Name: EDVAR JÚNIOR RONCETTI COELHO
Type: MSc dissertation
Publication date: 23/02/2017
Advisor:
Name |
Role |
|---|---|
| Silvia Tamie Matsumoto | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Gilberto Fonseca Barroso | External Alternate * |
| Maria do Carmo de Freitas Veneroso | Internal Examiner * |
| Silvia Tamie Matsumoto | Advisor * |
| Tatiana da Silva Souza | External Examiner * |
| Viviana Borges Corte | Internal Alternate * |
Summary: ABSTRACT
The increase of the population and its rural, industrial and urban activities are closely related to impacts caused to the environment and water bodies are the most affected ecosystems. Bioassays with higher plants are very common to determine the environmental quality of a polluted ecosystem. Therefore, this work proposed to evaluate the water and sediment samples quality from the Suíça, Rio Bonito and Duas Bocas dams, present in the Santa Maria da Vitória Hydrographical basin, using physical and chemical parameters and toxicological and bioassay tests in Allium cepa . Three sampling stations were established at the Rio Bonito dam (RB1, RB2 and RB3), two at Suíça dam (SU1 and SU2) and another one at Duas Bocas (DB). The water and sediment samples were collected in March (dry period) and November (rainy season) in 2016 and parameters such as conductivity, dissolved oxygen, turbidity, temperature and metals were analyzed. The determination of metal has occurred by mass spectrometry analysis. From the sediment samples the solubilized soil was extracted to execute the tests. The bioassays with Allium cepa were conducted from seeds germinated in exposure to water and solubilized soil samples. Cytogenetic evaluation involved the analysis of mitotic index (MI), chromosomal aberrations (CA), and frequency of micronuclei (MN) in meristematic roots and micronuclei frequency in f1 of A. cepa. The evaluation of toxicity parameters were obtained through analysis of root growth and germination. For biochemical analysis of oxidative stress, SOD, CAT, GST, GHS and LPO were quantified. For statistical analysis, analysis of variance followed by Tukey test (p <0.05). Physical and chemical results indicate that all three dams presents evidence of eutrophication. The Rio Bonito and Suíça dams presented cytotoxic, mutagenic and genotoxic potential in both campaigns for water and solubilized soil samples. Duas Bocas dam shows only cytotoxic and genotoxic potential. Cytogenetic damages were higher in the solubilized samples. The same occurred in the rainy season, when we compared the damages between rainy and dry periods. We can emphasize that bioassays with Allium cepa are a great tool to verify the environmental quality, complementing the physical and chemical analyzes carried out in biomonitoring of polluted environments.
Key words: cytotoxicity, genotoxicity, mutagenicity, toxicity , oxidative stress, enzymes
