Rhaul Oliveira

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. GRAPHICAL ABSTRACT

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.

Parhyale hawaiensis is an marine amphipod and attractive model organism for ecotoxicology. The insect growth regulator diflubenzuron (DFB) is a chitin syntheis inhibitor insecticide with have pronounced toxic effects on non-target organisms, especially insects and crustaceans. This study aimed to evaluate the toxicity assessment of diflubenzuron using a miniaturized approach for chronic test with Parhyale hawaiensis, previousily standarized in our reasearch group.

Embriões de vertebrados aquáticos, nomeadamente peixes e anfíbios, são modelos experimentais consolidados com aplicação para avaliação toxicológica de substâncias químicas como corantes sintéticos. Os dados toxicológicos gerados com esses modelos contribuem para um uso e registro mais seguro desses químicos, tanto do ponto de vista da saúde humana quanto ambiental. O presente trabalho teve como objetivo realizar uma revisão bibliográfica do uso de embriões de vertebrados aquáticos na avaliação toxicológica de corantes. Um total de 22 artigos foram encontrados sobre o tema entre os anos 2001 e 2019. Nesses, foram analisadas informações sobre 35 corantes diferentes, distribuídos em 8 classes, sendo a mais estudada a dos corantes Azo, com 54 % to total de corantes estudados. Os embriões de Danio rerio se destacam como organismo modelo experimental mais utilizado (73 % dos estudos). Os parâmetros toxicológicos abordados nos estudos podem ser agrupados nas seguintes categorias: bioquímico, genético, morfológico, comportamental e sobrevivência.