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The herbicides atrazine and glyphosate are used worldwide and their excessive usage results in the frequent presence of these pesticides in environmental compartments. We evaluated the effects of environmentally relevant concentrations of analytical standards and commercial formulations of atrazine (2 µg L

The microbiological diversity of cultivable bacteria was analyzed in an aerated facultative lagoon. The removal of specific compounds and measures of pollutant load was evaluated with isolated native bacteria, selected and identified in kraft cellulose effluent. The system was operated with an organic loading rate of 0.2 kgCODm-3d-1 for 60 days. Analyses of the fluorescence excitation-emission matrix, acute ecotoxicity, and microbiology were performed. Bioaugmentation tests were done to emphasize the removal of color, using promising species. The removals of biochemical oxygen demand, chemical oxygen demand, and total organic carbon in AFL were 94%, 51%, and 41%, respectively. Regarding color, removal was up to 4%, and the total phenolic compounds were not removed through biological treatment. The treatment also decreased turbidity by 94% and lignin derivatives by 12%. The bacteria identified through NCBI-BLAST and statistical similarity totaled 9 species in the cellulose effluent, three of which have the potential for color treatment: Bacillus cereus, Bacillus thuringiensis, and Paenibacillus sp. The Bacillus cereus combined with biomass removed color (69%), total phenolic compounds (37%), and compounds derived from lignin (53%). These species are promising for removing specific parameters combined with biomass from biological AFL treatment systems.

Losartan potassium (LOS) is one of the most antihypertensives used in the world, and its presence in environmental matrices can cause impacts to biota. In this study, the ecotoxicity and genotoxicity of LOS was assessed before and after treatment by UVC/photolysis and UV/H2O2. The photodegradations were carried out at LOS solutions (2.5 mg L-1; 4.6 μM) for 30, 60, 90, 120, 240, and 480 min of treatment. For chromatographic analysis, the samples were submitted to solid-phase extraction (SPE) and analyzed by HPLC-DAD. Ecotoxicity bioassays were conducted using Daphnia magna (acute) and Desmodesmus subspicatus (chronic) for all the degradation times. To evaluate the genotoxicity, the comet assay was performed with a D. magna whole organism cell suspension applying the alkaline gel electrophoresis technique. For both process, the degradation rate was over 99% at 30 min, which reduced the acute toxicity of LOS to D. magna. In addition, only the sample treated at 240 min by UV/H2O2 showed significant chronic and acute toxicity. However, the genotoxicity effect was observed for samples treated LOS before treatment and at 480 min by UV/H2O2. Therefore, even reaching high LOS degradation rates, for both processes, the bioassays demonstrated the importance of ecotoxicological analyses by AOPs treatment.

Modern agriculture is threatened by the possibility of nutrient losses, largely attributable the presence of competing weeds in these spaces. The challenge is to manage these weeds efficiently with...

The objective of this work was to evaluate the effects following exposure (96 h) of South American catfish (R. quelen) embryos to active ingredients and commercial formulations from atrazine and glyphosate, isolated and in mixtures, at environmentally relevant concentrations. While the survival rates were not affected, sublethal effects were evidenced after exposure. The most frequent deformities were fin damage and axial and thoracic damage. The mixture of active ingredients caused an increase in SOD and GST, differing from the treatment with the mixture of commercial formulations. The activity of AChE was significantly reduced following the treatment with the active ingredient atrazine and in the mixture of active ingredients. In general, herbicide mixtures were responsible for causing more toxic effects to R. quelen embryos. Therefore, these responses showed to be suitable biomarkers of herbicides' exposure, in addition to generating more environmentally relevant baseline data for re-stablishing safety levels of these substances in aquatic bodies.

Herbicide mixture is used as an alternative to obtain different mechanisms of action acting on weeds, resulting in the frequent presence of pesticides in environmental compartments. As they are products used worldwide, this study evaluated effects of environmentally relevant concentrations of the analytical standards and commercial formulations of the herbicides atrazine (2 µg L− 1) and glyphosate (65 µg L− 1), in isolation and also in mixture (2 + 65 µg L− 1) on the microcrustacean Daphnia magna. Through chronic exposure (21 days) of two generations of organisms, effects on survival and reproductive capacity were observed, as well as responses regarding oxidative stress, determined through the analysis of biochemical biomarkers such as catalase and glutathione S-transferase. In the evaluation of the first generation of test organisms, no significant results related to biochemical biomarkers were observed, only effects over sexual maturation of organisms. However, in the second generation of exposed organisms, changes were observed in all parameters evaluated, with the mixture of herbicide active principles being the treatment responsible for more significant responses (p

Titanium dioxide nanoparticles (NpTiO2) are the most widely-used nanoparticle type and the adsorption of metals such as lead (PbII) onto their surface is a major source of concern to scientists. This study evaluated the effects of the associated exposure to both types of contaminant, i.e., lead (a known genotoxic metal) and NpTiO2, in a freshwater fish (Astyanax serratus) through intraperitoneal injection for an acute assay of 96 h. The effects of this exposure were evaluated using the comet assay, DNA diffusion assay and piscine micronucleus test, as well as the quantification of antioxidant enzymes (SOD, CAT, and GST) and metallothioneins. Our findings indicate that co-exposure of PbII with NpTiO2 can provoke ROS imbalances, leading to DNA damage in the blood and liver tissue of A. serratus, as well as modifying erythropoiesis in this species, inducing necrosis and changing the nuclear morphology of the erythrocytes.

Literature is scarce on the performance of Fenton-based processes as post-treatment of municipal wastewater treated by upflow anaerobic sludge blanket (UASB) reactor. This study aims to perform Fenton and photo-Fenton from UASB influent and effluent matrices to remove micropollutants (MPs) models: atrazine (ATZ), rifampicin (RIF), and 17α-ethynylestradiol (EE2). A UASB reactor at bench-scale (14 L) was operated with these MPs, and the AOPs experiments at bench-scale were performed on a conventional photochemical reactor (1 L). A high-pressure vapor mercury lamp was used for photo-Fenton process (UVA-Vis) as a radiation source. Microcrustacean Daphnia magna (acute toxicity) and seeds of Lactuca sativa (phytotoxicity) were indicator organisms for toxicity monitoring. The UASB reactor showed stability removing 90% of the mean chemical oxygen demand, and removal efficiencies for ATZ, RIF, and EE2 were 16.5%, 45.9%, and 15.7%, respectively. A matrix effect was noted regarding the application of both Fenton and photo-Fenton in UASB influent and effluent to remove MPs and toxicity responses. The pesticide ATZ was the most recalcitrant compound, yet the processes carried out from UASB effluent achieved removal99.99%. The post-treatment of the UASB reactor by photo-Fenton removed acute toxicity in D. magna for all treatment times. However, only the photo-Fenton conducted for 90 min did not result in a phytotoxic effect in L. sativa.

Made available in DSpace on 2022-04-28T19:43:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The intensive use of the antihypertensive losartan potassium (LOS) has culminated in its high occurrence in aquatic environments. However, insufficient studies had investigated its effects in non-target organisms. In this study, ecotoxicity of LOS was assessed in aquatic organisms from distinct trophic levels (Desmodesmus subspicatus, Daphnia magna, and Astyanax altiparanae). Genotoxicity was assessed by the comet assay in D. magna and A. altiparanae, and biochemical biomarkers for the fish. LOS was more toxic to D. subspicatus (EC50(72h) = 27.93 mg L−1) than D. magna (EC50 = 303.69 mg L−1). Subsequently, this drug showed to induce more DNA damage in D. magna than A. altiparanae, when exposed to 2.5 mg L−1. No significant stress responses were observed by the fish biomarkers, suggesting that higher trophic levels organisms are more tolerant to LOS toxicity. LOS showed relatively low toxic potential for a short period of exposure, but with different patterns of toxicity for the organisms from distinct trophic levels, contributing to further risk assessment of LOS. Laboratory of Ecotoxicology Department of Chemistry and Biology Federal University of Technology - Paraná Institute of Biosciences State University of São Paulo Research Institute Pelé Pequeno Príncipe Faculdades Pequeno Príncipe FAPESP: 2016/15229-1

Polybrominated diphenyl esters are emerging environmental contaminants with few toxicological data, being a concern for the scientific community. This study evaluated the effects of BDE-47 on the health of Oreochromis niloticus fish. The animals were exposed to three doses of BDE-47 (0, 0.253, 2.53, 25.3 ng g−1) every 10 days, for 80 days. The BDE-47 affected the hepatosomatic and gonadosomatic index in female and the condition factor by intermediate dose in both sexes. The levels of estradiol decreased and the T4 are increased, but the vitellogenin production was not modulated in male individuals. Changes in AChE, GST, LPO and histopathology were observed while the integrated biomarker response index suggests that the lowest dose of BDE-47 compromised the activity of antioxidant enzymes. The oral exposure to BDE-47 in environmental concentrations is toxic to O. niloticus and the use of multiple biomarkers is an attribution in ecotoxicology studies and biomonitoring programs.

Cylindrospermopsin (CYN) is a cyanotoxin that is cytotoxic to a wide variety of cells, particularly to the hepatocytes. In this study, the toxic effects of purified CYN were investigated in primary cultured hepatocytes of Neotropical fish Hoplias malabaricus. After isolation, attachment, and recovery for 72 h, the cells were exposed for 72 h to 0, 0.1, 1.0, 10, and 100 μg l−1 of CYN. Then, cell viability and a set of oxidative stress biomarker responses were determined. Catalase, superoxide dismutase, glucose-6-phosphate dehydrogenase, and glutathione S-transferase activities were not affected by exposure to CYN. Concentration-dependent decrease of glutathione reductase activity occurred for most CYN-exposed groups, whereas non-protein thiol content increased only for the highest CYN concentration. Lipid peroxidation, protein carbonylation, and DNA damage levels were not altered, but reactive oxygen species levels increased in the cells exposed to the highest concentration of CYN. Cell viability decreased in all the groups exposed to CYN. Thus, CYN may cause a slight change in redox balance, but it is not the main cause of cell death in H. malabaricus hepatocytes.

Malathion is a highly toxic organophosphate insecticide, being one of the most widely used in the world and is generally used for insect control in food production. Thus, ecotoxicological studies have been used to verify its toxic effects on aquatic organisms, such as Daphnia magna and biomarkers, as the comet assay. The comet assay is a microgel electrophoresis method for the detection and quantification of DNA strand breaks in individual cells. Cells were obtained from Daphnia magna after disaggregation of newborn organisms, exposed at concentrations of 0.23 μg L−1 and 0.47 μg L−1 for 48 h. Malathion has shown to cause damage to DNA of the exposed organisms. It was also observed the need of further studies to standardize the comet assay technique for Daphnia magna, once methodologies used present several differences.

Estuaries are dynamic environments, key for the survival of innumerous ecologically or economically important fish species. Among these species are Neotropical silversides (Atherinella brasiliensis), which are resident and abundant in Brazilian estuaries and used as a complementary source of income and food for local communities. To better understand silverside populations in Brazil, we evaluated the genetic diversity, structure and demography of fish sampled at six estuaries from the northeastern to the southern coast, using Random Amplified Polymorphic DNA and mitochondrial DNA (D-loop) markers. High haplotype diversities (h ranging from 0.75 to 0.99) were found in all populations except Carapebus, located in Southeast Brazil (h = 0.54). A total of 69 mtDNA haplotypes were found, with Itaparica (Northeast Brazil) and Carapebus presenting only exclusive haplotypes, while some were shared among populations in the South. Strong regional structure was observed, with very high differentiation between Itaparica and Carapebus, as well as among these two populations and the ones from the Southern region (Paranagua, Conceicao, Camacho and Patos). Among southern areas, low/moderate structure was detected. Most populations showed unimodal mismatch distributions indicating recent demographic expansion, while Carapebus presented a multimodal distribution characteristic of a stable or bottlenecked population. Times since possible population expansion were highest in Itaparica (32,500 ya) and Carapebus (29,540 ya), while in the Southern region longest time was observed at Conceicao (25,540 ya) and shortest at Patos (9720 ya). In a general manner, haplotype diversities were directly related to times since population expansions; again, Carapebus was the exception, displaying long time since expansion but low diversity, possibly due to a recent bottleneck caused by the isolation and human impacts this lagoon is subject to. Isolation by Distance was significant for Itaparica and Carapebus, and considering the extremely high differentiation of these populations, we suggest that they could be undergoing speciation. To adequately manage and maintain the genetic variability of silversides in Brazilian estuaries, we propose three distinct management units for this species: 1) Itaparica; 2) Carapebus; and 3) Southern Brazil.

Titanium dioxide nanoparticles (NpTiO

Carbon Nanotubes are among the most promising materials for the technology industry. Their unique physical and chemical proprieties may reduce the production costs and improve the efficiency of a large range of products. However, the same characteristics that have made nanomaterials interesting for industry may be responsible for inducing toxic effects on the aquatic organisms. Since the carbon nanotubes toxicity is still a controversial issue, we performed tests of acute and subchronic exposure to a commercial sample of multiwalled carbon nanotubes in two fish species, an exotic model (Danio rerio) and a native one (Astyanax altiparanae). Using the alkaline version of the comet assay on erythrocytes and the piscine micronucleous, also performed on erythrocytes, it was verified that the tested carbon nanotubes sample did not generate apparent genotoxicity by means of single/double DNA strand break or clastogenic/aneugenic effects over any of the species, independently of the exposure period. Although, our findings indicate the possibility of the occurrence of CNTs-DNA crosslinks. Apparently, the sample tested induces oxidative stress after subchronic exposure as shown by activity of superoxide dismutase and catalase. The data obtained by the activity levels of acetylcholinesterase suggests acute neurotoxicity in Astyanax altiparanae and subchronic neurotoxicity in Danio rerio.

Astyanax is widely used in ecotoxicological bioassays and in biomonitoring studies because of the similarities that different species of the genus have regarding their ecological, morphological and behavioral characteristics. Due to these similarities, ecotoxicological studies are commonly conducted using any sampled Astyanax as if they were the same, i.e. without separating the species and using any gathering as a whole representative of the genus. This conduct is worrying since there are no studies showing the ecotoxicological relationship among the species. Therefore, this article addressed to this issue by inducing, through acute water exposure bioassays, the ecotoxicological responses of biomarkers of three species of Astyanax (A. altiparanae, A. bifasciatus and A. ribeirae). The antioxidant systems were induced by Cu contamination and were verified through the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and carbonic anhydrase (CA), while the responses of biotransformation (activity of etoxiresorufin-O-deetilase (EROD) and glutathione S-transferase (GST)), the neurotoxicity (activity of acetylcholinesterase (AChE)) and liver histopathology were checked against the contamination by malathion. Also, for both bioassays, the damage to macromolecules (lipids (LPO) and DNA (comet assay in blood (ECA) and liver (HCA), micronucleus test (MNA) and polichromatic erythrocytes (PCE)) were evaluated. Overall, the study showed that, despite the non-induction or the unclear action of some of the enzyme systems, all three species of Astyanax were susceptible to the contamination of both xenobiotics, since damages to their macromolecules were observed. From these results, a cluster analysis was performed and was efficient in integrating all the data of the three species to display the ecotoxicological relationship between them, which was consistent and representative. With this paper, we hope to contribute in promoting the investigation of the interspecifc relationship of ecotoxicological responses of Astyanax by creating a database on the genus and by encouraging further studies with this and other genera.

The Comet Assay is a rapid and sensitive method for detection of breaks in the DNA strand into individual cells, commonly used at ecotoxicology. At this time, the method has been refined, but not yet fully standardized and variations on protocol are common. When environmental reviews are performed, the large number of samples required and the conditions of handling during transportation of samples to the laboratory are frequent problems. Until now, however, no truly effective method for samples preservation for this test was described. Therefore, we tested three stock solutions: fetal bovine serum (FBS), phosphate buffered saline (PBS) e Tris. Gill cells of Rhamdia quelen contaminated with insecticide Fipronil were maintained in these solutions, for 0, 24 and 48 hours to perform Comet Assay. It was found that fetal bovine serum was the solution that best preserved the DNA integrity of gill cells, followed by Tris and finally by PBS. We concluded in this study that fetal bovine serum is the solution that best conserve the gill cells and genetic material of R. quelen for a time until 48 hours in the absence of light and at 4oC.

The bioaccumulation of saxitoxins (STX) in the trophic chain, mainly in freshwater, are not completely known. This work aimed to elucidate the effects of STX on Hoplias malabaricus through trophic bioassay. The fish were fed once every five days with Astyanax sp. before being subjected to an intraperitoneal inoculation with the lysate of Cylindrospermopsis raciborskii culture containing 97% STX and 3% by neosaxitoxin and gonyautoxin during 20 days. The animal's liver was assessed using biomarkers as activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx), and concentrations of reduced glutathione (GSH) and lipoperoxidation (LPO) and protein carbonylation (PCO). In the blood was analyzed the genotoxic and hematological parameters. The hepatosomatic index and the relative condition factor did not show a significant difference between the exposed and control groups. The values of mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin increased in the STX group. The hepatic tissue from both groups exhibited a typical pattern that have been already described for most teleost fish. The results suggested the generation of reactive oxygen species, with increased activity of GPx and concentrations of LPO and GSH; whereas the specific activity of SOD decreased. However, no changes were observed in the CAT, PCO, and DNA damage. Although the STX effects are known as neurotoxic, this cyanotoxin caused liver biochemical alterations that can be considered ecologically relevant.

The survey of the effects of toxic metals and its organic compounds are of critical importance because these compounds tend to accumulate in aquatic environments. In the present work, the genotoxic potential of methylmercury, an organomercurial compound with high toxicity and present in large amounts in fish of the Amazon due to the mining process, was evaluated using the piscine micronucleus test and comet assay in fish. Specimens of Hoplias malabaricus (popularly known as traira), a neotropical specie, was exposed to methylmercury via food web, over 70 days, in two different concentrations: two groups of fifteen fish were tested with 0.075 μg CH3Hg+/g and 0.75 μg CH3Hg+/g of methylmercury per gram of fish, at 5-day intervals and over 14 successive intervals whereas control group, composed by nine fish, was fed by uncontaminated prey fish (Astyanax sp). One of the aims of this study was to reproduce the contamination found in nature in an attempt to increase our biological knowledge on the neotropical species. Hoplias malabaricus specimens were then anesthetized for removal of blood samples and dissected, for cephalic kidney removal. As a result, it was observed that the piscine micronucleus test showed no significant differences between exposed groups and control group. The comet assay performed on erythrocyte system cells, showed a significant difference between controls and contaminated, but there was no difference between doses. In contrast, the kidney cells comet assay showed no significant difference between groups, probably due to the type of damage caused by xenobiotics to be related to the tissues of most contact with it, as well as its mode of action and the chain of bioaccumulation within bodies.

Aquatic environmental pollution may cause biodiversity loss. Thus, monitoring studies are very important because fish health reflects both quality and sustainability of the environment, as well as of the individuals that live there. In the present report, genetic biomarkers (piscine micronucleus test; comet assay with blood, liver, and kidney cells) were used in specimens of Astyanax sp. to analyze the contamination level of the Cangüiri Farm through biomonitoring. The Cangüiri Farm, the old school farm of the Federal University of Paraná, is inside the Iraí River Environment Preservation Area, created in 1996 to preserve the sources of public water supply in Curitiba and metropolitan area. We verified that the fishes collected within the Cangüiri Farm area presented high damage levels, showing more environment contamination when compared to the specimens collected in the Costa Ecologic Park, used as reference in the present report. The results indicate that the Cangüiri Farm, which is inside an environment protection area, created especially for the protection of the fountainhead for water supply, may be contaminated. These toxic residues, which were remarkably persistent in the environment, are possibly derived from agricultural activities in the wider area. Thus, we suggest the analysis of the area with other biomarkers and for a longer time period.

The use of the non-steroidal anti-inflammatory drugs such as dipyrone is so widespread that this drug and its metabolites have been detected in effluents and surface water. This study aimed to evaluate the potential toxic effects of dipyrone on the aquatic environment, using a native fish species, Rhamdia quelen. Fish were exposed to three concentrations of dipyrone, 0.5, 5 and 50 μg/L, in the water for 15 days, and hematological, biochemical, genetic and morphological biomarkers were evaluated. The glutathione S-transferase activity decreased in the highest concentration in relation to the control group. In addition, hematocrit, red blood cells and thrombocyte counts were decreased in all three exposed groups in relation to the control group. The comet assay showed DNA damage at the lowest concentration of dipyrone and significant kidney damage. Those results suggest that a constant exposure of aquatic organisms to dipyrone presents potential toxic effects.

Diverse genetic biomarkers have been used to evaluate the effects of pollution by mutagenic agents such as metals and pesticides, as well as a large variety of chemical substances derived from human activities. This work researched the effects that an exposure of 60 days to the insecticide Fipronil (concentrations of 0.05, 0.10 and 0.23 μg/L) can cause in the fish Rhamdia quelen using Comet assay with gills, histopathological analysis of gills and the Piscine Micronucleus test and Nuclear Morphological Alterations. The results for the Comet assay and for gills histopathological injuries showed no difference between the control group and the contaminated groups. In the Piscine Micronucleus test, the smallest concentration of Fipronil (0.05 μg/L) was similar as the control group, while concentrations of 0.10 and 0.23 μg/L caused more damage to the DNA. These results suggested that only the highest concentrations of Fipronil tested cause damage in erythrocytes, but none of these concentrations was sufficient to alter the DNA in the gill cells. R. quelen may be a less sensitive bioindicator than other fish that have been tested. On the other hand, the concentrations used may not have been sufficient to detect alterations in the DNA of R. quelen with the chosen tests. Works like this take on great importance given the enormous quantity of substances that are thrown daily into the environment in an uncontrolled way, without evaluation of the consequences. The application of these tests with other concentrations, tissues and exposure times is suggested for future works.

In this study, we analyzed samples of water from a river and a lake located near a hospital waste landfill with respect to physico-chemical parameters and conducted bioassays of ecotoxicity using Vibrio fischeri and Daphnia magna, which are species commonly used to evaluate the water toxicity. We also evaluated damage to the genetic material of fish (Astyanax sp. B) that were exposed (96 h) to water from these two sites that were located near the tank ditch, using the alkaline comet assay and the piscine micronucleus test. Parameters including aluminum, manganese, biochemical oxygen demand, sulfide, conductivity, phenol, total coliforms and Escherichia coli counts, were above acceptable levels that have been established in environmental legislation. However, the toxicity bioassays that we carried out in Vibrio fischeri and Daphnia magna and the piscine micronucleus test in fish showed no immediate risk due to acute effects. Based on the results of the comet assay, however, it was possible to detect damage to genetic material in fish that were acutely exposed in the laboratory to water samples from the river and lake that are located near the trench septic tank. Thus, our results suggest that tests beyond those usually employed to test water toxicity, such as the comet assay we used in the fish, are required to assess the toxicity of water with greater accuracy.

When environmental analysis is performed, the high number of samples required and handling conditions during the transport of these samples to the laboratory are common problems. The comet assay is a useful, highly sensitive tool in biomonitoring. Some studies in the literature aim to preserve slides in lysis solution for use in the comet assay. Until now, however, no efficient methodology for preserving blood samples for this assay has been described. Because of this, the present report aimed to establish the proper conditions for samples maintenance prior to comet assay analysis. Samples were conserved in three different solutions: a high protein concentration solution (fetal bovine serum—FBS), an anticoagulant agent (a calcium chelator – ethylenediaminetetracetic acid – EDTA), and a salt buffered solution (phosphate buffered saline—PBS). Therefore, peripheral blood samples of Rhamdia quelen specimens were collected and maintained in these solutions until testing at 72 h. Analyses of DNA fragmentation via the comet assay and cell viability via flow cytometry were performed at intervals of 24 h. The results showed that samples maintained in FBS were preserved better; this was followed by those preserved in PBS and then last by those preserved in EDTA. In conclusion, blood samples from freshwater fish can be preserved up to 48 h in fetal bovine serum at 4 °C in the absence of light. In this period, no DNA fragmentation occurs. We thus describe an excellent method of sample conservation for subsequent analysis in the laboratory.

We aimed to evaluate the ecological integrity of a large river, which receives agricultural and urban effluents and is used to water public supply. The fish species Astyanax bifasciatus was used as bioindicator during winter and spring 2012, and summer 2013 at the Middle Iguacu River basin in Parana state, Brazil. Water chemical and physical measures and ecotoxicological tests were carried out as well biochemical and genetic biomarkers in sampled fish in each period. The studied area was divided in three sample points: SP1, located where the water is collected to public supply; SP2, located in an urbanized area, and SP3, located at an urbanized area with the discharge of the sewage treatment. Although water chemical and physical analyzes were range of the Brazilian law to hydric bodies, anticholinesterasic effects were found in winter, oxidative stress in summer and spring. The higher genotoxic effect was in winter to all sample points. The temporal variation in biomarkers and the detection of caffeine in the water call attention to the water quality in this river mainly to be used to public supply.

The survey of the effects of toxic metals and its organic compounds are of critical importance because these compounds tend to accumulate in aquatic environments. In the present work, the genotoxic potential of methylmercury, an organomercurial compound with high toxicity and present in large amounts in fish of the Amazon due to the mining process, was evaluated using the piscine micronucleus test and comet assay in fish. Specimens of Hoplias malabaricus (popularly known as traira), a neotropical specie, was exposed to methylmercury via food web, over 70 days, in two different concentrations: two groups of fifteen fish were tested with 0.075 μg CH(3)Hg(+)/g and 0.75 μg CH(3)Hg(+)/g of methylmercury per gram of fish, at 5-day intervals and over 14 successive intervals whereas control group, composed by nine fish, was fed by uncontaminated prey fish (Astyanax sp). One of the aims of this study was to reproduce the contamination found in nature in an attempt to increase our biological knowledge on the neotropical species. Hoplias malabaricus specimens were then anesthetized for removal of blood samples and dissected, for cephalic kidney removal. As a result, it was observed that the piscine micronucleus test showed no significant differences between exposed groups and control group. The comet assay performed on erythrocyte system cells, showed a significant difference between controls and contaminated, but there was no difference between doses. In contrast, the kidney cells comet assay showed no significant difference between groups, probably due to the type of damage caused by xenobiotics to be related to the tissues of most contact with it, as well as its mode of action and the chain of bioaccumulation within bodies.

Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1--Santa Marta Lake, P2 and P3--Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.

The Alagados Reservoir (Brazil) is an important source for the supply of water, recreation and fishery. Since 2002, the occurrence of cyanobacterial blooms (paralytic shellfish toxins - PST producers) have been noted. This study was aimed at the monitoring of PST occurrence in the Reservoir's water and fish. Biomarkers such as ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), and acetylcholinesterase (AchE) activities, lipoperoxidation (LPO), histopathology, and comet assay were analyzed in fish. Water and fish were sampled in spring, summer and autumn. The PST concentrations in water were 5.15, 43.84, and 50.78 ng equiv Saxitoxin/L in the spring, summer and autumn, respectively. The PST muscle concentration was below the limit for shellfish. Gonyautoxins (GTX) were found in water samples and fish muscle, and GTX 5 was the major analogous found in muscle. In the summer samples, the LPO, genetic damage, and the GST and AchE activities increased while in the autumn an increase in EROD activity and genetic damage were observed. In all samplings, histopathological alterations in the fish gills and liver were found. The results showed a seasonal variation in the fishes health, which could be related also to farming activities and to the contaminants bioavailability during the year.