GENOTOXICITY OF SHALLOW WATERS NEAR THE BRAZILIAN ANTARCTIC STATION "COMANDANTE FERRAZ" (EACF), ADMIRALTY BAY, KING GEORGE ISLAND, ANTARCTICA

Series of biomonitoring surveys were undertaken weekly in February 2012 to investigate the genotoxicity of the shallow waters around the Brazilian Antarctic Station "Comandante Ferraz" (EACF). The comet assay was applied to assess the damage to the DNA of hemocytes of the crustacean amphipods Gondogeneia antarctica collected from shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) of the research station, and compare it to the DNA damage of animals from Punta Plaza (PPL) and Yellow Point (YP), natural sites far from the EACF defined as experimental controls. The damage to the DNA of hemocytes of G. antarctica was not significantly different between sites in the biomonitoring surveys I and II. In survey III, the damage to the DNA of animals captured in shallow waters near the Fuel Tanks (FT) and Sewage Treatment Outflow (STO) was significantly higher than that of the control site of Punta Plaza (PPL). In biomonitoring survey IV, a significant difference was detected only between the FT and PPL sites. Results demonstrated that the shallow waters in front of the station may be genotoxic and that the comet assay and hemocytes of G. antarctica are useful tools for assessing genotoxicity in biomonitoring studies of Antarctic marine coastal habitats.Séries de biomonitoramentos foram executadas semanalmente, durante o mês de fevereiro de 2012, para se investigar a genotoxicidade de ambientes costeiros rasos no entorno da Estação Antártica "Comandante Ferraz (EACF). O ensaio cometa foi aplicado para se avaliar os danos ao DNA hemocitário de crustáceos anfípodes Gondogeneia antarctica coletados em áreas rasas próximas aos tanques de armazenamento de combustível (FT) e saída de efluentes da estação de tratamento de esgoto (STO), em comparação aos danos ao DNA de animais provenientes de Punta Plaza (PPL) e Yellow Point (YP), locais naturais distantes da EACF, definidos como controles experimentais. O dano ao DNA hemocitário de G. antarctica não foi significativamente diferente entre locais, nos biomonitoramentos I e II. No biomonitoramento III, o dano ao DNA de animais coletados em águas rasas próximas aos tanques de combustível e saída de efluentes de esgoto foi significativamente maior do que aquele do controle de Punta Plaza. No biomonitoramento IV, a diferença foi significativa somente entre os locais dos tanques de combustível e de Punta Plaza. Estes resultados demonstram que a contaminação das águas em frente à EACF pode ser genotóxica e que, tanto o ensaio cometa quanto os hemócitos de G. antarctica são ferramentas úteis na avaliação da genotoxicidade em estudos de biomonitoramento de habitats marinhos costeiros da Antártica

Study on the genotoxicity of titanium dioxide nanoparticle in juvenille pompano, Trachinotus carolinus (Linnaeus, 1766), using cytogenotoxic methods

Nanopartículas possuem características físico-químicas úteis para o uso humano, com aplicação na ciência, tecnologia, medicina e produtos de uso diário. A fabricação e a variedade destes produtos vêm crescendo rapidamente, gerando uma preocupação quanto ao risco de exposição aos efeitos tóxicos da contaminação por nanopartículas. Vários efeitos adversos, derivados da exposição de nanopartículas foram descritos tanto para organismos terrestres como aquáticos, porém efeitos genotóxicos ainda são pouco conhecidos para organismos marinhos. Para avaliar a citogenotoxicidade da nanopartícula de dióxido de titânio no peixe marinho T. carolinus, foram administradas injeções intraperitoneais com dosagens de 1,5 e 3,0 ?g-nano-TiO2/grama-de-peixe. Amostras de sangue foram coletadas para realização do teste de micronúcleo (MN) e outras anormalidades nucleares eritrocitárias (ANE) e ensaio cometa (pH>13), 24, 48 e 72 horas após a injeção. Foram investigadas a viabilidade de eritrócitos e a possibilidade de acumulação da nano-TiO2 nos tecidos dos peixes injetados com a maior dosagem, após 72 horas, pelo teste de exclusão do azul de tripano e por microscopia eletrônica de transmissão. Os resultados mostraram que a nano-TiO2 é uma substância possivelmente capaz de entrar nas células e induzir efeito genotóxico e citotóxico para esta espécie, por provocar uma diminuição na viabilidade de eritrócitos, um aumento no dano ao DNA e formação de MN e outras ANE. De acordo com nosso conhecimento, este é o único trabalho sobre a genotoxicidade de nano-TiO2 em um peixe marinho.Nanoparticles have physicochemical characteristics useful for human use, with applications in science, technology, medicine and everyday products. The manufacture and variety of these products have been growing rapidly, creating a concern about the risk of exposure to the toxic effects of contamination by nanoparticles. Several adverse effects of exposure to nanoparticles have been reported for both terrestrial and aquatic organisms, but genotoxic effects are still poorly known for marine organisms. To evaluate the citogenotoxicity of titanium dioxide nanoparticles (nano-TiO2) in marine fish T. carolinus, the substance was administered with intraperitoneal injections at dosages of 1,5 and 3,0 ?g-nano-TiO2/gram-of-fish. Blood samples were collected for the tests of micronucleus (MN) and other erythrocytes nuclear abnormalities (ENA) and comet assay (pH> 13), 24, 48 and 72 hours after injection. We also investigated the viability of erythrocytes and the possibility of accumulation of nano-TiO2 in the tissues of fish injected with the highest dose after 72 hours using trypan blue exclusion test and transmission electron microscopy. The results showed that the nano-TiO2 is a substance that can possibly be able to enter cells and induce cytotoxic and genotoxic effect for this species, by causing a decrease in the viability of erythrocytes, an increase in DNA damage and formation of MN and other ANE. As far as we know, this is the only work done on the genotoxicity of nano-TiO2 in a marine fis

Ecological implications of copper-based nanoparticles in aquatic complex matrices: Fate, behavior, and toxicity assessment

Engineered nanomaterials (ENMs) are likely to undergo some degree of modification when released into the environment, which can influence the fate, behavior, and toxicity of nanoparticles (NPs). The environmental factors in natural aquatic ecosystems, such as water chemistry, hydrology, disturbance, and biotic interactions, can transform or “age” toxic chemicals through physical, chemical, and biological processes, including aggregation and disaggregation, adsorption, redox reaction, dissolution, complexation and biotransformation. The extent of aging can vary considerably over time and within a single or a number of water bodies, such as a river that flows into the ocean through an estuary. However, the ecological effects of NPs under realistic environmental exposure scenarios are not yet fully understood. Adding to these challenges are problems arising from traditional ecotoxicological risk assessments, which are inevitably hampered by narrow subsets of relevant species, toxicants, exposure conditions, and levels of impact. The present work examined the toxicity of copper-based nanoparticles (CBNPs), which frequently enter natural aquatic ecosystems due to their increasing application in consumer products, by assessing their impact on marine phytoplankton and estuarine amphipods, organisms that are central to aquatic ecosystems. Standard toxicological methods were used, along with physiological measurements, studies of fate and transport, and mechanistic biological models based on Dynamic Energy Budget (DEB) theory. The aim of the work was to understand 1) the influence of aging processes on CBNPs under environmentally relevant test conditions, 2) the impact of aged CBNPs on a marine phytoplankton population, 3) the potential impact of CBNPs on non-target estuarine organisms, and 4) the potential for detecting and predicting the toxic effects of CBNPs on an individual, to generate model estimates of effects on populations and communities. CBNPs were found to be toxic to benthic estuarine organisms at concentrations of CBNPs already found in the natural environment. However, sublethal toxicity may not be detected by traditional ecotoxicological tests. Additionally, aging was found to influence the fate and transport of CBNPs through oxidation, aggregation, and dissolution processes, increasing Cu toxic ion bioavailability to pelagic organisms over time. While current studies increasingly consider more realistic environmental exposure scenarios, this work, as well as that of other researchers, suggests that CBNPs behave differently under prolonged environmental exposure, and nanoecotoxicological research should focus on sublethal impacts, integrated with mechanistic biological models and based on Dynamic Energy Budget (DEB) theory

Ecological implications of copper-based nanoparticles in aquatic complex matrices: Fate, behavior, and toxicity assessment

Engineered nanomaterials (ENMs) are likely to undergo some degree of modification when released into the environment, which can influence the fate, behavior, and toxicity of nanoparticles (NPs). The environmental factors in natural aquatic ecosystems, such as water chemistry, hydrology, disturbance, and biotic interactions, can transform or “age” toxic chemicals through physical, chemical, and biological processes, including aggregation and disaggregation, adsorption, redox reaction, dissolution, complexation and biotransformation. The extent of aging can vary considerably over time and within a single or a number of water bodies, such as a river that flows into the ocean through an estuary. However, the ecological effects of NPs under realistic environmental exposure scenarios are not yet fully understood. Adding to these challenges are problems arising from traditional ecotoxicological risk assessments, which are inevitably hampered by narrow subsets of relevant species, toxicants, exposure conditions, and levels of impact. The present work examined the toxicity of copper-based nanoparticles (CBNPs), which frequently enter natural aquatic ecosystems due to their increasing application in consumer products, by assessing their impact on marine phytoplankton and estuarine amphipods, organisms that are central to aquatic ecosystems. Standard toxicological methods were used, along with physiological measurements, studies of fate and transport, and mechanistic biological models based on Dynamic Energy Budget (DEB) theory. The aim of the work was to understand 1) the influence of aging processes on CBNPs under environmentally relevant test conditions, 2) the impact of aged CBNPs on a marine phytoplankton population, 3) the potential impact of CBNPs on non-target estuarine organisms, and 4) the potential for detecting and predicting the toxic effects of CBNPs on an individual, to generate model estimates of effects on populations and communities. CBNPs were found to be toxic to benthic estuarine organisms at concentrations of CBNPs already found in the natural environment. However, sublethal toxicity may not be detected by traditional ecotoxicological tests. Additionally, aging was found to influence the fate and transport of CBNPs through oxidation, aggregation, and dissolution processes, increasing Cu toxic ion bioavailability to pelagic organisms over time. While current studies increasingly consider more realistic environmental exposure scenarios, this work, as well as that of other researchers, suggests that CBNPs behave differently under prolonged environmental exposure, and nanoecotoxicological research should focus on sublethal impacts, integrated with mechanistic biological models and based on Dynamic Energy Budget (DEB) theory