Rafaela Debastiani

Evaluation of genetic damage in open-cast coal mine workers using the buccal micronucleus cytome assay.

Coal is the largest fossil fuel source used for the generation of energy. However, coal extraction and its use constitute important pollution factors; thus, risk characterization and estimation are extremely important for the safety of coal workers and the environment. Candiota is located to the southeast of the state of Rio Grande do Sul and has the largest coal reserves in Brazil, and the largest thermal power complex in the state. In the open‐cast mines, the coal miners are constantly exposed to coal dust. The human buccal micronucleus cytome (BMCyt) assay has been used widely to investigate biomarkers for DNA damage, cell death, and basal cell frequency in buccal cells. The aim of this study was to assess whether prolonged exposure to coal dust could lead to an increase in genomic instability, cell death, and frequency of basal cells using the BMCyt assay. In the analysis of epithelial cells, the exposed group (n = 41) presented with a significantly higher frequency of basal cells, micronuclei in basal and differentiated cells, and binucleated cells compared to the non‐exposed group (n = 29). The exposed group showed a significantly lower frequency of condensed chromatin cells than the non‐exposed group. However, we found no correlation between DNA damage and metal concentration in the blood of mine workers. DNA damage observed in the mine workers may be a consequence of oxidative damage resulting from exposure to coal residue mixtures. In addition, our findings confirm that the BMCyt assay can be used to identify occupational risk. Mol. Mutagen. 2013.

Genetic damage in coal miners evaluated by buccal micronucleus cytome assay

During coal mining activities, large quantities of coal dust, ashes, polycyclic aromatic hydrocarbons and metals are released into the environment. This complex mixture presents one of the most important occupational hazards for health of workers. The aim of the present study was to evaluate the genetic damage together with the presence of inorganic elements, in an exposed workers population to coal mining residues of Guajira-Colombia. Thus, 100 exposed workers and 100 non-exposed control individuals were included in this study. To determine genetic damage we assessed the micronucleus (MN) frequencies and nuclear buds in buccal mucosa samples (BMCyt) assay, which were significantly higher in the exposed group than non-exposed control group. In addition, karyorrhectic and karyolytic cells were also significantly higher in the exposed group (cell death). No significant difference was observed between the exposed groups engaged in different mining activities. No correlation between age, alcohol consumption, time of service and MN assay data were found in this study. However, the content of inorganic elements in blood samples analyzed by a Particle-induced X-ray emission technique (PIXE) showed higher values of silicon (Si) and aluminum (Al) in the exposed group. In this study we discuss the possibility of DNA damage observed in the mine workers cells be a consequence of oxidative damage.

Assessment of heavy metal content and DNA damage in Hypsiboas faber (anuran amphibian) in coal open-casting mine.

The aims of the study were to determine the heavy metal content in the tissues of Hypsiboas faber from a coal mining area and to compare the DNA damage in the blood cells of these animals with that of animals living in an unpolluted area. The heavy metal content was detected according to the technique of Particle-Induced X-ray Emission (PIXE) and the DNA damage was assessed by the Comet assay. Our results reveal that the specimens of H. faber collected from the coal mining area exhibited elements of order Fe>Cu>Al>Zn>Rb>Mn>Br, independently of the organ. The values of Comet assay parameters (DNA damage index and DNA damage frequency) were significantly higher in specimens collected from the coal mining area than in the reference animals. Our study concludes that the coal mining residues are genotoxic to amphibians and may have adverse effects on soil, water, vegetation and wild animals.

Structural characterization of CdSe/ZnS quantum dots using medium energy ion scattering

In the present work, we have analyzed CdSe/ZnS core-shell quantum dots by medium energy ion scattering (MEIS), which is a powerful technique to explore the synthesis, formation, stability, and elemental distribution of such core-shell structures, along with other auxiliary analytical techniques. By comparing different quantum-dot structural models spectra with the experimental MEIS data, we were able to obtain some sample structural information. We found that, despite the well known non stoichiometric Cd:Se ratio, the core is stoichiometric, and there is an excess of cadmium distributed in the shell.