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Poços de Caldas, Brazil

Andrade-Vieira L.F.,Federal University of Lavras | Davide L.C.,Federal University of Lavras | Gedraite L.S.,Federal University of Lavras | Campos J.M.S.,Federal University of Juiz de fora | Azevedo H.,Pocos Of Caldas Laboratory
Ecotoxicology and Environmental Safety | Year: 2011

Spent Pot Liner (SPL) is a solid waste product generated in the process of aluminum production. Tradescantia micronuclei (Trad-MN) and stamen hair mutation (Trad-SHM) bioassays are very useful tests to assess genotoxicity of environmental pollutants. In the present study, we intended to investigate the genotoxicity of this waste with Tradescantia bioassays using leachates of SPL simulating the natural leachability of SPL in soil. The formation of micronuclei (MN) was found to be concentration dependent. MN frequency enhanced significantly with SPL treatment. In addition, SPL also appeared to increase the percentage of dyads and triads. Trad-SHM assay showed that SPL increases pink mutation events as SPL concentration increases. These results demonstrated that SPL is a cytogenotoxic agent that affects different genetic end-points (induction of micronuclei and point mutations) even at low concentration (2% and 3%). © 2011 Elsevier Inc.

Brito P.P.,Pocos Of Caldas Laboratory | Azevedo H.,Pocos Of Caldas Laboratory | Cipolli K.M.V.A.B.,Food Technology Institute | Fukuma H.T.,Pocos Of Caldas Laboratory | And 4 more authors.
Journal of Food Science | Year: 2011

Frozen samples of mechanically deboned chicken meat (MDCM) with skin were irradiated with gamma radiation doses of 0.0 kGy (control) and 3 kGy at 2 different radiation dose rates: 0.32 kGy/h (3 kGy) and 4.04 kGy/h (3 kGy). Batches of irradiated and control samples were evaluated during 11 d of refrigerated (2 ± 1 °C) storage for the following parameters: total psychrotrophic bacteria count, thiobarbituric acid reactive substances (TBARS), evaluation of objective color (L*, a*, and b*) and a sensory evaluation (irradiated odor, oxidized odor, pink and brown colors). No statistical difference (P > 0.05) was found amongst the TBARS values obtained for the MDCM samples irradiated with dose rates of 0.32 and 4.04 kGy/h. There was a significant increase (P < 0.05) in the psychrotrophic bacterial count as from the 7th day of refrigerated storage, for the MDCM samples irradiated at the dose rate of 4.04 kGy/h. With respect to the attribute of oxidized odor, the samples irradiated with a dose rate of 0.32 kGy/h showed a stronger intensity and were significantly different (P < 0.05) from the sample irradiated with a dose rate of 4.04 kGy/h on days 0 and 2 of refrigerated storage. Irradiation with a dose rate of 4.04 kGy/h (3 kGy) was shown to be the best condition for the processing of MDCM according to the evaluation of all the variables, under the conditions of this study. © 2011 Institute of Food Technologists®.

Ronqui L.B.,Pocos Of Caldas Laboratory | Azevedo H.,Pocos Of Caldas Laboratory | Nascimento M.R.L.,Pocos Of Caldas Laboratory | Macacini J.F.,Pocos Of Caldas Laboratory | And 2 more authors.
Atoms for Peace | Year: 2010

The Antas Reservoir (AR) receives treated effluents coming from the acid drainage of uranium ore from the Ore Treatment Unit-Brazilian Nuclear Industries (UTM-INB) plant located in Caldas, Minas Gerais, Brazil. This study was conducted in order to determine the possible radioecological impact caused by discharges of the treated liquid effluent from the UTM into the reservoir. Biological and physicochemical variables were evaluated in the present study. Sampling in the AR (Cab, P41, P14S and P14F points) took place during the dry winter (July 2006) and rainy summer seasons (February 2007). Each day, samples were collected four times (6:00 am, 12:00 noon, 6:00 pm and 12:00 midnight). The average trophic state index values obtained for samples in the dry and rainy periods allowed the areas to be classified as oligotrophic and mesotrophic, respectively. Chemical parameters indicated failures in the nuclear facility effluent treatment system, showing that effluents discharged at P41 do not agree with the standards that have been established by the Brazilian current legislation for Class II water. These results agreed with biological analyses, since P41 has the lowest density values for ciliated protozoa, indicating possible environmental impacts on the ecosystem due to the release of effluents by the mining company. © 2010 Inderscience Enterprises Ltd.

Ronqui L.B.,Pocos Of Caldas Laboratory | Azevedo H.,Pocos Of Caldas Laboratory | Seleghim M.H.R.,Federal University of Sao Carlos | Ferrari C.R.,Pocos Of Caldas Laboratory | And 5 more authors.
Radioprotection | Year: 2011

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. © 2011 EDP Sciences.

Campos M.B.,Pocos Of Caldas Laboratory | de Azevedo H.,Pocos Of Caldas Laboratory | Nascimento M.R.L.,Pocos Of Caldas Laboratory | Roque C.V.,Pocos Of Caldas Laboratory | Rodgher S.,Pocos Of Caldas Laboratory
Environmental Earth Sciences | Year: 2011

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. © 2010 Springer-Verlag.

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