Publications by authors named "Claudio M Jonsson"

The quality of the aquatic environment can be compromised by the practice of intensive use of pesticides in agriculture and by the misuse of veterinary drugs. Therefore, organisms that live in aquatic ecosystems may be affected due to the presence of these chemicals, through runoff, leaching and other processes. Exposure of aquatic organisms to these xenobiotics could pose health risks.

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In the field of agriculture, nanopesticides have been developed as an alternative to the conventional pesticides, being more efficient for pest control. However, before their widespread application it is essential to evaluate their safe application and no environmental impacts. In this paper, we evaluated the toxicological effects of two kinds of atrazine nanoformulations (ATZ NPs) in different biological models (Raphidocelis subcapitata, Danio rerio, Lemna minor, Artemia salina, Lactuca sativa and Daphnia magna) and compared the results with nanoparticle stability over time and the presence of natural organic matter (NOM).

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The demand for healthier foods with high nutritional value has resulted in intensive fish farming. In this production system, high-frequency infections occur, and antibiotics are administrated for control. Only two antibiotics are allowed for use in Brazilian aquaculture, one of which is florfenicol.

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Intensive fish cultivation has a high incidence of infection, which is often controlled by administering antibiotics. Florfenicol (FF) is one of the two antimicrobial drugs permitted for aquaculture in Brazil. Due to their intensive use, potentially harmful effects on aquatic organisms are of great concern.

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The present study aimed to evaluate the risk assessment, median lethal concentration LC, development, and mortality of Nile tilapia larvae exposed to atrazine after stress management. An LC trial was carried out using fish (n = 147; 8.5 ± 1.

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The aim of this study was to determine the median lethal concentration (LC), effective concentration (EC), risk assessment, and development of Nile tilapia Oreochromis niloticus larvae submitted to florfenicol (FF) exposure. Fish (n = 147; 8.6 ± 0.

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Plants are a potential source of active molecules and are environmentally safer and cheaper than synthetic antibiotics. Bioactive compounds of Artemisia annua have shown pharmacological activities and are used globally as a supplement. The present study tested whether dietary supplementation with alcohol extract of the plant A.

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The practice of intensive herbicide use in the sugarcane industry has a high risk of compromising the quality of the water and the organisms that live there due to losses through runoff, leaching and other processes. In this work, the dynamics of four herbicides present in three different mixtures were evaluated through their incorporation and elimination in the muscle tissue of tilapia (). The highest mean values of bioconcentration factors were 1.

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A multiresidue method for detecting and quantifying sulfonamides (sulfapyridine, sulfamerazine, sulfathiazole, sulfamethazine, sulfadimethoxine, sulfamethoxazole, and sulfamethoxypyridazine) and trimethoprim in tilapia fillet () using liquid chromatography coupled to mass spectrometry was developed and validated. The sample preparation was optimized using the QuEChERS approach. The chromatographic separation was performed using a C18 column and 0.

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The residue depletion of sulfamethazine (SMZ) was evaluated in tilapia (Oreochromis niloticus) after 11 days of administration of medicated feed containing SMZ, at the dose of 422 mg/kg body weight (bw). The determination of SMZ in feed and tilapia fillet was carried out using the QuEChERS approach for sample preparation, and high performance liquid chromatography with diode array detector (HPLC-DAD) and ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) for quantitation, respectively. Both methods were validated based on international and Brazilian guidelines and shown to be suitable for the intended purposes.

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The insecticide Diflubenzuron (DFB), used by many fish farming, when metabolized or degraded produces the extremely toxic compound p-chloroaniline (PCA). Once in the aquatic environment, these compounds can form mixtures and their bioavailability depends on factors such as the presence of soil. The toxic effects of the isolated compounds and their mixtures in the proportions: 75%, 50%, and 25% of PCA were analyzed in tilapia (Oreochromis niloticus) in the presence and absence of soil after 96h.

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Ametryn (AMT) is one of the most widely used herbicides in tropical sugarcane crops, the main culture of São Paulo State, Brazil. It is known as a diffuse pollutant, being found in surface water and sediment of water bodies adjacent to the crop fields. In the present study, the toxicity of AMT to zebrafish (Danio rerio) embryos was evaluated using developmental and biochemical endpoints.

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Sulfamethazine (SMZ) is one of the most commonly used sulfonamide compounds in fish farming, and its physiological effects on fish are unknown. SMZ was administered to juvenile Nile tilapia (Oreochromis niloticus) at a dose level of 422 mg kg(-1) body weight, for a period of 11 days, via medicated feed. Fish were divided into two groups, the control group (CG) and the group fed with SMZ in feed.

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Polymeric nanoparticles have been developed for several applications, among them as carrier system of pesticides. However, few studies have investigated the fate of these materials in the environment in relation to colloidal stability and toxicity. In nature, humic substances are the main agents responsible for complexation with metals and organic compounds, as well as responsible for the dynamics of these nanoparticles in aquatic and terrestrial environments.

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This research work investigated the bioconcentration of tebuconazole [(±)-α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol] fungicide in zebrafish (Danio rerio) under laboratory conditions and a first-order kinetic pesticide dissipation in the water. The concentrations of tebuconazole fitted to an equivalent nonlinear kinetic type model which allowed the calculation of the following parameters: bioconcentration factor (38.80 L kg(-1) ), time to reach maximum fish concentration (6 days), maximum concentration in fish (0.

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Microbial pest control agents or entomopathogens have been considered an interesting alternative to use instead of chemical insecticides. Knowledge of ecotoxicity data is very important to predict the hazard of any product released in the environment and subsidize the regulation of these products by governmental agencies. In the present study four new Brazilian strains of Bacillus and one fungus were tested to evaluate their acute toxicity to the microcrustacean Daphnia similis, the snail Biomphalaria glabrata and the dung beetle Digitonthophagus gazella.

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Risk assessment guidelines for the environmental release of microbial agents are performed in a tiered sequence which includes evaluation of exposure effects on non-target organisms. However, it becomes important to verify whether environmental risk assessment from temperate studies is applicable to tropical countries, as Brazil. Pseudomonas putida is a bacteria showing potential to be used for environmental applications as bioremediation and plant disease control.

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The presence of copper in water environment may have detrimental effects on aquatic organisms, including algae, where different enzymatic systems can be affected. Algae acid phosphatase plays important roles in metabolic processes such as decomposition of organic phosphate, autophagic digestive process, recycling cellular materials and zygote formation during reproduction. This work describes an in vitro activation effect of copper on the acid phosphatase of the green algae Pseudokirchneriella subcapitata (formely Selenastrum capricornutum) under preincubation condition.

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Sewage sludge applied to soils as a fertilizer often contains metals and linear alkylbenzene sulphonate (LAS) as contaminants. These pollutants can be transported to the aquatic environment where they can alter the phosphatase activity in living organisms. The acid phosphatase of algae plays important roles in metabolism such as decomposing organic phosphate into free phosphate and autophagic digestive processes.

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Acid phosphatase plays important roles in algae metabolism such as availability and recycling of inorganic phosphate, autophagic digestive processes and fertilization. Chemicals released into the environment from agriculture activities may impair algae phosphatase activity. The aim of this work was to evaluate the in vitro effect of twenty-four organic compounds and six metals used as pesticides, or present as contaminants in sewage sludge, on the acid phosphatase activity extracted from Pseudokirchneriella subcapitata.

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