Suzelei Rodgher

Universidade Federal de São Carlos, São Carlos do Pinhal, São Paulo, Brazil

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Publications (12)20.94 Total impact

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    ABSTRACT: Water samples were collected quarterly for 1 year from the newly created Osamu Utsumi uranium mine pit lake, Brazil, which is affected by acid mine drainage (AMD). The water presented mean pH values of 3.8, high mean electrical conductivity values (2391 µS/cm), manganese (74 mg/L), sulfate (1413 mg/L) and uranium (3 mg/L). The density of rotifera was significantly higher than that of cladoceran. Rotifera Keratella americana, K. cochlearis and the Cladocera Bosminopsis deitersi, Bosmina sp., are being reported for the first time in samples from a uranium pit lake with AMD. Of the species registered, the order Bdelloidea was the most important in terms of density (17,500–77,778 ind/m3), since it occurred throughout the whole sampling period. The combined effect of moderately acidic pH and other potential stress factors, such as high concentrations of stable and radioactive contaminants, probably influenced the zooplankton species composition in the pit lake.
    Mine Water and the Environment 09/2015; 34(3). DOI:10.1007/s10230-015-0333-9 · 1.21 Impact Factor
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    ABSTRACT: The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.
    Ecotoxicology 09/2014; 23(9). DOI:10.1007/s10646-014-1346-z · 2.71 Impact Factor
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    ABSTRACT: The quality of the water in a uranium-ore-mining area located in Caldas (Minas Gerais State, Brazil) and in a reservoir (Antas reservoir) that receives the neutralized acid solution leaching from the waste heaps generated by uranium mining was investigated. The samples were collected during four periods (October 2008, January, April and July 2009) from six sampling stations. Physical and chemical analyses were performed on the water samples, and the data obtained were compared with those of the Brazilian Environmental Standards and WHO standard. The water samples obtained from waste rock piles showed high uranium concentrations (5.62 mg L(-1)), high manganese values (75 mg L(-1)) and low average pH values (3.4). The evaluation of the water quality at the point considered the limit between the Ore Treatment Unit of the Brazilian Nuclear Industries and the environment (Consulta Creek) indicated contamination by fluoride, manganese, uranium and zinc. The Antas reservoir showed seasonal variations in water quality, with mean concentrations for fluoride (0.50 mg L(-1)), sulfate (16 mg L(-1)) and hardness (20 mg L(-1)) which were low in January, evidencing the effect of rainwater flowing into the system. The concentrations for fluoride, sulfate and manganese were close or above to the limits established by current legislation at the point where the treated mining effluent was discharged and downstream from this point. This study demonstrated that the effluent discharged by the UTM affected the quality of the water in the Antas reservoir, and thus the treatments currently used for effluent need to be reviewed.
    Environmental Monitoring and Assessment 06/2012; 185(3). DOI:10.1007/s10661-012-2719-5 · 1.68 Impact Factor
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    Brazilian Archives of Biology and Technology 02/2012; 55(1):161-169. DOI:10.1590/S1516-89132012000100020 · 0.55 Impact Factor
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    ABSTRACT: In this study, we investigated the microbial community (bacteria and protozooplankton) of a Brazilian reservoir that receives neutralized acid mine drainage flowing from piles of earth produced during uranium extraction. Thus, this research represents an attempt to fill a gap in the information on the ecology of freshwater microorganisms in tropical oligotrophic habitats, in particular in systems affected by high levels of the uranium. During the study, we observed very low chlorophyll a contents and protozooplankton cell densities and biomass. These cell densities were between 0 and 89 cells L-1 and were lower than those frequently reported for oligotrophic freshwater lakes. In contrast, bacterial densities were normal or even slightly high, between 1.85 to 6.0 × 109 cells L-1. The present study has demonstrated very low protozooplankton cell densities and biomass in oligotrophic reservoir under the influence of acidic mining effluents and of high levels of ionizing radiation. It is likely that the ciliate cell densities and biomasses recorded in this study, which fall significantly below the previously published values, can be explained by the chronic fractionated exposure of these protozoa to the high levels of uranium to this system.
    Radioprotection 01/2012; 46(6):S331-S337. DOI:10.1051/radiopro/20116985s · 0.54 Impact Factor
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    ABSTRACT: The present study was carried out in a uranium ore mining area located in Caldas, in the southern region of the state of Minas Gerais, Brazil. The present study was undertaken to evaluate the ecologies of populations of the bioleaching microorganisms (Acidithiobacillus ferrooxidans and A. thiooxidans) in effluents from mining companies containing sulfides and associated radionuclides, and to assess the physico-chemical and radiological uranium mining impact on surface water quality. Water samples collected from eight points were analyzed chemically and microbiologically. In water samples from points in the region called the pit mine–waste rock piles, high average oxide-reduction potential value (429–525 mV), high ferrous ion concentration (0.72–12.56 mg L−1), low average pH value (3.37–3.47) and highest average population densities of A. ferrooxidans (59–2,551 MPN mL−1) and A. thiooxidans (833–6,359 MPN mL−1) were detected. These findings indicate that these points are the main places of acid mine drainage and biolixiviation action in the Ore Treatment Unit (UTM). The study reported here also found that water quality in the point considered a link between the UTM and the environment was degraded. These points should be considered as critical sites in the event of a decommissioning act. The average concentration values of fluorite (10.60 mg L−1) and manganese (10.49 mg L−1) in the water samples of treated effluents are above the limits permitted by law. Long-term utilization of these waters is considered to be unhealthy for the local environment and humans.
    Environmental Earth Sciences 02/2011; 62(4):857-863. DOI:10.1007/s12665-010-0572-9 · 1.77 Impact Factor
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    ABSTRACT: The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 x 10(5) and 1 x 10(6) cells ml(-1) on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL(+) showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC(50) determination. LC(50) for D. similis was 5.15 x 10(-7) mol l(-1) dissolved Cd without algal cells, whereas with 1 x 10(5) cells ml(-1), it was significantly higher (7.15 x 10(-7) mol l(-1) dissolved Cd). For Cr, the 48 h-LC(50) value of 9.17 x 10(-7) mol l(-1) obtained for the cladoceran in tests with 1 x 10(6) cells ml(-1) of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 x 10(-7) mol l(-1) dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.
    Ecotoxicology 03/2010; 19(6):1027-33. DOI:10.1007/s10646-010-0484-1 · 2.71 Impact Factor
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    ABSTRACT: The present study aimed to investigate the response of several life history parameters (body length and age of primipara, duration of embryonic development, maximum body length, reproduction and survival) of the zooplankton Ceriodaphnia silvestrii while exposed to copper contaminated algae Pseudokirchneriella subcapitata. In order to evaluate chronic exposure on the animal's life history, long-term experimental design was used. Cladocerans were fed with a dietary copper concentration ranging from 3 to 68 fg Cu cell(-1). Low waterborne copper exposure (around 10(-10)molL(-1) free Cu(2+) ions) was kept in the experiments. The results showed that by exposure of cladocerans during 7 days to contaminated food with 68 fg Cu cell(-1), a significant reduction in neonate production, survival and body size were obtained. Inhibition on egg production of zooplankton at 38 fg Cu cell(-1) were observed in 36 days chronic dietary copper exposure. The importance of entire life cycle study to better evaluate cladoceran responses to chronic dietary metal exposure was demonstrated.
    Ecotoxicology and Environmental Safety 05/2009; 72(6):1748-53. DOI:10.1016/j.ecoenv.2009.03.009 · 2.76 Impact Factor
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    ABSTRACT: Changes in life cycle parameters (survival, growth, reproduction) and feeding rate of the tropical cladoceran Ceriodaphnia silvestrii as affected by Cu contaminated algae Pseudokirchneriella subcapitata were investigated. The dietary copper exposure ranged from 3 x 10(-15) to 68 x 10(-15) g Cu algal cell(-1). Low waterborne copper exposure (around 10(-10) mol l(-1) free Cu2+ ions) was kept in the experiments. The results show an increasing toxic effect on C. silvestrii with copper increase in algal cells; at the highest copper exposure, all life cycle parameters were significantly affected. A concentration of 38 x 10(-15) g Cu algal cell(-1) reduced egg hatching percentile and the number of neonates produced per female, but did not cause any statistically significant effect on animals survival nor to the number of eggs produced per female. The following sequence of events was observed from the lowest to the highest copper contamination: reproduction, feeding rate, body length and, at last, survival was affected. We conclude that algal cells are an important route of copper exposure and toxicity to cladocerans.
    Ecotoxicology 11/2008; 17(8):826-33. DOI:10.1007/s10646-008-0245-6 · 2.71 Impact Factor
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    S Rodgher · E L G Espíndola
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    ABSTRACT: Food availability may affect metal toxicity for aquatic organisms. In the present study, the influence of high, medium and low densities of the algae Pseudokirchneriella subcapitata (10(6), 10(5) and 10(4) cells.mL(-1), respectively) on the chronic toxicity of chromium to the cladoceran Ceriodaphnia dubia was investigated. C. dubia was exposed to a range of chromium concentration from 2.71 to 34.04 microg.L(-1) and fed with algae at various densities. In another experiment, the green alga was exposed to chromium concentrations (94 to 774 microg.L(-1)) and supplied as food in different densities to zooplankton. The survival and reproduction of the cladoceran were measured in these toxicity tests. The IC50 for Cr to P. subcapitata and metal accumulated by algal cells were determined. The results of a bifactorial analysis (metal versus algal densities) showed that metal toxicity to zooplankton was dependent on algal densities. Significant toxic effects on the reproduction and survival of C. dubia were observed at 8.73, 18.22 and 34.04 microg.L(-1) Cr when the test organisms were fed with 10(6) cells.mL(-1) of P. subcapitata. Although the chlorophyta retain low chromium content, a decrease in the reproduction and survival of C. dubia occurred when they were fed with high algal density contaminated with 774 microg.L(-1) Cr. It was concluded that high algal density have an appreciable influence on chromium toxicity to daphnids.
    Brazilian Journal of Biology 05/2008; 68(2):341-8. DOI:10.1590/S1519-69842008000200015 · 0.78 Impact Factor
  • Suzelei Rodgher · Evaldo Luiz Gaeta Espindola
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    ABSTRACT: The influence of different densities of the algae Pseudokirchneriella subcapitata on the chronic toxicity of cadmium to Ceriodaphnia dubia was investigated. The importance of algal cells as a source of metal to zooplankton was studied by exposing P. subcapitata cells to free cadmium ions and supplying the algae as food to C. dubia. The results of a bifactorial analysis (metal versus food levels) showed that metal toxicity to zooplankton was dependent on food level. Significant toxic effects on the fecundity and survival of C. dubia were observed at low metal concentrations with high algal density. Algae contaminated with Cd(2+) were less toxic to cladoceran than was the Cd(2+) in solution. Green algae retained cadmium and released low metal concentration in the test medium. We concluded that algal cells are an important route of exposure to metal and a factor that has an appreciable influence on the expression of metal toxicity to daphnids.
    Ecotoxicology and Environmental Safety 11/2007; 71(3):765-73. DOI:10.1016/j.ecoenv.2007.08.012 · 2.76 Impact Factor
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    ABSTRACT: An evaluation was made of the quality of samples of water and sediment collected from a series of reservoirs in the Tietê River (SP), based on limnological and ecotoxicological analyses. The samples were collected during two periods (Feb and Jul 2000) from 15 sampling stations. Acute toxicity bioassays were performed using the test organism Daphnia similis, while chronic bioassays were carried out with Ceriodaphnia dubia and Danio rerio larvae. The water samples were analyzed for total nutrients, total suspended matter and total cadmium, chromium, copper and zinc concentrations, while the sediment samples were examined for organic matter, granulometry and potentially bioavailable metals (cadmium, chromium, copper and zinc). The results obtained for the limnological variable, revealed differences in the water quality, with high contribution of nutrients and metals for Tietê and Piracicaba rivers, besides the incorporation and sedimentation, consequently causing a reduction of materials in Barra Bonita reservoir, thus promoting the improvement of the water quality in the other reservoirs. The toxicity bioassays revealed acute toxicity for Daphnia similis only in the reservoirs located below Barra Bonita dam. On the other hand, chronic toxicity for Ceriodaphnia dubia and acute for Danio rerio showed a different pattern, decreasing in magnitude from Barra Bonita to Três Irmãos, demonstrating an environmental degradation gradient in the reservoirs.
    Brazilian Journal of Biology 12/2005; 65(4):697-710. DOI:10.1590/S1519-69842005000400017 · 0.78 Impact Factor

Publication Stats

69 Citations
20.94 Total Impact Points


  • 2008–2012
    • Universidade Federal de São Carlos
      • Departamento de Hidrobiologia (DHb)
      São Carlos do Pinhal, São Paulo, Brazil
  • 2005–2012
    • University of São Paulo
      • • Centro de Recursos Hídricos e Ecologia Aplicada (CRHEA) (Sao Carlos)
      • • School of Engineering (POLI)
      San Paulo, São Paulo, Brazil