Intergenerational effects of coal dust on Tribolium castaneum, Herbst

Oxidative stress and alterations in the expression of genes related to inflammation, DNA damage, and metal exposure in lung cells exposed to a hydroethanolic coal dust extract

BACKGROUND

Open cast mining is well known as a concerning source of environmental and public health problems. This work aimed to obtain a hydroethanolic coal dust extract (≤ 38 µm) and to characterize its composition with particular regard to content of organic compounds by GC/MS, as well as describe its toxicity in vitro on Calu-1 after exposure to several concentrations (0-500 μg/mL).

MATERIALS AND RESULTS

Cytotoxicity was measured with MTT assay and DCFH-DA probe was employed to estimate the amount of reactive oxygen species (ROS) in Calu-1 cells. RT-PCR was employed to quantify relative expression of genes associated with inflammation, oxidative stress, as well as metals, and lipid metabolism. Seventeen organic compounds were identified in the extract, highlighting undecane, dodecane, pentadecane and benzo[a]anthracene, 6,12-dimethyl-1,2,3,4-tetrahydro-. Cytotoxicity test showed a decrease trend in the cell viability after 24 h hours from the concentration of 62.5 µg/mL. Further, the extract raised intracellular ROS when compared with control. Expression levels of CYP1A1, IL-8, IL-6, MT1X, and NQO1 were up-regulated when cells were exposed to 125 µg/mL of coal dust, whereas PPAR-α was down-regulated, likely involving aryl hydrocarbon receptor regulation.

CONCLUSIONS

In short, this study shows that despite hydroethanolic coal dust extract is not cytotoxic to Calu-1 cells, it produces an elevation of intracellular ROS and alters the expression in marker genes of oxidative stress, inflammation, metal transport, xenobiotic and lipid metabolism. These findings suggest that chemicals present in coal dust are biologically active and may interfere key biochemical process in the living organisms.

Toxicological effects of bituminous coal dust on the earthworm Eisenia fetida (Oligochaeta: Lumbricidae)

The exploitation of coal is an important resource to generate energy worldwide. However, during the processes of coal extraction, transport, and cargo, dust particles are released into the environment. The aim of this study was to determine the toxicological effects of bituminous coal dust (<38 µm), obtained from a sample collected in a coal mine in Colombia, on the annelid Eisenia fetida. The earthworm culture was standardized under laboratory conditions to evaluate mortality, as well as morphological, physiological and histological changes using concentrations varying from 1 to 4% w/w coal dust in artificial soil, after 7, 14, and 28 days of exposure. In addition, an avoidance assay was carried out after 48-h treatment. Histopathological analysis was performed at the end of the experiment. After the sub-chronic exposure, an increase in mortality was observed at the highest coal dust concentration compared to the untreated group. Alterations in morphology and physiology of the exposed annelids were mostly evidenced at the greatest tested concentrations (3-4%) and exposure times (≥14 days). Changes included loss of weight and color, abundant mucus production, constriction, peeling of the epidermis, clitellum involution, violent movements and lethargy. Avoidance of coal dust-polluted soil followed a concentration-response relationship. Histopathological findings revealed changes on the cuticle, as well as in the circular and longitudinal muscle layers in animals living in soils containing 3 and 4% coal particles. In short, E. fetida exposed to coal dust experienced several pathological changes, suggesting that this pollutant may induce population problems in macroinvertebrates present in coal mining areas.

Synthesis and Performance of a Novel High-Efficiency Coal Dust Suppressant Based on Self-Healing Gel

During transportation and storage, coal produces a lot of dust, which pollutes the environment and threatens the occupational health of workers. Although many dust suppressants have been developed for dust prevention at work, the implementation of current dust suppressants does not meet the requirements due to various factors such as the hydrophobic nature of coal dust and a harsh external environment. In this study, hydroxyethyl cellulose, acrylamide, and stearyl methyl acrylate were used for micelle polymerization to prepare an environmental protection dust suppressant for preventing dust during coal storage and transportation. The microstructure of the reactants and the products was analyzed by Fourier transform infrared as well as scanning electron microscopy. The strength and self-healing tensile properties of binder coal were taken as indicators to determine the best synthesis dosage and conditions. The dust suppressant particles are applied to the dust accumulation area, contact each other after water absorption, and swell to complete the healing, to achieve the purpose of dust control. The evaluation of the relevant properties of the dust suppressant reveals that the dust suppressant has a good covering effect, an excellent dust suppressant performance, and a significant dust suppression action.