , Programas Governamentais , Programas Nacionais de Saúde , Populações VulneráveisRESUMO
This paper reports on the acute inflammatory and cellular process in the yellow clam, Mesodesma mactroides, induced by injection of India ink into the muscular foot. Histological observations with optical and electronic microscopy were made at 24 and 48 h after injection. The induced cellular inflammatory response consisted of a general hemocyte infiltration without necrosis and apoptotic activity. Migration of ink-laden phagocytes across the intestinal epithelium was recorded. It appeared that the yellow clam "excreted" ink particles through the gill and kidney. The positive staining for apoptosis was observed in the digestive gland. Electronic microscopy revealed ultrastructural changes of endoplasmic reticulum stress and apoptotic bodies in the digestive gland. The mechanism by which the India ink particles induce apoptosis remains unknown, but might possibly be associated with the endoplasmic reticulum stress. This work has highlighted features that require further discussion in the restricted field the inflammatory responses of mollusks.
Assuntos
Apoptose/efeitos dos fármacos , Bivalves/efeitos dos fármacos , Carbono/toxicidade , Animais , Bivalves/ultraestrutura , Inflamação/induzido quimicamente , Microscopia Eletrônica , Necrose/induzido quimicamente , Fatores de TempoRESUMO
The removal of oxidation debris from the oxidized carbon nanotube surface with a NaOH treatment is a key step for an effective functionalization and quality improvement of the carbon nanotube samples. In this work, we show via infrared spectroscopy and ultrahigh resolution and accuracy mass spectrometry that oxidation debris obtained from HNO(3)-treated multiwalled carbon nanotubes is a complex mixture of highly condensed aromatic oxygenated carbonaceous fragments. We have also evaluated their cytotoxicity by using BALB/c 3T3 mouse fibroblasts and HaCaT human keratinocytes as models. By knowing the negative aspects of dissolved organic carbon (DOC) to the water quality, we have demonstrated the removal of these carbon nanotube residues from the NaOH solution (wastewater) by using aluminium sulphate, which is a standard coagulant agent used in conventional drinking water purification and wastewater treatment plants. Our results contribute to elucidate the structural and proactive safety aspects of oxidation debris from oxidized carbon nanotubes towards a greener nanotechnology.
Assuntos
Carbono/toxicidade , Nanotubos de Carbono/química , Oxigênio/química , Purificação da Água/métodos , Compostos de Alúmen , Animais , Linhagem Celular , Fibroblastos/citologia , Humanos , Queratinócitos/citologia , Camundongos , Nanotubos de Carbono/toxicidade , Segurança , Testes de ToxicidadeRESUMO
Though exposure to air pollution has a detrimental effect on respiratory health, few studies have examined the association between elemental carbon exposure and lung function among schoolchildren. The aim of the present study was to present the association between short-term elemental carbon exposure and lung function in schoolchildren from Mexico City. 55 asthmatic and 40 non-asthmatic children were followed for an average of 22 weeks. A spirometry test was performed every 15 days during follow-up. Portable air samplers collected particulate matter onto Teflon filters. Gravimetric analysis was conducted and elemental carbon was quantified using transmission densitometry. The association between the main variables was analysed using linear mixed effects models. The mean ± sd of elemental carbon light absorption was 92.7 ± 54.7 Mm(-1). An increase of one interquartile range in the 24-h average of elemental carbon (100.93 Mm(-1)) was associated with a significant negative impact on forced expiratory volume in 1 s (FEV(1)) (-62.0 (95% CI -123.3- -1.2) mL) and forced expiratory flow at 25-75% of forced vital capacity (FVC) (FEF(25-75%)) (-111 (95% CI -228.3- -4.1) mL) among asthmatic children, equal to 3.3% and 5.5%, respectively; and on FEV(1) (-95.0 (95% CI -182.3- -8.5) mL) and FVC (-105.0 (95% CI -197.0- -13.7) mL) among non-asthmatic children. Exposure to elemental carbon resulted in an important negative effect on lung function in atopic schoolchildren, regardless of asthma status.
Assuntos
Asma/epidemiologia , Carbono/toxicidade , Pulmão/efeitos dos fármacos , Adolescente , Poluição do Ar , Asma/induzido quimicamente , Criança , Cidades , Densitometria/métodos , Exposição Ambiental , Feminino , Humanos , Pulmão/patologia , Masculino , México , Testes de Função Respiratória , Espirometria/métodosRESUMO
Neste trabalho foi realizado um estudo sobre o impacto sobre a atmosfera e a biota terrestre devido às emissões antrópicas na Baia do Almirantado/Ilha Rei George Antártica. Foram monitoradas as emissões dos compostos orgânicos voláteis e semi-voláteis, tanto nas fontes emissoras como no entorno da Estação Antártica Comandante Ferraz e estimadas as emissões dos navios, dos geradores a diesel e da incineração de lixo. Na avaliação do entorno, coletaram-se amostras de ar, neve e penas de aves. Com os resultados das emissões, do estudo topográfico e da meteorologia, realizou-se uma modelagem de plumas gaussiana para avaliar os impactos. Quatro cenários foram avaliados: dois com a presença dos navios NApOc Ary Rongel e Maximiano apresentaram concentrações máximas de até 356 µg m-3 de COV e 18 µg m-3 de material particulado, enquanto os demais, sem a presença dos navios, apenas considerando as estações de pesquisa EACF e Arctowski, apresentaram concentrações máximas de até 2,5 µg m-3 de COV e 1,3 µg m-3 de material particulado. Amostras de COV coletadas foram compatíveis com o cenário mais crítico. O estudo de correlação para carbonilas e HPA atmosférico e Carbono elementar e HPA, depositados em neve, apontaram a EACF como a principal fonte de emissão. As concentrações de levoglucosano detectadas a aproximadamente 2 km da EACF apontaram para a prática de incineração de lixo da EACF. Todas as áreas de interesse biológicos, anteriormente mapeados, dentro da AAEG, são vulneráveis às emissões antrópicas, como sugeriu o modelo de dispersão e a sobreposição dos resultados encontrados.
In this study it was conducted a study on the impact on the atmosphere and terrestrial biota due to anthropogenic emissions in Admiralty Bay / King George Island - Antarctica. It was monitored the emissions of volatile organic compounds and semi-volatile, both in emission sources and in the surrounding of Antarctic Station Comandante Ferraz, and estimated emissions from ships, diesel generators and waste incineration. In assessing the environment, it were collected air, snow and feathers samples. With the emissions results, meteorology database and topographical study, it was used a Gaussian plume modeling to assess impacts. Four scenarios were evaluated: the presence of two ships NApOca Ary Rongel and Maximiano had concentrations up to 356 mg m-3 for VOCs and 18 mg m-3 for particulate matter, while the other, without the presence of the vessels, only considering research stations EACF Arctowski showed concentrations of up to 2.5 mg m-3 for VOC and 1.3 mg m-3 for particulate matter. VOC samples collected were consistent with the most critical scenario. The correlation study for atmospheric carbonyls and HPA and HPA and Black Carbon, deposited on snow, EACF pointed to be the main emissions source. The levoglucosan concentrations found approximately 2 km from EACF pointed to the practice of waste incineration at EACF. All areas of biological interest, previously mapped within the AAEG are vulnerable to anthropogenic emissions, as suggested by the dispersion model and the overlap of results.
Assuntos
Meio Ambiente , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Regiões Antárticas , Biota , Benzeno/toxicidade , Carbono/toxicidade , Compostos Orgânicos Voláteis/análise , Emissões de Veículos/toxicidade , Atividades Humanas , Poluentes Atmosféricos/análiseRESUMO
Epidemiological studies have demonstrated the adverse effects of particulate matter (PM) inhalation on the respiratory and cardiovascular systems. It has been reported that air pollution may affect the central nervous system and decrease cognitive function. In rats, residual oil fly ash (ROFA) instillation causes decreased motor activity and increased lipid peroxidation in the striatum and the cerebellum. Our objective was to determine whether chronic instillation of particles induces changes in learning and memory in rats and whether oxidants in the hippocampus may contribute to these adverse effects. Forty-five-day-old male Wistar rats were exposed to ROFA by intranasal instillation and were treated with N-acetylcysteine (NAC) at 150 mg/kg i.p. for 30 days. Control groups were exposed to ROFA, NAC, or neither. On days 1, 8, and 30 of the protocol, rats were submitted to the open field test to evaluate habituation. After the last open field session, the rats were killed by decapitation. The hippocampus was used to determine lipid peroxidation (LP) by the thiobarbituric acid-reactive substances test. ROFA instillation induced an increase in LP in the hippocampus compared to all treatment groups (p = .012). NAC treatment blocked these changes. All of the treatment groups presented a decrease in the frequency of peripheral walking (p = .001), rearing (p = .001), and exploration (p = .001) over time. Our study demonstrates that exposure to particles for 30 days and/or NAC treatment do not modify habituation to an open field, a simple form of learning and memory in rats, and that oxidative damage induced by ROFA does not modulate these processes.
Assuntos
Poluentes Atmosféricos/toxicidade , Comportamento Animal/efeitos dos fármacos , Carbono/toxicidade , Habituação Psicofisiológica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Material Particulado/toxicidade , Acetilcisteína/farmacologia , Administração Intranasal , Animais , Comportamento Animal/fisiologia , Cinza de Carvão , Antagonismo de Drogas , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Sequestradores de Radicais Livres/farmacologia , Habituação Psicofisiológica/fisiologia , Hipocampo/metabolismo , Masculino , Malondialdeído/metabolismo , Memória/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Desempenho Psicomotor/fisiologia , Ratos , Ratos WistarRESUMO
Several epidemiological studies have linked particulate matter exposure to numerous adverse health effects on the respiratory, cardiovascular, and reproductive systems (Braga et al., 1999; Zanobetti et al., 2000; Anderson et al., 2001; Farhat et al., 2005). More recently, ambient levels of black carbon were associated to impaired cognitive function in children (Suglia et al., 2008), suggesting that the central nervous system (CNS) may be a target of air pollutants. The present study was conducted to (a) determine whether chronic residual oil fly ash (ROFA) exposure promotes behavioral changes and lipid peroxidation in rat brain areas, and (b) determine whether N-acetylcysteine (NAC), a general antioxidant, prevents these effects. Forty-five-day-old male Wistar rats were exposed or not to ROFA by intranasal instillation and were treated or not with NAC (150 mg/kg) ip for 30 days. One day later, rats were submitted to the open field test to evaluate the motor/exploratory activities and emotionality followed by decapitation. Striatum and cerebellum were dissected to determine lipid peroxidation by the accumulation of thiobarbituric acid-reactive substances (TBARS). ROFA instillation induced an increase in lipid peroxidation level in striatum (p = .033) and cerebellum (p = .030), as compared with the control group. NAC treatment blocked these changes. ROFA promoted a decrease in the frequency of peripheral walking (p = .006) and a decrease in exploration (p = .001), which were not blocked by N-acetylcysteine. The present study provides evidence that toxic particles, administered by the respiratory route, induce oxidative stress in structures of the central nervous system, as well as behavioral alterations. The administration of NAC reduces lipid peroxidation at the striatum and cerebellum levels, but does not influence behavioral disturbances.
Assuntos
Poluentes Atmosféricos/toxicidade , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Carbono/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Acetilcisteína/farmacologia , Administração Intranasal , Animais , Encéfalo/metabolismo , Cinza de Carvão , Modelos Animais de Doenças , Comportamento Exploratório/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Exposure to particulate matter (PM) air pollution is associated with increased asthma morbidity. Residual oil flash ash (ROFA) is rich in water-soluble transition metals, which are involved in the pathological effects of PM. The objective of this study was to investigate the effects of intranasal administration of ROFA on pulmonary inflammation, pulmonary responsiveness, and excess mucus production in a mouse model of chronic pulmonary allergic inflammation. BALB/c mice received intraperitoneal injections of ovalbumin (OVA) solution (days 1 and 14). OVA challenges were performed on days 22, 24, 26, and 28. After the challenge, mice were intranasally instilled with ROFA. After forty-eight hours, pulmonary responsiveness was performed. Mice were sacrificed, and lungs were removed for morphometric analysis. OVA-exposed mice presented eosinophilia in the bronchovascular space (p < .001), increased pulmonary responsiveness (p < .001), and epithelial remodeling (p = .003). ROFA instillation increased pulmonary responsiveness (p = .004) and decreased the area of ciliated cells in the airway epithelium (p = .006). The combined ROFA instillation and OVA exposure induced a further increase in values of pulmonary responsiveness (p = .043) and a decrease in the number of ciliated cells in the airway epithelium (p = .017). PM exposure results in pulmonary effects that are more intense in mice with chronic allergic pulmonary inflammation.