Coal extraction causes sediment toxicity in aquatic environments in Santa Catarina, Brazil

Abstract

This study evaluated water parameters in ponds affected by coal extraction. Allium cepa assay was used to measure genotoxicity/mutagenicity of the sediment. Samples were collected from four ponds in the southern state of Santa Catarina. Water temperature, pH, dissolved oxygen, conductivity and turbidity were measured. Sediments were analyzed for heavy metals. Elutriate samples were prepared at a ratio of 1:4 sediment:water. Allium cepa bulbs were placed in samples prepared from each pond, with ultrapure water used as negative control and methyl methane sulfonate as positive control. Root length, mitotic index, chromosomal aberrations, micronuclei, and nuclear abnormalities were measured. The pH of two ponds, as well as electrical conductivity and dissolved oxygen of all ponds were below the minimum limits set by Brazilian regulation. All heavy metals analyzed were found in all sediment samples, but only Cd concentration was above the legal limit set by Brazilian law. Allium cepa root growth for samples from Ponds 1, 2, and 4 was significantly lower than the negative control. Meristematic cells exposed to elutriate samples showed no significant changes in cell division. There was a significant increase in total chromosomal aberrations in all treated samples in comparison with the negative control. This study demonstrates that even low concentrations of heavy metals can damage exposed biota, possibly due to synergistic effects. We also found the A. cepa bioassay to be a simple and useful tool for genotoxicity/mutagenicity analyses, and recommend its use for environmental monitoring and management in areas influenced by mining activities.

Biodegradation of atrazine, glyphosate and pendimetaline employing fungal consortia

“…To detect possible residues after herbicide degradation by fungal consortia, genotoxicity analyzes were performed. The bioindicator used was Allium cepa and the technique was described by Freitas et al (2017) where 12.5 g soil samples treated in microcosms and soil samples free of contamination were placed in 125 mL Erlenmeyers, then Research, Society and Development, v. 9, n. 11, e1549119679, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.9679 hour and sedimentation for 24 hours under refrigeration, the suspensions were centrifuged at 3000 rpm for 5 minutes to obtain the supernatant, called elutriate.…”

Legacy coal mines in Southern Brazil: Actions from National Mining Agency to promote fair mine closure and their transitions to another land-use

“…Mining operations underwent transformations, enabling the operation of large mines and consequently high production rates. The expansion of production rates had harmful effects on soil and water contamination, resulting from the uncontrolled disposal of coal waste rock and tailings containing sulphides, such as pyrite and Marcasite (Gothe 1993;Lattuada 2009;Freitas et al 2017).…”

Surface water resources of Santa Catarina state’s southern region - geochemical background of the coal mining territory

“…These impacts are observed in the explored sites, in those with irregular coal refuse disposal and, primarily, in the region's water resources. Scientific research in the region featuring subjects related to these impacts has been carried out since the 90's (Alexandre, 1999;Alexandre & Krebs, 1995;Cardoso & Fan, 2021;Freitas et al, 2017;Gothe, 1993;Ilha, 2019;Leyen, 2019;Lattuada et al, 2009;Simão et al, 2019;Volpato et al, 2017). Among the existing work in the literature, the research by Simão et al (2019) is of particular note, establishing the geochemical background for pH, sulfate, iron and manganese values of the water springs in the municipality of Criciúma, a breakthrough in the understanding of these variables in the region.…”