RESUMO
Fish constitutes the main protein source for the Amazonian population. However, the impact of different anthropogenic activities on trace element and metal accumulation in fish and their risks for human health at a regional scale remain largely unexplored. Here we assessed exposure levels of 10 trace elements and metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Pb, and Hg) in 56 samples belonging to 11 different species of fish from the Brazilian Amazon. We studied the relationship between exposure levels, fish origin, and fish feeding habits, and assessed toxicological and carcinogenic risks for the Amazonian population. No significant correlation was found between sampling site and exposure levels to the studied elements, but a significant difference was found between the accumulation of some metals and the position of the fish species in the food chain. The concentrations of Cr and Hg in fish flesh were found to exceed the Brazilian limits for human consumption. This study shows that current fish consumption patterns can lead to estimated daily intakes of Hg, As and Cr that exceed the oral reference dose, thus posing a toxicological concern. Furthermore, carcinogenic risks may be expected due to the continued exposure to Cr and As. The results of this study show that the consumption of wild caught fish in the Amazon region should be controlled. Moreover, continued monitoring of trace element and metal contamination in fish and on the health of the Amazonian population is recommended, particularly for riverine and indigenous communities.
Assuntos
Peixes , Contaminação de Alimentos , Metais , Oligoelementos , Poluentes Químicos da Água , Animais , Brasil , Humanos , Poluentes Químicos da Água/análise , Oligoelementos/análise , Contaminação de Alimentos/análise , Medição de Risco , Metais/análise , Monitoramento AmbientalRESUMO
Carbamazepine (CBZ) is the most commonly used drug in epilepsy treatment, and its metabolites are commonly detected among persistent pharmaceuticals in the aquatic environment. This study aimed to investigate CBZ effects on early-life-stage zebrafish (Danio rerio) (from 2 to 168 hpf) by employing of an integrative approach linking endpoints from molecular to individual level: (i) development; (ii) locomotor activity; (iii) biochemical markers (lactate dehydrogenase, glutathione-S-transferase, acetylcholinesterase and catalase) and (iv) transcriptome analysis using microarray. A 168 h - LC50 of 73.4 mg L-1 and a 72 h - EC50 of 66.8 mg L-1 for hatching were calculated while developmental effects (oedemas and tail deformities) were observed at CBZ concentrations above 37.3 mg L-1. At the biochemical level, AChE activity proved to be the most sensitive parameter, as evidenced by its decrease across all concentrations tested (â¼25% maximum reduction, LOEC (lowest observed effect concentration) < 0.6 µg L-1). Locomotor behaviour seemed to be depressed by CBZ although this effect was only evident at the highest concentration tested (50 mg L-1). Molecular analysis revealed a dose-dependent effect of CBZ on gene expression. Although only 25 genes were deregulated in organisms exposed to CBZ when compared to controls, both 0.6 and 2812 µg L-1 treatments impaired gene expression related to development (e.g. crygmxl1, org, klf2a, otos, stx16 and tob2) and the nervous system (e.g. Rtn3, Gdf10, Rtn3), while activated genes were associated with behavioural response (e.g. prlbr and taar). Altogether, our results indicate that environmentally relevant CBZ concentrations might affect biochemical and genetic traits of fish. Thus, the environmental risk of CBZ cannot be neglected, especially in a realistic scenario of constant input of domestic effluents into aquatic systems.
Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Acetilcolinesterase/metabolismo , Carbamazepina/metabolismo , Dose Letal Mediana , Poluentes Químicos da Água/metabolismo , Embrião não MamíferoRESUMO
The use of pesticides in households and peri-urban areas of the Amazon has increased notably during the last years. Yet, the presence of these contaminants in Amazonian freshwater ecosystems remains unexplored. Here, we assessed the exposure to 18 pesticides and 5 transformation products in the Amazon River and in the urban streams of Manaus, Santarém, Macapá, and Belém (Brazil). Pesticide concentrations were analyzed by liquid and gas chromatography methods. Ecological risks were assessed following a two-tiered approach. First, hazard quotients and an overall hazard index were calculated using toxicity data for standard test species of primary producers, invertebrates, and fish. Second, the pesticides showing moderate-to-high ecological risks in the first tier were evaluated using Species Sensitivity Distributions (SSDs). Our study shows that pesticides are widespread in urban and peri-urban areas of the Brazilian Amazon. The frequency of detection was higher in urban streams than in the Amazon River, with some samples taken in Manaus, Santarém, and Belém containing up to 8 compounds. Most pesticides were measured at relatively low concentrations (ng L-1), except for malathion, carbendazim and the bulk concentration of chlorpyrifos, which were monitored at concentrations above 100 ng L-1. Based on the first-tier assessment, we found moderate-to-high risks for freshwater invertebrates for malathion, chlorpyrifos, and chlorpyrifos-methyl, and moderate risks for malathion to fish. The risk assessment performed with SSDs indicated high risks of malathion and chlorpyrifos-methyl in urban areas, with up to 15% and 5% of invertebrate species potentially affected, respectively. The bulk concentrations of chlorpyrifos resulted in high risks in some urban areas (14-22% of species affected) and in areas of the main river (32-44%) impacted by agriculture. We conclude that pesticide residues may contribute to a biodiversity impact in the Amazon and should be further monitored in urban and peri-urban areas, particularly after heavy rainfall events.
Assuntos
Praguicidas , Poluentes Químicos da Água , Animais , Brasil , Ecossistema , Monitoramento Ambiental , Praguicidas/análise , Praguicidas/toxicidade , Medição de Risco , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Caffeine (CAF), a neuroactive compound, has been found in surface waters at concentrations ranging from few nanograms up to micrograms and may induce adverse effects in aquatic vertebrates. Thus, the aim of this study was to evaluate the potential of CAF in affecting fish early-life stages in a wide concentration range, including occurring levels in surface waters. Specimens of zebrafish in early-life stages were exposed to CAF for 168 h and survival, developmental alterations, locomotor activity and acetylcholinesterase activity were evaluated. CAF induced mortality in embryos unable to hatch or in larvae after hatching (LC50 - 168 h = 283.2 mg/L). Tail deformities were observed in organisms exposed to concentrations ≥ 40 mg/L, while edemas were found at concentrations of 100 mg/L. CAF also decreased the total swimming time and distance moved of exposed organisms (LOEC = 0.0006 mg/L). Locomotor inhibition may be associated with an acetylcholinesterase inhibition observed at concentration ≥ 0.0088 mg/L. Therefore, the hazard of CAF for fish populations deserves further attention since unexpected effects on neuro-behavioral parameters occurs at concentrations often detected in natural aquatic ecosystems.
Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Acetilcolinesterase , Animais , Cafeína/toxicidade , Ecossistema , Embrião não Mamífero , Larva , Poluentes Químicos da Água/toxicidadeRESUMO
Only a limited number of households in the Amazon are served by sewage collection or treatment facilities, suggesting that there might be a significant emission of pharmaceuticals and other wastewater contaminants into freshwater ecosystems. In this work, we performed a wide-scope screening to assess the occurrence of pharmaceuticals, illicit drugs and their metabolites in freshwater ecosystems of the Brazilian Amazon. Our study included 40 samples taken along the Amazon River, in three of its major tributaries, and in small tributaries crossing four important urban areas (Manaus, Santarém, Macapá, Belém). More than 900 compounds were investigated making use of target and suspect screening approaches, based on liquid chromatography coupled to high-resolution mass spectrometry with ion mobility separation. Empirical collision-cross section (CCS) values were used to help and confirm identifications in target screening, while in the suspect screening approach CCS values were predicted using Artificial Neural Networks to increase the confidence of the tentative identification. In this way, 51 compounds and metabolites were identified. The highest prevalence was found in streams crossing the urban areas of Manaus, Macapá and Belém, with some samples containing up to 30 - 40 compounds, while samples taken in Santarém showed a lower number (8 - 11), and the samples taken in the main course of the Amazon River and its tributaries contained between 1 and 7 compounds. Most compounds identified in areas with significant urban impact belonged to the analgesics and antihypertensive categories, followed by stimulants and antibiotics. Compounds such as caffeine, cocaine and its metabolite benzoylecgonine, and cotinine (the metabolite of nicotine), were also detected in areas with relatively low anthropogenic impact and showed the highest total prevalence. This study supports the need to improve the sanitation system of urban areas in the Brazilian Amazon and the development of follow-up studies aimed at quantifying exposure levels and risks for Amazonian freshwater biodiversity.
Assuntos
Drogas Ilícitas , Preparações Farmacêuticas , Poluentes Químicos da Água , Brasil , Ecossistema , Monitoramento Ambiental , Rios , Poluentes Químicos da Água/análiseRESUMO
Regeneration is a widely spread process across the animal kingdom, including many species of marine crustaceans. It is strongly linked to hormonal cycles and, therefore, a great endpoint candidate for toxicology studies. We selected the amphipod Parhyale hawaiensis as test organism, already used in ecotoxicological studies and able to regenerate its body appendages. We are proposing a protocol to use the antenna regeneration as a toxicity endpoint. First, we evaluated differences in time of completion of regeneration in males and females after the amputation of one antenna of 6 months old animals. Then we compared the influence of different testing volumes in the regeneration process (100 and 5 mL). We used as testing substances, dimethyl sulfoxide (DMSO) and diflubenzuron, a chitin synthesis inhibitor. The most suitable protocol consisted of volumes of 5 mL in 12-well microplates, with 1 organism per well, 12 organisms per concentration (1:1 females/males) and test time duration of around 5 weeks. DMSO accelerated regeneration time with a NOEC of 0.06%. Diflubenzuron inhibited the time necessary to its completion with a NOEC of 0.32 µg L-1. We conclude that the Parhyale hawaiensis antenna regeneration protocol proposed here is a potential tool in ecotoxicology, but more studies are required for its validation not only to verify its utility for testing chemicals but also environmental samples.
Assuntos
Anfípodes , Diflubenzuron , Animais , Dimetil Sulfóxido/toxicidade , Ecotoxicologia , Feminino , MasculinoRESUMO
Psychiatric drugs are among the leading medications prescribed for humans, with their presence in aquatic environments raising concerns relating to potentially harmful effects on non-target organisms. Nortriptyline (NTP) is a selective serotonin-norepinephrine reuptake inhibitor antidepressant, widely used in clinics and found in environmental water matrices. In this study, we evaluated the toxic effects of NTP on zebrafish (Danio rerio) embryos and early larval stages. Developmental and mortality analyses were performed on zebrafish exposed to NTP for 168 h at concentrations ranging from 500 to 46,900 µg/L. Locomotor behaviour and acetylcholinesterase (AChE) activity were evaluated by exposing embryos/larvae to lower NTP concentrations (0.006-500 µg/L). The median lethal NTP concentration after 168 h exposure was 2190 µg/L. Although we did not identify significant developmental changes in the treated groups, lack of equilibrium was already visible in surviving larvae exposed to ≥ 500 µg/L NTP. The behavioural analyses showed that NTP was capable of modifying zebrafish larvae swimming behaviour, even at extremely low (0.006 and 0.088 µg/L) environmentally relevant concentrations. We consistently observed a significant reduction in AChE activity in the animals exposed to 500 µg/L NTP. Our results highlight acute toxic effects of NTP on the early-life stages of zebrafish. Most importantly, exposure to environmentally relevant NTP concentrations may affect zebrafish larvae locomotor behaviour, which in turn could reduce the fitness of the species. More studies involving chronic exposure and sensitive endpoints are warranted to better understand the effect of NTP in a more realistic exposure scenario.
Assuntos
Inibidores da Captação Adrenérgica/toxicidade , Antidepressivos Tricíclicos/toxicidade , Nortriptilina/toxicidade , Inibidores Seletivos de Recaptação de Serotonina/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Acetilcolinesterase/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Locomoção/efeitos dos fármacosRESUMO
The dyes Auramine and Auramine O are used in several industrial products, despite the scarce information regarding their ecotoxicity. The aim of the present study was to assess the acute and chronic toxicity of both dyes to aquatic organisms from different trophic levels (Raphidocelis subcapitata, Daphnia similis, Hydra attenuata, and Danio rerio) and calculate their predicted non-effect concentrations (PNEC). Auramine and Auramine O induced toxicity to all selected test organisms with L(E)C50 values ranging from 300 to 4800 ug/L. Both dyes induced inhibition in the growth rate of exposed algae, negatively affecting the reproduction of D. similis and induced deformities in H. attenuata (clubbed tentacles and shortened tentacles) and D. rerio (edemas, tail malformation and delay in yolk sac absorption). PNEC values of 0.92 µg/L and 4.0 µg/L were obtained for Auramine and Auramine O, respectively, based on results of the most sensitive test system (algae). Test results were analyzed using the Criteria of Reporting and Evaluating Ecotoxicity Data (CRED), confirming their reliability and relevance. Thus, PNEC values can be used in future risk assessments of those substances in freshwater systems.
Assuntos
Organismos Aquáticos , Poluentes Químicos da Água , Animais , Benzofenoneídio , Corantes , Daphnia , Reprodutibilidade dos Testes , Poluentes Químicos da Água/toxicidadeRESUMO
The 17 alpha methyltestosterone (MT) hormone is fed to Oreochromis niloticus larvae in fish farms with the purpose of inducing sex reversal. The aim of this study was to evaluate the toxicity and sub-lethality of MT (99.9% purity) and cMT (a commercial MT with 90% purity) in zebrafish (Danio rerio) adults, where the animals were exposed to concentrations of 0, 4, 23, 139, 833 and 5000 µg/L for 96 hours. Genotoxicity was evaluated by micronucleus test (MN), nuclear abnormalities (NA) and comet assay. A low genotoxic potential of MT was showed, inducing micronucleus, nuclear abnormalities and DNA damage in Danio rerio, depending on the use of MT or cMT, gender and tested concentrations. In the sub-lethality trials, there was a basal difference in the activity of the enzymatic biochemical markers for males and females, while the Glutatione S transferase (GST) activity decreased in all analyzed tissues, and for males the enzymatic activity decreased only in the intestine. Results suggest that MT has a toxic potential to fish because it alters enzymatic metabolic pathways and may pose a risk to the ecosystems.
Assuntos
Androgênios/toxicidade , Dano ao DNA , Metiltestosterona/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética , Androgênios/farmacologia , Animais , Ciclídeos/crescimento & desenvolvimento , Ensaio Cometa , Relação Dose-Resposta a Droga , Ecossistema , Feminino , Pesqueiros , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Masculino , Metiltestosterona/farmacologia , Poluentes Químicos da Água/farmacologiaRESUMO
Glyphosate (GLY) is the active ingredient of several herbicide formulations widely used to control weeds in agricultural and non-agricultural areas. Due to the intensive use of GLY-based herbicides and their direct application on soils, some of their components, including the active ingredient, may reach the aquatic environment through direct run-off and leaching. The present study assessed the acute toxicity and genotoxicity of the GLY-based formulation Atanor 48 (ATN) and its major constituents GLY, surfactant polyethoxylated tallow amine (POEA), as well as the main metabolite of GLY aminomethylphosphonic acid (AMPA) on non-target aquatic organisms. The toxic effects of these chemicals were evaluated in the fish embryo acute toxicity test with zebrafish (Danio rerio), while genotoxic effects were investigated in the comet assays with cells from zebrafish larvae and rainbow trout gonad-2 (RTG-2). GLY and AMPA caused no acute toxic effect, while ATN and POEA induced significant lethal effects in zebrafish (LC50-96 h 76.50 mg/L and 5.49 mg/L, respectively). All compounds were genotoxic in comet experiments with zebrafish larvae (LOEC 1.7 mg/L for GLY, ATN, AMPA and 0.4 mg/L for POEA). Unlike in vivo, only POEA induced DNA damage in RTG-2 cells (LOEC 1.6 mg/L), suggesting that it is a direct acting genotoxic agent. In summary, these data indicate that the lethal effects on zebrafish early-life stages can be ranked in the following order from most to least toxic: surfactant POEA > formulation ATN > active ingredient GLY ≈ metabolite AMPA. Genotoxic effects were observed in both RTG-2 cells (only POEA) and zebrafish (all test compounds) with the lowest tested concentrations. Therefore, it is important to evaluate different toxicological endpoints as well as use different non-target organisms to predict the hazards of GLY-based formulations and their components and breakdown product to aquatic biota.