RESUMO
A large-scale oil spill along the northeastern Brazilian coast in 2019-2020 severely impacted primary manatee habitats in Brazil. This study aimed to assess metal and metalloid contamination in a dead manatee calf found following this oil spill. Several elements were detected, including chromium, iron, nickel, lead, and vanadium, which are crude oil components, and thallium, a component of dispersants used to degrade and dissipate crude oil. The presence of these contaminants in the manatee calf is indicative of maternal exposure, metabolism, and newborn transference via placenta and lactation. This is the first report of mother-calf metal transfer in manatees, highlighting the species' vulnerability and potential long-term population dynamics effects, and the first report for several metals and metalloids in these animals, laying the foundation for future research efforts. These findings highlight the urgent need for continued environmental monitoring, ecotoxicological assessments, and conservation initiatives.
Assuntos
Desastres , Poluição por Petróleo , Petróleo , Trichechus manatus , Animais , Feminino , Brasil , Trichechus , MetaisRESUMO
Organochlorine pesticides (OCP) are legacy anthropogenic compounds known to persist for several years in the environment. The continuous use of some OCP, such as DDT, after restrictions in developing countries are cause of concern, due to their deleterious effects to marine life and humans. Studies assessing OCP contamination in coastal environments are still scarce in South America and there is a need to understand the impacts from trophic chain accumulation of these pollutants in marine life. In this study, we have assessed OCP levels in muscle and liver and estimated the biomagnification factor in several upwelling system trophic chain members, including fish, squid, and marine mammal from Southeastern Brazil. DDT degradation product DDE was the OCP detected in the highest concentrations in Franciscana dolphins (Pontoporia blainvillei), 86.4 ng·g-1 wet weight, and fish muscle and liver. In general, higher OCP levels were found in liver than in muscle, except for croaker. Biomagnification factors (BMF) of OCP in the top predator P. blainvillei and the carnivorous cutlass fish (Trichiurus lepturus) were on average between 0.2 and 1.8. Continued OCP monitoring in this region is warranted to better understand the distribution and fate of these compounds over time, with the goal to establish strategies for the conservation of local dolphin species and to assess human health risks from local coastal region populations.
Assuntos
Golfinhos , Hidrocarbonetos Clorados , Perciformes , Praguicidas , Poluentes Químicos da Água , Animais , Humanos , DDT , Brasil , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Golfinhos/metabolismo , Peixes/metabolismo , Perciformes/metabolismo , Poluentes Químicos da Água/análise , Monitoramento AmbientalRESUMO
This study comprises a novel report on subcellular metal partitioning and metallothionein (MT) metal detoxification efforts in lesser numbfish (Narcine brasiliensis) electric ray specimens, as well as the first assessment on MT contents in any ray electric organ. Individuals sampled from an area in Southeastern Brazil affected by the Mariana dam rupture disaster were assessed concerning subcellular metal partitioning and MT metal-detoxification in the liver, gonads, electric organ and muscle of both adults and embryos. Yolk was also assessed when available. Relative total and heat-stable (bioavailable) metal and metalloid comparisons between adults and embryos in different developmental stages demonstrates maternal transfer of both total and bioavailable metals and significant MT associations demonstrate the detoxification of As, Ag, Mn, Ni, Cd, Co, Cu, Se and V through this biochemical pathway. Our findings expand the lacking ecotoxicological assessments for this near-threatened species and indicates significant ecological concerns, warranting further biomonitoring efforts.
Assuntos
Desastres , Poluentes Químicos da Água , Animais , Brasil , Metais/metabolismo , Torpedo/metabolismo , Poluentes Químicos da Água/químicaRESUMO
Seabirds are suitable biomonitors for several persistent organic pollutants (POP), such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs), although scarce studies of PAHs in seabirds are available, especially in South American populations. Therefore, this study aimed to assess OCPs, PCBs and PAHs, through gas chromatography-electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS) analyses, in liver (n = 9) and muscle tissue (n = 13) from juvenile Magellanic penguins (Spheniscus magellanicus) found stranded on the coast of Rio de Janeiro, Southeastern Brazil. DDT-related compounds were the most frequently detected OCP, and 4,4'-dichlorodiphenyldichloroethylene (DDE), the main DDT metabolite found in penguin tissues. OCP concentrations in liver were two-fold higher than in muscle tissues. Compound specific ratios identified recent exposure of penguins to some OCPs as well as evidence of legacy pollution associated with industrial sources. The predominant PCB congeners were PCB 8/5, PCB 138/160 and PCB 153/132, with concentrations ranging from Assuntos
Hidrocarbonetos Clorados
, Praguicidas
, Bifenilos Policlorados
, Hidrocarbonetos Policíclicos Aromáticos
, Spheniscidae
, Animais
, Brasil
, Monitoramento Ambiental
, Cromatografia Gasosa-Espectrometria de Massas
, Hidrocarbonetos Clorados/análise
, Praguicidas/análise
, Bifenilos Policlorados/análise
, Hidrocarbonetos Policíclicos Aromáticos/análise
, Distribuição Tecidual
RESUMO
Titanium (Ti), used in many dailyuse products, such as shampoos and sunscreen filters, in the form of TiO2 nanoparticles (NPs), may elicit adverse marine biota effects. Marine mammal Ti data is scarce, and subcellular distribution and detoxification information is non-existent. Ti concentrations and metalloprotein detoxification in Pontoporia blainvillei and Steno bredanensis dolphins from Southeastern Brazil were assessed. Metallothionein (MT) concentrations were determined spectrophotometrically, total and subcellular Ti, by ICP-MS and detoxification, by HPLC-ICP-MS. Ti detoxification occurred through MT complexation. Statistical Ti-MT associations were observed in S. bredanensis liver, indicating TiO2 NPs contamination, as Ti binds to MT only as NPs. MT-Ti correlations were observed for both the coastal (P. blainvillei) and offshore (S. bredanensis) dolphins, evidencing oceanic TiO2 diffusion. Ti detoxification through binding to reduced glutathione occurred in both species. Thermostable subcellular fractions are a valuable tool for cetacean Ti detoxification assessments and should be applied to conservation efforts.
Assuntos
Golfinhos/metabolismo , Titânio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Inativação MetabólicaRESUMO
Metals are subject to internal subcellular compartmentalization, altering their bioavailability. Thus, subcellular metal assessments are crucial in biomonitoring efforts. Metal distribution in three subcellular fractions (insoluble - ISF, thermolabile - TLF and thermostable - TSF) were determined by ICP-MS in Steno bredanensis specimens from Southeastern Brazil. Associations between metals, metallothionein (MT) and reduced glutathione (GSH) were also investigated. Differential metal-detoxification mechanisms were observed. MT detoxification was mostly noted for As, Cd, and Pb, while Cu, Cr, Hg, Ni, Se and Ti displayed lower MT-associations. Fe, Zn and Se, on the other hand, were poorly associated to MT, and mostly present in the ISF, indicating low bioavailability. This is the first report on subcellular Sn and Ti distribution in cetaceans and the first in this species in Brazil. Potential protective roles of essential metals against toxic elements are postulated. This study indicates that important biochemical detoxification information is obtained through subcellular fraction analyses in marine mammals.
Assuntos
Golfinhos/metabolismo , Monitoramento Ambiental/métodos , Metalotioneína/metabolismo , Metais/metabolismo , Frações Subcelulares/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Glutationa/metabolismo , Inativação Metabólica , Metais Pesados/análise , Estanho/metabolismo , Titânio/metabolismoRESUMO
Chemical pollution is a growing issue for ocean ecosystems, threatening especially apex predators because they bioaccumulate persistent chemical pollutants such as non-essential trace elements. The trophic position is thus a key aspect when assessing the impacts of environmental pollution in marine organisms. Here we investigate the differences in the concentrations of essential (Cu, Cr, Se, and Zn) and non-essential elements (Hg, Al, As, Cd, and Sr), in muscular and hepatic tissues of four sympatric non-migratory seabirds (namely Sula leucogaster, Larus dominicanus, Fregata magnificens, and Thalasseus acuflavidus), which were found stranded along the Brazilian coast. The observed hepatic and muscular interspecific differences in elemental concentrations indicated that these sympatric seabirds are differently exposed to persistent contaminants circulating in the food web due to differences with respect to known feeding behaviours and prey preferences. Moreover, we found a consistent co-accumulative relationship between Se and Hg molar levels in liver tissues with mean Se:Hg molar ratio above 1. This relationship supports previous studies indicating that Se, via the formation of SeHg complexes, plays an essential biochemical role in the detoxification process of methyl mercury in seabirds. Our results suggest that feeding behaviour is an important factor associated to the interspecific differences of trace element concentrations in seabirds. However, traits other than feeding preferences (e.g. age) may also play an important role in the accumulation of these elements.
Assuntos
Aves/metabolismo , Monitoramento Ambiental , Oligoelementos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Ecossistema , Cadeia Alimentar , Fígado/química , Mercúrio/análise , Compostos de Metilmercúrio , Músculos/química , Oligoelementos/análise , Poluentes Químicos da Água/análiseRESUMO
The vulnerability of seabirds related to their migratory dynamics is frequently linked to environmental problems along the migration path. In this context, Magellanic penguins (Sphenicus magellanicus) seem to be vulnerable to an extensive range of environmental disturbances during their northward migration along the Atlantic waters of South America, which include by catch, marine debris ingestion, overfishing and environmental contamination. In this study, we investigate mercury accumulation in muscle and hepatic tissues of juveniles penguins collected along the Brazilian coast during three migratory seasonal years (2006, 2008 and 2012) and three areas along a latitudinal gradient. We found significant differences in Hg levels across the years, with higher hepatic Hg levels found in tissues of penguins sampled in 2008. The higher Hg levels in samples of penguins from 2008 might be attributed to variations in body condition or Hg uptake, associated with the trophic imbalance linked to an extreme El Niño event during that year. Significant differences in Hg accumulation across the latitudinal areas were also observed. The penguins sampled at the farthest area from the breeding ground presented the higher levels of Hg and also the poorest body condition. Body condition and other traits may influence the levels of chemical pollutants and decrease the migratory success rate in the juvenile age phase, compromising population dynamics.
Assuntos
Monitoramento Ambiental , Poluentes Ambientais/metabolismo , Mercúrio/metabolismo , Spheniscidae/metabolismo , Animais , Oceano Atlântico , Brasil , Mercúrio/análiseRESUMO
With less than 60 records being reported worldwide, the megamouth (Megachasma pelagios) is today one of the least known shark species inhabiting our oceans. Therefore, information concerning the biology and ecology of this enigmatic organism is very scarce and limited to feeding behaviour and preferred habitat. The present work reports new data on the concentrations of trace elements, organic mercury, POPs and (210)Po in hepatic and muscular tissues of a specimen found stranded in the southeastern coast of Brazil. Additionally, we provide new evidence based on stable isotope analysis (δ(15)N and δ(13)C) confirming the preference for the pelagic habitat and the zooplanktivorous feeding behaviour of the megamouth. These results are consistent with the low concentrations of organic pollutant compounds and other elements measured in our samples.
Assuntos
Polônio/análise , Tubarões/fisiologia , Poluentes Químicos da Água/análise , Animais , Brasil , Isótopos de Carbono/análise , Ecossistema , Comportamento Alimentar , Mercúrio/análise , Isótopos de Nitrogênio/análise , Compostos Orgânicos/análise , Tubarões/genética , Oligoelementos/análise , Poluentes Químicos da Água/farmacocinéticaRESUMO
Guiana dolphins (Sotalia guianensis) are small cetaceans that inhabit coastal regions down to a 50 m depth. As a coastally distributed species, they are exposed to a variety of human-induced risks that include passive fishing nets, persistent environmental pollution, and emerging diseases. As a top predatorS. guianensis occupies an important ecological niche in marine ecosystems. However, this niche also exposes this dolphin to extensive biomagnification of marine contaminants that may accumulate and be stored throughout their life of about 30 years.In this paper, we have compiled available data on the Guiana dolphin as regards its exposure to chemical pollutants, pathogenic microbes, infectious diseases, and injuries caused by interactions with passive fishing gears. Our analysis of the data shows that Guiana dolphins are particularly sensitive to environmental changes.Although the major mortal threat to dolphins results from contact with fishing other human-related activities in coastal zones also pose risks and need more attention.Such human-related risks include the presence of persistent toxicants in the marine environment, such as PCBs and PBDEs. Residues of these chemicals have been detected in Guiana dolphin's tissues at similar or higher levels that exist in cetaceans from other known polluted areas. Another risk encountered by this species is the non lethal injuries caused by fishing gear. Several incidents of this sort have occurred along the Brazilian coast with this species. When injuries are produced by interaction with fishing gear, the dorsal fin is the part of the dolphin anatomy that is more affected, commonly causing severe laceration or even total loss.The Guiana dolphins also face risks from infectious diseases. The major ones thus far identified include giardiasis, lobomycosis, toxoplasmosis, skin and skeletal lesions. Many bacterial pathogens from the family Aeromonadaceae and Vibrionaceae have been isolated from Guiana dolphins. Several helminth species have also been observed to affectS. guianensis. These results suggest a vulnerability of this species to environmental disturbances. Moreover, there is some evidence that the effects of some infectious diseases may be enhanced from stress caused by habitat impairment. For example, certain diseases and pathogenic organisms in S.guianensis may be associated with the high levels of endocrine-disruptor contaminants(e.g., PCBs; DDTs; PBDEs) that have been detected in marine waters.Although the data available on S. guianensis is growing, most of the work has been focused on a small portion of the species total area of distribution. Most studies,to date, have been carried out in the Southern region of the distribution, and in north eastern Brazil. Few studies have been conducted in the northern region of the South America or in Central America. Therefore, future studies should be conducted that address the heterogeneity of this species total distribution.The biology and ecology of the Guiana dolphin renders this species potentially useful as a sentinel species for detecting environmental changes, such as chemical and biological pollution. Research about this dolphin is encouraged as a way to assess what coastal environmental changes have occurred and to continue evaluating the health status of this vulnerable species in a changing environment.
Assuntos
Golfinhos/fisiologia , Ecossistema , Ecotoxicologia , Animais , Golfinhos/microbiologia , Pesqueiros , Humanos , Infecções/veterinária , Poluentes Químicos da Água/toxicidadeRESUMO
Essential (Cu, Mn, Se and Zn) and non-essential (Cd and Hg) elements were analyzed in the hepatic tissue of 22 individuals of seven different species of small cetaceans (Feresa attenuata; Orcinus orca; Pontoporia blainvillei; Sotalia guianensis; Stenella frontalis; Steno bredanensis; Tursiops truncatus) accidentally caught in fishing nets or found stranded along the northern coast of the state of Rio de Janeiro, Brazil, between 2001 and 2010. Atlantic spotted dolphin (S. frontalis) showed the highest levels of Cd (20.23µgg(-1), dry weight), while rough-toothed dolphin (S. bredanensis) showed the highest levels of Hg (825.9µgg(-1)dw) and Se (221.9µgg(-1)dw). Killer whale (O. orca) presented the highest levels of Cu (64.80µgg(-1)dw) and Zn (2220µgg(-1)dw), and Guiana dolphin (S. guianensis), the highest level of Mn (13.05µgg(-1)dw). Cu, Hg, Mn and Zn in the hepatic tissue of killer whale (O. orca), Cu, Hg, Mn, Se and Zn in the hepatic tissue of rough-toothed dolphin (S. bredanensis) and Cd and Zn in the hepatic tissue of Guiana dolphin (S. guianensis) were significantly higher when compared to other studies with these species around the world. No significant correlations were observed between element accumulation and sex, sexual maturity and body length. An analysis of the interelemental relationships in the Guiana dolphin specimens showed strong positive correlations between Cd and Se, Cu and Zn, and Hg and Se. Differences were observed in the bioaccumulation of elements between the analyzed species, probably related to each species feeding habit, and differences between different element concentrations in the different dolphin species were probably due to the preference for certain preys and their bioavailability in the environment. Thus, the bioavailability of the analyzed elements in the marine environment should also be taken in consideration. This study also presents the first data ever reported for pygmy killer whale (F. attenuata) regarding trace element concentrations in hepatic tissue.
Assuntos
Cetáceos/fisiologia , Fígado/química , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Cetáceos/metabolismo , Monitoramento Ambiental , Feminino , Masculino , Metais/análise , Maturidade SexualRESUMO
O presente estudo teve como objetivo analisar o efeito agudo de duas sessöes de exercício físico aeróbico de diferentes volumes, na magnitude da eventual queda pressórica observada no período pós-exercício em indivíduos hipertensos controlados, de ambos os sexos, com idade entre 35 e 65 anos, praticantes de exercícios físicos regulares. Buscou-se verificar se há hipotensäo aguda causada pele exercício físico em indivíduos hipertensos controlados e se a duraçäo da sessäo de exercício físico poderia influenciar na magnitude dessa hipotensäo. Os sujeitos (n=23) foram submetidos a uma sessäo controle e duas sessöes complementares de exercício físico dinâmico em cicloergômetro com 25 a 45 minutos de duraçäo, a 75 porcento da freqüência cardíaca máxima. Os valores da pressäo arterial sistólica (PAS), pressäo arterial diastólica (PAD) e freqüência cardíaca (FC) foram medidos no pré-exercício (após 15 minutos de repouso) e no período pós-exercício (primeiro, quinto, décimo, vigésimo e trigésimo minuto de recuperaçäo) tanto nas duas sessöes experimentais, como na sessäo controle. Os resultados obtidos convergem para uma diminuLçäo nos níveis de pressäo arterial no período de recuperaçäo nas sessöes experimentais, quando comparados às sessöes controle sem exercícios físicos. Além disso, observou-se também que a magnitude pressórica provocada pelo exercício é influenciada pela sua duraçäo, isto é, o exercício físico com duraçäo de 45 minutos proporcionou queda mais ecentuada da PAS e PAD que na sessäo de 25 minutos, quando comparados à sessäo controle. Em relaçäo à comparaçäo entre as duas sessöes experimentais, observou-se queda significativa da PAS no primeiro minuto de recuperaçäo, enquanto que a PAD näo apresentou diferença significativa em nenhum momento da recuperaçäo. A magnitude e duraçäo do efeito hipotensor do exerc1cio físico parecem ser maiores após uma sessäo de maior volume quando comparados a uma sessäo de menor volume, verificando-se a duraçäo do exercício na hipotensäo pós-exercício.(au)
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Pressão Arterial , Terapia por Exercício , Hipertensão/prevenção & controle , Hipotensão , Esforço FísicoRESUMO
Este estudo se propôs a analisar os efeitos de diferentes tratamentos em pacientes coronarianos acometidos de infarto agudo do miocárdio, observando eventuais alteraçöes na qualidade de vida. Foram formados , retrospectivamente, três grupos: Grupo I, que realizou tratamento clínico convencional e participou de um programa de reabilitaçäo cardíaca, com exercícios supervisionados em cicloergômetro (cinco sessöes semanais de 40 minutos, mais exercícios de resistência muscular local e alongamentos, com duraçäo de aproximadamente 15 min); GrupoII, que seguiu tratamento clínico convencional (medicamentoso e ambulatorial), mais atividade física espontânea; e Grupo III, que seguiu tratamento clínico convencional, sem atividade física de qualquer natureza. Buscou-se verificar quais desses tratamentos proporcionou modificaçöes benéficas mais significativas na qualidade de vida, determinada através do questionário MaCNew QLMI desenvolvido por Oldridge (1998). Foi estanbelecido um protocolo para coleta de dados, obtendo-se informaçöes de um grupo de 45 pacientes residentes na regiäo de Florianópolis, S.C., dos quais 15 foram da clínica Cardiosport (grupo I) e 30 cadastrados no Instituto de Cardiologia do Hospital Regional (grupos II e III). Os casos nos grupos II e III foram selecionados a partir do diagnóstico, quadro clínico, história familiar, sexo, tabagismo e faixa etária, pareados com os sugeitos do Grupo I. As informaçöes coletadas nos prontuários dos pacientes foram, além das variáveis de pareamento as seguintes: dados pessoais, escolaridade, no início do tratamento até 6 meses. Foi utilizada estatística descritiva, ANOVA one e two way e o Qui-Quadrado para análise dos dados. Os resultados obtidos convergem para uma melhora na qualidade de vida significativamente maior no grupo I em comparaçäo aos grupos II e III, com uma melhor percepçäo de bem estar geral e em todos os quadrantes (físico, social e emocional) para este mesmo grupo.(au)